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Jiao D, Xu L, Gu Z, Yan H, Shen D, Gu X. Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies. Neural Regen Res 2025; 20:917-935. [PMID: 38989927 DOI: 10.4103/nrr.nrr-d-23-01444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/18/2024] [Indexed: 07/12/2024] Open
Abstract
Epilepsy is a severe, relapsing, and multifactorial neurological disorder. Studies regarding the accurate diagnosis, prognosis, and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy. The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression, protein expression, ion channel activity, energy metabolites, and gut microbiota composition. Satisfactory results are lacking for conventional treatments for epilepsy. Surgical resection of lesions, drug therapy, and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy. Non-pharmacological treatments, such as a ketogenic diet, gene therapy for nerve regeneration, and neural regulation, are currently areas of research focus. This review provides a comprehensive overview of the pathogenesis, diagnostic methods, and treatments of epilepsy. It also elaborates on the theoretical basis, treatment modes, and effects of invasive nerve stimulation in neurotherapy, including percutaneous vagus nerve stimulation, deep brain electrical stimulation, repetitive nerve electrical stimulation, in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation. Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures. Additionally, many new technologies for the diagnosis and treatment of epilepsy are being explored. However, current research is mainly focused on analyzing patients' clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level, which has led to a lack of consensus regarding the mechanisms related to the disease.
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Affiliation(s)
- Dian Jiao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Lai Xu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Zhen Gu
- Key Laboratory of Advanced Drug Delivery Systems of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hua Yan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Dingding Shen
- Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiaosong Gu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
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2
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Polis B, Cuda CM, Putterman C. Animal models of neuropsychiatric systemic lupus erythematosus: deciphering the complexity and guiding therapeutic development. Autoimmunity 2024; 57:2330387. [PMID: 38555866 DOI: 10.1080/08916934.2024.2330387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 03/10/2024] [Indexed: 04/02/2024]
Abstract
Systemic lupus erythematosus (SLE) poses formidable challenges due to its multifaceted etiology while impacting multiple tissues and organs and displaying diverse clinical manifestations. Genetic and environmental factors contribute to SLE complexity, with relatively limited approved therapeutic options. Murine models offer insights into SLE pathogenesis but do not always replicate the nuances of human disease. This review critically evaluates spontaneous and induced animal models, emphasizing their validity and relevance to neuropsychiatric SLE (NPSLE). While these models undoubtedly contribute to understanding disease pathophysiology, discrepancies persist in mimicking some NPSLE intricacies. The lack of literature addressing this issue impedes therapeutic progress. We underscore the urgent need for refining models that truly reflect NPSLE complexities to enhance translational fidelity. We encourage a comprehensive, creative translational approach for targeted SLE interventions, balancing scientific progress with ethical considerations to eventually improve the management of NPSLE patients. A thorough grasp of these issues informs researchers in designing experiments, interpreting results, and exploring alternatives to advance NPSLE research.
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Affiliation(s)
- Baruh Polis
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
- Research Institute, Galilee Medical Center, Nahariya, Israel
| | - Carla M Cuda
- Division of Rheumatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Chaim Putterman
- Azrieli Faculty of Medicine, Bar-Ilan University, Safed, Israel
- Research Institute, Galilee Medical Center, Nahariya, Israel
- Division of Rheumatology and Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA
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3
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Farhatullah, Chen X, Zeng D, Mehmood A, Khan R, Shahid F, Ibrahim MM. 3-Way hybrid analysis using clinical and magnetic resonance imaging for early diagnosis of Alzheimer's disease. Brain Res 2024; 1840:149021. [PMID: 38810771 DOI: 10.1016/j.brainres.2024.149021] [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: 01/19/2024] [Revised: 05/02/2024] [Accepted: 05/18/2024] [Indexed: 05/31/2024]
Abstract
Alzheimer's is a progressive neurodegenerative disorder that leads to cognitive impairment and ultimately death. To select the most effective treatment options, it is crucial to diagnose and classify the disease early, as current treatments can only delay its progression. However, previous research on Alzheimer's disease (AD) has had limitations, such as inaccuracies and reliance on a small, unbalanced binary dataset. In this study, we aimed to evaluate the early stages of AD using three multiclass datasets: OASIS, EEG, and ADNI MRI. The research consisted of three phases: pre-processing, feature extraction, and classification using hybrid learning techniques. For the OASIS and ADNI MRI datasets, we computed the mean RGB value and used an averaging filter to enhance the images. We balanced and augmented the dataset to increase its size. In the case of the EEG dataset, we applied a band-pass filter for digital filtering to reduce noise and also balanced the dataset using random oversampling. To extract and classify features, we utilized a hybrid technique consisting of four algorithms: AlexNet-MLP, AlexNet-ETC, AlexNet-AdaBoost, and AlexNet-NB. The results showed that the AlexNet-ETC hybrid algorithm achieved the highest accuracy rate of 95.32% for the OASIS dataset. In the case of the EEG dataset, the AlexNet-MLP hybrid algorithm outperformed other approaches with the highest accuracy of 97.71%. For the ADNI MRI dataset, the AlexNet-MLP hybrid algorithm achieved an accuracy rate of 92.59%. Comparing these results with the current state of the art demonstrates the effectiveness of our findings.
