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Jaap C, Rose M. Relevance of pre-stimulus oscillatory activity for the perceived valence of emotional facial expressions. Sci Rep 2024; 14:19263. [PMID: 39164318 PMCID: PMC11336227 DOI: 10.1038/s41598-024-69433-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Accepted: 08/05/2024] [Indexed: 08/22/2024] Open
Abstract
The interpretation of emotional facial expressions is crucial in everyday social interactions, and rapid processing of these expressions is necessary. Although extensive research has shed light on the mechanisms involved in facial expression processing, there is limited research on the potential role of the state of neural activity that directly precedes the occurrence of a face. Here, we investigated the potential modulatory role of pre-stimulus oscillatory activity in emotional facial expression processing. We tested emotional facial processing in two experiments, one utilizing artificial and the other natural facial expressions. The participants had to evaluate the emotional valence of the presented ambiguous facial expressions. In a univariate analysis, differences in the oscillation activity of the later rated valence of the faces were observed in both experiments, and these differences were observed even before the presentation of the facial expressions. Importantly, two different multivariate approaches directly supported the relevance of pre-stimulus oscillatory activity by exclusively using pre-stimulus oscillatory data to predict the perceived valence of the latter rated facial expression across the two experiments within as well as across subjects. The behavioral data shows the often observed negativity bias, i.e. ambiguous faces resulted in the tendency to rate them as negative. This negativity bias was related to neural activity modulations in the pre-stimulus period and also within post-stimulus processing related activity. These findings underscore the significance of pre-stimulus oscillatory activity in facial expression processing, indicating a functional role of ongoing neural states that affects the processing of facial expressions and constitute a basis for the well described negativity bias.
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Affiliation(s)
- Carina Jaap
- Department for Systems Neuroscience, NeuroImage Nord, University Medical Center Hamburg Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany
| | - Michael Rose
- Department for Systems Neuroscience, NeuroImage Nord, University Medical Center Hamburg Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany.
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2
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Ostrowski J, Rose M. Increases in pre-stimulus theta and alpha oscillations precede successful encoding of crossmodal associations. Sci Rep 2024; 14:7895. [PMID: 38570599 PMCID: PMC10991485 DOI: 10.1038/s41598-024-58227-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
A central aspect of episodic memory is the formation of associations between stimuli from different modalities. Current theoretical approaches assume a functional role of ongoing oscillatory power and phase in the theta band (3-7 Hz) for the encoding of crossmodal associations. Furthermore, ongoing activity in the theta range as well as alpha (8-12 Hz) and low beta activity (13-20 Hz) before the presentation of a stimulus is thought to modulate subsequent cognitive processing, including processes that are related to memory. In this study, we tested the hypothesis that pre-stimulus characteristics of low frequency activity are relevant for the successful formation of crossmodal memory. The experimental design that was used specifically allowed for the investigation of associative memory independent from individual item memory. Participants (n = 51) were required to memorize associations between audiovisual stimulus pairs and distinguish them from newly arranged ones consisting of the same single stimuli in the subsequent recognition task. Our results show significant differences in the state of pre-stimulus theta and alpha power between remembered and not remembered crossmodal associations, clearly relating increased power to successful recognition. These differences were positively correlated with memory performance, suggesting functional relevance for behavioral measures of associative memory. Further analysis revealed similar effects in the low beta frequency ranges, indicating the involvement of different pre-stimulus-related cognitive processes. Phase-based connectivity measures in the theta band did not differ between remembered and not remembered stimulus pairs. The findings support the assumed functional relevance of theta band oscillations for the formation of associative memory and demonstrate that an increase of theta as well as alpha band oscillations in the pre-stimulus period is beneficial for the establishment of crossmodal memory.
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Affiliation(s)
- Jan Ostrowski
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
| | - Michael Rose
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
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3
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McNerney MW, Gurkoff GG, Beard C, Berryhill ME. The Rehabilitation Potential of Neurostimulation for Mild Traumatic Brain Injury in Animal and Human Studies. Brain Sci 2023; 13:1402. [PMID: 37891771 PMCID: PMC10605899 DOI: 10.3390/brainsci13101402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/29/2023] Open
Abstract
Neurostimulation carries high therapeutic potential, accompanied by an excellent safety profile. In this review, we argue that an arena in which these tools could provide breakthrough benefits is traumatic brain injury (TBI). TBI is a major health problem worldwide, with the majority of cases identified as mild TBI (mTBI). MTBI is of concern because it is a modifiable risk factor for dementia. A major challenge in studying mTBI is its inherent heterogeneity across a large feature space (e.g., etiology, age of injury, sex, treatment, initial health status, etc.). Parallel lines of research in human and rodent mTBI can be collated to take advantage of the full suite of neuroscience tools, from neuroimaging (electroencephalography: EEG; functional magnetic resonance imaging: fMRI; diffusion tensor imaging: DTI) to biochemical assays. Despite these attractive components and the need for effective treatments, there are at least two major challenges to implementation. First, there is insufficient understanding of how neurostimulation alters neural mechanisms. Second, there is insufficient understanding of how mTBI alters neural function. The goal of this review is to assemble interrelated but disparate areas of research to identify important gaps in knowledge impeding the implementation of neurostimulation.
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Affiliation(s)
- M. Windy McNerney
- Mental Illness Research Education and Clinical Center (MIRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; (M.W.M.); (C.B.)
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gene G. Gurkoff
- Department of Neurological Surgery, and Center for Neuroscience, University of California, Davis, Sacramento, CA 95817, USA;
- Department of Veterans Affairs, VA Northern California Health Care System, Martinez, CA 94553, USA
| | - Charlotte Beard
- Mental Illness Research Education and Clinical Center (MIRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304, USA; (M.W.M.); (C.B.)
- Program in Neuroscience and Behavioral Biology, Emory University, Atlanta, GA 30322, USA
| | - Marian E. Berryhill
- Programs in Cognitive and Brain Sciences, and Integrative Neuroscience, Department of Psychology, University of Nevada, Reno, NV 89557, USA
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4
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Rubinstein DY, Weidemann CT, Sperling MR, Kahana MJ. Direct brain recordings suggest a causal subsequent-memory effect. Cereb Cortex 2023; 33:6891-6901. [PMID: 36702495 PMCID: PMC10233277 DOI: 10.1093/cercor/bhad008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 01/28/2023] Open
Abstract
Endogenous variation in brain state and stimulus-specific evoked activity can both contribute to successful encoding. Previous studies, however, have not clearly distinguished among these components. We address this question by analysing intracranial EEG recorded from epilepsy patients as they studied and subsequently recalled lists of words. We first trained classifiers to predict recall of either single items or entire lists and found that both classifiers exhibited similar performance. We found that list-level classifier output-a biomarker of successful encoding-tracked item presentation and recall events, despite having no information about the trial structure. Across widespread brain regions, decreased low- and increased high-frequency activity (HFA) marked successful encoding of both items and lists. We found regional differences in the hippocampus and prefrontal cortex, where in the hippocampus HFA correlated more strongly with item recall, whereas, in the prefrontal cortex, HFA correlated more strongly with list performance. Despite subtle differences in item- and list-level features, the similarity in overall classification performance, spectral signatures of successful recall and fluctuations of spectral activity across the encoding period argue for a shared endogenous process that causally impacts the brain's ability to learn new information.
