1
|
Li Y, Pazdera JK, Kahana MJ. EEG decoders track memory dynamics. Nat Commun 2024; 15:2981. [PMID: 38582783 PMCID: PMC10998865 DOI: 10.1038/s41467-024-46926-0] [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: 04/19/2021] [Accepted: 03/14/2024] [Indexed: 04/08/2024] Open
Abstract
Encoding- and retrieval-related neural activity jointly determine mnemonic success. We ask whether electroencephalographic activity can reliably predict encoding and retrieval success on individual trials. Each of 98 participants performed a delayed recall task on 576 lists across 24 experimental sessions. Logistic regression classifiers trained on spectral features measured immediately preceding spoken recall of individual words successfully predict whether or not those words belonged to the target list. Classifiers trained on features measured during word encoding also reliably predict whether those words will be subsequently recalled and further predict the temporal and semantic organization of the recalled items. These findings link neural variability predictive of successful memory with item-to-context binding, a key cognitive process thought to underlie episodic memory function.
Collapse
Affiliation(s)
- Yuxuan Li
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Psychology, Stanford University, Stanford, CA, USA
| | - Jesse K Pazdera
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Psychology, Neuroscience & Behaviour, McMaster University, Hamilton, ON, Canada
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, USA.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Sakon JJ, Halpern DJ, Schonhaut DR, Kahana MJ. Human Hippocampal Ripples Signal Encoding of Episodic Memories. J Neurosci 2024; 44:e0111232023. [PMID: 38233218 PMCID: PMC10883616 DOI: 10.1523/jneurosci.0111-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 11/28/2023] [Accepted: 12/01/2023] [Indexed: 01/19/2024] Open
Abstract
Direct human brain recordings have confirmed the presence of high-frequency oscillatory events, termed ripples, during awake behavior. While many prior studies have focused on medial temporal lobe (MTL) ripples during memory retrieval, here we investigate ripples during memory encoding. Specifically, we ask whether ripples during encoding predict whether and how memories are subsequently recalled. Detecting ripples from MTL electrodes implanted in 116 neurosurgical participants (n = 61 male) performing a verbal episodic memory task, we find that encoding ripples do not distinguish recalled from not recalled items in any MTL region, even as high-frequency activity during encoding predicts recall in these same regions. Instead, hippocampal ripples increase during encoding of items that subsequently lead to recall of temporally and semantically associated items during retrieval, a phenomenon known as clustering. This subsequent clustering effect arises specifically when hippocampal ripples co-occur during encoding and retrieval, suggesting that ripples mediate both encoding and reinstatement of episodic memories.
Collapse
Affiliation(s)
- John J Sakon
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
| | - David J Halpern
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
| | - Daniel R Schonhaut
- Department of Neuroscience, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104
| |
Collapse
|
4
|
Herz N, Bukala BR, Kragel JE, Kahana MJ. Hippocampal activity predicts contextual misattribution of false memories. Proc Natl Acad Sci U S A 2023; 120:e2305292120. [PMID: 37751551 PMCID: PMC10556612 DOI: 10.1073/pnas.2305292120] [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: 03/31/2023] [Accepted: 08/02/2023] [Indexed: 09/28/2023] Open
Abstract
Failure of contextual retrieval can lead to false recall, wherein people retrieve an item or experience that occurred in a different context or did not occur at all. Whereas the hippocampus is thought to play a crucial role in memory retrieval, we lack understanding of how the hippocampus supports retrieval of items related to a target context while disregarding related but irrelevant information. Using direct electrical recordings from the human hippocampus, we investigate the neural process underlying contextual misattribution of false memories. In two large datasets, we characterize key physiological differences between correct and false recalls that emerge immediately prior to vocalization. By differentiating between false recalls that share high or low contextual similarity with the target context, we show that low-frequency activity (6 to 18 Hz) in the hippocampus tracks similarity between the current and retrieved context. Applying multivariate decoding methods, we were able to reliably predict the contextual source of the to-be-recalled item. Our findings elucidate one of the hallmark features of episodic memory: our ability to distinguish between memories that were formed on different occasions.
Collapse
Affiliation(s)
- Noa Herz
- Department of Psychology, University of Pennsylvania, Philadelphia, PA19104
| | - Bernard R. Bukala
- Department of Psychology, University of Pennsylvania, Philadelphia, PA19104
| | - James E. Kragel
- Department of Neurology, University of Chicago, Chicago, IL60637
| | - Michael J. Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA19104
| |
Collapse
|
5
|
Koizumi K, Kunii N, Ueda K, Nagata K, Fujitani S, Shimada S, Nakao M. Paving the Way for Memory Enhancement: Development and Examination of a Neurofeedback System Targeting the Medial Temporal Lobe. Biomedicines 2023; 11:2262. [PMID: 37626758 PMCID: PMC10452721 DOI: 10.3390/biomedicines11082262] [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: 06/23/2023] [Revised: 08/01/2023] [Accepted: 08/11/2023] [Indexed: 08/27/2023] Open
Abstract
Neurofeedback (NF) shows promise in enhancing memory, but its application to the medial temporal lobe (MTL) still needs to be studied. Therefore, we aimed to develop an NF system for the memory function of the MTL and examine neural activity changes and memory task score changes through NF training. We created a memory NF system using intracranial electrodes to acquire and visualise the neural activity of the MTL during memory encoding. Twenty trials of a tug-of-war game per session were employed for NF and designed to control neural activity bidirectionally (Up/Down condition). NF training was conducted with three patients with drug-resistant epilepsy, and we observed an increasing difference in NF signal between conditions (Up-Down) as NF training progressed. Similarities and negative correlation tendencies between the transition of neural activity and the transition of memory function were also observed. Our findings demonstrate NF's potential to modulate MTL activity and memory encoding. Future research needs further improvements to the NF system to validate its effects on memory functions. Nonetheless, this study represents a crucial step in understanding NF's application to memory and provides valuable insights into developing more efficient memory enhancement strategies.