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Affiliation(s)
- Farhatullah
- School of Computer Science, China University of Geosciences, Wuhan 430074, China.
| | - Xin Chen
- School of Automation, China University of Geosciences, Wuhan 430074, China.
| | - Deze Zeng
- School of Computer Science, China University of Geosciences, Wuhan 430074, China.
| | - Atif Mehmood
- School of Computer Science and Technology, Zhejiang Normal University, Jinhua, 321002, China.
| | - Rizwan Khan
- School of Computer Science and Technology, Zhejiang Normal University, Jinhua, 321002, China.
| | - Farah Shahid
- School of Computer Science and Technology, Zhejiang Normal University, Jinhua, 321002, China.
| | - Mostafa M Ibrahim
- Department of Electrical Engineering, Faculty of Engineering, Minia University, Minia 61519, Egypt.
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4
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Wagner JN. Pain and temporality: a merleau-pontyian approach. MEDICINE, HEALTH CARE, AND PHILOSOPHY 2024; 27:321-331. [PMID: 38760624 PMCID: PMC11310234 DOI: 10.1007/s11019-024-10205-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 04/16/2024] [Indexed: 05/19/2024]
Abstract
Chronic pain is a common disorder with enormous sociomedical importance. A major part of primary and secondary costs of illness is caused by the various pain syndromes. Nociception - the sensory perception of a painful stimulus - is a complex process relying on an intricate system of anatomical, neurophysiological and biochemical networks. This applies even more so to pain - the state of experiencing a nociceptive event, of interpreting it in terms of meaning for the affected individual and of suffering a range of emotions it elicits. This intricacy renders it obvious, that the empirical medical sciences alone cannot explain all aspects of pain. Hence, it has also become a focus of phenomenological research. One aspect of these investigations is the interaction of pain and the perception of the lived body's spatiality. The focus of this article will build on these concepts to develop a construct of the alteration of temporality caused by chronic pain and the effects this spells out for the affected subject. To this end, I will primarily draw on Merleau-Ponty's ideas of the lived body as well as on theories of enactivism and embodiment. I will also point out parallels to neuroscientific data, thereby demonstrating the proximity of phenomenology and neuroscience. A possible partial solution to the pain dilemma may be derived from psychology: techniques relying on cognitive behavioural intervention, awareness training, and existential analysis may provide alleviation to patients suffering from chronic pain.
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Affiliation(s)
- Judith N Wagner
- Faculty of Humanities, Department of Philosophy, Charles University, Prague, Czech Republic.
- Evangelisches Klinikum Gelsenkirchen, Teaching Hospital University Duisburg-Essen, Munckelstrasse 27, 45879, Gelsenkirchen, Germany.