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Affiliation(s)
- Daniel Y Rubinstein
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Christoph T Weidemann
- Department of Psychology, Swansea University, Swansea SA2 8PP, UK
- Department of Bioengineering, Columbia University, New York, NY 10027, USA
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA
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5
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Yeh N, Koen JD. Informative and uninformative prestimulus cues at encoding benefit familiarity and source memory. Memory 2023; 31:367-379. [PMID: 36546483 PMCID: PMC10085852 DOI: 10.1080/09658211.2022.2156546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022]
Abstract
Previous research has shown that neural activity elicited by informative prestimulus cues during encoding differ with respect to subsequent memory outcomes. These findings indicate prestimulus cues create a "brain state" associated with subsequent memory that, potentially, also has downstream effects benefitting processes associated with successful encoding and subsequent memory performance. However, previous studies have not included the conditions necessary to appropriately test this latter assumption. The present study examines how informative and uninformative prestimulus encoding cues affect memory accuracy for upcoming stimuli compared to a no cue condition. At encoding, participants made one of two semantic judgments on words preceded by an informative prestimulus cue that identified the upcoming semantic judgment, an uninformative prestimulus cue that signalled an upcoming trial but no information about the semantic judgment, or no cue. Dual process estimates of familiarity, but not recollection, demonstrated a graded pattern with the informativeness of the prestimulus cues (i.e., informative > uninformative > no cues). Moreover, both informative and uninformative prestimulus cues enhanced subsequent source memory accuracy for the encoding task compared to the no cue condition. These findings suggest that prestimulus cues can strengthen the processes that support successful memory encoding and benefit subsequent familiarity and source memory.
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6
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Jun S, Kim JS, Chung CK. Hippocampal Neuronal Activity Preceding Stimulus Predicts Later Memory Success. eNeuro 2023; 10:ENEURO.0252-22.2023. [PMID: 36720645 PMCID: PMC9933931 DOI: 10.1523/eneuro.0252-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 01/13/2023] [Accepted: 01/20/2023] [Indexed: 02/02/2023] Open
Abstract
Hippocampal neuronal activity at a time preceding stimulus onset affects episodic memory performance. We hypothesized that neuronal activity preceding an event supports successful memory formation; therefore, we explored whether a characterized encoding-associated brain activity, viz. the neuronal activity preceding a stimulus, predicts subsequent memory formation. To address this issue, we assessed the activity of single neurons recorded from the hippocampus in humans, while participants performed word memory tasks. Human hippocampal single-unit activity elicited by a fixation cue preceding words increased the firing rates (FRs) and predicted whether the words are recalled in a subsequent memory test; this indicated that successful memory formation in humans can be predicted by a preceding stimulus activity during encoding. However, the predictive effect of preceding stimulus activity did not occur during retrieval. These findings suggest that the preparative arrangement of brain activity before stimulus encoding improves subsequent memory performance.
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Affiliation(s)
- Soyeon Jun
- Neuroscience Research Institute, Seoul National University College of Medicine, Seoul, South Korea, 03080
- Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea, 03080
| | - June Sic Kim
- Research Institute of Basic Sciences, Seoul National University, Seoul, South Korea, 03080
| | - Chun Kee Chung
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea, 08826
- Department of Neurosurgery, Seoul National University Hospital, Seoul, South Korea, 03080
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7
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Kalafatovich J, Lee M, Lee SW. Decoding declarative memory process for predicting memory retrieval based on source localization. PLoS One 2022; 17:e0274101. [PMID: 36074790 PMCID: PMC9455842 DOI: 10.1371/journal.pone.0274101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Accepted: 08/22/2022] [Indexed: 11/18/2022] Open
Abstract
Many studies have focused on understanding memory processes due to their importance in daily life. Differences in timing and power spectra of brain signals during encoding task have been linked to later remembered items and were recently used to predict memory retrieval performance. However, accuracies remain low when using non-invasive methods for acquiring brain signals, mainly due to the low spatial resolution. This study investigates the prediction of successful retrieval using estimated source activity corresponding either to cortical or subcortical structures through source localization. Electroencephalogram (EEG) signals were recorded while participants performed a declarative memory task. Frequency-time analysis was performed using signals from encoding and retrieval tasks to confirm the importance of neural oscillations and their relationship with later remembered and forgotten items. Significant differences in the power spectra between later remembered and forgotten items were found before and during the presentation of the stimulus in the encoding task. Source activity estimation revealed differences in the beta band power over the medial parietal and medial prefrontal areas prior to the presentation of the stimulus, and over the cuneus and lingual areas during the presentation of the stimulus. Additionally, there were significant differences during the stimuli presentation during the retrieval task. Prediction of later remembered items was performed using surface potentials and estimated source activity. The results showed that source localization increases classification performance compared to the one using surface potentials. These findings support the importance of incorporating spatial features of neural activity to improve the prediction of memory retrieval.
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Affiliation(s)
- Jenifer Kalafatovich
- Department of Artificial Intelligence, Korea University, Seoul, Republic of Korea
| | - Minji Lee
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea
| | - Seong-Whan Lee
- Department of Artificial Intelligence, Korea University, Seoul, Republic of Korea
- Department of Brain and Cognitive Engineering, Korea University, Seoul, Republic of Korea
- * E-mail:
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8
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Halonen R, Kuula L, Antila M, Pesonen AK. The Overnight Retention of Novel Metaphors Associates With Slow Oscillation-Spindle Coupling but Not With Respiratory Phase at Encoding. Front Behav Neurosci 2021; 15:712774. [PMID: 34531730 PMCID: PMC8439423 DOI: 10.3389/fnbeh.2021.712774] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 08/04/2021] [Indexed: 11/16/2022] Open
Abstract
Accumulating evidence emphasizes the relevance of oscillatory synchrony in memory consolidation during sleep. Sleep spindles promote memory retention, especially when occurring in the depolarized upstate of slow oscillation (SO). A less studied topic is the inter-spindle synchrony, i.e. the temporal overlap and phasic coherence between spindles perceived in different electroencephalography channels. In this study, we examined how synchrony between SOs and spindles, as well as between simultaneous spindles, is associated with the retention of novel verbal metaphors. Moreover, we combined the encoding of the metaphors with respiratory phase (inhalation/exhalation) with the aim of modulating the strength of memorized items, as previous studies have shown that inhalation entrains neural activity, thereby benefiting memory in a waking condition. In the current study, 27 young adults underwent a two-night mixed-design study with a 12-h delayed memory task during both sleep and waking conditions. As expected, we found better retention over the delay containing sleep, and this outcome was strongly associated with the timing of SO–spindle coupling. However, no associations were observed regarding inter-spindle synchrony or respiratory phase. These findings contribute to a better understanding of the importance of SO–spindle coupling for memory. In contrast, the observed lack of association with inter-spindle synchrony may emphasize the local nature of spindle-related plasticity.