Collapse
Affiliation(s)
- Koji Koizumi
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan; (K.U.); (M.N.)
| | - Naoto Kunii
- Department of Neurosurgery, The University of Tokyo, Tokyo 113-8655, Japan; (N.K.); (K.N.); (S.F.); (S.S.)
| | - Kazutaka Ueda
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan; (K.U.); (M.N.)
| | - Keisuke Nagata
- Department of Neurosurgery, The University of Tokyo, Tokyo 113-8655, Japan; (N.K.); (K.N.); (S.F.); (S.S.)
| | - Shigeta Fujitani
- Department of Neurosurgery, The University of Tokyo, Tokyo 113-8655, Japan; (N.K.); (K.N.); (S.F.); (S.S.)
| | - Seijiro Shimada
- Department of Neurosurgery, The University of Tokyo, Tokyo 113-8655, Japan; (N.K.); (K.N.); (S.F.); (S.S.)
| | - Masayuki Nakao
- Department of Mechanical Engineering, The University of Tokyo, Tokyo 113-8656, Japan; (K.U.); (M.N.)
| |
Collapse
|
6
|
Kahana MJ, Ezzyat Y, Wanda PA, Solomon EA, Adamovich-Zeitlin R, Lega BC, Jobst BC, Gross RE, Ding K, Diaz-Arrastia RR. Biomarker-guided neuromodulation aids memory in traumatic brain injury. Brain Stimul 2023; 16:1086-1093. [PMID: 37414370 DOI: 10.1016/j.brs.2023.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 06/15/2023] [Accepted: 07/01/2023] [Indexed: 07/08/2023] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of cognitive disability in adults, often characterized by marked deficits in episodic memory and executive function. Prior studies have found that direct electrical stimulation of the temporal cortex yielded improved memory in epilepsy patients, but it is not clear if these results generalize to patients with a specific history of TBI. Here we asked whether applying closed-loop, direct electrical stimulation to lateral temporal cortex could reliably improve memory in a TBI cohort. Among a larger group of patients undergoing neurosurgical evaluation for refractory epilepsy, we recruited a subset of patients with a history of moderate-to-severe TBI. By analyzing neural data from indwelling electrodes as patients studied and recalled lists of words, we trained personalized machine-learning classifiers to predict momentary fluctuations in mnemonic function in each patient. We subsequently used these classifiers to trigger high-frequency stimulation of the lateral temporal cortex (LTC) at moments when memory was predicted to fail. This strategy yielded a 19% boost in recall performance on stimulated as compared with non-stimulated lists (P = 0.012). These results provide a proof-of-concept for using closed-loop stimulation of the brain in treatment of TBI-related memory impairment.
Collapse
Affiliation(s)
- Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Youssef Ezzyat
- Department of Psychology, Wesleyan University, Middletown, CT, 06459, USA
| | - Paul A Wanda
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Ethan A Solomon
- Department of Psychology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | | | - Bradley C Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Barbara C Jobst
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH, 03766, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University, Atlanta, GA, 30322, USA
| | - Kan Ding
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, TX, 75390, USA
| | | |
Collapse
|
7
|
Xiao Y, Nie A. Does Expecting Matter? The Impact of Experimentally Established Expectations on Subsequent Memory Retrieval of Emotional Words. J Intell 2023; 11:130. [PMID: 37504773 PMCID: PMC10381812 DOI: 10.3390/jintelligence11070130] [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: 03/21/2023] [Revised: 06/16/2023] [Accepted: 06/28/2023] [Indexed: 07/29/2023] Open
Abstract
Previous studies have confirmed that different degrees of expectation, including the bipolarity of the expected and unexpected, as well as an intermediate level (no expectation), can affect memory. However, only a few investigations have manipulated expectation through experimentally established schema, with no consideration of how expectation impacts both item and source memory. Furthermore, stimulus emotionality may also impact memory. Therefore, we conducted a study to investigate the effects of three levels of expectation on item and source memory while considering the impact of stimulus emotionality. The experiment began with a phase dedicated to learning the rules. In the subsequent study phase, negative and neutral words were manipulated as expected, no expectation, and unexpected, based on these rules. This was followed by tasks focused on item and source memory. The study found that there was a "U-shape" relationship between expectation and item memory. Additionally, the study revealed the distinct impacts of expectation on item and source memory. When it came to item memory, both expected and unexpected words were better remembered than those with no expectations. In source memory, expected words showed memory inferiority for expectation-irrelevant source information, but an advantage for expectation-relevant source information. Stimulus emotionality modulated the effect of expectation on both item and source memory. Our findings provide behavioral evidence for the schema-linked interactions between medial prefrontal and medial temporal regions (SLIMM) theory, which proposes that congruent and incongruent events enhance memory through different brain regions. The different patterns between item and source memory also support dual-process models. Moreover, we speculate that processing events with varying levels of emotionality may undermine the impact of expectation, as implied by other neural investigations.
Collapse
Affiliation(s)
- Yueyue Xiao
- Department of Psychology and Behavioral Sciences, Zhejiang University, Hangzhou 310028, China
| | - Aiqing Nie
- Department of Psychology, College of Educational Sciences, Shanxi Normal University, Taiyuan 030031, China
| |
Collapse
|
8
|
Ahmed H, Pauly-Takacs K, Abraham A. Evaluating the effects of episodic and semantic memory induction procedures on divergent thinking in younger and older adults. PLoS One 2023; 18:e0286305. [PMID: 37267278 DOI: 10.1371/journal.pone.0286305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 05/13/2023] [Indexed: 06/04/2023] Open
Abstract
Evidence suggesting that episodic specificity induction improves divergent thinking performance in younger and older adults has been taken as indicative of the role of declarative memory processes in creativity. A series of studies were carried out to verify the specificity of such findings by investigating the effects of several novel episodic and semantic memory induction procedures on a widely employed measure of divergent creative thinking (the Alternate Uses Task), in comparison to a control induction and a no-induction baseline in both younger and older adults. There was no clear evidence for a specific role played by the induction of episodic or semantic memory processes in facilitating creative thinking across the three experiments, and the effects of the induction procedures (episodic, semantic and control) on divergent thinking were not comparable across age groups. On the other hand, higher levels of creativity were generally associated with older adults (60-80 years). In Experiments 2 and 3, older adults generated a greater number of responses (fluency), more unique responses (average originality, peak originality, creativity ratings) and more varied responses (flexibility) than younger adults (18-30 years). The findings are discussed in relation to the specificity of declarative memory operations and their impact on creative thinking, especially within the context of healthy ageing.
