101
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Amin HU, Ousta F, Yusoff MZ, Malik AS. Modulation of cortical activity in response to learning and long-term memory retrieval of 2D verses stereoscopic 3D educational contents: Evidence from an EEG study. COMPUTERS IN HUMAN BEHAVIOR 2021. [DOI: 10.1016/j.chb.2020.106526] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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102
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Zhang Q, Hu Y, Dong X, Feng X. Clinical significance of electroencephalography power spectrum density and functional connection analysis in neonates with hypoxic-ischemic encephalopathy. Int J Dev Neurosci 2020; 81:142-150. [PMID: 33354792 DOI: 10.1002/jdn.10083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/16/2020] [Accepted: 12/18/2020] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE To investigate the effects of electroencephalography (EEG) power and functional connectivity analysis on cerebral cortex function in neonates with hypoxic-ischemic encephalopathy (HIE), and to identify the neurobiological indicators of neural development in HIE. METHODS We recruited 20 mild HIE neonates, 15 moderate HIE neonates, and 30 controls. EEG was performed about 72 hr after birth. The power spectral density (PSD) and imaginary part of coherency (ICOH) were analyzed. Gesell developmental schedule (GDS) was used to evaluate the neural development in the mild and moderate HIE groups at 1 year of age, and the correlation between the quantitative EEG results and the state of neural development was analyzed. RESULTS Compared with the controls, FP1, FP2, C3, C4, Fz, Cz, Pz , F3, and P4 of moderate HIE neonates showed that the PSD of theta, alpha and beta bands decreased significantly. In terms of the mean whole-brain PSD, the moderate HIE group showed a significant decrease in all frequency bands. ICOH of the moderate HIE group showed that functional connectivity was significantly less than that in the controls mainly in the delta band, and the functional connectivity of the delta, theta, alpha1, and alpha2 bands was markedly reduced compared with the mild HIE. GDS test at 1 year old showed that two infants in the moderate HIE group had suspected neurological delay in gross motor and language. The developmental quotient(DQ) of gross motor, language, and personal-social ability in the moderate HIE group were significantly lower than in the mild HIE group. And there was a significant positive correlation between PSD in each EEG frequency band and GDS score in the moderate HIE group. CONCLUSION PSD and ICOH can be used to evaluate brain function. PSD can detect the delayed neurological development in infants with moderate HIE, and can be a neurobiomarker of brain development in HIE.
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Affiliation(s)
- Qinfen Zhang
- Neonatology Department, Children's Hospital of Soochow University, Suzhou, China.,Neonatology Department, Affiliated Changzhou Children's Hospital of Nantong University, Changzhou, China
| | - Yongsu Hu
- Medical College, Nantong University, Nantong, China
| | - Xuan Dong
- Neonatology Department, Affiliated Changzhou Children's Hospital of Nantong University, Changzhou, China
| | - Xing Feng
- Neonatology Department, Children's Hospital of Soochow University, Suzhou, China
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103
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Vivekananda U, Bush D, Bisby JA, Baxendale S, Rodionov R, Diehl B, Chowdhury FA, McEvoy AW, Miserocchi A, Walker MC, Burgess N. Theta power and theta-gamma coupling support long-term spatial memory retrieval. Hippocampus 2020; 31:213-220. [PMID: 33263940 PMCID: PMC7898809 DOI: 10.1002/hipo.23284] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 11/11/2020] [Accepted: 11/15/2020] [Indexed: 11/07/2022]
Abstract
Hippocampal theta oscillations have been implicated in spatial memory function in both rodents and humans. What is less clear is how hippocampal theta interacts with higher frequency oscillations to support long‐term memory. Here we asked 10 presurgical epilepsy patients undergoing intracranial EEG recording to perform a long‐term spatial memory task in desktop virtual reality and found that increased theta power in two discrete bands (“low” 2‐5 Hz and “high” 6‐11 Hz) during cued retrieval was associated with improved task performance. Similarly, increased coupling between “low” theta phase and gamma amplitude during the same period was associated with improved task performance. Finally, low and high gamma amplitude appeared to peak at different phases of the theta cycle; providing a novel connection between human hippocampal function and rodent data. These results help to elucidate the role of theta oscillations and theta‐gamma phase‐amplitude coupling in human long‐term memory.
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Affiliation(s)
- Umesh Vivekananda
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Daniel Bush
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,UCL Institute of Cognitive Neuroscience, London, UK
| | - James A Bisby
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,UCL Institute of Cognitive Neuroscience, London, UK
| | - Sallie Baxendale
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Roman Rodionov
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Beate Diehl
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Fahmida A Chowdhury
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Andrew W McEvoy
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Anna Miserocchi
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Neil Burgess
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK.,UCL Institute of Cognitive Neuroscience, London, UK.,Wellcome Centre for Human NeuroImaging, University College London, London, UK
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104
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Watrous AJ, Buchanan RJ. The Oscillatory ReConstruction Algorithm adaptively identifies frequency bands to improve spectral decomposition in human and rodent neural recordings. J Neurophysiol 2020; 124:1914-1922. [DOI: 10.1152/jn.00292.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Neural oscillations show substantial variability within and across individuals and brain regions, yet most existing studies analyze oscillations using canonical, fixed-frequency bands. Thus, there is an ongoing need for tools that capture oscillatory variability in neural signals. Toward this end, Oscillatory ReConstruction Algorithm is a novel and adaptive analytic tool that allows researchers to measure neural oscillations with more precision and less researcher bias.
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Affiliation(s)
- Andrew J. Watrous
- Department of Neurology, Dell Medical School, The University of Texas at Austin, Austin, Texas
- Institute for Neuroscience, The University of Texas at Austin, Austin, Texas
- Center for Learning and Memory, The University of Texas at Austin, Austin, Texas
- Department of Psychology, The University of Texas at Austin, Austin, Texas
- Seton Brain and Spine Institute, Division of Neurosurgery, Austin, Texas
| | - Robert J. Buchanan
- Institute for Neuroscience, The University of Texas at Austin, Austin, Texas
- Department of Psychology, The University of Texas at Austin, Austin, Texas
- Seton Brain and Spine Institute, Division of Neurosurgery, Austin, Texas
- Department of Neurosurgery, Dell Medical School, The University of Texas at Austin, Austin, Texas
- Department of Psychiatry, Dell Medical School, The University of Texas at Austin, Austin, Texas
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105
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Kumar S, Gander PE, Berger JI, Billig AJ, Nourski KV, Oya H, Kawasaki H, Howard MA, Griffiths TD. Oscillatory correlates of auditory working memory examined with human electrocorticography. Neuropsychologia 2020; 150:107691. [PMID: 33227284 PMCID: PMC7884909 DOI: 10.1016/j.neuropsychologia.2020.107691] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/23/2020] [Accepted: 11/16/2020] [Indexed: 02/08/2023]
Abstract
This work examines how sounds are held in auditory working memory (AWM) in humans by examining oscillatory local field potentials (LFPs) in candidate brain regions. Previous fMRI studies by our group demonstrated blood oxygenation level-dependent (BOLD) response increases during maintenance in auditory cortex, inferior frontal cortex and the hippocampus using a paradigm with a delay period greater than 10s. The relationship between such BOLD changes and ensemble activity in different frequency bands is complex, and the long delay period raised the possibility that long-term memory mechanisms were engaged. Here we assessed LFPs in different frequency bands in six subjects with recordings from all candidate brain regions using a paradigm with a short delay period of 3 s. Sustained delay activity was demonstrated in all areas, with different patterns in the different areas. Enhancement in low frequency (delta) power and suppression across higher frequencies (beta/gamma) were demonstrated in primary auditory cortex in medial Heschl’s gyrus (HG) whilst non-primary cortex showed patterns of enhancement and suppression that altered at different levels of the auditory hierarchy from lateral HG to superior- and middle-temporal gyrus. Inferior frontal cortex showed increasing suppression with increasing frequency. The hippocampus and parahippocampal gyrus showed low frequency increases and high frequency decreases in oscillatory activity. This work demonstrates sustained activity patterns during AWM maintenance, with prominent low-frequency increases in medial temporal lobe regions. Local field potentials recorded in humans while they keep sound in working memory. Sustained increase in delta power observed in primary auditory cortex. Pattern of change in power in non-primary cortex depends on the hierarchical level. Hippocampus and parahippocampus showed increase in low frequency power.
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Affiliation(s)
- Sukhbinder Kumar
- Newcastle University Medical School, Newcastle Upon Tyne, Tyne and Wear NE2 4HH, UK.
| | - Phillip E Gander
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Joel I Berger
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA
| | | | - Kirill V Nourski
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
| | - Hiroyuki Oya
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Hiroto Kawasaki
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA
| | - Matthew A Howard
- Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA; Pappajohn Biomedical Institute, The University of Iowa, Iowa City, IA, 52242, USA
| | - Timothy D Griffiths
- Newcastle University Medical School, Newcastle Upon Tyne, Tyne and Wear NE2 4HH, UK; Department of Neurosurgery, The University of Iowa, Iowa City, IA, 52242, USA; Wellcome Centre for Human Neuroimaging, University College London, London, WC1N 3BG, UK
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106
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Kim D, Jeong W, Kim JS, Chung CK. Single-Trial EEG Connectivity of Default Mode Network Before and During Encoding Predicts Subsequent Memory Outcome. Front Syst Neurosci 2020; 14:591675. [PMID: 33328911 PMCID: PMC7710990 DOI: 10.3389/fnsys.2020.591675] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/19/2020] [Indexed: 11/13/2022] Open
Abstract
The successful memory process produces specific activity in the brain network. As the brain activity of the prestimulus and encoding phases has a crucial effect on subsequent memory outcomes (e.g., remembered or forgotten), previous studies have tried to predict the memory performance in this period. Conventional studies have used the spectral power or event-related potential of specific regions as the classification feature. However, as multiple brain regions work collaboratively to process memory, it could be a better option to use functional connectivity within the memory-related brain network to predict subsequent memory performance. In this study, we acquired the EEG signals while performing an associative memory task that remembers scene-word pairs. For the connectivity analysis, we estimated the cross-mutual information within the default mode network with the time-frequency spectra at the prestimulus and encoding phases. Then, we predicted the success or failure of subsequent memory outcome with the connectivity features. We found that the classifier with support vector machine achieved the highest classification accuracy of 80.83% ± 12.65% (mean ± standard deviation) using the beta (13-30 Hz) connectivity at encoding phase among the multiple frequency bands and task phases. Using the prestimulus beta connectivity, the classification accuracy of 72.45% ± 12.52% is also achieved. Among the features, the connectivity related to the dorsomedial prefrontal cortex was found to contribute to successful memory encoding. The connectivity related to the posterior cingulate cortex was found to contribute to the failure of memory encoding. The present study showed for the first time the successful prediction with high accuracy of subsequent memory outcome using single-trial functional connectivity.
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Affiliation(s)
- Dahye Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Woorim Jeong
- College of Sungsim General Education, Youngsan University, Yangsan, South Korea
| | - June Sic Kim
- The Research Institute of Basic Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea
| | - Chun Kee Chung
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, South Korea.,Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea.,Neuroscience Research Institute, College of Medicine, Seoul National University, Seoul, South Korea
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107
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Wang Z. Brain Entropy Mapping in Healthy Aging and Alzheimer's Disease. Front Aging Neurosci 2020; 12:596122. [PMID: 33240080 PMCID: PMC7683386 DOI: 10.3389/fnagi.2020.596122] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 10/06/2020] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease, for which aging remains the major risk factor. Aging is under a consistent pressure of increasing brain entropy (BEN) due to the progressive brain deteriorations. Noticeably, the brain constantly consumes a large amount of energy to maintain its functional integrity, likely creating or maintaining a big "reserve" to counteract the high entropy. Malfunctions of this latent reserve may indicate a critical point of disease progression. The purpose of this study was to characterize BEN in aging and AD and to test an inverse-U-shape BEN model: BEN increases with age and AD pathology in normal aging but decreases in the AD continuum. BEN was measured with resting state fMRI and compared across aging and the AD continuum. Associations of BEN with age, education, clinical symptoms, and pathology were examined by multiple regression. The analysis results highlighted resting BEN in the default mode network, medial temporal lobe, and prefrontal cortex and showed that: (1) BEN increased with age and pathological deposition in normal aging but decreased with age and pathological deposition in the AD continuum; (2) AD showed catastrophic BEN reduction, which was related to more severe cognitive impairment and daily function disability; and (3) BEN decreased with education years in normal aging, but not in the AD continuum. BEN evolution follows an inverse-U trajectory when AD progresses from normal aging to AD dementia. Education is beneficial for suppressing the entropy increase potency in normal aging.