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5
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Hwang MJ, Lee SA. Scene construction processes in the anterior hippocampus during temporal episodic memory retrieval. Hippocampus 2024. [PMID: 39096199 DOI: 10.1002/hipo.23624] [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: 12/14/2023] [Revised: 06/06/2024] [Accepted: 07/15/2024] [Indexed: 08/05/2024]
Abstract
Although the hippocampus has been implicated in both the temporal organization of memories and association of scene elements, some theoretical accounts posit that the role of the hippocampus in episodic memory is largely atemporal. In this study, we set out to explore this discrepancy by identifying hippocampal activity patterns related to scene construction while participants performed a temporal order memory task. Participants in the fMRI scanner were shown a sequence of photographs, each consisting of a central object and a contextual background scene. On each retrieval trial, participants were shown a pair of the original photographs (FULL), objects from the scenes without the background (OBJ), or background contexts without the main foreground object (BACK). In the temporal order judgment (TOJ) task, participants judged the temporal order of the pair of scenes; in the Viewing trials, two identical scenes were shown without any task. First, we found that the anterior hippocampus-particularly the CA1 and subiculum-showed similar patterns of activation between the BACK and OBJ conditions, suggesting that scene construction occurred spontaneously during both TOJ and Viewing. Furthermore, neural markers of scene construction in the anterior hippocampus did not apply to incorrect trials, showing that successful temporal memory retrieval was functionally linked to scene construction. In the cortex, time-processing areas, such as the supplementary motor area and the precuneus, and scene-processing areas, such as the parahippocampal cortex, were activated and functionally connected with the hippocampus. Together, these results support the view that the hippocampus is concurrently involved in scene construction and temporal organization of memory and propose a model of hippocampal episodic memory that takes both processes into account.
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Affiliation(s)
- Maria Jieun Hwang
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
| | - Sang Ah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul, South Korea
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6
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Courellis HS, Valiante TA, Mamelak AN, Adolphs R, Rutishauser U. Neural dynamics underlying minute-timescale persistent behavior in the human brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.16.603717. [PMID: 39071326 PMCID: PMC11275932 DOI: 10.1101/2024.07.16.603717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
The ability to pursue long-term goals relies on a representations of task context that can both be maintained over long periods of time and switched flexibly when goals change. Little is known about the neural substrate for such minute-scale maintenance of task sets. Utilizing recordings in neurosurgical patients, we examined how groups of neurons in the human medial frontal cortex and hippocampus represent task contexts. When cued explicitly, task context was encoded in both brain areas and changed rapidly at task boundaries. Hippocampus exhibited a temporally dynamic code with fast decorrelation over time, preventing cross-temporal generalization. Medial frontal cortex exhibited a static code that decorrelated slowly, allowing generalization across minutes of time. When task context needed to be inferred as a latent variable, hippocampus encoded task context with a static code. These findings reveal two possible regimes for encoding minute-scale task-context representations that were engaged differently based on task demands.
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7
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Choucry A, Nomoto M, Inokuchi K. Engram mechanisms of memory linking and identity. Nat Rev Neurosci 2024; 25:375-392. [PMID: 38664582 DOI: 10.1038/s41583-024-00814-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2024] [Indexed: 05/25/2024]
Abstract
Memories are thought to be stored in neuronal ensembles referred to as engrams. Studies have suggested that when two memories occur in quick succession, a proportion of their engrams overlap and the memories become linked (in a process known as prospective linking) while maintaining their individual identities. In this Review, we summarize the key principles of memory linking through engram overlap, as revealed by experimental and modelling studies. We describe evidence of the involvement of synaptic memory substrates, spine clustering and non-linear neuronal capacities in prospective linking, and suggest a dynamic somato-synaptic model, in which memories are shared between neurons yet remain separable through distinct dendritic and synaptic allocation patterns. We also bring into focus retrospective linking, in which memories become associated after encoding via offline reactivation, and discuss key temporal and mechanistic differences between prospective and retrospective linking, as well as the potential differences in their cognitive outcomes.
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Affiliation(s)
- Ali Choucry
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Cairo University, Cairo, Egypt
| | - Masanori Nomoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan
- Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
| | - Kaoru Inokuchi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
- Research Center for Idling Brain Science, University of Toyama, Toyama, Japan.
- CREST, Japan Science and Technology Agency (JST), University of Toyama, Toyama, Japan.