Collapse
Affiliation(s)
- Halima Ahmed
- School of Humanities and Social Sciences, Leeds Beckett University, Leeds, United Kingdom
| | - Kata Pauly-Takacs
- School of Humanities and Social Sciences, Leeds Beckett University, Leeds, United Kingdom
| | - Anna Abraham
- Department of Educational Psychology, Mary Frances Early College of Education, University of Georgia, Athens, GA, United States of America
- Torrance Center for Creativity and Talent Development, Mary Frances Early College of Education, University of Georgia, Athens, GA, United States of America
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Hippocampal Theta and Episodic Memory. J Neurosci 2023; 43:613-620. [PMID: 36639900 PMCID: PMC9888505 DOI: 10.1523/jneurosci.1045-22.2022] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 10/16/2022] [Accepted: 11/17/2022] [Indexed: 12/13/2022] Open
Abstract
Computational models of rodent physiology implicate hippocampal theta as a key modulator of learning and memory (Buzsáki and Moser, 2013; Lisman and Jensen, 2013), yet human hippocampal recordings have shown divergent theta correlates of memory formation. Herweg et al. (2020) suggest that decreases in memory-related broadband power mask narrowband theta increases. Their survey also notes that the theta oscillations appear most prominently in contrasts that isolate memory retrieval processes and when aggregating signals across large brain regions. We evaluate these hypotheses by analyzing human hippocampal recordings captured as 162 neurosurgical patients (n = 86 female) performed a free recall task. Using the Irregular-Resampling Auto-Spectral Analysis (IRASA) to separate broad and narrowband components of the field potential, we show that (1) broadband and narrowband components of theta exhibit opposite effects, with broadband signals decreasing and narrowband theta increasing during successful encoding; (2) whereas low-frequency theta oscillations increase before successful recall, higher-frequency theta and alpha oscillations decrease, masking the positive effect of theta when aggregating across the full band; and (3) the effects of theta on memory encoding and retrieval do not differ between reference schemes that accentuate local signals (bipolar) and those that aggregate signals globally (whole-brain average). In line with computational models that ascribe a fundamental role for hippocampal theta in memory, our large-scale study of human hippocampal recordings shows that 3-4 Hz theta oscillations reliably increase during successful memory encoding and before spontaneous recall of previously studied items.SIGNIFICANCE STATEMENT Analyzing recordings from 162 participants, we resolve a long-standing question regarding the role of hippocampal theta oscillations in the formation and retrieval of episodic memories. We show that broadband spectral changes confound estimates of narrowband theta activity, thereby accounting for inconsistent results in the literature. After accounting for broadband effects, we find that increased theta activity marks successful encoding and retrieval of episodic memories, supporting rodent models that ascribe a key role for hippocampal theta in memory function.
Collapse
|
11
|
Qasim SE, Mohan UR, Stein JM, Jacobs J. Neuronal activity in the human amygdala and hippocampus enhances emotional memory encoding. Nat Hum Behav 2023; 7:754-764. [PMID: 36646837 DOI: 10.1038/s41562-022-01502-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 11/25/2022] [Indexed: 01/17/2023]
Abstract
Emotional events comprise our strongest and most valuable memories. Here we examined how the brain prioritizes emotional information for storage using direct brain recording and deep brain stimulation. First, 148 participants undergoing intracranial electroencephalographic (iEEG) recording performed an episodic memory task. Participants were most successful at remembering emotionally arousing stimuli. High-frequency activity (HFA), a correlate of neuronal spiking activity, increased in both the hippocampus and the amygdala when participants successfully encoded emotional stimuli. Next, in a subset of participants (N = 19), we show that applying high-frequency electrical stimulation to the hippocampus selectively diminished memory for emotional stimuli and specifically decreased HFA. Finally, we show that individuals with depression (N = 19) also exhibit diminished emotion-mediated memory and HFA. By demonstrating how direct stimulation and symptoms of depression unlink HFA, emotion and memory, we show the causal and translational potential of neural activity in the amygdalohippocampal circuit for prioritizing emotionally arousing memories.
Collapse
Affiliation(s)
- Salman E Qasim
- Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Uma R Mohan
- Surgical Neurology Branch, NINDS, National Institutes of Health, Bethesda, MD, USA
| | - Joel M Stein
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Joshua Jacobs
- Department of Biomedical Engineering, Columbia University, New York, NY, USA. .,Department of Neurological Surgery, Columbia University, New York, NY, USA.
| |
Collapse
|
12
|
Abstract
High-frequency oscillatory events, termed ripples, represent synchrony of neural activity in the brain. Recent evidence suggests that medial temporal lobe (MTL) ripples support memory retrieval. However, it is unclear if ripples signal the reinstatement of episodic memories. Analyzing electrophysiological MTL recordings from 245 neurosurgical participants performing episodic recall tasks, we find that the rate of hippocampal ripples rises just prior to the free recall of recently formed memories. This prerecall ripple effect (PRE) is stronger in the CA1 and CA3/dentate gyrus (CA3/DG) subfields of the hippocampus than the neighboring MTL regions entorhinal and parahippocampal cortex. PRE is also stronger prior to the retrieval of temporally and semantically clustered, as compared with unclustered, recalls, indicating the involvement of ripples in contextual reinstatement, which is a hallmark of episodic memory.