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Affiliation(s)
- Ze Wang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, United States
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108
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Hippocampal Theta Oscillations Support Successful Associative Memory Formation. J Neurosci 2020; 40:9507-9518. [PMID: 33158958 DOI: 10.1523/jneurosci.0767-20.2020] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 11/21/2022] Open
Abstract
Models of memory formation posit that episodic memory formation depends critically on the hippocampus, which binds features of an event to its context. For this reason, the contrast between study items that are later recollected with their associative pair versus those for which no association is made fails should reveal electrophysiological patterns in the hippocampus selectively involved in associative memory encoding. Extensive data from studies in rodents support a model in which theta oscillations fulfill this role, but results in humans have not been as clear. Here, we used an associative recognition memory procedure to identify hippocampal correlates of successful associative memory encoding and retrieval in patients (10 females and 9 males) undergoing intracranial EEG monitoring. We identified a dissociation between 2-5 Hz and 5-9 Hz theta oscillations, by which power increases in 2-5 Hz oscillations were uniquely linked with successful associative memory in both the anterior and posterior hippocampus. These oscillations exhibited a significant phase reset that also predicted successful associative encoding and distinguished recollected from nonrecollected items at retrieval, as well as contributing to relatively greater reinstatement of encoding-related patterns for recollected versus nonrecollected items. Our results provide direct electrophysiological evidence that 2-5 Hz hippocampal theta oscillations preferentially support the formation of associative memories, although we also observed memory-related effects in the 5-9 Hz frequency range using measures such as phase reset and reinstatement of oscillatory activity.SIGNIFICANCE STATEMENT Models of episodic memory encoding predict that theta oscillations support the formation of interitem associations. We used an associative recognition task designed to elicit strong hippocampal activation to test this prediction in human neurosurgical patients implanted with intracranial electrodes. The findings suggest that 2-5 Hz theta oscillatory power and phase reset in the hippocampus are selectively associated with associative memory judgments. Furthermore, reinstatement of oscillatory patterns in the hippocampus was stronger for successful recollection. Collectively, the findings support a role for hippocampal theta oscillations in human associative memory.
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109
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van der Plas M, Wang D, Brittain JS, Hanslmayr S. Investigating the role of phase-synchrony during encoding of episodic memories using electrical stimulation. Cortex 2020; 133:37-47. [PMID: 33099074 DOI: 10.1016/j.cortex.2020.09.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/03/2020] [Accepted: 09/15/2020] [Indexed: 01/15/2023]
Abstract
The multi-sensory nature of episodic memories indicates that communication between a multitude of brain areas is required for their effective creation and recollection. Previous studies have suggested that the effectiveness of memory processes depends on theta synchronization (4 Hz) of sensory areas relevant to the memory. This study aimed to manipulate theta synchronization between different sensory areas in order to further test this hypothesis. We intend to entrain visual cortex with 4 Hz alternating current stimulation (tACS), while simultaneously entraining auditory cortex with 4 Hz amplitude-modulated sounds. By entraining these different sensory areas, which pertain to learned audio-visual memory associations, we expect to find that when theta is synchronized across the different sensory areas, the memory performance would be enhanced compared to when theta is not synchronized across the sensory areas. We found no evidence for such an effect in this study. It is unclear whether this is due to an inability of 4 Hz tACS to entrain the visual cortex reliably, or whether sensory entrainment is not the underlying mechanism required for episodic memory.
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Affiliation(s)
- Mircea van der Plas
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, United Kingdom
| | - Danying Wang
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, United Kingdom
| | - John-Stuart Brittain
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Simon Hanslmayr
- School of Psychology, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Human Brain Health, University of Birmingham, Edgbaston, Birmingham, United Kingdom; Centre for Cognitive Neuroimaging, University of Glasgow, Glasgow, United Kingdom.
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110
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Electrophysiological correlates of the brain-derived neurotrophic factor (BDNF) Val66Met polymorphism. Sci Rep 2020; 10:17915. [PMID: 33087740 PMCID: PMC7578797 DOI: 10.1038/s41598-020-74780-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 08/25/2020] [Indexed: 12/20/2022] Open
Abstract
The brain-derived neurotrophic factor (BDNF) protein is essential for neuronal development. Val66Met (rs6265) is a functional polymorphism at codon 66 of the BDNF gene that affects neuroplasticity and has been associated with cognition, brain structure and function. The aim of this study was to clarify the relationship between BDNF Val66Met polymorphism and neuronal oscillatory activity, using the electroencephalogram (EEG), in a normative cohort. Neurotypical (N = 92) young adults were genotyped for the BDNF Val66Met polymorphism and had eyes open resting-state EEG recorded for four minutes. Focal increases in right fronto-parietal delta, and decreases in alpha-1 and right hemispheric alpha-2 amplitudes were observed for the Met/Met genotype group compared to Val/Val and Val/Met groups. Stronger frontal topographies were demonstrated for beta-1 and beta-2 in the Val/Met group versus the Val/Val group. Findings highlight BDNF Val66Met genotypic differences in EEG spectral amplitudes, with increased cortical excitability implications for Met allele carriers.
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111
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Tierney TM, Levy A, Barry DN, Meyer SS, Shigihara Y, Everatt M, Mellor S, Lopez JD, Bestmann S, Holmes N, Roberts G, Hill RM, Boto E, Leggett J, Shah V, Brookes MJ, Bowtell R, Maguire EA, Barnes GR. Mouth magnetoencephalography: A unique perspective on the human hippocampus. Neuroimage 2020; 225:117443. [PMID: 33059052 PMCID: PMC8214102 DOI: 10.1016/j.neuroimage.2020.117443] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 09/02/2020] [Accepted: 10/09/2020] [Indexed: 02/07/2023] Open
Abstract
Traditional magnetoencephalographic (MEG) brain imaging scanners consist of a rigid sensor array surrounding the head; this means that they are maximally sensitive to superficial brain structures. New technology based on optical pumping means that we can now consider more flexible and creative sensor placement. Here we explored the magnetic fields generated by a model of the human hippocampus not only across scalp but also at the roof of the mouth. We found that simulated hippocampal sources gave rise to dipolar field patterns with one scalp surface field extremum at the temporal lobe and a corresponding maximum or minimum at the roof of the mouth. We then constructed a fitted dental mould to accommodate an Optically Pumped Magnetometer (OPM). We collected data using a previously validated hippocampal-dependant task to test the empirical utility of a mouth-based sensor, with an accompanying array of left and right temporal lobe OPMs. We found that the mouth sensor showed the greatest task-related theta power change. We found that this sensor had a mild effect on the reconstructed power in the hippocampus (~10% change) but that coherence images between the mouth sensor and reconstructed source images showed a global maximum in the right hippocampus. We conclude that augmenting a scalp-based MEG array with sensors in the mouth shows unique promise for both basic scientists and clinicians interested in interrogating the hippocampus.
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Affiliation(s)
- Tim M Tierney
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK.
| | - Andrew Levy
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
| | - Daniel N Barry
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
| | - Sofie S Meyer
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK; Institute of Cognitive Neuroscience, University College London, 17-19 Queen Square, London WC1N 3AZ, UK
| | | | - Matt Everatt
- S4S (UK) Limited & Smilelign Ltd, 151 Rutland Road, Sheffield S3 9PT, UK
| | - Stephanie Mellor
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
| | - Jose David Lopez
- Engineering Faculty, Universidad de Antioquia UDEA, calle 70 No 52-21, Medellín, Colombia
| | - Sven Bestmann
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
| | - Niall Holmes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Gillian Roberts
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Ryan M Hill
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Elena Boto
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - James Leggett
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Vishal Shah
- QuSpin Inc., 2011 Cherry Street, Unit 112, Louisville, CO 80027, USA
| | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Richard Bowtell
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | - Eleanor A Maguire
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, 12 Queen Square, London WC1N 3AR, UK
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112
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Johnson EL, Kam JWY, Tzovara A, Knight RT. Insights into human cognition from intracranial EEG: A review of audition, memory, internal cognition, and causality. J Neural Eng 2020; 17:051001. [PMID: 32916678 PMCID: PMC7731730 DOI: 10.1088/1741-2552/abb7a5] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
By recording neural activity directly from the human brain, researchers gain unprecedented insight into how neurocognitive processes unfold in real time. We first briefly discuss how intracranial electroencephalography (iEEG) recordings, performed for clinical practice, are used to study human cognition with the spatiotemporal and single-trial precision traditionally limited to non-human animal research. We then delineate how studies using iEEG have informed our understanding of issues fundamental to human cognition: auditory prediction, working and episodic memory, and internal cognition. We also discuss the potential of iEEG to infer causality through the manipulation or 'engineering' of neurocognitive processes via spatiotemporally precise electrical stimulation. We close by highlighting limitations of iEEG, potential of burgeoning techniques to further increase spatiotemporal precision, and implications for future research using intracranial approaches to understand, restore, and enhance human cognition.
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Affiliation(s)
- Elizabeth L Johnson
- Helen Wills Neuroscience Institute, University of California, Berkeley, United States of America
- Life-Span Cognitive Neuroscience Program, Institute of Gerontology, Wayne State University, United States of America
| | - Julia W Y Kam
- Helen Wills Neuroscience Institute, University of California, Berkeley, United States of America
- Department of Psychology, University of Calgary, Canada
- Hotchkiss Brain Institute, University of Calgary, Canada
| | - Athina Tzovara
- Helen Wills Neuroscience Institute, University of California, Berkeley, United States of America
- Institute for Computer Science, University of Bern, Switzerland
- Sleep Wake Epilepsy Center | NeuroTec, Department of Neurology, Inselspital, Bern University Hospital, University of Bern, Switzerland
| | - Robert T Knight
- Helen Wills Neuroscience Institute, University of California, Berkeley, United States of America
- Department of Psychology, University of California, Berkeley, United States of America
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113
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McCormick C, Barry DN, Jafarian A, Barnes GR, Maguire EA. vmPFC Drives Hippocampal Processing during Autobiographical Memory Recall Regardless of Remoteness. Cereb Cortex 2020; 30:5972-5987. [PMID: 32572443 PMCID: PMC7899055 DOI: 10.1093/cercor/bhaa172] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 12/25/2022] Open
Abstract
Our ability to recall past experiences, autobiographical memories (AMs), is crucial to cognition, endowing us with a sense of self and underwriting our capacity for autonomy. Traditional views assume that the hippocampus orchestrates event recall, whereas recent accounts propose that the ventromedial prefrontal cortex (vmPFC) instigates and coordinates hippocampal-dependent processes. Here we sought to characterize the dynamic interplay between the hippocampus and vmPFC during AM recall to adjudicate between these perspectives. Leveraging the high temporal resolution of magnetoencephalography, we found that the left hippocampus and the vmPFC showed the greatest power changes during AM retrieval. Moreover, responses in the vmPFC preceded activity in the hippocampus during initiation of AM recall, except during retrieval of the most recent AMs. The vmPFC drove hippocampal activity during recall initiation and also as AMs unfolded over subsequent seconds, and this effect was evident regardless of AM age. These results recast the positions of the hippocampus and the vmPFC in the AM retrieval hierarchy, with implications for theoretical accounts of memory processing and systems-level consolidation.