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Affiliation(s)
- Risto Halonen
- Sleepwell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Liisa Kuula
- Sleepwell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Minea Antila
- Sleepwell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anu-Katriina Pesonen
- Sleepwell Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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9
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Cohen N, Ben-Yakov A, Weber J, Edelson MG, Paz R, Dudai Y. Prestimulus Activity in the Cingulo-Opercular Network Predicts Memory for Naturalistic Episodic Experience. Cereb Cortex 2021; 30:1902-1913. [PMID: 31740917 DOI: 10.1093/cercor/bhz212] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 08/19/2019] [Accepted: 08/21/2019] [Indexed: 11/13/2022] Open
Abstract
Human memory is strongly influenced by brain states occurring before an event, yet we know little about the underlying mechanisms. We found that activity in the cingulo-opercular network (including bilateral anterior insula [aI] and anterior prefrontal cortex [aPFC]) seconds before an event begins can predict whether this event will subsequently be remembered. We then tested how activity in the cingulo-opercular network shapes memory performance. Our findings indicate that prestimulus cingulo-opercular activity affects memory performance by opposingly modulating subsequent activity in two sets of regions previously linked to encoding and retrieval of episodic information. Specifically, higher prestimulus cingulo-opercular activity was associated with a subsequent increase in activity in temporal regions previously linked to encoding and with a subsequent reduction in activity within a set of regions thought to play a role in retrieval and self-referential processing. Together, these findings suggest that prestimulus attentional states modulate memory for real-life events by enhancing encoding and possibly by dampening interference from competing memory substrates.
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Affiliation(s)
- Noga Cohen
- Department of Special Education and The Edmond J. Safra Brain Research Center for the Study of Learning Disabilities, University of Haifa, Haifa 3498838, Israel
| | - Aya Ben-Yakov
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge, CB2 2EF, UK
| | - Jochen Weber
- Department of Psychology, Columbia University, New York, NY, 10027, USA
| | - Micah G Edelson
- Department of Economics, University of Zurich, Zürich, CH-8032, Switzerland
| | - Rony Paz
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel
| | - Yadin Dudai
- Department of Neurobiology, Weizmann Institute of Science, Rehovot, 76100, Israel
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10
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Cruzat J, Torralba M, Ruzzoli M, Fernández A, Deco G, Soto-Faraco S. The phase of Theta oscillations modulates successful memory formation at encoding. Neuropsychologia 2021; 154:107775. [PMID: 33592222 DOI: 10.1016/j.neuropsychologia.2021.107775] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Revised: 01/07/2021] [Accepted: 02/03/2021] [Indexed: 12/01/2022]
Abstract
Several studies have shown that attention and perception can depend upon the phase of ongoing neural oscillations at stimulus onset. Here, we extend this idea to the memory domain. We tested the hypothesis that ongoing fluctuations in neural activity impact memory encoding in two experiments using a picture paired-associates task in order to gauge episodic memory performance. Experiment 1 was behavioural only and capitalized on the principle of phase resetting. We tested if subsequent memory performance fluctuates rhythmically, time-locked to a resetting cue presented before the to-be-remembered pairs at different time intervals. We found an indication that behavioural performance was periodically and selectively modulated at Theta frequency (~4 Hz). In Experiment 2, we focused on pre-stimulus ongoing activity using scalp EEG while participants performed a paired-associates task. The pre-registered analysis, using large electrode clusters and generic Theta and Alpha spectral ranges, returned null results of the pre-stimulus phase-behaviour correlation. However, as expected from prior literature, we found that variations in stimulus-related Theta-power predicted subsequent memory performance. Therefore, we used this post-stimulus effect in Theta power to guide a post-hoc pre-stimulus phase analysis in terms of scalp and frequency of interest. This analysis returned a correlation between the pre-stimulus Theta phase and subsequent memory. Altogether, these results suggest that pre-stimulus Theta activity at encoding may impact later memory performance.
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Affiliation(s)
- Josephine Cruzat
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain.
| | - Mireia Torralba
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain
| | - Manuela Ruzzoli
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, G12 8QQ, Glasgow, UK
| | - Alba Fernández
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain
| | - Gustavo Deco
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain; Institució Catalana de la Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona, 08010, Spain; Department of Neuropsychology, Max Planck Institute for Human Cognitive and Brain Sciences, 04103, Leipzig, Germany; School of Psychological Sciences, Monash University, Melbourne, Clayton, VIC, 3800, Australia
| | - Salvador Soto-Faraco
- Center for Brain and Cognition, Computational Neuroscience Group, Department of Information and Communication Technologies, Universitat Pompeu Fabra, Roc Boronat 138, Barcelona, 08018, Spain; Institució Catalana de la Recerca i Estudis Avançats (ICREA), Passeig Lluís Companys 23, Barcelona, 08010, Spain
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11
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Kang T, Chen Y, Fazli S, Wallraven C. EEG-Based Prediction of Successful Memory Formation During Vocabulary Learning. IEEE Trans Neural Syst Rehabil Eng 2020; 28:2377-2389. [PMID: 32915743 DOI: 10.1109/tnsre.2020.3023116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Previous Electroencephalography (EEG) and neuroimaging studies have found differences between brain signals for subsequently remembered and forgotten items during learning of items - it has even been shown that single trial prediction of memorization success is possible with a few target items. There has been little attempt, however, in validating the findings in an application-oriented context involving longer test spans with realistic learning materials encompassing more items. Hence, the present study investigates subsequent memory prediction within the application context of foreign-vocabulary learning. We employed an off-line, EEG-based paradigm in which Korean participants without prior German language experience learned 900 German words in paired-associate form. Our results using convolutional neural networks optimized for EEG-signal analysis show that above-chance classification is possible in this context allowing us to predict during learning which of the words would be successfully remembered later.