Collapse
|
13
|
Chrysanthidis N, Fiebig F, Lansner A, Herman P. Traces of semantization - from episodic to semantic memory in a spiking cortical network model. eNeuro 2022; 9:ENEURO.0062-22.2022. [PMID: 35803714 PMCID: PMC9347313 DOI: 10.1523/eneuro.0062-22.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2022] [Revised: 05/05/2022] [Accepted: 05/28/2022] [Indexed: 11/21/2022] Open
Abstract
Episodic memory is a recollection of past personal experiences associated with particular times and places. This kind of memory is commonly subject to loss of contextual information or" semantization", which gradually decouples the encoded memory items from their associated contexts while transforming them into semantic or gist-like representations. Novel extensions to the classical Remember/Know behavioral paradigm attribute the loss of episodicity to multiple exposures of an item in different contexts. Despite recent advancements explaining semantization at a behavioral level, the underlying neural mechanisms remain poorly understood. In this study, we suggest and evaluate a novel hypothesis proposing that Bayesian-Hebbian synaptic plasticity mechanisms might cause semantization of episodic memory. We implement a cortical spiking neural network model with a Bayesian-Hebbian learning rule called Bayesian Confidence Propagation Neural Network (BCPNN), which captures the semantization phenomenon and offers a mechanistic explanation for it. Encoding items across multiple contexts leads to item-context decoupling akin to semantization. We compare BCPNN plasticity with the more commonly used spike-timing dependent plasticity (STDP) learning rule in the same episodic memory task. Unlike BCPNN, STDP does not explain the decontextualization process. We further examine how selective plasticity modulation of isolated salient events may enhance preferential retention and resistance to semantization. Our model reproduces important features of episodicity on behavioral timescales under various biological constraints whilst also offering a novel neural and synaptic explanation for semantization, thereby casting new light on the interplay between episodic and semantic memory processes.Significance StatementRemembering single episodes is a fundamental attribute of cognition. Difficulties recollecting contextual information is a key sign of episodic memory loss or semantization. Behavioral studies demonstrate that semantization of episodic memory can occur rapidly, yet the neural mechanisms underlying this effect are insufficiently investigated. In line with recent behavioral findings, we show that multiple stimulus exposures in different contexts may advance item-context decoupling. We suggest a Bayesian-Hebbian synaptic plasticity hypothesis of memory semantization and further show that a transient modulation of plasticity during salient events may disrupt the decontextualization process by strengthening memory traces, and thus, enhancing preferential retention. The proposed cortical network-of-networks model thus bridges micro and mesoscale synaptic effects with network dynamics and behavior.
Collapse
Affiliation(s)
- Nikolaos Chrysanthidis
- Division of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
| | - Florian Fiebig
- Division of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
| | - Anders Lansner
- Division of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
- Department of Mathematics, Stockholm University, 10691 Stockholm, Sweden
| | - Pawel Herman
- Division of Computational Science and Technology, School of Electrical Engineering and Computer Science, KTH Royal Institute of Technology, 10044 Stockholm, Sweden
- Digital Futures, Stockholm, Sweden
- Swedish e-Science Research Centre, Stockholm, Sweden
| |
Collapse
|
14
|
Berezutskaya J, Vansteensel MJ, Aarnoutse EJ, Freudenburg ZV, Piantoni G, Branco MP, Ramsey NF. Open multimodal iEEG-fMRI dataset from naturalistic stimulation with a short audiovisual film. Sci Data 2022; 9:91. [PMID: 35314718 PMCID: PMC8938409 DOI: 10.1038/s41597-022-01173-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Accepted: 01/24/2022] [Indexed: 12/19/2022] Open
Abstract
Intracranial human recordings are a valuable and rare resource of information about the brain. Making such data publicly available not only helps tackle reproducibility issues in science, it helps make more use of these valuable data. This is especially true for data collected using naturalistic tasks. Here, we describe a dataset collected from a large group of human subjects while they watched a short audiovisual film. The dataset has several unique features. First, it includes a large amount of intracranial electroencephalography (iEEG) data (51 participants, age range of 5-55 years, who all performed the same task). Second, it includes functional magnetic resonance imaging (fMRI) recordings (30 participants, age range of 7-47) during the same task. Eighteen participants performed both iEEG and fMRI versions of the task, non-simultaneously. Third, the data were acquired using a rich audiovisual stimulus, for which we provide detailed speech and video annotations. This dataset can be used to study neural mechanisms of multimodal perception and language comprehension, and similarity of neural signals across brain recording modalities.
Collapse
Affiliation(s)
- Julia Berezutskaya
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands.
- Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, the Netherlands.
| | - Mariska J Vansteensel
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Erik J Aarnoutse
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Zachary V Freudenburg
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Giovanni Piantoni
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Mariana P Branco
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Nick F Ramsey
- Brain Center, Department of Neurology and Neurosurgery, University Medical Center Utrecht, Utrecht, the Netherlands
| |
Collapse
|
15
|
Scan Once, Analyse Many: Using Large Open-Access Neuroimaging Datasets to Understand the Brain. Neuroinformatics 2022; 20:109-137. [PMID: 33974213 PMCID: PMC8111663 DOI: 10.1007/s12021-021-09519-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2021] [Indexed: 02/06/2023]
Abstract
We are now in a time of readily available brain imaging data. Not only are researchers now sharing data more than ever before, but additionally large-scale data collecting initiatives are underway with the vision that many future researchers will use the data for secondary analyses. Here I provide an overview of available datasets and some example use cases. Example use cases include examining individual differences, more robust findings, reproducibility-both in public input data and availability as a replication sample, and methods development. I further discuss a variety of considerations associated with using existing data and the opportunities associated with large datasets. Suggestions for further readings on general neuroimaging and topic-specific discussions are also provided.
Collapse
|
16
|
Kragel JE, Voss JL. Looking for the neural basis of memory. Trends Cogn Sci 2022; 26:53-65. [PMID: 34836769 PMCID: PMC8678329 DOI: 10.1016/j.tics.2021.10.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 01/03/2023]
Abstract
Memory neuroscientists often measure neural activity during task trials designed to recruit specific memory processes. Behavior is championed as crucial for deciphering brain-memory linkages but is impoverished in typical experiments that rely on summary judgments. We criticize this approach as being blind to the multiple cognitive, neural, and behavioral processes that occur rapidly within a trial to support memory. Instead, time-resolved behaviors such as eye movements occur at the speed of cognition and neural activity. We highlight successes using eye-movement tracking with in vivo electrophysiology to link rapid hippocampal oscillations to encoding and retrieval processes that interact over hundreds of milliseconds. This approach will improve research on the neural basis of memory because it pinpoints discrete moments of brain-behavior-cognition correspondence.