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Affiliation(s)
- Cornelia McCormick
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
- Department of Neurodegenerative Diseases and Geriatric Psychiatry, University Hospital Bonn, 53127 Bonn, Germany
| | - Daniel N Barry
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
| | - Amirhossein Jafarian
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
| | - Eleanor A Maguire
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London WC1N 3AR, UK
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114
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Begus K, Bonawitz E. The rhythm of learning: Theta oscillations as an index of active learning in infancy. Dev Cogn Neurosci 2020; 45:100810. [PMID: 33040970 PMCID: PMC7371744 DOI: 10.1016/j.dcn.2020.100810] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/22/2020] [Accepted: 06/25/2020] [Indexed: 01/05/2023] Open
Abstract
Active learning is a critical component of human development, however, the mechanisms supporting it are not fully understood. Given that early learning experiences may affect both infants' immediate learning success, as well as their motivation to learn, it is particularly important to investigate the mechanisms of active learning in this period, when the foundations of learning habits and curiosity are built. Traditional behavioural approaches of studying infant learning face challenges that emerging tools from neuroscience may help relieve. We introduce one such tool, EEG theta oscillations, and propose this neural marker has great potential for offering novel insights into active learning. Theta activity, recorded prior to or during learning, has been shown to be predictive of learning success. We argue that this involvement in memory formation, combined with theta activity's tight association with reward processing, makes theta oscillations a uniquely suited tool for the investigation of motivational mechanisms underlying active learning. We outline research questions as well as methodological approaches pertinent to infant learning and suggest how and why theta oscillations may offer complementary insights. As such, we aim to bridge the gap between cognitive and neural approaches, and advance our knowledge of active learning in development more broadly.
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115
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Stoiljkovic M, Kelley C, Stutz B, Horvath TL, Hajós M. Altered Cortical and Hippocampal Excitability in TgF344-AD Rats Modeling Alzheimer's Disease Pathology. Cereb Cortex 2020; 29:2716-2727. [PMID: 29920597 DOI: 10.1093/cercor/bhy140] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 04/20/2018] [Indexed: 12/27/2022] Open
Abstract
Current findings suggest that accumulation of amyloid-β (Aβ) and hyperphosphorylated tau in the brain disrupt synaptic function in hippocampal-cortical neuronal networks leading to impairment in cognitive and affective functions in Alzheimer's disease (AD). Development of new disease-modifying AD drugs are challenging due to the lack of predictive animal models and efficacy assays. In the present study we recorded neural activity in TgF344-AD rats, a transgenic model with a full array of AD pathological features, including age-dependent Aβ accumulation, tauopathy, neuronal loss, and cognitive impairments. Under urethane anesthesia, TgF344-AD rats showed significant age-dependent decline in brainstem-elicited hippocampal theta oscillation and decreased theta-phase gamma-amplitude coupling comparing to their age-matched wild-type counterparts. In freely-behaving condition, the power of hippocampal theta oscillation and gamma power during sharp-wave ripples were significantly lower in TgF344-AD rats. Additionally, these rats showed impaired coherence in both intercortical and hippocampal-cortical network dynamics, and increased incidence of paroxysmal high-voltage spindles, which occur during awake, behaviorally quiescent state. TgF344-AD rats demonstrated impairments in sensory processing, having diminished auditory gating and 40-Hz auditory evoked steady-state response. The observed differences in neurophysiological activities in TgF344-AD rats, which mirror several abnormalities described in AD patients, may be used as promising markers to monitor disease-modifying therapies.
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Affiliation(s)
- Milan Stoiljkovic
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Craig Kelley
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Bernardo Stutz
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Tamas L Horvath
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Mihály Hajós
- Department of Comparative Medicine, Yale University School of Medicine, New Haven, CT, USA
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116
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Cerebellar Theta and Beta Noninvasive Stimulation Rhythms Differentially Influence Episodic Memory versus Semantic Prediction. J Neurosci 2020; 40:7300-7310. [PMID: 32817245 DOI: 10.1523/jneurosci.0595-20.2020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2020] [Revised: 05/21/2020] [Accepted: 06/29/2020] [Indexed: 12/11/2022] Open
Abstract
The human cerebellum is thought to interact with distributed brain networks to support cognitive abilities such as episodic memory and semantic prediction. Hippocampal and fronto-temporo-parietal networks that respectively support episodic memory versus semantic prediction have been associated with distinct endogenous oscillatory activity frequency bands: theta (∼3-8 Hz) versus beta (∼13-30 Hz) respectively. We sought to test whether it is possible to toggle cerebellar participation in episodic memory versus semantic prediction by noninvasively stimulating with theta versus beta rhythmic transcranial magnetic stimulation. In human subjects of both sexes, cerebellar theta stimulation improved episodic memory encoding but did not influence neural signals of semantic prediction, whereas beta stimulation of the same cerebellar location increased neural signals of semantic prediction but did not influence episodic memory encoding. This constitutes evidence for double dissociation of cerebellar contributions to semantic prediction versus episodic memory based on stimulation rhythm, supporting the hypothesis that the cerebellum can be biased to support these distinct cognitive abilities at the command of network-specific rhythmic activity.SIGNIFICANCE STATEMENT The cerebellum interacts with several distinct large-scale brain networks for cognitive function, but the factors governing selectivity of such interactions for particular functions are not fully understood. We tested the hypothesis that cerebellar contributions to cognition are guided by neural oscillations with function-specific frequency bands. We demonstrated that matching noninvasive stimulation to network-specific frequencies selectively enhanced episodic memory versus semantic prediction. These findings suggest that cerebellar contributions to cognitive networks are selected based on corresponding activity rhythms and could be used to develop cerebellar stimulation interventions for specific neurocognitive impairments.
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117
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Meier JK, Weymar M, Schwabe L. Stress Alters the Neural Context for Building New Memories. J Cogn Neurosci 2020; 32:2226-2240. [PMID: 32762518 DOI: 10.1162/jocn_a_01613] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Stressful events affect mnemonic processing, in particular for emotionally arousing events. Previous research on the mechanisms underlying stress effects on human memory focused on stress-induced changes in the neural activity elicited by a stimulus. We tested an alternative mechanism and hypothesized that stress may already alter the neural context for successful memory formation, reflected in the neural activity preceding a stimulus. Therefore, 69 participants underwent a stress or control procedure before encoding neutral and negative pictures. During encoding, we recorded high-density EEG and analyzed-based on multivariate searchlight analyses-oscillatory activity and cross-frequency coupling patterns before stimulus onset that were predictive of memory tested 24 hr later. Prestimulus theta predicted subsequent memory in controls but not in stressed participants. Instead, prestimulus gamma predicted successful memory formation after stress, specifically for emotional material. Likewise, stress altered the patterns of prestimulus theta-beta and theta-gamma phase-amplitude coupling predictive of subsequent memory, again depending on the emotionality of the presented material. Our data suggest that stress changes the neural context for building new memories, tuning this neural context specifically to the encoding of emotionally salient events. These findings point to a yet unknown mechanism through which stressful events may change (emotional) memory formation.
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118
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Adams RA, Bush D, Zheng F, Meyer SS, Kaplan R, Orfanos S, Marques TR, Howes OD, Burgess N. Impaired theta phase coupling underlies frontotemporal dysconnectivity in schizophrenia. Brain 2020; 143:1261-1277. [PMID: 32236540 PMCID: PMC7174039 DOI: 10.1093/brain/awaa035] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/21/2019] [Accepted: 12/16/2019] [Indexed: 12/17/2022] Open
Abstract
Frontotemporal dysconnectivity is a key pathology in schizophrenia. The specific nature of this dysconnectivity is unknown, but animal models imply dysfunctional theta phase coupling between hippocampus and medial prefrontal cortex (mPFC). We tested this hypothesis by examining neural dynamics in 18 participants with a schizophrenia diagnosis, both medicated and unmedicated; and 26 age, sex and IQ matched control subjects. All participants completed two tasks known to elicit hippocampal-prefrontal theta coupling: a spatial memory task (during magnetoencephalography) and a memory integration task. In addition, an overlapping group of 33 schizophrenia and 29 control subjects underwent PET to measure the availability of GABAARs expressing the α5 subunit (concentrated on hippocampal somatostatin interneurons). We demonstrate-in the spatial memory task, during memory recall-that theta power increases in left medial temporal lobe (mTL) are impaired in schizophrenia, as is theta phase coupling between mPFC and mTL. Importantly, the latter cannot be explained by theta power changes, head movement, antipsychotics, cannabis use, or IQ, and is not found in other frequency bands. Moreover, mPFC-mTL theta coupling correlated strongly with performance in controls, but not in subjects with schizophrenia, who were mildly impaired at the spatial memory task and no better than chance on the memory integration task. Finally, mTL regions showing reduced phase coupling in schizophrenia magnetoencephalography participants overlapped substantially with areas of diminished α5-GABAAR availability in the wider schizophrenia PET sample. These results indicate that mPFC-mTL dysconnectivity in schizophrenia is due to a loss of theta phase coupling, and imply α5-GABAARs (and the cells that express them) have a role in this process.
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Affiliation(s)
- Rick A Adams
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AZ, UK.,Division of Psychiatry, University College London, 149 Tottenham Court Road, London, W1T 7NF, UK.,Max Planck-UCL Centre for Computational Psychiatry and Ageing Research, 10-12 Russell Square, London, WC1B 5EH, UK.,Centre for Medical Image Computing, Department of Computer Science, University College London, Malet Place, London, WC1E 7JE, UK.,Wellcome Centre for Human Neuroimaging, University College London, 12 Queen Square, London, WC1N 3BG, UK
| | - Daniel Bush
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AZ, UK.,Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Fanfan Zheng
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AZ, UK.,Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, 95 Zhongguancun East Road, 100190 Beijing, China
| | - Sofie S Meyer
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AZ, UK.,Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
| | - Raphael Kaplan
- Wellcome Centre for Human Neuroimaging, University College London, 12 Queen Square, London, WC1N 3BG, UK.,Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Stelios Orfanos
- South West London and St George's Mental Health NHS Trust, Springfield University Hospital, 61 Glenburnie Rd, London SW17 7DJ, UK.,Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, De Crespigny Park, Denmark Hill, London SE5 8AF, UK
| | - Tiago Reis Marques
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, SE5 8AF, UK
| | - Oliver D Howes
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Hammersmith Hospital, London, W12 0NN, UK.,Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience (IoPPN), King's College London, London, SE5 8AF, UK
| | - Neil Burgess
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, WC1N 3AZ, UK.,Wellcome Centre for Human Neuroimaging, University College London, 12 Queen Square, London, WC1N 3BG, UK.,Queen Square Institute of Neurology, University College London, London, WC1N 3BG, UK
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119
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Benear SL, Ngo CT, Olson IR. Dissecting the Fornix in Basic Memory Processes and Neuropsychiatric Disease: A Review. Brain Connect 2020; 10:331-354. [PMID: 32567331 DOI: 10.1089/brain.2020.0749] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Background: The fornix is the primary axonal tract of the hippocampus, connecting it to modulatory subcortical structures. This review reveals that fornix damage causes cognitive deficits that closely mirror those resulting from hippocampal lesions. Methods: We reviewed the literature on the fornix, spanning non-human animal lesion research, clinical case studies of human patients with fornix damage, as well as diffusion-weighted imaging (DWI) work that evaluates fornix microstructure in vivo. Results: The fornix is essential for memory formation because it serves as the conduit for theta rhythms and acetylcholine, as well as providing mnemonic representations to deep brain structures that guide motivated behavior, such as when and where to eat. In rodents and non-human primates, fornix lesions lead to deficits in conditioning, reversal learning, and navigation. In humans, damage to the fornix manifests as anterograde amnesia. DWI research reveals that the fornix plays a key role in mild cognitive impairment and Alzheimer's Disease, and can potentially predict conversion from the former to the latter. Emerging DWI findings link perturbations in this structure to schizophrenia, mood disorders, and eating disorders. Cutting-edge research has investigated how deep brain stimulation of the fornix can potentially attenuate memory loss, control epileptic seizures, and even improve mood. Conclusions: The fornix is essential to a fully functioning memory system and is implicated in nearly all neurological functions that rely on the hippocampus. Future research needs to use optimized DWI methods to study the fornix in vivo, which we discuss, given the difficult nature of fornix reconstruction. Impact Statement The fornix is a white matter tract that connects the hippocampus to several subcortical brain regions and is pivotal for episodic memory functioning. Functionally, the fornix transmits essential neurotransmitters, as well as theta rhythms, to the hippocampus. In addition, it is the conduit by which memories guide decisions. The fornix is biomedically important because lesions to this tract result in irreversible anterograde amnesia. Research using in vivo imaging methods has linked fornix pathology to cognitive aging, mild cognitive impairment, psychosis, epilepsy, and, importantly, Alzheimer's Disease.