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8
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Zhang Y, Chen Y, Zhang J, Luo X, Zhang M, Qu H, Yi Z. Minicolumn-Based Episodic Memory Model With Spiking Neurons, Dendrites and Delays. IEEE TRANSACTIONS ON NEURAL NETWORKS AND LEARNING SYSTEMS 2024; 35:7072-7086. [PMID: 36279337 DOI: 10.1109/tnnls.2022.3213688] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Episodic memory is fundamental to the brain's cognitive function, but how neuronal activity is temporally organized during its encoding and retrieval is still unknown. In this article, combining hippocampus structure with a spiking neural network (SNN), a new bionic spiking temporal memory (BSTM) model is proposed to explore the encoding, formation, and retrieval of episodic memory. For encoding episodic memory, the spike-timing-dependent-plasticity (STDP) learning algorithm and a proposed minicolumn selection algorithm are used to encode each input item into several active minicolumns. For the formation of episodic memory, a sequential memory algorithm is proposed to store the contexts between items. For retrieval of episodic memory, the local retrieval algorithm and the global retrieval algorithm are proposed to retrieve sequence information, achieving multisentence prediction and multitime step prediction. All functions of BSTM are based on bionic spiking neurons, which have biological characteristics including columnar and dendritic structures, firing and receiving spikes, and delaying transmission. To test the performance of the BSTM model, the Children's Book Test (CBT) data set was used to conduct a series of experiments under different settings, including changing the number of minicolumns, neurons and sequences, modifying sequence items, etc. Compared to other sequence memory algorithms, the experimental results show that the proposed BSTM achieves higher accuracy and better robustness.
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9
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Kulkarni N, Lega BC. Episodic boundaries affect neural features of representational drift in humans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.20.553078. [PMID: 37662212 PMCID: PMC10473664 DOI: 10.1101/2023.08.20.553078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
A core feature of episodic memory is representational drift, the gradual change in aggregate oscillatory features that supports temporal association of memory items. However, models of drift overlook the role of episodic boundaries, which indicate a shift from prior to current context states. Our study focuses on the impact of task boundaries on representational drift in the parietal and temporal lobes in 99 subjects during a free recall task. Using intracranial EEG recordings, we show boundary representations reset gamma band drift in the medial parietal lobe, selectively enhancing the recall of early list (primacy) items. Conversely, the lateral temporal cortex shows increased drift for recalled items but lacked sensitivity to task boundaries. Our results suggest regional sensitivity to varied contextual features: the lateral temporal cortex uses drift to differentiate items, while the medial parietal lobe uses drift-resets to associate items with the current context. We propose drift represents relational information tailored to a region's sensitivity to unique contextual elements. Our findings offer a mechanism to integrate models of temporal association by drift with event segmentation by episodic boundaries.
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10
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López-Madrona VJ, Trébuchon A, Mindruta I, Barbeau EJ, Barborica A, Pistol C, Oane I, Alario FX, Bénar CG. Identification of Early Hippocampal Dynamics during Recognition Memory with Independent Component Analysis. eNeuro 2024; 11:ENEURO.0183-23.2023. [PMID: 38514193 PMCID: PMC10993203 DOI: 10.1523/eneuro.0183-23.2023] [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: 05/30/2023] [Revised: 11/24/2023] [Accepted: 12/11/2023] [Indexed: 03/23/2024] Open
Abstract
The hippocampus is generally considered to have relatively late involvement in recognition memory, its main electrophysiological signature being between 400 and 800 ms after stimulus onset. However, most electrophysiological studies have analyzed the hippocampus as a single responsive area, selecting only a single-site signal exhibiting the strongest effect in terms of amplitude. These classical approaches may not capture all the dynamics of this structure, hindering the contribution of other hippocampal sources that are not located in the vicinity of the selected site. We combined intracerebral electroencephalogram recordings from epileptic patients with independent component analysis during a recognition memory task involving the recognition of old and new images. We identified two sources with different responses emerging from the hippocampus: a fast one (maximal amplitude at ∼250 ms) that could not be directly identified from raw recordings and a latter one, peaking at ∼400 ms. The former component presented different amplitudes between old and new items in 6 out of 10 patients. The latter component had different delays for each condition, with a faster activation (∼290 ms after stimulus onset) for recognized items. We hypothesize that both sources represent two steps of hippocampal recognition memory, the faster reflecting the input from other structures and the latter the hippocampal internal processing. Recognized images evoking early activations would facilitate neural computation in the hippocampus, accelerating memory retrieval of complementary information. Overall, our results suggest that the hippocampal activity is composed of several sources with an early activation related to recognition memory.