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12
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Evidence for Immediate Enhancement of Hippocampal Memory Encoding by Network-Targeted Theta-Burst Stimulation during Concurrent fMRI. J Neurosci 2020; 40:7155-7168. [PMID: 32817326 DOI: 10.1523/jneurosci.0486-20.2020] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 06/10/2020] [Accepted: 06/15/2020] [Indexed: 12/21/2022] Open
Abstract
The hippocampus supports episodic memory via interaction with a distributed brain network. Previous experiments using network-targeted noninvasive brain stimulation have identified episodic memory enhancements and modulation of activity within the hippocampal network. However, mechanistic insights were limited because these effects were measured long after stimulation and therefore could have reflected various neuroplastic aftereffects with extended time courses. In this experiment with human subjects of both sexes, we tested for immediate stimulation impact on encoding-related activity of the hippocampus and immediately adjacent medial-temporal cortex by delivering theta-burst transcranial magnetic stimulation (TBS) concurrent with fMRI, as an immediate impact of stimulation would suggest an influence on neural activity. We reasoned that TBS would be particularly effective for influencing the hippocampus because rhythmic neural activity in the theta band is associated with hippocampal memory processing. First, we demonstrated that it is possible to obtain robust fMRI correlates of task-related activity during concurrent TBS. We then identified immediate effects of TBS on encoding of visual scenes. Brief volleys of TBS targeting the hippocampal network increased activity of the targeted (left) hippocampus during scene encoding and increased subsequent recollection. Stimulation did not influence activity during an intermixed numerical task with no memory demand. Control conditions using beta band and out-of-network stimulation also did not influence hippocampal activity or recollection. TBS targeting the hippocampal network therefore immediately impacted hippocampal memory processing. This suggests direct, beneficial influence of stimulation on hippocampal neural activity related to memory and supports the role of theta-band activity in human episodic memory.SIGNIFICANCE STATEMENT Can noninvasive stimulation directly impact function of indirect, deep-brain targets, such as the hippocampus? We tested this by targeting an accessible region of the hippocampal network via transcranial magnetic stimulation during concurrent fMRI. We reasoned that theta-burst stimulation would be particularly effective for impacting hippocampal function, as this stimulation rhythm should resonate with the endogenous theta-nested-gamma activity prominent in hippocampus. Indeed, theta-burst stimulation targeting the hippocampal network immediately impacted hippocampal activity during encoding, improving memory formation as indicated by enhanced later recollection. Rhythm- and location-control stimulation conditions had no such effects. These findings suggest a direct influence of noninvasive stimulation on hippocampal neural activity and highlight that the theta-burst rhythm is relatively privileged in its ability to influence hippocampal memory function.
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13
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Spiking activity in the human hippocampus prior to encoding predicts subsequent memory. Proc Natl Acad Sci U S A 2020; 117:13767-13770. [PMID: 32482860 PMCID: PMC7306990 DOI: 10.1073/pnas.2001338117] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Encoding activity in the medial temporal lobe, presumably evoked by the presentation of stimuli (postonset activity), is known to predict subsequent memory. However, several independent lines of research suggest that preonset activity also affects subsequent memory. We investigated the role of preonset and postonset single-unit and multiunit activity recorded from epilepsy patients as they completed a continuous recognition task. In this task, words were presented in a continuous series and eventually began to repeat. For each word, the patient's task was to decide whether it was novel or repeated. We found that preonset spiking activity in the hippocampus (when the word was novel) predicted subsequent memory (when the word was later repeated). Postonset activity during encoding also predicted subsequent memory, but was simply a continuation of preonset activity. The predictive effect of preonset spiking activity was much stronger in the hippocampus than in three other brain regions (amygdala, anterior cingulate, and prefrontal cortex). In addition, preonset and postonset activity around the encoding of novel words did not predict memory performance for novel words (i.e., correctly classifying the word as novel), and preonset and postonset activity around the time of retrieval did not predict memory performance for repeated words (i.e., correctly classifying the word as repeated). Thus, the only predictive effect was between preonset activity (along with its postonset continuation) at the time of encoding and subsequent memory. Taken together, these findings indicate that preonset hippocampal activity does not reflect general arousal/attention but instead reflects what we term "attention to encoding."
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14
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Winterling SL, Shields SM, Rose M. Reduced memory-related ongoing oscillatory activity in healthy older adults. Neurobiol Aging 2019; 79:1-10. [PMID: 31026617 DOI: 10.1016/j.neurobiolaging.2019.03.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 03/19/2019] [Accepted: 03/20/2019] [Indexed: 10/27/2022]
Abstract
Age-related impairments in episodic memory have been linked to alterations in encoding-induced neural activity. In young individuals, even prestimulus activity has been shown to influence the encoding of an upcoming stimulus, with ongoing theta and beta oscillations being predictive of subsequent recognition. The present study investigated if these memory-related ongoing oscillations are also affected by aging. In an EEG experiment, healthy older and young individuals performed an encoding task with a subsequent recognition test on picture and word stimuli. The group of younger participants showed an increased oscillatory activity in the lower frequency range (ranging from 3 to 17 Hz) in the pre- and post-stimulus period compared with the older adults. Only in young participants, ongoing beta power during encoding was related to later memory in both stimulus categories, whereas in older participants, this effect was diminished. Interestingly, there was no general age-related decrease in recognition performance. These results indicate that ongoing low beta oscillations might constitute a functional indicator of cognitive aging that reveals itself even before a strong decline in behavioral performance is noticeable, and that could be a potential target for neuromodulatory interventions.
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Affiliation(s)
- Signe L Winterling
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Stephanie M Shields
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Michael Rose
- Department of Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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15
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Moxon KA, Shahlaie K, Girgis F, Saez I, Kennedy J, Gurkoff GG. From adagio to allegretto: The changing tempo of theta frequencies in epilepsy and its relation to interneuron function. Neurobiol Dis 2019; 129:169-181. [PMID: 30798003 DOI: 10.1016/j.nbd.2019.02.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 02/06/2019] [Accepted: 02/20/2019] [Indexed: 12/29/2022] Open
Abstract
Despite decades of research, our understanding of epilepsy, including how seizures are generated and propagate, is incomplete. However, there is growing recognition that epilepsy is more than just the occurrence of seizures, with patients often experiencing comorbid deficits in cognition that are poorly understood. In addition, the available therapies for treatment of epilepsy, from pharmaceutical treatment to surgical resection and seizure prevention devices, often exacerbate deficits in cognitive function. In this review, we discuss the hypothesis that seizure generation and cognitive deficits have a similar pathological source characterized by, but not limited to, deficits in theta oscillations and their influence on interneurons. We present a new framework that describes oscillatory states in epilepsy as alternating between hyper- and hypo-synchrony rather than solely the spontaneous transition to hyper-excitability characterized by the seizures. This framework suggests that as neural oscillations, specifically in the theta range, vary their tempo from a slowed almost adagio tempo during interictal periods to faster, more rhythmic allegretto tempo preictally, they impact the function of interneurons, modulating their ability to control seizures and their role in cognitive processing. This slow wave oscillatory framework may help explain why current therapies that work to reduce hyper-excitability do not completely eliminate seizures and often lead to exacerbated cognitive deficits.