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Affiliation(s)
- Susan L Benear
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA
| | - Chi T Ngo
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
| | - Ingrid R Olson
- Department of Psychology, Temple University, Philadelphia, Pennsylvania, USA
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120
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Jones EJH, Goodwin A, Orekhova E, Charman T, Dawson G, Webb SJ, Johnson MH. Infant EEG theta modulation predicts childhood intelligence. Sci Rep 2020; 10:11232. [PMID: 32641754 PMCID: PMC7343785 DOI: 10.1038/s41598-020-67687-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 06/04/2020] [Indexed: 11/08/2022] Open
Abstract
Intellectual functioning is a critical determinant of economic and personal productivity. Identifying early neural predictors of cognitive function in infancy will allow us to map the neurodevelopmental pathways that underpin individual differences in intellect. Here, in three different cohorts we investigate the association between a putative neurophysiological indicator of information encoding (change in frontal theta during a novel video) in infancy and later general cognitive outcome. In a discovery cohort of 12-month-old typically developing infants, we recorded EEG during presentation of dynamic movies of people and objects. Frontal theta power (3-6 Hz) significantly increased during the course of viewing each video. Critically, increase in frontal theta during viewing of a video was associated with a differential response to repetition of that specific video, confirming relation to learning. Further, individual differences in the magnitude of change in frontal theta power were related to concurrent nonverbal cognitive level. We then sought to extend this association in two independent samples enriched for variation in cognitive outcome due to the inclusion of infants at familial risk for autism. We observed similar patterns of theta EEG change at 12 months, and found a predictive relation to verbal and nonverbal cognitive skills measured at 2, 3 and 7 years of age. For the subset of high-risk infants later diagnosed with autism, infant theta EEG explained over 80% of the variance in nonverbal skills at age 3 years. We suggest that EEG theta change in infancy is an excellent candidate predictive biomarker that could yield substantial insight into the mechanisms that underlie individual differences in childhood intelligence, particularly in high risk populations.
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Affiliation(s)
- E J H Jones
- Centre for Brain and Cognitive Development, Birkbeck, University of London, Malet Street, London, WC1E 7HX, UK.
| | - A Goodwin
- Institute of Psychiatry, King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AF, UK
| | - E Orekhova
- MedTech West and the Institute of Neuroscience and Physiology, Sahlgrenska Academ, The University of Gothenburg, Kungsgatan 12, SE 411 19, Gothenburg, Sweden
- MEG Centre, Moscow State University of Psychology and Education, 123290, Moscow, Russia
| | - T Charman
- Institute of Psychiatry, King's College London, 16 De Crespigny Park, Camberwell, London, SE5 8AF, UK
| | - G Dawson
- Duke Centre for Autism and Brain Development, Department of Psychiatry and Behavioral Sciences, Duke University, 4584 White Zone, Duke South, Durham, 27705, NC, USA
| | - S J Webb
- Center On Human Development and Disability, University of Washington, 1701 NE Columbia Rd, Seattle, WA, 98195, USA
- Department of Psychiatry & Behavioral Science, University of Washington, 2815 Eastlake Ave E, Seattle, WA, 98102, USA
- Center On Child Behavior and Development, Seattle Children's Research Institute, 2001 Eighth Ave, Suite 400, Seattle, WA, 98121, USA
| | - M H Johnson
- Centre for Brain and Cognitive Development, Birkbeck, University of London, Malet Street, London, WC1E 7HX, UK
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121
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Braithwaite EK, Jones EJH, Johnson MH, Holmboe K. Dynamic modulation of frontal theta power predicts cognitive ability in infancy. Dev Cogn Neurosci 2020; 45:100818. [PMID: 32741754 PMCID: PMC7393453 DOI: 10.1016/j.dcn.2020.100818] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 05/18/2020] [Accepted: 06/29/2020] [Indexed: 12/14/2022] Open
Abstract
Cognitive ability is a key factor that contributes to individual differences in life trajectories. Identifying early neural indicators of later cognitive ability may enable us to better elucidate the mechanisms that shape individual differences, eventually aiding identification of infants with an elevated likelihood of less optimal outcomes. A previous study associated a measure of neural activity (theta EEG) recorded at 12-months with non-verbal cognitive ability at ages two, three and seven in individuals with older siblings with autism (Jones et al., 2020). In a pre-registered study (https://osf.io/v5xrw/), we replicate and extend this finding in a younger, low-risk infant sample. EEG was recorded during presentation of a non-social video to a cohort of 6-month-old infants and behavioural data was collected at 6- and 9-months-old. Initial analyses replicated the finding that frontal theta power increases over the course of video viewing, extending this to 6-month-olds. Further, individual differences in the magnitude of this change significantly predicted non-verbal cognitive ability measured at 9-months, but not early executive function. Theta change at 6-months-old may therefore be an early indicator of later cognitive ability. This could have important implications for identification of, and interventions for, children at risk of poor cognitive outcomes.
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Affiliation(s)
- Eleanor K Braithwaite
- Centre for Brain and Cognitive Development, Birkbeck, University of London, United Kingdom
| | - Emily J H Jones
- Centre for Brain and Cognitive Development, Birkbeck, University of London, United Kingdom
| | - Mark H Johnson
- Centre for Brain and Cognitive Development, Birkbeck, University of London, United Kingdom; Department of Psychology, University of Cambridge, United Kingdom
| | - Karla Holmboe
- Department of Experimental Psychology, University of Oxford, United Kingdom.
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122
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Bice K, Yamasaki BL, Prat CS. Bilingual Language Experience Shapes Resting-State Brain Rhythms. NEUROBIOLOGY OF LANGUAGE (CAMBRIDGE, MASS.) 2020; 1:288-318. [PMID: 37215228 PMCID: PMC10158654 DOI: 10.1162/nol_a_00014] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 04/27/2020] [Indexed: 05/24/2023]
Abstract
An increasing body of research has investigated how bilingual language experience changes brain structure and function, including changes to task-free, or "resting-state" brain connectivity. Such findings provide important evidence about how the brain continues to be shaped by different language experiences throughout the lifespan. The neural effects of bilingual language experience can provide evidence about the additional processing demands placed on the linguistic and/or executive systems by dual-language use. While considerable research has used MRI to examine where these changes occur, such methods cannot reveal the temporal dynamics of functioning brain networks at rest. The current study used data from task-free EEGS to disentangle how the linguistic and cognitive demands of bilingual language use impact brain functioning. Data analyzed from 106 bilinguals and 91 monolinguals revealed that bilinguals had greater alpha power, and significantly greater and broader coherence in the alpha and beta frequency ranges than monolinguals. Follow-up analyses showed that higher alpha was related to language control: more second-language use, higher native-language proficiency, and earlier age of second-language acquisition. Bilateral beta power was related to native-language proficiency, whereas theta was related to native-language proficiency only in left-hemisphere electrodes. The results contribute to our understanding of how the linguistic and cognitive requirements of dual-language use shape intrinsic brain activity, and what the broader implications for information processing may be.
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Affiliation(s)
| | - Brianna L. Yamasaki
- Institute for Learning and Brain Sciences and Department of Psychology, University of Washington
- Department of Psychology and Human Development, Vanderbilt University
| | - Chantel S. Prat
- Institute for Learning and Brain Sciences and Department of Psychology, University of Washington
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123
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Abstract
The entorhinal cortex (EC) is a critical element of the hippocampal formation located within the medial temporal lobe (MTL) in primates. The EC has historically received attention for being the primary mediator of cortical information going into and coming from the hippocampus proper. In this review, we highlight the significance of the EC as a major player in memory processing, along with other associated structures in the primate MTL. The complex, convergent topographies of cortical and subcortical input to the EC, combined with short-range intrinsic connectivity and the selective targeting of EC efferents to the hippocampus, provide evidence for subregional specialization and integration of information beyond what would be expected if this structure were a simple conduit of information for the hippocampus. Lesion studies of the EC provide evidence implicating this region as critical for memory and the flexible use of complex relational associations between experienced events. The physiology of this structure's constituent principal cells mirrors the complexity of its anatomy. EC neurons respond preferentially to aspects of memory-dependent paradigms including object, place, and time. EC neurons also show striking spatial representations as primates explore visual space, similar to those identified in rodents navigating physical space. In this review, we highlight the great strides that have been made toward furthering our understanding of the primate EC, and we identify paths forward for future experiments to provide additional insight into the role of this structure in learning and memory.
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Affiliation(s)
- Aaron D Garcia
- Graduate Program in Neuroscience, University of Washington, Seattle, Washington 98195, USA.,Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, Washington 98195, USA;
| | - Elizabeth A Buffalo
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, Washington 98195, USA; .,Washington National Primate Research Center, University of Washington, Seattle, Washington 98195, USA
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124
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Towards a Pragmatic Approach to a Psychophysiological Unit of Analysis for Mental and Brain Disorders: An EEG-Copeia for Neurofeedback. Appl Psychophysiol Biofeedback 2020; 44:151-172. [PMID: 31098793 DOI: 10.1007/s10484-019-09440-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This article proposes what we call an "EEG-Copeia" for neurofeedback, like the "Pharmacopeia" for psychopharmacology. This paper proposes to define an "EEG-Copeia" as an organized list of scientifically validated EEG markers, characterized by a specific association with an identified cognitive process, that define a psychophysiological unit of analysis useful for mental or brain disorder evaluation and treatment. A characteristic of EEG neurofeedback for mental and brain disorders is that it targets a EEG markers related to a supposed cognitive process, whereas conventional treatments target clinical manifestations. This could explain why EEG neurofeedback studies encounter difficulty in achieving reproducibility and validation. The present paper suggests that a first step to optimize EEG neurofeedback protocols and future research is to target a valid EEG marker. The specificity of the cognitive skills trained and learned during real time feedback of the EEG marker could be enhanced and both the reliability of neurofeedback training and the therapeutic impact optimized. However, several of the most well-known EEG markers have seldom been applied for neurofeedback. Moreover, we lack a reliable and valid EEG targets library for further RCT to evaluate the efficacy of neurofeedback in mental and brain disorders. With the present manuscript, our aim is to foster dialogues between cognitive neuroscience and EEG neurofeedback according to a psychophysiological perspective. The primary objective of this review was to identify the most robust EEG target. EEG markers linked with one or several clearly identified cognitive-related processes will be identified. The secondary objective was to organize these EEG markers and related cognitive process in a psychophysiological unit of analysis matrix inspired by the Research Domain Criteria (RDoC) project.