Collapse
Affiliation(s)
- James E Kragel
- Department of Neurology, The University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA.
| | - Joel L Voss
- Department of Neurology, The University of Chicago, 5841 South Maryland Avenue, Chicago, IL 60637, USA
| |
Collapse
|
17
|
Danilov GV, Shifrin MA, Kotik KV, Ishankulov TA, Orlov YN, Kulikov AS, Potapov AA. Artificial Intelligence Technologies in Neurosurgery: a Systematic Literature Review Using Topic Modeling. Part II: Research Objectives and Perspectives. Sovrem Tekhnologii Med 2021; 12:111-118. [PMID: 34796024 PMCID: PMC8596229 DOI: 10.17691/stm2020.12.6.12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Indexed: 12/29/2022] Open
Abstract
The current increase in the number of publications on the use of artificial intelligence (AI) technologies in neurosurgery indicates a new trend in clinical neuroscience. The aim of the study was to conduct a systematic literature review to highlight the main directions and trends in the use of AI in neurosurgery.
Collapse
Affiliation(s)
- G V Danilov
- Scientific Board Secretary; N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia; Head of the Laboratory of Biomedical Informatics and Artificial Intelligence; N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia
| | - M A Shifrin
- Scientific Consultant, Laboratory of Biomedical Informatics and Artificial Intelligence; N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia
| | - K V Kotik
- Physics Engineer, Laboratory of Biomedical Informatics and Artificial Intelligence; N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia
| | - T A Ishankulov
- Engineer, Laboratory of Biomedical Informatics and Artificial Intelligence; N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia
| | - Yu N Orlov
- Head of the Department of Computational Physics and Kinetic Equations; Keldysh Institute of Applied Mathematics, Russian Academy of Sciences, 4 Miusskaya Sq., Moscow, 125047, Russia
| | - A S Kulikov
- Staff Anesthesiologist; N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia
| | - A A Potapov
- Professor, Academician of the Russian Academy of Sciences, Chief Scientific Supervisor N.N. Burdenko National Medical Research Center for Neurosurgery, Ministry of Health of the Russian Federation, 16, 4 Tverskaya-Yamskaya St., Moscow, 125047, Russia
| |
Collapse
|
18
|
Yoo HB, Umbach G, Lega B. Neurons in the human medial temporal lobe track multiple temporal contexts during episodic memory processing. Neuroimage 2021; 245:118689. [PMID: 34742943 PMCID: PMC8802214 DOI: 10.1016/j.neuroimage.2021.118689] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 10/23/2021] [Accepted: 10/28/2021] [Indexed: 01/04/2023] Open
Abstract
Episodic memory requires associating items with temporal context, a process for which the medial temporal lobe (MTL) is critical. This study uses recordings from 27 human subjects who were undergoing surgical intervention for intractable epilepsy. These same data were also utilized in Umbach et al. (2020). We identify 103 memory-sensitive neurons in the hippocampus and entorhinal cortex, whose firing rates predicted successful episodic memory encoding as subjects performed a verbal free recall task. These neurons exhibit important properties. First, as predicted from the temporal context model, they demonstrate reinstatement of firing patterns observed during encoding at the time of retrieval. The magnitude of reinstatement predicted the tendency of subjects to cluster retrieved memory items according to input serial position. Also, we found that spiking activity of these neurons was locked to the phase of hippocampal theta oscillations, but that the mean phase of spiking shifted between memory encoding versus retrieval. This unique observation is consistent with predictions of the “Separate Phases at Encoding And Retrieval (SPEAR)” model. Together, the properties we identify for memory-sensitive neurons characterize direct electrophysiological mechanisms for the representation of contextual information in the human MTL.
Collapse
Affiliation(s)
- Hye Bin Yoo
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Gray Umbach
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Bradley Lega
- Department of Neurological Surgery, University of Texas Southwestern, Dallas, TX 75390, USA.
| |
Collapse
|
19
|
Wang S, Feng SF, Bornstein AM. Mixing memory and desire: How memory reactivation supports deliberative decision-making. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2021; 13:e1581. [PMID: 34665529 DOI: 10.1002/wcs.1581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Revised: 08/24/2021] [Accepted: 09/16/2021] [Indexed: 11/09/2022]
Abstract
Memories affect nearly every aspect of our mental life. They allow us to both resolve uncertainty in the present and to construct plans for the future. Recently, renewed interest in the role memory plays in adaptive behavior has led to new theoretical advances and empirical observations. We review key findings, with particular emphasis on how the retrieval of many kinds of memories affects deliberative action selection. These results are interpreted in a sequential inference framework, in which reinstatements from memory serve as "samples" of potential action outcomes. The resulting model suggests a central role for the dynamics of memory reactivation in determining the influence of different kinds of memory in decisions. We propose that representation-specific dynamics can implement a bottom-up "product of experts" rule that integrates multiple sets of action-outcome predictions weighted based on their uncertainty. We close by reviewing related findings and identifying areas for further research. This article is categorized under: Psychology > Reasoning and Decision Making Neuroscience > Cognition Neuroscience > Computation.
Collapse
Affiliation(s)
- Shaoming Wang
- Department of Psychology, New York University, New York, New York, USA
| | - Samuel F Feng
- Department of Mathematics, Khalifa University of Science and Technology, Abu Dhabi, UAE.,Khalifa University Centre for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi, UAE
| | - Aaron M Bornstein
- Department of Cognitive Sciences, University of California-Irvine, Irvine, California, USA.,Center for the Neurobiology of Learning & Memory, University of California-Irvine, Irvine, California, USA.,Institute for Mathematical Behavioral Sciences, University of California-Irvine, Irvine, California, USA
| |
Collapse
|
20
|
Kragel JE, Ezzyat Y, Lega BC, Sperling MR, Worrell GA, Gross RE, Jobst BC, Sheth SA, Zaghloul KA, Stein JM, Kahana MJ. Distinct cortical systems reinstate the content and context of episodic memories. Nat Commun 2021; 12:4444. [PMID: 34290240 PMCID: PMC8295370 DOI: 10.1038/s41467-021-24393-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/07/2021] [Indexed: 02/06/2023] Open
Abstract
Episodic recall depends upon the reinstatement of cortical activity present during the formation of a memory. Evidence from functional neuroimaging and invasive recordings in humans suggest that reinstatement organizes our memories by time or content, yet the neural systems involved in reinstating these unique types of information remain unclear. Here, combining computational modeling and intracranial recordings from 69 epilepsy patients, we show that two cortical systems uniquely reinstate the semantic content and temporal context of previously studied items during free recall. Examining either the posterior medial or anterior temporal networks, we find that forward encoding models trained on the brain's response to the temporal and semantic attributes of items can predict the serial position and semantic category of unseen items. During memory recall, these models uniquely link reinstatement of temporal context and semantic content to these posterior and anterior networks, respectively. These findings demonstrate how specialized cortical systems enable the human brain to target specific memories.