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Affiliation(s)
- Karen A Moxon
- Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, United States of America.
| | - Kiarash Shahlaie
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| | - Fady Girgis
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America
| | - Ignacio Saez
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
| | - Jeffrey Kennedy
- Department of Neurology, University of California Davis, Sacramento, CA 95817, United States of America
| | - Gene G Gurkoff
- Department of Neurological Surgery, University of California Davis, Sacramento, CA 95817, United States of America; Center for Neuroscience, University of California Davis, Davis, CA 95618, United States of America
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16
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Strunk J, Duarte A. Prestimulus and poststimulus oscillatory activity predicts successful episodic encoding for both young and older adults. Neurobiol Aging 2019; 77:1-12. [PMID: 30763880 DOI: 10.1016/j.neurobiolaging.2019.01.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 01/08/2019] [Accepted: 01/10/2019] [Indexed: 11/28/2022]
Abstract
Healthy aging is associated with declines in episodic memory performance that are due in part to deficits in encoding. Emerging results from young adult studies suggest that the neural activity during the time preceding stimulus presentation is sensitive to episodic memory performance. It is unknown whether age-related declines in episodic memory are due solely to changes in the recruitment of processes elicited by stimuli during encoding or also in processes recruited in anticipation of these stimuli. Here, we recorded oscillatory electroencephalography while young and old participants encoded visual and auditory words that were preceded by cues indicating the stimulus modality. Individual differences in alpha oscillatory activity preceding, and following, stimulus onset was predictive of subsequent memory performance similarly across age. Poststimulus theta power correlated positively with episodic memory performance for old but not young adults, potentially reflecting older adults' tendency to self-generate associations during encoding. Collectively, these results suggest that the preparatory mobilization of neural processes before encoding that benefits episodic memory performance is not affected by age but instead dependent on the individual's propensity to preemptively mobilize task-specific processes.
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Affiliation(s)
- Jon Strunk
- Department of Psychology, Georgia Institute of Technology, Atlanta, GA.
| | - Audrey Duarte
- Department of Psychology, Georgia Institute of Technology, Atlanta, GA
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17
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Buch VP, Richardson AG, Brandon C, Stiso J, Khattak MN, Bassett DS, Lucas TH. Network Brain-Computer Interface (nBCI): An Alternative Approach for Cognitive Prosthetics. Front Neurosci 2018; 12:790. [PMID: 30443203 PMCID: PMC6221897 DOI: 10.3389/fnins.2018.00790] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 10/12/2018] [Indexed: 11/13/2022] Open
Abstract
Brain computer interfaces (BCIs) have been applied to sensorimotor systems for many years. However, BCI technology has broad potential beyond sensorimotor systems. The emerging field of cognitive prosthetics, for example, promises to improve learning and memory for patients with cognitive impairment. Unfortunately, our understanding of the neural mechanisms underlying these cognitive processes remains limited in part due to the extensive individual variability in neural coding and circuit function. As a consequence, the development of methods to ascertain optimal control signals for cognitive decoding and restoration remains an active area of inquiry. To advance the field, robust tools are required to quantify time-varying and task-dependent brain states predictive of cognitive performance. Here, we suggest that network science is a natural language in which to formulate and apply such tools. In support of our argument, we offer a simple demonstration of the feasibility of a network approach to BCI control signals, which we refer to as network BCI (nBCI). Finally, in a single subject example, we show that nBCI can reliably predict online cognitive performance and is superior to certain common spectral approaches currently used in BCIs. Our review of the literature and preliminary findings support the notion that nBCI could provide a powerful approach for future applications in cognitive prosthetics.
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Affiliation(s)
- Vivek P Buch
- Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Andrew G Richardson
- Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Cameron Brandon
- Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Jennifer Stiso
- Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, United States
| | - Monica N Khattak
- Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States
| | - Danielle S Bassett
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, United States.,Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, United States.,Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States.,Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Timothy H Lucas
- Department of Neurosurgery, Hospital of the University of Pennsylvania, Philadelphia, PA, United States.,Department of Neuroscience, University of Pennsylvania, Philadelphia, PA, United States
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18
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Direct Brain Stimulation Modulates Encoding States and Memory Performance in Humans. Curr Biol 2017; 27:1251-1258. [PMID: 28434860 DOI: 10.1016/j.cub.2017.03.028] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/24/2017] [Accepted: 03/13/2017] [Indexed: 11/21/2022]
Abstract
People often forget information because they fail to effectively encode it. Here, we test the hypothesis that targeted electrical stimulation can modulate neural encoding states and subsequent memory outcomes. Using recordings from neurosurgical epilepsy patients with intracranially implanted electrodes, we trained multivariate classifiers to discriminate spectral activity during learning that predicted remembering from forgetting, then decoded neural activity in later sessions in which we applied stimulation during learning. Stimulation increased encoding-state estimates and recall if delivered when the classifier indicated low encoding efficiency but had the reverse effect if stimulation was delivered when the classifier indicated high encoding efficiency. Higher encoding-state estimates from stimulation were associated with greater evidence of neural activity linked to contextual memory encoding. In identifying the conditions under which stimulation modulates memory, the data suggest strategies for therapeutically treating memory dysfunction.
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19
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Riley EA, McFarland DJ. EEG Error Prediction as a Solution for Combining the Advantages of Retrieval Practice and Errorless Learning. Front Hum Neurosci 2017; 11:140. [PMID: 28396630 PMCID: PMC5366324 DOI: 10.3389/fnhum.2017.00140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 03/09/2017] [Indexed: 11/19/2022] Open
Abstract
Given the frequency of naming errors in aphasia, a common aim of speech and language rehabilitation is the improvement of naming. Based on evidence of significant word recall improvements in patients with memory impairments, errorless learning methods have been successfully applied to naming therapy in aphasia; however, other evidence suggests that although errorless learning can lead to better performance during treatment sessions, retrieval practice may be the key to lasting improvements. Task performance may vary with brain state (e.g., level of arousal, degree of task focus), and changes in brain state can be detected using EEG. With the ultimate goal of designing a system that monitors patient brain state in real time during therapy, we sought to determine whether errors could be predicted using spectral features obtained from an analysis of EEG. Thus, this study aimed to investigate the use of individual EEG responses to predict error production in aphasia. Eight participants with aphasia each completed 900 object-naming trials across three sessions while EEG was recorded and response accuracy scored for each trial. Analysis of the EEG response for seven of the eight participants showed significant correlations between EEG features and response accuracy (correct vs. incorrect) and error correction (correct, self-corrected, incorrect). Furthermore, upon combining the training data for the first two sessions, the model generalized to predict accuracy for performance in the third session for seven participants when accuracy was used as a predictor, and for five participants when error correction category was used as a predictor. With such ability to predict errors during therapy, it may be possible to use this information to intervene with errorless learning strategies only when necessary, thereby allowing patients to benefit from both the high within-session success of errorless learning as well as the longer-term improvements associated with retrieval practice.
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Affiliation(s)
- Ellyn A Riley
- Aphasia Lab, Communication Sciences and Disorders, Syracuse University Syracuse, NY, USA
| | - Dennis J McFarland
- National Center for Adaptive Neurotechnologies, Wadsworth Center, New York State Department of Health Albany, NY, USA
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20
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Braeutigam S, Lee N, Senior C. A Role for Endogenous Brain States in Organizational Research: Moving Toward a Dynamic View of Cognitive Processes. ORGANIZATIONAL RESEARCH METHODS 2017. [DOI: 10.1177/1094428117692104] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The dominant view in neuroscience, including functional neuroimaging, is that the brain is an essentially reactive system, in which some sensory input causes some neural activity, which in turn results in some important response such as a motor activity or some hypothesized higher-level cognitive or affective process. This view has driven the rise of neuroscience methods in management and organizational research. However, the reactive view offers at best a partial understanding of how living organisms function in the real world. In fact, like any neural system, the human brain exhibits a constant ongoing activity. This intrinsic brain activity is produced internally, not in response to some environmental stimulus, and is thus termed endogenous brain activity (EBA). In the present article we introduce EBA to organizational research conceptually, explain its measurement, and go on to show that including EBA in management and organizational theory and empirical research has the potential to revolutionize how we think about human choice and behavior in organizations.