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125
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Goyal A, Miller J, Qasim SE, Watrous AJ, Zhang H, Stein JM, Inman CS, Gross RE, Willie JT, Lega B, Lin JJ, Sharan A, Wu C, Sperling MR, Sheth SA, McKhann GM, Smith EH, Schevon C, Jacobs J. Functionally distinct high and low theta oscillations in the human hippocampus. Nat Commun 2020; 11:2469. [PMID: 32424312 PMCID: PMC7235253 DOI: 10.1038/s41467-020-15670-6] [Citation(s) in RCA: 93] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/23/2020] [Indexed: 11/08/2022] Open
Abstract
Based on rodent models, researchers have theorized that the hippocampus supports episodic memory and navigation via the theta oscillation, a ~4-10 Hz rhythm that coordinates brain-wide neural activity. However, recordings from humans have indicated that hippocampal theta oscillations are lower in frequency and less prevalent than in rodents, suggesting interspecies differences in theta's function. To characterize human hippocampal theta, we examine the properties of theta oscillations throughout the anterior-posterior length of the hippocampus as neurosurgical subjects performed a virtual spatial navigation task. During virtual movement, we observe hippocampal oscillations at multiple frequencies from 2 to 14 Hz. The posterior hippocampus prominently displays oscillations at ~8-Hz and the precise frequency of these oscillations correlates with the speed of movement, implicating these signals in spatial navigation. We also observe slower ~3 Hz oscillations, but these signals are more prevalent in the anterior hippocampus and their frequency does not vary with movement speed. Our results converge with recent findings to suggest an updated view of human hippocampal electrophysiology. Rather than one hippocampal theta oscillation with a single general role, high- and low-frequency theta oscillations, respectively, may reflect spatial and non-spatial cognitive processes.
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Affiliation(s)
- Abhinav Goyal
- Mayo Clinic Medical Scientist Training Program, Mayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN, 55905, USA
| | - Jonathan Miller
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Salman E Qasim
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | | | - Honghui Zhang
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA
| | - Joel M Stein
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Cory S Inman
- Department of Neurosurgery, Emory University, Atlanta, GA, 30322, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University, Atlanta, GA, 30322, USA
| | - Jon T Willie
- Department of Neurosurgery, Emory University, Atlanta, GA, 30322, USA
| | - Bradley Lega
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Jui-Jui Lin
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Ashwini Sharan
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, PA, 9107, USA
- Jefferson Comprehensive Epilepsy Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Chengyuan Wu
- Department of Neurological Surgery, Thomas Jefferson University, Philadelphia, PA, 9107, USA
| | - Michael R Sperling
- Jefferson Comprehensive Epilepsy Center, Thomas Jefferson University, Philadelphia, PA, USA
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Sameer A Sheth
- Department of Neurological Surgery, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Guy M McKhann
- Department of Neurosurgery, Columbia University Medical Center, New York, NY, 10032, USA
| | - Elliot H Smith
- Department of Neurosurgery, University of Utah, Salt Lake City, UT, USA
| | - Catherine Schevon
- Department of Neurology, Columbia University Medical Center, New York, NY, 10032, USA
| | - Joshua Jacobs
- Department of Biomedical Engineering, Columbia University, New York, NY, 10027, USA.
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126
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Kamiński J, Brzezicka A, Mamelak AN, Rutishauser U. Combined Phase-Rate Coding by Persistently Active Neurons as a Mechanism for Maintaining Multiple Items in Working Memory in Humans. Neuron 2020; 106:256-264.e3. [PMID: 32084331 PMCID: PMC7217299 DOI: 10.1016/j.neuron.2020.01.032] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 12/25/2019] [Accepted: 01/23/2020] [Indexed: 01/01/2023]
Abstract
Maintaining multiple items in working memory (WM) is central to human behavior. Persistently active neurons are thought to be a mechanism to maintain WMs, but it remains unclear how such activity is coordinated when multiple items are kept in memory. We show that memoranda-selective persistently active neurons in the human medial temporal lobe phase lock to ongoing slow-frequency (1-7 Hz) oscillations during WM maintenance. The properties of phase locking are dependent on memory content and load. During high memory loads, the phase of the oscillatory activity to which neurons phase lock provides information about memory content not available in the firing rate of the neurons. We provide a computational model that reveals that inhibitory-feedback-mediated competition between multiple persistently active neurons reproduces this phenomenon. This work reveals a mechanism for the active maintenance of multiple items in WM that relies on persistently active neurons whose activation is orchestrated by oscillatory activity.
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Affiliation(s)
- Jan Kamiński
- Department of Neurosurgery, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA; Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA.
| | - Aneta Brzezicka
- Department of Neurosurgery, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA; Institute of Psychology, SWPS University of Social Sciences and Humanities, Warsaw 03-815, Poland
| | - Adam N Mamelak
- Department of Neurosurgery, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA
| | - Ueli Rutishauser
- Department of Neurosurgery, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA; Department of Neurology, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA; Center for Neural Science and Medicine, Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048, USA; Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Boulevard, Pasadena, CA 91125, USA.
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127
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Choi K, Bagen L, Robinson L, Umbach G, Rugg M, Lega B. Longitudinal Differences in Human Hippocampal Connectivity During Episodic Memory Processing. Cereb Cortex Commun 2020; 1:tgaa010. [PMID: 32864613 PMCID: PMC7446229 DOI: 10.1093/texcom/tgaa010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 02/20/2020] [Accepted: 04/01/2020] [Indexed: 01/01/2023] Open
Abstract
The question of longitudinal hippocampal functional specialization is critical to human episodic memory because an accurate understanding of this phenomenon would impact theories of mnemonic function and entail practical consequences for the clinical management of patients undergoing temporal lobe surgery. The implementation of the robotically assisted stereo electroencephalography technique for seizure mapping has provided our group with the opportunity to obtain recordings simultaneously from the anterior and posterior human hippocampus, allowing us to create an unparalleled data set of human subjects with simultaneous anterior and posterior hippocampal recordings along with several cortical regions. Using these data, we address several key questions governing functional hippocampal connectivity in human memory. First, we ask whether functional networks during episodic memory encoding and retrieval are significantly different for the anterior versus posterior hippocampus (PH). We also examine how connections differ across the 2-5 Hz versus 4-9 Hz theta frequency ranges, directly addressing the relative contribution of each of these separate bands in hippocampal-cortical interactions. While we report some overlapping connections, we observe evidence of distinct anterior versus posterior hippocampal networks during memory encoding related to frontal and parietal connectivity as well as hemispheric differences in aggregate connectivity. We frame these findings in light of the proposed AT/PM memory systems. We also observe distinct encoding versus retrieval connectivity patterns between anterior and posterior hippocampal networks, we find that overall connectivity is greater for the PH in the right hemisphere, and further that these networks significantly differ in terms of frontal and parietal connectivity. We place these findings in the context of existing theoretical treatments of human memory systems, especially the proposed AT/PM system. During memory retrieval, we observe significant differences between slow-theta (2-5 Hz) and fast-theta (4-9 Hz) connectivity between the cortex and hippocampus. Finally, we test how these distinct theta frequency oscillations propagate within the hippocampus, using phase slope index to estimate the direction slow-theta and fast-theta oscillations travel during encoding and retrieval. We uncover evidence that 2-5 Hz oscillations travel in the posterior-to-anterior direction, while 5-9 Hz oscillations travel from anterior-to-posterior. Taken together, our findings describe mnemonically relevant functional connectivity differences along the longitudinal axis of the human hippocampus that will inform interpretation of models of hippocampal function that seek to integrate rodent and human data.
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Affiliation(s)
- Kyuwan Choi
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Lisa Bagen
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Linley Robinson
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Gray Umbach
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Michael Rugg
- Center for Vital Longevity, University of Texas at Dallas, Dallas, TX 75235, USA
- School of Behavioral and Brain Sciences, University of Texas at Dallas, Dallas, TX 75080, USA
- Department of Psychiatry, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Bradley Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
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128
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Kragel JE, VanHaerents S, Templer JW, Schuele S, Rosenow JM, Nilakantan AS, Bridge DJ. Hippocampal theta coordinates memory processing during visual exploration. eLife 2020; 9:e52108. [PMID: 32167468 PMCID: PMC7069726 DOI: 10.7554/elife.52108] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 03/02/2020] [Indexed: 12/23/2022] Open
Abstract
The hippocampus supports memory encoding and retrieval, which may occur at distinct phases of the theta cycle. These processes dynamically interact over rapid timescales, especially when sensory information conflicts with memory. The ability to link hippocampal dynamics to memory-guided behaviors has been limited by experiments that lack the temporal resolution to segregate encoding and retrieval. Here, we simultaneously tracked eye movements and hippocampal field potentials while neurosurgical patients performed a spatial memory task. Phase-locking at the peak of theta preceded fixations to retrieved locations, indicating that the hippocampus coordinates memory-guided eye movements. In contrast, phase-locking at the trough of theta followed fixations to novel object-locations and predicted intact memory of the original location. Theta-gamma phase amplitude coupling increased during fixations to conflicting visual content, but predicted memory updating. Hippocampal theta thus supports learning through two interleaved processes: strengthening encoding of novel information and guiding exploration based on prior experience.
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Affiliation(s)
- James E Kragel
- Department of Medical Social Sciences, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Stephen VanHaerents
- Department of Neurology, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Jessica W Templer
- Department of Neurology, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Stephan Schuele
- Department of Neurology, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Joshua M Rosenow
- Department of Neurological Surgery, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Aneesha S Nilakantan
- Department of Medical Social Sciences, Northwestern University Feinberg School of MedicineChicagoUnited States
| | - Donna J Bridge
- Department of Medical Social Sciences, Northwestern University Feinberg School of MedicineChicagoUnited States
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129
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Herweg NA, Solomon EA, Kahana MJ. Theta Oscillations in Human Memory. Trends Cogn Sci 2020; 24:208-227. [PMID: 32029359 PMCID: PMC8310425 DOI: 10.1016/j.tics.2019.12.006] [Citation(s) in RCA: 195] [Impact Index Per Article: 48.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 12/05/2019] [Accepted: 12/10/2019] [Indexed: 11/21/2022]
Abstract
Theta frequency (4-8 Hz) fluctuations of the local field potential have long been implicated in learning and memory. Human studies of episodic memory, however, have provided mixed evidence for theta's role in successful learning and remembering. Re-evaluating these conflicting findings leads us to conclude that: (i) successful memory is associated both with increased narrow-band theta oscillations and a broad-band tilt of the power spectrum; (ii) theta oscillations specifically support associative memory, whereas the spectral tilt reflects a general index of activation; and (iii) different cognitive contrasts (generalized versus specific to memory), recording techniques (invasive versus noninvasive), and referencing schemes (local versus global) alter the balance between the two phenomena to make one or the other more easily detectable.
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Affiliation(s)
- Nora A Herweg
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Ethan A Solomon
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
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130
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Zioga I, Harrison PM, Pearce MT, Bhattacharya J, Di Bernardi Luft C. From learning to creativity: Identifying the behavioural and neural correlates of learning to predict human judgements of musical creativity. Neuroimage 2020; 206:116311. [DOI: 10.1016/j.neuroimage.2019.116311] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 10/18/2019] [Accepted: 10/22/2019] [Indexed: 10/25/2022] Open
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131
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Sander MC, Fandakova Y, Grandy TH, Shing YL, Werkle-Bergner M. Oscillatory Mechanisms of Successful Memory Formation in Younger and Older Adults Are Related to Structural Integrity. Cereb Cortex 2020; 30:3744-3758. [PMID: 31989153 PMCID: PMC7232990 DOI: 10.1093/cercor/bhz339] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/01/2019] [Indexed: 01/21/2023] Open
Abstract
We studied oscillatory mechanisms of memory formation in 48 younger and 51 older adults in an intentional associative memory task with cued recall. While older adults showed lower memory performance than young adults, we found subsequent memory effects (SME) in alpha/beta and theta frequency bands in both age groups. Using logistic mixed effects models, we investigated whether interindividual differences in structural integrity of key memory regions could account for interindividual differences in the strength of the SME. Structural integrity of inferior frontal gyrus (IFG) and hippocampus was reduced in older adults. SME in the alpha/beta band were modulated by the cortical thickness of IFG, in line with its hypothesized role for deep semantic elaboration. Importantly, this structure–function relationship did not differ by age group. However, older adults were more frequently represented among the participants with low cortical thickness and consequently weaker SME in the alpha band. Thus, our results suggest that differences in the structural integrity of the IFG contribute not only to interindividual, but also to age differences in memory formation.