Collapse
Affiliation(s)
- James E. Kragel
- grid.25879.310000 0004 1936 8972Department of Psychology, University of Pennsylvania, Philadelphia, PA USA
| | - Youssef Ezzyat
- grid.25879.310000 0004 1936 8972Department of Psychology, University of Pennsylvania, Philadelphia, PA USA
| | - Bradley C. Lega
- grid.267313.20000 0000 9482 7121Department of Neurosurgery, University of Texas Southwestern, Dallas, TX USA
| | - Michael R. Sperling
- grid.265008.90000 0001 2166 5843Department of Neurology, Thomas Jefferson University, Philadelphia, PA USA
| | - Gregory A. Worrell
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN USA
| | - Robert E. Gross
- grid.189967.80000 0001 0941 6502Department of Neurosurgery, Emory School of Medicine, Atlanta, GA USA
| | - Barbara C. Jobst
- grid.413480.a0000 0004 0440 749XDepartment of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH USA
| | - Sameer A. Sheth
- grid.239585.00000 0001 2285 2675Department of Neurosurgery, Columbia University Medical Center, New York, NY USA
| | - Kareem A. Zaghloul
- grid.94365.3d0000 0001 2297 5165Surgical Neurology Branch, National Institutes of Health, Bethesda, MD USA
| | - Joel M. Stein
- grid.411115.10000 0004 0435 0884Department of Radiology, Hospital of the University of Pennsylvania, Philadelphia, PA USA
| | - Michael J. Kahana
- grid.25879.310000 0004 1936 8972Department of Psychology, University of Pennsylvania, Philadelphia, PA USA
| |
Collapse
|
21
|
Ye M, Wang L, Xiong J, Zheng G. The effect of mind-body exercise on memory in older adults: a systematic review and meta-analysis. Aging Clin Exp Res 2021; 33:1163-1173. [PMID: 32329024 DOI: 10.1007/s40520-020-01557-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 04/06/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVES The current systematic review aims to examine the effect of mind-body exercise on different memory types in the elderly population. METHODS Four literature databases (Pubmed, Cochrane library, Embase and Sinomed) were searched from inception to March 19, 2019. Randomized controlled trials (RCTs) examining the effect of mind-body exercise on memory in older adults were included. The assessment of risk of bias for the included studies and data synthesis were conducted using the software of review manager 5.3 based on the Cochrane handbook. RESULTS Twelve eligible RCTs with a total 1051 participants were identified that met the inclusion criteria for the systematic review. Meta-analysis in elderly adults without known neurological diseases showed mind-body exercise intervention had a large effect on general memory (SMD = 1.24, p = 0.005), a moderate effect on short-term memory (SMD = 0.51, p = 0.02) and long-term memory (SMD = 0.78, p < 0.001), a small effect on working memory (SMD = 0.28, p = 0.009), and a moderate effect on episodic memory (SMD = 0.74, p < 0.001) and semantic memory (SMD = 0.59, p = 0.003) compared to no specific exercise intervention. Similar results were also found in elderly adults with known neurological diseases, showing a moderate effect on general memory (SMD = 0.56, p < 0.001), short-term memory (SMD = 0.68, p = 0.01), and long-term memory (SMD = 0.80, p = 0.003); a small effect on working memory (SMD = 0.46, p < 0.001); and a large effect on episodic memory (SMD = 0.91, p < 0.001). CONCLUSION Compared with no specific exercise, mind-body exercise enhances memory in older adults. However, larger, more robust trials with longer follow-up periods and standardized neuropsychological outcome measures are needed before more definitive conclusions can be drawn.
Collapse
Affiliation(s)
- Mingzhu Ye
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Lecong Wang
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Jian Xiong
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Guohua Zheng
- Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China.
- College of Nursing and Health Management, Shanghai University of Medicine and Health Sciences, Shanghai, 201318, China.
| |
Collapse
|
22
|
Thye M, Geller J, Szaflarski JP, Mirman D. Intracranial EEG evidence of functional specialization for taxonomic and thematic relations. Cortex 2021; 140:40-50. [PMID: 33933929 DOI: 10.1016/j.cortex.2021.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 02/19/2021] [Accepted: 03/12/2021] [Indexed: 10/21/2022]
Abstract
The dual-hub account posits that the neural organization of semantic knowledge is segregated by the type of semantic relation with anterior temporal lobe (ATL) specializing for taxonomic relations and inferior parietal lobule (IPL) for thematic relations. This study critically examined this account by recording intracranial EEG from an array of depth electrodes within ATL, IPL, and two regions within the semantic control network, inferior frontal gyrus (IFG) and posterior middle temporal gyrus (pMTG), while 17 participants with refractory epilepsy completed a semantic relatedness judgment task. We observed a significant difference between relation types in ATL and IPL approximately 600-800 ms after trial presentation, and no significant differences in IFG or pMTG. Within this time window, alpha and theta suppression indexing cognitive effort and memory retrieval was observed in ATL for taxonomic trials and in IPL for thematic trials. These results suggest taxonomic specialization in ATL and thematic specialization in IPL, consistent with the dual-hub account of semantic cognition.