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Affiliation(s)
- Sven Braeutigam
- Department of Psychiatry, Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK
| | - Nick Lee
- Warwick Business School, University of Warwick, Coventry, UK
| | - Carl Senior
- School of Life and Health Sciences, Aston University, Birmingham, UK
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21
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Differential effects of ongoing EEG beta and theta power on memory formation. PLoS One 2017; 12:e0171913. [PMID: 28192459 PMCID: PMC5305097 DOI: 10.1371/journal.pone.0171913] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/27/2017] [Indexed: 12/20/2022] Open
Abstract
Recently, elevated ongoing pre-stimulus beta power (13–17 Hz) at encoding has been associated with subsequent memory formation for visual stimulus material. It is unclear whether this activity is merely specific to visual processing or whether it reflects a state facilitating general memory formation, independent of stimulus modality. To answer that question, the present study investigated the relationship between neural pre-stimulus oscillations and verbal memory formation in different sensory modalities. For that purpose, a within-subject design was employed to explore differences between successful and failed memory formation in the visual and auditory modality. Furthermore, associative memory was addressed by presenting the stimuli in combination with background images. Results revealed that similar EEG activity in the low beta frequency range (13–17 Hz) is associated with subsequent memory success, independent of stimulus modality. Elevated power prior to stimulus onset differentiated successful from failed memory formation. In contrast, differential effects between modalities were found in the theta band (3–7 Hz), with an increased oscillatory activity before the onset of later remembered visually presented words. In addition, pre-stimulus theta power dissociated between successful and failed encoding of associated context, independent of the stimulus modality of the item itself. We therefore suggest that increased ongoing low beta activity reflects a memory promoting state, which is likely to be moderated by modality-independent attentional or inhibitory processes, whereas high ongoing theta power is suggested as an indicator of the enhanced binding of incoming interlinked information.
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22
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Lee DJ, Izadi A, Melnik M, Seidl S, Echeverri A, Shahlaie K, Gurkoff GG. Stimulation of the medial septum improves performance in spatial learning following pilocarpine-induced status epilepticus. Epilepsy Res 2017; 130:53-63. [PMID: 28152425 DOI: 10.1016/j.eplepsyres.2017.01.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 12/22/2016] [Accepted: 01/09/2017] [Indexed: 01/20/2023]
Abstract
Temporal lobe epilepsy often leads to hippocampal sclerosis and persistent cognitive deficits, including difficulty with learning and memory. Hippocampal theta oscillations are critical in optimizing hippocampal function and facilitating plasticity. We hypothesized that pilocarpine-induced status epilepticus would disrupt oscillations and behavioral performance and that electrical neuromodulation to entrain theta would improve cognition specifically in injured rats. Rats received a pilocarpine (n=30) or saline injection (n=27) and unilateral bi-polar electrodes were implanted into the medial septum and hippocampus the following day. Hippocampal and septal theta were recorded in a Plexiglas box over the first week following implantation. Control and pilocarpine-treated rats were split into stimulation (continuous 7.7Hz, 80μA, 1ms pulse width) and non-stimulation groups for behavioral analysis. Continuous stimulation was initiated one-minute prior to and throughout an object exploration task (post-injury day seven) and again for each of six trials on the Barnes maze (post-injury days 12-14). There was a significant reduction in hippocampal theta power (p<0.05) and percentage of time oscillating in theta (p<0.05). In addition there was a significant decrease in object exploration in rats post-pilocarpine (p<0.05) and an impairment in spatial learning. Specifically, pilocarpine-treated rats were more likely to use random search strategies (p<0.001) and had an increase in latency to find the hidden platform (p<0.05) on the Barnes maze. Stimulation of the medial septum at 7.7Hz in pilocarpine-treated rats resulted in performance similar to shams in both the object recognition and Barnes maze tasks. Stimulation of sham rats resulted in impaired object exploration (p<0.05) with no difference in Barnes maze latency or strategy. In conclusion, pilocarpine-induced seizures diminished hippocampal oscillations and impaired performance in both an object exploration and a spatial memory task in pilocarpine-treated rats. Theta stimulation at 7.7Hz improved behavioral outcome on the Barnes maze task; this improvement in function was not related to a general cognitive enhancement, as shams did not benefit from stimulation. Therefore, stimulation of the medial septum represents an exciting target to improve behavioral outcome in patients with epilepsy.
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Affiliation(s)
- Darrin J Lee
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States
| | - Ali Izadi
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States; Center for Neuroscience, University of California, 1544 Newton Court, Davis, CA 95618, United States.
| | - Mikhail Melnik
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States.
| | - Stacey Seidl
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States; Center for Neuroscience, University of California, 1544 Newton Court, Davis, CA 95618, United States.
| | - Angela Echeverri
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States.
| | - Kiarash Shahlaie
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States; Center for Neuroscience, University of California, 1544 Newton Court, Davis, CA 95618, United States.
| | - Gene G Gurkoff
- Department of Neurological Surgery, UC Davis School of Medicine, 4860 Y Street, Suite 3740, Sacramento, CA 95817, United States; Center for Neuroscience, University of California, 1544 Newton Court, Davis, CA 95618, United States.
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23
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Horak PC, Meisenhelter S, Song Y, Testorf ME, Kahana MJ, Viles WD, Bujarski KA, Connolly AC, Robbins AA, Sperling MR, Sharan AD, Worrell GA, Miller LR, Gross RE, Davis KA, Roberts DW, Lega B, Sheth SA, Zaghloul KA, Stein JM, Das SR, Rizzuto DS, Jobst BC. Interictal epileptiform discharges impair word recall in multiple brain areas. Epilepsia 2016; 58:373-380. [PMID: 27935031 DOI: 10.1111/epi.13633] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/04/2016] [Indexed: 01/15/2023]
Abstract
OBJECTIVES Interictal epileptiform discharges (IEDs) have been linked to memory impairment, but the spatial and temporal dynamics of this relationship remain elusive. In the present study, we aim to systematically characterize the brain areas and times at which IEDs affect memory. METHODS Eighty epilepsy patients participated in a delayed free recall task while undergoing intracranial electroencephalography (EEG) monitoring. We analyzed the locations and timing of IEDs relative to the behavioral data in order to measure their effects on memory. RESULTS Overall IED rates did not correlate with task performance across subjects (r = 0.03, p = 0.8). However, at a finer temporal scale, within-subject memory was negatively affected by IEDs during the encoding and recall periods of the task but not during the rest and distractor periods (p < 0.01, p < 0.001, p = 0.3, and p = 0.8, respectively). The effects of IEDs during encoding and recall were stronger in the left hemisphere than in the right (p < 0.05). Of six brain areas analyzed, IEDs in the inferior-temporal, medial-temporal, and parietal areas significantly affected memory (false discovery rate < 0.05). SIGNIFICANCE These findings reveal a network of brain areas sensitive to IEDs with key nodes in temporal as well as parietal lobes. They also demonstrate the time-dependent effects of IEDs in this network on memory.