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Affiliation(s)
- Myriam C Sander
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Yana Fandakova
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Thomas H Grandy
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
| | - Yee Lee Shing
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany.,Department of Developmental Psychology, Goethe University Frankfurt, Frankfurt am Main 60323, Germany
| | - Markus Werkle-Bergner
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin 14195, Germany
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132
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Jun S, Lee SA, Kim JS, Jeong W, Chung CK. Task-dependent effects of intracranial hippocampal stimulation on human memory and hippocampal theta power. Brain Stimul 2020; 13:603-613. [PMID: 32289685 DOI: 10.1016/j.brs.2020.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/11/2020] [Accepted: 01/16/2020] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Despite its potential to revolutionize the treatment of memory dysfunction, the efficacy of direct electrical hippocampal stimulation for memory performance has not yet been well characterized. One of the main challenges to cross-study comparison in this area of research is the diversity of the cognitive tasks used to measure memory performance. OBJECTIVE We hypothesized that the tasks that differentially engage the hippocampus may be differentially influenced by hippocampal stimulation and the behavioral effects would be related to the underlying hippocampal activity. METHODS To investigate this issue, we recorded intracranial EEG from and directly applied stimulation to the hippocampus of 10 epilepsy patients while they performed two different verbal memory tasks - a word pair associative memory task and a single item memory task. RESULTS Hippocampal stimulation modulated memory performance in a task-dependent manner, improving associative memory performance, while impairing item memory performance. In addition, subjects with poorer baseline cognitive function improved much more with stimulation. iEEG recordings from the hippocampus during non-stimulation encoding blocks revealed that the associative memory task elicited stronger theta oscillations than did item memory and that stronger theta power was related to memory performance. CONCLUSIONS We show here for the first time that stimulation-induced associative memory enhancement was linked to increased theta power during retrieval. These results suggest that hippocampal stimulation enhances associative memory but not item memory because it engages more hippocampal theta activity and that, in general, increasing hippocampal theta may provide a neural mechanism for successful memory enhancement.
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Affiliation(s)
- Soyeon Jun
- Department of Brain & Cognitive Sciences, Seoul National University, Seoul, 03080, Republic of Korea; Department of Neurosurgery, Seoul National University Hospital, Seoul, 03080, Republic of Korea.
| | - Sang Ah Lee
- Department of Bio & Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - June Sic Kim
- Department of Brain & Cognitive Sciences, Seoul National University, Seoul, 03080, Republic of Korea; Research Institute of Basic Sciences, Seoul National University, Seoul, Republic of Korea.
| | - Woorim Jeong
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, 03080, Republic of Korea; Department of Neurosurgery, Seoul National University Hospital, Seoul, 03080, Republic of Korea
| | - Chun Kee Chung
- Department of Brain & Cognitive Sciences, Seoul National University, Seoul, 03080, Republic of Korea; Department of Neurosurgery, Seoul National University Hospital, Seoul, 03080, Republic of Korea.
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133
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Reactivated Spatial Context Guides Episodic Recall. J Neurosci 2020; 40:2119-2128. [PMID: 31974207 DOI: 10.1523/jneurosci.1640-19.2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/21/2019] [Accepted: 11/23/2019] [Indexed: 01/01/2023] Open
Abstract
The medial temporal lobe (MTL) is known as the locus of spatial coding and episodic memory, but the interaction between these cognitive domains as well as the extent to which they rely on common neurophysiological mechanisms is poorly understood. Here, we use intracranial electroencephalography and a hybrid spatial-episodic memory task (29 subjects, 15 female) to determine how spatial information is dynamically reactivated in subregions of the human MTL and how this reactivation guides recall of episodic information. Our results implicate theta oscillations across the MTL as a common neurophysiological substrate for spatial coding in navigation and episodic recall. We further show that our index of retrieved spatial context is high in the hippocampus (HC) in an early time window preceding recall. Closer to recall, it decreases in the HC and increases in the parahippocampal gyrus. Finally, we demonstrate that hippocampal theta phase modulates parahippocampal gamma amplitude during retrieval of spatial context, suggesting a role for cross-frequency coupling in coding and transmitting retrieved spatial information.SIGNIFICANCE STATEMENT By recording from the human medial temporal lobe (MTL) while subjects recall items experienced in a virtual environment, we establish a direct relation between the strength of theta activity during memory search and the extent to which memories are organized by their spatial locations. We thereby pinpoint a role for theta oscillations in accessing the "cognitive map" during episodic retrieval and further highlight the dynamic interplay of hippocampus and extrahippocampal MTL in representing retrieved spatial context. Our results provide an important step toward a unified theory of MTL function encompassing its role in spatial navigation and episodic memory.
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134
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Lu L, Ren Y, Yu T, Liu Z, Wang S, Tan L, Zeng J, Feng Q, Lin R, Liu Y, Guo Q, Luo M. Control of locomotor speed, arousal, and hippocampal theta rhythms by the nucleus incertus. Nat Commun 2020; 11:262. [PMID: 31937768 PMCID: PMC6959274 DOI: 10.1038/s41467-019-14116-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 12/13/2019] [Indexed: 01/06/2023] Open
Abstract
Navigation requires not only the execution of locomotor programs but also high arousal and real-time retrieval of spatial memory that is often associated with hippocampal theta oscillations. However, the neural circuits for coordinately controlling these important processes remain to be fully dissected. Here we show that the activity of the neuromedin B (NMB) neurons in the nucleus incertus (NI) is tightly correlated with mouse locomotor speed, arousal level, and hippocampal theta power. These processes are reversibly suppressed by optogenetic inhibition and rapidly promoted by optogenetic stimulation of NI NMB neurons. These neurons form reciprocal connections with several subcortical areas associated with arousal, theta oscillation, and premotor processing. Their projections to multiple downstream stations regulate locomotion and hippocampal theta, with the projection to the medial septum being particularly important for promoting arousal. Therefore, NI NMB neurons functionally impact the neural circuit for navigation control according to particular brains states. In addition to activation of locomotor circuits, navigation also requires regulation of arousal and spatial memory processes. Here the authors identify neuromedin B neurons in the nucleus incertus and their subcortical projections in controlling these various processes during navigation.
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Affiliation(s)
- Lihui Lu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Yuqi Ren
- School of Life Sciences, Peking University, Beijing, 100871, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Tao Yu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Zhixiang Liu
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Sice Wang
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China.,School of Life Sciences, Peking University, Beijing, 100871, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Lubin Tan
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Jiawei Zeng
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Qiru Feng
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China.,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China
| | - Rui Lin
- National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Yang Liu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China.,National Institute of Biological Sciences (NIBS), Beijing, 102206, China
| | - Qingchun Guo
- Chinese Institute for Brain Research, Beijing, 102206, China
| | - Minmin Luo
- School of Life Sciences, Tsinghua University, Beijing, 100084, China. .,Tsinghua-Peking Joint Center for Life Sciences, Tsinghua University, Beijing, 100084, China. .,National Institute of Biological Sciences (NIBS), Beijing, 102206, China. .,Peking University-Tsinghua University-NIBS Joint Graduate Program, Beijing, 102206, China. .,Chinese Institute for Brain Research, Beijing, 102206, China.
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135
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Keppler J. The Common Basis of Memory and Consciousness: Understanding the Brain as a Write-Read Head Interacting With an Omnipresent Background Field. Front Psychol 2020; 10:2968. [PMID: 31998199 PMCID: PMC6966770 DOI: 10.3389/fpsyg.2019.02968] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 12/16/2019] [Indexed: 12/27/2022] Open
Abstract
The main goal of this article consists in addressing two fundamental issues of consciousness research and cognitive science, namely, the question of why declarative memory functions are inextricably linked with phenomenal awareness and the question of the physical basis of memory traces. The presented approach proposes that high-level cognitive processes involving consciousness employ a universal mechanism by means of which they access and modulate an omnipresent background field that is identified with the zero-point field (ZPF) specified by stochastic electrodynamics (SED), a branch of physics that deals with the universal principles underlying quantum systems. In addition to its known physical properties and memory capacities, the ZPF is hypothesized to be an immanently sentient medium. It is propounded that linking up to a particular field mode of the ZPF activates a particular phenomenal nuance, implying that the phase-locked coupling of a set of field modes, i.e., the formation of a so-called ZPF information state, constitutes an appropriate mechanism for the amalgamation of elementary shades of consciousness into a complex state of consciousness. Since quantum systems rest exactly on this mechanism, conscious memory processes in the brain are expected to differ from unconscious processes by the presence of the typical features of many-body quantum systems, particularly long-range coherence and attractor formation, which is supported by a huge body of empirical evidence. On this basis, the conceptual framework set out in this article paves the way for a new understanding of the brain as a write-read head interacting with the ZPF, leading to self-consistent interpretations of the neural correlates of memory formation and memory retrieval and explaining why these memory processes are closely intertwined with phenomenal awareness. In particular, the neural correlates suggest that the brain produces consciously perceived memory traces by writing sequences of information states into the ZPF and retrieves consciously experienced memory traces by reading sequences of information states from the ZPF. Using these theoretical foundations, altered states of consciousness and memory disorders can be traced back to impairments of the ZPF write-read mechanism. The mechanism should reveal itself through characteristic photon emissions, resulting in testable predictions.
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136
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Peña-Ortega F. Brain Arrhythmias Induced by Amyloid Beta and Inflammation: Involvement in Alzheimer’s Disease and Other Inflammation-related Pathologies. Curr Alzheimer Res 2020; 16:1108-1131. [DOI: 10.2174/1567205017666191213162233] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 10/29/2019] [Accepted: 11/05/2019] [Indexed: 12/13/2022]
Abstract
A variety of neurological diseases, including Alzheimer’s disease (AD), involve amyloid beta (Aβ) accumulation and/or neuroinflammation, which can alter synaptic and neural circuit functions. Consequently, these pathological conditions induce changes in neural network rhythmic activity (brain arrhythmias), which affects many brain functions. Neural network rhythms are involved in information processing, storage and retrieval, which are essential for memory consolidation, executive functioning and sensory processing. Therefore, brain arrhythmias could have catastrophic effects on circuit function, underlying the symptoms of various neurological diseases. Moreover, brain arrhythmias can serve as biomarkers for a variety of brain diseases. The aim of this review is to provide evidence linking Aβ and inflammation to neural network dysfunction, focusing on alterations in brain rhythms and their impact on cognition and sensory processing. I reviewed the most common brain arrhythmias characterized in AD, in AD transgenic models and those induced by Aβ. In addition, I reviewed the modulations of brain rhythms in neuroinflammatory diseases and those induced by immunogens, interleukins and microglia. This review reveals that Aβ and inflammation produce a complex set of effects on neural network function, which are related to the induction of brain arrhythmias and hyperexcitability, both closely related to behavioral alterations. Understanding these brain arrhythmias can help to develop therapeutic strategies to halt or prevent these neural network alterations and treat not only the arrhythmias but also the symptoms of AD and other inflammation-related pathologies.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiologia del Desarrollo y Neurofisiologia, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Queretaro, Qro., 76230, Mexico
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137
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Thébault-Dagher F, Deguire F, Knoth IS, Lafontaine MP, Barlaam F, Côté V, Agbogba K, Lippé S. Prolonged and unprolonged complex febrile seizures differently affect frontal theta brain activity. Epilepsy Res 2020; 159:106217. [DOI: 10.1016/j.eplepsyres.2019.106217] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 09/27/2019] [Accepted: 10/13/2019] [Indexed: 01/29/2023]
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138
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Barry DN, Tierney TM, Holmes N, Boto E, Roberts G, Leggett J, Bowtell R, Brookes MJ, Barnes GR, Maguire EA. Imaging the human hippocampus with optically-pumped magnetoencephalography. Neuroimage 2019; 203:116192. [PMID: 31521823 PMCID: PMC6854457 DOI: 10.1016/j.neuroimage.2019.116192] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 09/07/2019] [Accepted: 09/12/2019] [Indexed: 12/17/2022] Open
Abstract
Optically-pumped (OP) magnetometers allow magnetoencephalography (MEG) to be performed while a participant's head is unconstrained. To fully leverage this new technology, and in particular its capacity for mobility, the activity of deep brain structures which facilitate explorative behaviours such as navigation, must be detectable using OP-MEG. One such crucial brain region is the hippocampus. Here we had three healthy adult participants perform a hippocampal-dependent task - the imagination of novel scene imagery - while being scanned using OP-MEG. A conjunction analysis across these three participants revealed a significant change in theta power in the medial temporal lobe. The peak of this activated cluster was located in the anterior hippocampus. We repeated the experiment with the same participants in a conventional SQUID-MEG scanner and found similar engagement of the medial temporal lobe, also with a peak in the anterior hippocampus. These OP-MEG findings indicate exciting new opportunities for investigating the neural correlates of a range of crucial cognitive functions in naturalistic contexts including spatial navigation, episodic memory and social interactions.