Collapse
Affiliation(s)
- Melissa Thye
- Department of Psychology, University of Edinburgh, Edinburgh, UK.
| | - Jason Geller
- Center for Cognitive Science, Rutgers University, Piscataway, NJ, USA
| | - Jerzy P Szaflarski
- Department of Neurology and the University of Alabama at Birmingham (UAB) Epilepsy Center, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Daniel Mirman
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| |
Collapse
|
23
|
Meisenhelter S, Quon RJ, Steimel SA, Testorf ME, Camp EJ, Moein P, Culler GW, Gross RE, Lega BC, Sperling MR, Kahana MJ, Jobst BC. Interictal Epileptiform Discharges are Task Dependent and are Associated with Lasting Electrocorticographic Changes. Cereb Cortex Commun 2021; 2:tgab019. [PMID: 34296164 PMCID: PMC8152941 DOI: 10.1093/texcom/tgab019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 12/24/2022] Open
Abstract
The factors that control the occurrence of interictal epileptiform discharges (IEDs) are not well understood. We suspected that this phenomenon reflects an attention-dependent suppression of interictal epileptiform activity. We hypothesized that IEDs would occur less frequently when a subject viewed a task-relevant stimulus compared with viewing a blank screen. Furthermore, IEDs have been shown to impair memory when they occur in certain regions during the encoding or recall phases of a memory task. Although these discharges have a short duration, their impact on memory suggests that they have longer lasting electrophysiological effects. We found that IEDs were associated with an increase in low-frequency power and a change in the balance between low- and high-frequency oscillations for several seconds. We found that the occurrence of IEDs is modified by whether a subject is attending to a word displayed on screen or is observing a blank screen. In addition, we found that discharges in brain regions in every lobe impair memory. These findings elucidate the relationship between IEDs and memory impairment and reveal the task dependence of the occurrence of IEDs.
Collapse
Affiliation(s)
- Stephen Meisenhelter
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03766, USA
- Department of Neurology, Geisel School of Medicine at Dartmouth College Hanover, NH 03755, United States
| | - Robert J Quon
- Department of Neurology, Geisel School of Medicine at Dartmouth College Hanover, NH 03755, United States
| | - Sarah A Steimel
- Department of Neurology, Geisel School of Medicine at Dartmouth College Hanover, NH 03755, United States
| | - Markus E Testorf
- Thayer School of Engineering at Dartmouth College, Hanover, NH 03755, United States
| | - Edward J Camp
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03766, USA
| | - Payam Moein
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03766, USA
| | - George W Culler
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03766, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University, Atlanta, GA 30322, United States
| | - Bradley C Lega
- Department of Neurosurgery, University of Texas-Southwestern, Dallas, TX 75390, United States
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA 19144, United States
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, United States
| | - Barbara C Jobst
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03766, USA
- Department of Neurology, Geisel School of Medicine at Dartmouth College Hanover, NH 03755, United States
| |
Collapse
|
24
|
Adamovich-Zeitlin R, Wanda PA, Solomon E, Phan T, Lega B, Jobst BC, Gross RE, Ding K, Diaz-Arrastia R, Kahana MJ. Biomarkers of memory variability in traumatic brain injury. Brain Commun 2021; 3:fcaa202. [PMID: 33543140 PMCID: PMC7850041 DOI: 10.1093/braincomms/fcaa202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 09/08/2020] [Accepted: 10/05/2020] [Indexed: 11/18/2022] Open
Abstract
Traumatic brain injury is a leading cause of cognitive disability and is often associated with significant impairment in episodic memory. In traumatic brain injury survivors, as in healthy controls, there is marked variability between individuals in memory ability. Using recordings from indwelling electrodes, we characterized and compared the oscillatory biomarkers of mnemonic variability in two cohorts of epilepsy patients: a group with a history of moderate-to-severe traumatic brain injury (n = 37) and a group of controls without traumatic brain injury (n = 111) closely matched for demographics and electrode coverage. Analysis of these recordings demonstrated that increased high-frequency power and decreased theta power across a broad set of brain regions mark periods of successful memory formation in both groups. As features in a logistic-regression classifier, spectral power biomarkers effectively predicted recall probability, with little difference between traumatic brain injury patients and controls. The two groups also displayed similar patterns of theta-frequency connectivity during successful encoding periods. These biomarkers of successful memory, highly conserved between traumatic brain injury patients and controls, could serve as the basis for novel therapies that target disordered memory across diverse forms of neurological disease.
Collapse
Affiliation(s)
| | - Paul A Wanda
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Ethan Solomon
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tung Phan
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Bradley Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Barbara C Jobst
- Department of Neurology, Dartmouth-Hitchcock Medical Center, Hanover, NH 03766, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University, Atlanta, GA 30322, USA
| | - Kan Ding
- Department of Neurology and Neurotherapeutics, University of Texas Southwestern, Dallas, TX 75390, USA
| | - Ramon Diaz-Arrastia
- Department of Neurology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA
| |
Collapse
|
25
|
Chakravarty S, Chen YY, Caplan JB. Predicting memory from study-related brain activity. J Neurophysiol 2020; 124:2060-2075. [DOI: 10.1152/jn.00193.2020] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
For both basic and applied reasons, an important goal is to identify brain activity present while people study materials that enable us to predict whether they will remember those materials. We show that this is possible with the conventional event-related potential “subsequent-memory-effect” signals as well as with machine learning classifiers, but only to a small degree. This is in line with behavioral research, which supports many determinants of memory apart from the cognitive processes during study.
Collapse
Affiliation(s)
| | - Yvonne Y. Chen
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas
| | - Jeremy B. Caplan
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
26
|
Weidemann CT, Kahana MJ. Neural measures of subsequent memory reflect endogenous variability in cognitive function. J Exp Psychol Learn Mem Cogn 2020; 47:641-651. [PMID: 33151720 DOI: 10.1037/xlm0000966] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Human cognition exhibits a striking degree of variability: Sometimes we rapidly forge new associations whereas at other times new information simply does not stick. Correlations between neural activity during encoding and subsequent retrieval performance have implicated such "subsequent memory effects" (SMEs) as important for understanding the neural basis of memory formation. Uncontrolled variability in external factors that also predict memory performance, however, confounds the interpretation of these effects. By controlling for a comprehensive set of external variables, we investigated the extent to which neural correlates of successful memory encoding reflect variability in endogenous brain states. We show that external variables that reliably predict memory performance have relatively small effects on electroencephalographic (EEG) correlates of successful memory encoding. Instead, the brain activity that is diagnostic of successful encoding primarily reflects fluctuations in endogenous neural activity. These findings link neural activity during learning to endogenous states that drive variability in human cognition. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
Collapse
|
27
|
Owen LLW, Muntianu TA, Heusser AC, Daly PM, Scangos KW, Manning JR. A Gaussian Process Model of Human Electrocorticographic Data. Cereb Cortex 2020; 30:5333-5345. [PMID: 32495832 PMCID: PMC7472198 DOI: 10.1093/cercor/bhaa115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/15/2020] [Accepted: 04/16/2020] [Indexed: 12/17/2022] Open
Abstract
We present a model-based method for inferring full-brain neural activity at millimeter-scale spatial resolutions and millisecond-scale temporal resolutions using standard human intracranial recordings. Our approach makes the simplifying assumptions that different people's brains exhibit similar correlational structure, and that activity and correlation patterns vary smoothly over space. One can then ask, for an arbitrary individual's brain: given recordings from a limited set of locations in that individual's brain, along with the observed spatial correlations learned from other people's recordings, how much can be inferred about ongoing activity at other locations throughout that individual's brain? We show that our approach generalizes across people and tasks, thereby providing a person- and task-general means of inferring high spatiotemporal resolution full-brain neural dynamics from standard low-density intracranial recordings.