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Affiliation(s)
- Peter C Horak
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A
| | - Stephen Meisenhelter
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A
| | - Yinchen Song
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A.,Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, U.S.A
| | - Markus E Testorf
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A.,Thayer School of Engineering at Dartmouth, Hanover, New Hampshire, U.S.A
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Weston D Viles
- Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A
| | - Krzysztof A Bujarski
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A.,Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, U.S.A
| | - Andrew C Connolly
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A
| | - Ashlee A Robbins
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, U.S.A
| | - Ashwini D Sharan
- Department of Neurological Surgery, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania, U.S.A
| | - Gregory A Worrell
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, U.S.A.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Laura R Miller
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, U.S.A.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, U.S.A
| | - Robert E Gross
- Department of Neurosurgery, Emory University Hospital, Atlanta, Georgia, U.S.A
| | - Kathryn A Davis
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - David W Roberts
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A.,Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, U.S.A.,Department of Neurosurgery, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A
| | - Bradley Lega
- Department of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A
| | - Sameer A Sheth
- Department of Neurosurgery, Columbia University Medical Center, New York, New York, U.S.A
| | - Kareem A Zaghloul
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, Bethesda, Maryland, U.S.A
| | - Joel M Stein
- Department of Neuroradiology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Sandhitsu R Das
- Department of Neurology, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Daniel S Rizzuto
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, U.S.A
| | - Barbara C Jobst
- Department of Neurology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, U.S.A.,Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, U.S.A
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24
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Brain oscillations track the formation of episodic memories in the real world. Neuroimage 2016; 143:256-266. [DOI: 10.1016/j.neuroimage.2016.09.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 08/11/2016] [Accepted: 09/09/2016] [Indexed: 11/19/2022] Open
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25
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Crespo-García M, Zeiller M, Leupold C, Kreiselmeyer G, Rampp S, Hamer HM, Dalal SS. Slow-theta power decreases during item-place encoding predict spatial accuracy of subsequent context recall. Neuroimage 2016; 142:533-543. [PMID: 27521743 DOI: 10.1016/j.neuroimage.2016.08.021] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 07/26/2016] [Accepted: 08/09/2016] [Indexed: 12/31/2022] Open
Abstract
Human hippocampal theta oscillations play a key role in accurate spatial coding. Associative encoding involves similar hippocampal networks but, paradoxically, is also characterized by theta power decreases. Here, we investigated how theta activity relates to associative encoding of place contexts resulting in accurate navigation. Using MEG, we found that slow-theta (2-5Hz) power negatively correlated with subsequent spatial accuracy for virtual contextual locations in posterior hippocampus and other cortical structures involved in spatial cognition. A rare opportunity to simultaneously record MEG and intracranial EEG in an epilepsy patient provided crucial insights: during power decreases, slow-theta in right anterior hippocampus and left inferior frontal gyrus phase-led the left temporal cortex and predicted spatial accuracy. Our findings indicate that decreased slow-theta activity reflects local and long-range neural mechanisms that encode accurate spatial contexts, and strengthens the view that local suppression of low-frequency activity is essential for more efficient processing of detailed information.
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Affiliation(s)
- Maité Crespo-García
- Department of Psychology, University of Konstanz, 78464 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78464 Konstanz, Germany.
| | - Monika Zeiller
- Department of Psychology, University of Konstanz, 78464 Konstanz, Germany
| | - Claudia Leupold
- Department of Neurosurgery, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Gernot Kreiselmeyer
- Department of Neurology, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Stefan Rampp
- Department of Neurosurgery, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Hajo M Hamer
- Department of Neurology, Epilepsy Center, University Hospital Erlangen, 91054 Erlangen, Germany
| | - Sarang S Dalal
- Department of Psychology, University of Konstanz, 78464 Konstanz, Germany; Zukunftskolleg, University of Konstanz, 78464 Konstanz, Germany
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26
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Wolf JA, Koch PF. Disruption of Network Synchrony and Cognitive Dysfunction After Traumatic Brain Injury. Front Syst Neurosci 2016; 10:43. [PMID: 27242454 PMCID: PMC4868948 DOI: 10.3389/fnsys.2016.00043] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 04/26/2016] [Indexed: 11/13/2022] Open
Abstract
Traumatic brain injury (TBI) is a heterogeneous disorder with many factors contributing to a spectrum of severity, leading to cognitive dysfunction that may last for many years after injury. Injury to axons in the white matter, which are preferentially vulnerable to biomechanical forces, is prevalent in many TBIs. Unlike focal injury to a discrete brain region, axonal injury is fundamentally an injury to the substrate by which networks of the brain communicate with one another. The brain is envisioned as a series of dynamic, interconnected networks that communicate via long axonal conduits termed the "connectome". Ensembles of neurons communicate via these pathways and encode information within and between brain regions in ways that are timing dependent. Our central hypothesis is that traumatic injury to axons may disrupt the exquisite timing of neuronal communication within and between brain networks, and that this may underlie aspects of post-TBI cognitive dysfunction. With a better understanding of how highly interconnected networks of neurons communicate with one another in important cognitive regions such as the limbic system, and how disruption of this communication occurs during injury, we can identify new therapeutic targets to restore lost function. This requires the tools of systems neuroscience, including electrophysiological analysis of ensemble neuronal activity and circuitry changes in awake animals after TBI, as well as computational modeling of the effects of TBI on these networks. As more is revealed about how inter-regional neuronal interactions are disrupted, treatments directly targeting these dysfunctional pathways using neuromodulation can be developed.
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Affiliation(s)
- John A Wolf
- Center for Brain Injury and Repair, Department of Neurosurgery, University of PennsylvaniaPhiladelphia, PA, USA; Corporal Michael J. Crescenz VA Medical CenterPhiladelphia, PA, USA
| | - Paul F Koch
- Center for Brain Injury and Repair, Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA
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27
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Intention to encode boosts memory-related pre-stimulus EEG beta power. Neuroimage 2015; 125:978-987. [PMID: 26584862 DOI: 10.1016/j.neuroimage.2015.11.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 10/27/2015] [Accepted: 11/09/2015] [Indexed: 11/20/2022] Open
Abstract
Pre-stimulus oscillatory brain activity can predict the degree to which an upcoming stimulus will be remembered at a later point in time. Recently, increased pre-stimulus power in ongoing theta (5-8Hz) and low beta (13-17Hz) bands during encoding has been associated with enhanced memory performance. When a cue is presented before stimulus onset, encoding-related brain activations may be regarded as a sign of preparation for the upcoming stimulus. Here, we investigated whether the intention to encode the following stimulus into long-term memory affects these preparatory pre-stimulus activations during encoding. Two groups of 18 participants took part in a subsequent memory paradigm. Electroencephalogram (EEG) was recorded while participants were presented with a series of pictures, each one preceded by a cue, which were supposed to be classified according to animacy. One group was informed about the upcoming recognition task and therefore was enabled to develop the intention to encode the stimuli (intentional encoding), whereas the other group did not receive this information (incidental encoding). Afterwards, recognition of the pictures was tested. During intentional encoding only, power in theta and low beta bands was found to be significantly increased before the onset of pictures that were later remembered compared to later forgotten ones. Group comparisons confirmed greater memory-related power increases in the low beta band for intentional than incidental encoding. These findings indicate that oscillatory states that are associated with successful encoding can be initiated voluntarily if the intention to encode the stimuli is given. We therefore suggest low beta band activation before stimulus onset to be an indicator of memory-specific preparation for an upcoming stimulus.