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Affiliation(s)
- Daniel N Barry
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK
| | - Tim M Tierney
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK
| | - Niall Holmes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Elena Boto
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Gillian Roberts
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - James Leggett
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Richard Bowtell
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Matthew J Brookes
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK
| | - Eleanor A Maguire
- Wellcome Centre for Human Neuroimaging, UCL Queen Square Institute of Neurology, University College London, London, WC1N 3AR, UK.
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139
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A Neural Chronometry of Memory Recall. Trends Cogn Sci 2019; 23:1071-1085. [DOI: 10.1016/j.tics.2019.09.011] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/13/2019] [Accepted: 09/25/2019] [Indexed: 12/23/2022]
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140
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Chaitanya G, Hinds W, Kragel J, He X, Sideman N, Ezzyat Y, Sperling MR, Sharan A, Tracy JI. Tonic Resting State Hubness Supports High Gamma Activity Defined Verbal Memory Encoding Network in Epilepsy. Neuroscience 2019; 425:194-216. [PMID: 31786346 DOI: 10.1016/j.neuroscience.2019.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 10/25/2019] [Accepted: 11/01/2019] [Indexed: 01/06/2023]
Abstract
High gamma activity (HGA) of verbal-memory encoding using invasive-electroencephalogram has laid the foundation for numerous studies testing the integrity of memory in diseased populations. Yet, the functional connectivity characteristics of networks subserving these memory linkages remains uncertain. By integrating this electrophysiological biomarker of memory encoding from IEEG with resting-state BOLD fluctuations, we estimated the segregation and hubness of HGA-memory regions in drug-resistant epilepsy patients and matched healthy controls. HGA-memory regions express distinctly different hubness compared to neighboring regions in health and in epilepsy, and this hubness was more relevant than segregation in predicting verbal memory encoding. The HGA-memory network comprised regions from both the cognitive control and primary processing networks, validating that effective verbal-memory encoding requires integrating brain functions, and is not dominated by a central cognitive core. Our results demonstrate a tonic intrinsic set of functional connectivity, which provides the necessary conditions for effective, phasic, task-dependent memory encoding.
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Affiliation(s)
- Ganne Chaitanya
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, United States
| | - Walter Hinds
- School of Biomedical Engineering, Science and Health Systems, Drexel University, Philadelphia, PA 19104, United States
| | - James Kragel
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Xiaosong He
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, United States
| | - Noah Sideman
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, United States
| | - Youssef Ezzyat
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, United States
| | - Ashwini Sharan
- Department of Neurosurgery, Thomas Jefferson University, Philadelphia, PA 19107, United States
| | - Joseph I Tracy
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, United States.
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141
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Solomon EA, Lega BC, Sperling MR, Kahana MJ. Hippocampal theta codes for distances in semantic and temporal spaces. Proc Natl Acad Sci U S A 2019; 116:24343-24352. [PMID: 31723043 PMCID: PMC6883851 DOI: 10.1073/pnas.1906729116] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The medial temporal lobe (MTL) is known to support episodic memory and spatial navigation, raising the possibility that its true function is to form "cognitive maps" of any kind of information. Studies in humans and animals support the idea that the hippocampal theta rhythm (4 to 8 Hz) is key to this mapping function, as it has been repeatedly observed during spatial navigation tasks. If episodic memory and spatial navigation are 2 sides of the same coin, we hypothesized that theta oscillations might reflect relations between explicitly nonspatial items, such as words. We asked 189 neurosurgical patients to perform a verbal free-recall task, of which 96 had indwelling electrodes placed in the MTL. Subjects were instructed to remember short lists of sequentially presented nouns. We found that hippocampal theta power and connectivity during item retrieval coded for semantic distances between words, as measured using word2vec-derived subspaces. Additionally, hippocampal theta indexed temporal distances between words after filtering lists on recall performance, to ensure adequate dynamic range in time. Theta effects were noted only for semantic subspaces of 1 dimension, indicating a substantial compression of the possible semantic feature space. These results lend further support to our growing confidence that the MTL forms cognitive maps of arbitrary representational spaces, helping to reconcile longstanding differences between the spatial and episodic memory literatures.
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Affiliation(s)
- Ethan A Solomon
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104
| | - Bradley C Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, PA 19107
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
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142
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Hill PF, King DR, Lega BC, Rugg MD. Comparison of fMRI correlates of successful episodic memory encoding in temporal lobe epilepsy patients and healthy controls. Neuroimage 2019; 207:116397. [PMID: 31770638 PMCID: PMC7238288 DOI: 10.1016/j.neuroimage.2019.116397] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Revised: 10/23/2019] [Accepted: 11/22/2019] [Indexed: 12/30/2022] Open
Abstract
Intra-cranial electroencephalographic brain recordings (iEEG) provide a powerful tool for investigating the neural processes supporting episodic memory encoding and form the basis of experimental therapies aimed at improving memory dysfunction. However, given the invasiveness of iEEG, investigations are constrained to patients with drug-resistant epilepsy for whom such recordings are clinically indicated. Particularly in the case of temporal lobe epilepsy (TLE), neuropathology and the possibility of functional reorganization are potential constraints on the generalizability of intra-cerebral findings and pose challenges to the development of therapies for memory disorders stemming from other etiologies. Here, samples of TLE (N = 16; all of whom had undergone iEEG) and age-matched healthy control (N = 19) participants underwent fMRI as they studied lists of concrete nouns. fMRI BOLDresponses elicited by the study words were segregated according to subsequent performance on tests of delayed free recall and recognition memory. Subsequent memory effects predictive of both successful recall and recognition memory were evident in several neural regions, most prominently in the left inferior frontal gyrus, and did not demonstrate any group differences. Behaviorally, the groups did not differ in overall recall performance or in the strength of temporal contiguity effects. However, group differences in serial position effects and false alarm rates were evident during the free recall and recognition memory tasks, respectively. Despite these behavioral differences, neuropathology associated with temporal lobe epilepsy was apparently insufficient to give rise to detectable differences in the functional neuroanatomy of episodic memory encoding relative to neurologically healthy controls. The findings provide reassurance that iEEG findings derived from experimental paradigms similar to those employed here generalize to the neurotypical population.
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Affiliation(s)
- Paul F Hill
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX, 75235, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, USA.
| | - Danielle R King
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX, 75235, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, USA
| | - Bradley C Lega
- Department of Neurosurgery, University of Texas Southwestern Medical Center, 5303 Harry Hines Blvd 6th Floor Suite 108, Dallas, TX, 75390, USA
| | - Michael D Rugg
- Center for Vital Longevity, University of Texas at Dallas, 1600 Viceroy Dr. #800, Dallas, TX, 75235, USA; School of Behavioral and Brain Sciences, University of Texas at Dallas, 800 W Campbell Rd, Richardson, TX, 75080, USA; Department of Psychiatry, University of Texas Southwestern Medical Center, 6363 Forest Park Rd 7th Floor Suite 749, Dallas, TX, 75235, USA
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143
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Zerbes G, Schwabe L. Across time and space: spatial-temporal binding under stress. ACTA ACUST UNITED AC 2019; 26:473-484. [PMID: 31732708 PMCID: PMC6859825 DOI: 10.1101/lm.050237.119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 09/27/2019] [Indexed: 12/11/2022]
Abstract
Successful episodic memory requires binding of event details across spatial and temporal gaps. The neural processes underlying mnemonic binding, however, are not fully understood. Moreover, although acute stress is known to modulate memory, if and how stress changes mnemonic integration across time and space is unknown. To elucidate these issues, we exposed participants to a stressor or a control manipulation shortly before they completed, while electroencephalography was recorded, an encoding task that systematically varied the demands for spatial and temporal integration. Associative memory was tested 24 h later. While early event-related potentials, including the P300 and Late Positive Component, distinguished different levels of spatiotemporal discontinuity, only later Slow Waves were linked to subsequent remembering. Furthermore, theta oscillations were specifically associated with successful mnemonic binding. Although acute stress per se left mnemonic integration largely unaffected, autonomic activity facilitated object memory and glucocorticoids enhanced detail memory, indicative for mnemonic integration. At the neural level, stress amplified the effects of spatiotemporal discontinuity on early information processing. Together, our results indicate that temporal and spatial gaps recruit early neural processes, providing attentional resources. The actual binding success, however, appears to depend on later processes as well as theta power and may be shaped by major stress response systems.
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Affiliation(s)
- Gundula Zerbes
- Department of Cognitive Psychology, University of Hamburg, Hamburg 20146, Germany
| | - Lars Schwabe
- Department of Cognitive Psychology, University of Hamburg, Hamburg 20146, Germany
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144
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Kaplan R, Tauste Campo A, Bush D, King J, Principe A, Koster R, Ley Nacher M, Rocamora R, Friston KJ. Human hippocampal theta oscillations reflect sequential dependencies during spatial planning. Cogn Neurosci 2019; 11:122-131. [DOI: 10.1080/17588928.2019.1676711] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Raphael Kaplan
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, University College London, London, UK
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Adrià Tauste Campo
- Center for Brain and Cognition, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Barcelona, Spain
- Epilepsy Unit, Department of Neurology, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Barcelonaβeta Brain Research Center, Pasqual Maragall Foundation, Barcelona, Spain
| | - Daniel Bush
- UCL Institute of Cognitive Neuroscience, University College London, London, UK
- UCL Queen Square Institute of Neurology, University College London, London, UK
| | - John King
- UCL Institute of Cognitive Neuroscience, University College London, London, UK
- Clinical, Education and Health Psychology, University College London, London, UK
| | - Alessandro Principe
- Epilepsy Unit, Department of Neurology, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - Raphael Koster
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, University College London, London, UK
- UCL Institute of Cognitive Neuroscience, University College London, London, UK
| | - Miguel Ley Nacher
- Epilepsy Unit, Department of Neurology, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - Rodrigo Rocamora
- Epilepsy Unit, Department of Neurology, Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
| | - Karl J. Friston
- Wellcome Centre for Human Neuroimaging, UCL Institute of Neurology, University College London, London, UK
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145
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Scarpelli S, Bartolacci C, D'Atri A, Gorgoni M, De Gennaro L. Mental Sleep Activity and Disturbing Dreams in the Lifespan. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E3658. [PMID: 31569467 PMCID: PMC6801786 DOI: 10.3390/ijerph16193658] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 09/11/2019] [Accepted: 09/27/2019] [Indexed: 02/05/2023]
Abstract
Sleep significantly changes across the lifespan, and several studies underline its crucial role in cognitive functioning. Similarly, mental activity during sleep tends to covary with age. This review aims to analyze the characteristics of dreaming and disturbing dreams at different age brackets. On the one hand, dreams may be considered an expression of brain maturation and cognitive development, showing relations with memory and visuo-spatial abilities. Some investigations reveal that specific electrophysiological patterns, such as frontal theta oscillations, underlie dreams during sleep, as well as episodic memories in the waking state, both in young and older adults. On the other hand, considering the role of dreaming in emotional processing and regulation, the available literature suggests that mental sleep activity could have a beneficial role when stressful events occur at different age ranges. We highlight that nightmares and bad dreams might represent an attempt to cope the adverse events, and the degrees of cognitive-brain maturation could impact on these mechanisms across the lifespan. Future investigations are necessary to clarify these relations. Clinical protocols could be designed to improve cognitive functioning and emotional regulation by modifying the dream contents or the ability to recall/non-recall them.