Collapse
Affiliation(s)
- Lucy L W Owen
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Tudor A Muntianu
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
| | - Andrew C Heusser
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
- Akili Interactive, Boston, MA 02110, USA
| | - Patrick M Daly
- Department of Psychiatry, University of California, San Francisco, CA 94143, USA
| | - Katherine W Scangos
- Department of Psychiatry, University of California, San Francisco, CA 94143, USA
| | - Jeremy R Manning
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA
| |
Collapse
|
28
|
Cowell RA, Huber DE. Mechanisms of memory: An intermediate level of analysis and organization. Curr Opin Behav Sci 2020; 32:65-71. [PMID: 32851122 PMCID: PMC7444732 DOI: 10.1016/j.cobeha.2020.01.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Research in the last five years has made great strides toward mechanistic explanations of how the brain enables memory. This progress builds upon decades of research from two complementary strands: a Levels of Analysis approach and a Levels of Organization approach. We review how research in cognitive psychology and cognitive neuroscience under these two approaches has recently converged on mechanistic, brain-based theories, couched at the optimal level for explaining cognitive phenomena - the intermediate level. Furthermore, novel empirical and data analysis techniques are now providing ways to test these theories' predictions, a crucial step in unraveling the mechanisms of memory.
Collapse
Affiliation(s)
- Rosemary A. Cowell
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst
| | - David E. Huber
- Department of Psychological and Brain Sciences, University of Massachusetts Amherst
| |
Collapse
|
29
|
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: 191] [Impact Index Per Article: 47.8] [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.
Collapse
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.
| |
Collapse
|
30
|
Seubert J, Kalpouzos G, Larsson M, Hummel T, Bäckman L, Laukka EJ. Temporolimbic cortical volume is associated with semantic odor memory performance in aging. Neuroimage 2020; 211:116600. [PMID: 32018003 DOI: 10.1016/j.neuroimage.2020.116600] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 01/10/2020] [Accepted: 01/31/2020] [Indexed: 12/30/2022] Open
Abstract
Olfactory function, and specifically semantic olfactory memory (i.e., odor identification), has frequently been shown to predict cognitive functioning across multiple domains in old age. This observation suggests that olfactory function can serve as a marker for the integrity of temporolimbic cortical networks, but a clear delineation of this association is still missing. To address this issue, the present study employed voxel-based morphometry in a region of interest-based design to determine the extent to which gray matter volumes of core olfactory and memory areas are associated with olfactory memory performance in an aging population free from neurodegenerative disease. We further aimed to determine potential overlap in structural anatomical correlates, and differences in association strength, for semantic and episodic olfactory memory. Structural magnetic resonance imaging (MRI), episodic and semantic odor memory and episodic and semantic verbal memory data were collected in 422 participants from the Swedish National Study on Aging and Care in Kungsholmen (SNAC-K), all aged ≥ 60 years. Controlling for age and education, semantic, but not episodic, olfactory memory was positively related to gray matter volume in a cluster extending from the anterior hippocampus and amygdala into the posterior piriform cortex. The observed associations remained even when verbal memory performance was controlled for, supporting a link between the olfactory memory domain and cortical volume over and above more generalized memory abilities. As such, our data provide evidence for distinct functional-structural associations for semantic odor memory, supporting the idea of temporolimbic integrity as a neurobiological substrate linking olfactory function to cognitive health in old age.
Collapse
Affiliation(s)
- Janina Seubert
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Department of Clinical Neuroscience, Psychology Division, Karolinska Institutet, Stockholm, Sweden.
| | - Grégoria Kalpouzos
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Maria Larsson
- Gösta Ekman's Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Thomas Hummel
- Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Lars Bäckman
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden
| | - Erika J Laukka
- Department of Neurobiology, Care Sciences and Society, Aging Research Center, Karolinska Institutet and Stockholm University, Stockholm, Sweden; Stockholm Gerontology Research Center, Stockholm, Sweden
| |
Collapse
|
31
|
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.
Collapse
|
32
|
Medial Temporal Lobe Atrophy is Related to Learning Strategy Changes in Amnestic Mild Cognitive Impairment. J Int Neuropsychol Soc 2019; 25:706-717. [PMID: 31023395 DOI: 10.1017/s1355617719000353] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Deficits in the semantic learning strategy were observed in subjects with amnestic mild cognitive impairment (aMCI) in our previous study. In the present study, we explored the contributions of executive function and brain structure changes to the decline in the semantic learning strategy in aMCI. METHODS A neuropsychological battery was used to test memory and executive function in 96 aMCI subjects and 90 age- and gender-matched healthy controls (HCs). The semantic clustering ratio on the verbal learning test was calculated to evaluate learning strategy. Medial temporal lobe atrophy (MTA) and white matter hyperintensities (WMH) were measured on MRI with the MTA and Fazekas visual rating scales, respectively. RESULTS Compared to HCs, aMCI subjects had poorer performance in terms of memory, executive function, and the semantic clustering ratio (P < .001). In aMCI subjects, no significant correlation between learning strategy and executive function was observed. aMCI subjects with obvious MTA demonstrated a lower semantic clustering ratio than those without MTA (P < .001). There was no significant difference in the learning strategies between subjects with high-grade WMH and subjects with low-grade WMH. CONCLUSION aMCI subjects showed obvious impairment in the semantic learning strategy, which was attributable to MTA but independent of executive dysfunction and subcortical WMH. These findings need to be further validated in large cohorts with biomarkers identified using volumetric brain measurements. (JINS, 2019, 25, 706-717).
Collapse
|