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The human hippocampus contributes to both the recollection and familiarity components of recognition memory. Proc Natl Acad Sci U S A 2015; 112:14378-83. [PMID: 26578784 DOI: 10.1073/pnas.1513145112] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Despite a substantial body of work comprising theoretical modeling, the effects of medial temporal lobe lesions, and electrophysiological signal analysis, the role of the hippocampus in recognition memory remains controversial. In particular, it is not known whether the hippocampus exclusively supports recollection or both recollection and familiarity--the two latent cognitive processes theorized to underlie recognition memory. We studied recognition memory in a large group of patients undergoing intracranial electroencephalographic (iEEG) monitoring for epilepsy. By measuring high-frequency activity (HFA)--a signal associated with precise spatiotemporal properties--we show that hippocampal activity during recognition predicted recognition memory performance and tracked both recollection and familiarity. Through the lens of dual-process models, these results indicate that the hippocampus supports both the recollection and familiarity processes.
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Salari N, Rose M. Dissociation of the functional relevance of different pre-stimulus oscillatory activity for memory formation. Neuroimage 2015; 125:1013-1021. [PMID: 26484828 DOI: 10.1016/j.neuroimage.2015.10.037] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 09/23/2015] [Accepted: 10/15/2015] [Indexed: 11/30/2022] Open
Abstract
The state of a neural assembly preceding an incoming stimulus modulates the processing of that subsequently presented stimuli. For human memory formation, the role of oscillatory brain activity within different frequency ranges has been discussed but a more functional relation could not be established. In the present Experiment I, an increase of pre-stimulus theta- (3-7Hz) and beta- (13-17Hz) band oscillations during encoding for later remembered stimuli was observed. To establish a more direct functional relation, we adopted a novel brain-computer-interface (BCI) method to selectively detect oscillatory activity in real-time combined with an adaptive stimulus presentation at different levels of activity. Therefore, in the second experiment the BCI was used to present the visual stimuli with a high temporal resolution directly within defined brain states of beta- or theta-band activity. The quality of the subsequent processing of the stimuli was assessed at the behavioral level with a surprise recognition task. Results revealed a variation of memory performance in direct relation to the amount of pre-stimulus beta- but not theta-band oscillations, suggesting a functional relevance of beta-band oscillations for memory encoding. Thus, the BCI method enabled a more functional differentiation of the effective role of ongoing oscillatory activity.
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Affiliation(s)
- Neda Salari
- Department of Systems Neuroscience, University Medical Center Hamburg Eppendorf, Martinistr. 52, 20246 Hamburg, Germany
| | - Michael Rose
- Department of Systems Neuroscience, University Medical Center Hamburg Eppendorf, Martinistr. 52, 20246 Hamburg, Germany.
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Greenberg JA, Burke JF, Haque R, Kahana MJ, Zaghloul KA. Decreases in theta and increases in high frequency activity underlie associative memory encoding. Neuroimage 2015; 114:257-63. [PMID: 25862266 DOI: 10.1016/j.neuroimage.2015.03.077] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 03/05/2015] [Accepted: 03/28/2015] [Indexed: 12/24/2022] Open
Abstract
Episodic memory encoding refers to the cognitive process by which items and their associated contexts are stored in memory. To investigate changes directly attributed to the formation of explicit associations, we examined oscillatory power captured through intracranial electroencephalography (iEEG) as 27 neurosurgical patients receiving subdural and depth electrodes for seizure monitoring participated in a paired associates memory task. We examined low (3-8Hz) and high (45-95Hz) frequency activity, and found that the successful formation of new associations was accompanied by broad decreases in low frequency activity and a posterior to anterior progression of increases in high frequency activity in the left hemisphere. These data suggest that the observed patterns of activity may reflect the neural mechanisms underlying the formation of novel item-item associations.
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Affiliation(s)
| | - John F Burke
- Department of Psychology, University of Pennsylvania, 19104, USA
| | - Rafi Haque
- Surgical Neurology Branch, NINDS, National Institutes of Health, 20892, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, 19104, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, NINDS, National Institutes of Health, 20892, USA.
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Cohen N, Pell L, Edelson MG, Ben-Yakov A, Pine A, Dudai Y. Peri-encoding predictors of memory encoding and consolidation. Neurosci Biobehav Rev 2015; 50:128-42. [DOI: 10.1016/j.neubiorev.2014.11.002] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Revised: 10/05/2014] [Accepted: 11/02/2014] [Indexed: 10/24/2022]
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Burke JF, Merkow MB, Jacobs J, Kahana MJ, Zaghloul KA. Brain computer interface to enhance episodic memory in human participants. Front Hum Neurosci 2015; 8:1055. [PMID: 25653605 PMCID: PMC4299435 DOI: 10.3389/fnhum.2014.01055] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/18/2014] [Indexed: 11/13/2022] Open
Abstract
Recent research has revealed that neural oscillations in the theta (4-8 Hz) and alpha (9-14 Hz) bands are predictive of future success in memory encoding. Because these signals occur before the presentation of an upcoming stimulus, they are considered stimulus-independent in that they correlate with enhanced memory encoding independent of the item being encoded. Thus, such stimulus-independent activity has important implications for the neural mechanisms underlying episodic memory as well as the development of cognitive neural prosthetics. Here, we developed a brain computer interface (BCI) to test the ability of such pre-stimulus activity to modulate subsequent memory encoding. We recorded intracranial electroencephalography (iEEG) in neurosurgical patients as they performed a free recall memory task, and detected iEEG theta and alpha oscillations that correlated with optimal memory encoding. We then used these detected oscillatory changes to trigger the presentation of items in the free recall task. We found that item presentation contingent upon the presence of pre-stimulus theta and alpha oscillations modulated memory performance in more sessions than expected by chance. Our results suggest that an electrophysiological signal may be causally linked to a specific behavioral condition, and contingent stimulus presentation has the potential to modulate human memory encoding.
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Affiliation(s)
- John F Burke
- Department of Psychology, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Maxwell B Merkow
- Department of Neurosurgery, University of Pennsylvania Philadelphia, PA, USA
| | - Joshua Jacobs
- Department of Biomedical Engineering, Columbia University New York, NY, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania Philadelphia, PA, USA
| | - Kareem A Zaghloul
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health Bethesda, MD, USA
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