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Affiliation(s)
- Serena Scarpelli
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Chiara Bartolacci
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Aurora D'Atri
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Maurizio Gorgoni
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
| | - Luigi De Gennaro
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185 Rome, Italy.
- IRCCS Santa Lucia Foundation, 00142 Rome, Italy.
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146
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Scarpelli S, D'Atri A, Bartolacci C, Mangiaruga A, Gorgoni M, De Gennaro L. Oscillatory EEG Activity During REM Sleep in Elderly People Predicts Subsequent Dream Recall After Awakenings. Front Neurol 2019; 10:985. [PMID: 31620069 PMCID: PMC6763554 DOI: 10.3389/fneur.2019.00985] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 08/29/2019] [Indexed: 02/05/2023] Open
Abstract
Several findings underlined that the electrophysiological (EEG) background of the last segment of sleep before awakenings may predict the presence/absence of dream recall (DR) in young subjects. However, little is known about the EEG correlates of DR in elderly people. Only an investigation found differences between recall and non-recall conditions during NREM sleep EEG in older adults, while—surprisingly—no EEG predictor of DR was found for what concerns REM sleep. Considering REM sleep as a privileged scenario to produce mental sleep activity related to cognitive processes, our study aimed to investigate whether specific EEG topography and frequency changes during REM sleep in elderly people may predict a subsequent recall of mental sleep activity. Twenty-one healthy older volunteers (mean age 69.2 ± 6.07 SD) and 20 young adults (mean age 23.4 ± 2.76 SD) were recorded for one night from 19 scalp derivations. Dreams were collected upon morning awakenings from REM sleep. EEG signals of the last 5 min were analyzed by the Better OSCillation algorithm to detect the peaks of oscillatory activity in both groups. Statistical comparisons revealed that older as well as young individuals recall their dream experience when the last segment of REM sleep is characterized by frontal theta oscillations. No Recall (Recall vs. Non-Recall) × Age (Young vs. Older) interaction was found. This result replicated the previous evidence in healthy young subjects, as shown in within- and between-subjects design. The findings are completely original for older individuals, demonstrating that theta oscillations are crucial for the retrieval of dreaming also in this population. Furthermore, our results did not confirm a greater presence of the theta activity in healthy aging. Conversely, we found a greater amount of rhythmic theta and alpha activity in young than older participants. It is worth noting that the theta oscillations detected are related to cognitive functioning. We emphasize the notion that the oscillatory theta activity should be distinguished from the non-rhythmic theta activity identified in relation to other phenomena such as (a) sleepiness and hypoarousal conditions during the waking state and (b) cortical slowing, considered as an EEG alteration in clinical samples.
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Affiliation(s)
- Serena Scarpelli
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | - Aurora D'Atri
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | - Chiara Bartolacci
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | | | - Maurizio Gorgoni
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
| | - Luigi De Gennaro
- Department of Psychology, University of Rome "Sapienza", Rome, Italy
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147
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Burman DD. Hippocampal connectivity with sensorimotor cortex during volitional finger movements: Laterality and relationship to motor learning. PLoS One 2019; 14:e0222064. [PMID: 31536543 PMCID: PMC6752792 DOI: 10.1371/journal.pone.0222064] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Accepted: 08/21/2019] [Indexed: 12/03/2022] Open
Abstract
Hippocampal interactions with the motor system are often assumed to reflect the role of memory in motor learning. Here, we examine hippocampal connectivity with sensorimotor cortex during two tasks requiring paced movements, one with a mnemonic component (sequence learning) and one without (repetitive tapping). Functional magnetic resonance imaging activity was recorded from thirteen right-handed subjects; connectivity was identified from sensorimotor cortex correlations with psychophysiological interactions in hippocampal activity between motor and passive visual tasks. Finger movements in both motor tasks anticipated the timing of the metronome, reflecting cognitive control, yet evidence of motor learning was limited to the sequence learning task; nonetheless, hippocampal connectivity was observed during both tasks. Connectivity from corresponding regions in the left and right hippocampus overlapped extensively, with improved sensitivity resulting from their conjunctive (global) analysis. Positive and negative connectivity were both evident, with positive connectivity in sensorimotor cortex ipsilateral to the moving hand during unilateral movements, whereas negative connectivity was prominent in whichever hemisphere was most active during movements. Results implicate the hippocampus in volitional finger movements even in the absence of motor learning or recall.
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Affiliation(s)
- Douglas D. Burman
- Department of Radiology, NorthShore University HealthSystem, Evanston, Illinois, United States of America
- * E-mail:
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148
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Berto S, Wang GZ, Germi J, Lega BC, Konopka G. Human Genomic Signatures of Brain Oscillations During Memory Encoding. Cereb Cortex 2019; 28:1733-1748. [PMID: 28383644 DOI: 10.1093/cercor/bhx083] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 03/22/2017] [Indexed: 01/10/2023] Open
Abstract
Memory encoding is an essential step for all learning. However, the genetic and molecular mechanisms underlying human memory encoding remain poorly understood, and how this molecular framework permits the emergence of specific patterns of brain oscillations observed during mnemonic processing is unknown. Here, we directly compare intracranial electroencephalography recordings from the neocortex in individuals performing an episodic memory task with human gene expression from the same areas. We identify genes correlated with oscillatory memory effects across 6 frequency bands. These genes are enriched for autism-related genes and have preferential expression in neurons, in particular genes encoding synaptic proteins and ion channels, supporting the idea that the genes regulating voltage gradients are involved in the modulation of oscillatory patterns during successful memory encoding across brain areas. Memory-related genes are distinct from those correlated with other forms of cognitive processing and resting state fMRI. These data are the first to identify correlations between gene expression and active human brain states as well as provide a molecular window into memory encoding oscillations in the human brain.
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Affiliation(s)
- Stefano Berto
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Guang-Zhong Wang
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - James Germi
- Department of Neurosurgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Bradley C Lega
- Department of Neurosurgery, UT Southwestern Medical Center, Dallas, TX 75390, USA
| | - Genevieve Konopka
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX 75390, USA
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149
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Stimulation of the Posterior Cingulate Cortex Impairs Episodic Memory Encoding. J Neurosci 2019; 39:7173-7182. [PMID: 31358651 DOI: 10.1523/jneurosci.0698-19.2019] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Revised: 05/29/2019] [Accepted: 07/10/2019] [Indexed: 11/21/2022] Open
Abstract
Neuroimaging experiments implicate the posterior cingulate cortex (PCC) in episodic memory processing, making it a potential target for responsive neuromodulation strategies outside of the hippocampal network. However, causal evidence for the role that PCC plays in memory encoding is lacking. In human female and male participants (N = 17) undergoing seizure mapping, we investigated functional properties of the PCC using deep brain stimulation (DBS) and stereotactic electroencephalography. We used a verbal free recall paradigm in which the PCC was stimulated during presentation of half of the study lists, whereas no stimulation was applied during presentation of the remaining lists. We investigated whether stimulation affected memory and modulated hippocampal activity. Results revealed four main findings. First, stimulation during episodic memory encoding impaired subsequent free recall, predominantly for items presented early in the study lists. Second, PCC stimulation increased hippocampal gamma-band power. Third, stimulation-induced hippocampal gamma power predicted the magnitude of memory impairment. Fourth, functional connectivity between the hippocampus and PCC predicted the strength of the stimulation effect on memory. Our findings offer causal evidence implicating the PCC in episodic memory encoding. Importantly, the results indicate that stimulation targeted outside of the temporal lobe can modulate hippocampal activity and impact behavior. Furthermore, measures of connectivity between brain regions within a functional network can be informative in predicting behavioral effects of stimulation. Our findings have significant implications for developing therapies to treat memory disorders and cognitive impairment using DBS.SIGNIFICANCE STATEMENT Cognitive impairment and memory loss are critical public health challenges. Deep brain stimulation (DBS) is a promising tool for developing strategies to ameliorate memory disorders by targeting brain regions involved in mnemonic processing. Using DBS, our study sheds light on the lesser-known role of the posterior cingulate cortex (PCC) in memory encoding. Stimulating the PCC during encoding impairs subsequent recall memory. The degree of impairment is predicted by stimulation-induced hippocampal gamma oscillations and functional connectivity between PCC and hippocampus. Our findings provide the first causal evidence implicating PCC in memory encoding and highlight the PCC as a favorable target for neuromodulation strategies using a priori connectivity measures to predict stimulation effects. This has significant implications for developing therapies for memory diseases.
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150
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Leszczynski M, Schroeder CE. The Role of Neuronal Oscillations in Visual Active Sensing. Front Integr Neurosci 2019; 13:32. [PMID: 31396059 PMCID: PMC6664014 DOI: 10.3389/fnint.2019.00032] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 07/03/2019] [Indexed: 01/22/2023] Open
Abstract
Visual perception is most often studied as a "passive" process in which an observer fixates steadily at point in space so that stimuli can be delivered to the system with spatial precision. Analysis of neuronal signals related to vision is generally keyed to stimulus onset, stimulus movement, etc.; i.e., events external to the observer. In natural "active" vision, however, information is systematically acquired by using eye movements including rapid (saccadic) eye movements, as well as smooth ocular pursuit of moving objects and slower drifts. Here we consider the use of alternating saccades and fixations to gather information from a visual scene. The underlying motor sampling plan contains highly reliable information regarding "where" and "when" the eyes will land, this information can be used predictively to modify firing properties of neurons precisely at the time when this "contextual" information is most useful - when a volley of retinal input enters the system at the onset of each fixation. Analyses focusing on neural events leading to and resulting from shifts in fixation, as well as visual events external to the observer, can provide a more complete and mechanistic understanding of visual information processing. Studies thus far suggest that active vision may be a fundamentally different from that process we usually study with more traditional passive viewing paradigms. In this Perspective we note that active saccadic sampling behavior imposes robust temporal patterning on the activity of neuron ensembles and large-scale neural dynamics throughout the brain's visual pathways whose mechanistic effects on information processing are not yet fully understood. The spatio-temporal sequence of eye movements elicits a succession of temporally predictable quasi-rhythmic sensory inputs, whose encoding is enhanced by entrainment of low frequency oscillations to the rate of eye movements. Review of the pertinent findings underscores the fact that temporal coordination between motor and visual cortices is critical for understanding neural dynamics of active vision and posits that phase entrainment of neuronal oscillations plays a mechanistic role in this process.
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Affiliation(s)
- Marcin Leszczynski
- Department of Neurological Surgery, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Translational Neuroscience Laboratories, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - Charles E. Schroeder
- Department of Neurological Surgery, College of Physicians and Surgeons, Columbia University, New York, NY, United States
- Translational Neuroscience Laboratories, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, NY, United States
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