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Affiliation(s)
| | - Agnès Trébuchon
- Epileptology and Cerebral Rhythmology, APHM, Timone Hospital, Marseille 13005, France
- Functional and Stereotactic Neurosurgery, APHM, Timone Hospital, Marseille 13005, France
| | - Ioana Mindruta
- Physics Department, University of Bucharest, Bucharest, Romania
| | - Emmanuel J Barbeau
- Centre de Recherche Cerveau et Cognition, Université de Toulouse, Université Paul Sabatier Toulouse, Toulouse 31052, France
- Centre National de la Recherche Scientifique, CerCo (UMR5549), Toulouse 31052, France
| | | | - Costi Pistol
- Physics Department, University of Bucharest, Bucharest, Romania
| | - Irina Oane
- Physics Department, University of Bucharest, Bucharest, Romania
| | | | - Christian G Bénar
- Inst Neurosci Syst, INS, INSERM, Aix Marseille Univ, Marseille 13005, France
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11
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Yang Y, Leopold DA, Duyn JH, Liu X. Hippocampal replay sequence governed by spontaneous brain-wide dynamics. PNAS NEXUS 2024; 3:pgae078. [PMID: 38562584 PMCID: PMC10983782 DOI: 10.1093/pnasnexus/pgae078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 02/01/2024] [Indexed: 04/04/2024]
Abstract
Neurons in the hippocampus exhibit spontaneous spiking activity during rest that appears to recapitulate previously experienced events. While this replay activity is frequently linked to memory consolidation and learning, the underlying mechanisms are not well understood. Recent large-scale neural recordings in mice have demonstrated that resting-state spontaneous activity is expressed as quasi-periodic cascades of spiking activity that pervade the forebrain, with each cascade engaging a high proportion of recorded neurons. Hippocampal ripples are known to be coordinated with cortical dynamics; however, less is known about the occurrence of replay activity relative to other brain-wide spontaneous events. Here we analyzed responses across the mouse brain to multiple viewings of natural movies, as well as subsequent patterns of neural activity during rest. We found that hippocampal neurons showed time-selectivity, with individual neurons responding consistently during particular moments of the movie. During rest, the population of time-selective hippocampal neurons showed both forward and time-reversed replay activity that matched the sequence observed in the movie. Importantly, these replay events were strongly time-locked to brain-wide spiking cascades, with forward and time-reversed replay activity associated with distinct cascade types. Thus, intrinsic hippocampal replay activity is temporally structured according to large-scale spontaneous physiology affecting areas throughout the forebrain. These findings shed light on the coordination between hippocampal and cortical circuits thought to be critical for memory consolidation.
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Affiliation(s)
- Yifan Yang
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
| | - David A Leopold
- Neurophysiology Imaging Facility, National Institute of Mental Health, National Institute of Neurological Disorders and Stroke, and National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
- Section on Cognitive Neurophysiology and Imaging, Laboratory of Neuropsychology, National Institute of Mental Health, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeff H Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiao Liu
- Department of Biomedical Engineering, The Pennsylvania State University, University Park, PA 16802, USA
- Institute for Computational and Data Sciences, The Pennsylvania State University, University Park, PA 16802, USA
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12
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Bein O, Davachi L. Event Integration and Temporal Differentiation: How Hierarchical Knowledge Emerges in Hippocampal Subfields through Learning. J Neurosci 2024; 44:e0627232023. [PMID: 38129134 PMCID: PMC10919070 DOI: 10.1523/jneurosci.0627-23.2023] [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: 04/05/2023] [Revised: 11/10/2023] [Accepted: 11/16/2023] [Indexed: 12/23/2023] Open
Abstract
Everyday life is composed of events organized by changes in contexts, with each event containing an unfolding sequence of occurrences. A major challenge facing our memory systems is how to integrate sequential occurrences within events while also maintaining their details and avoiding over-integration across different contexts. We asked if and how distinct hippocampal subfields come to hierarchically and, in parallel, represent both event context and subevent occurrences with learning. Female and male human participants viewed sequential events defined as sequences of objects superimposed on shared color frames while undergoing high-resolution fMRI. Importantly, these events were repeated to induce learning. Event segmentation, as indexed by increased reaction times at event boundaries, was observed in all repetitions. Temporal memory decisions were quicker for items from the same event compared to across different events, indicating that events shaped memory. With learning, hippocampal CA3 multivoxel activation patterns clustered to reflect the event context, with more clustering correlated with behavioral facilitation during event transitions. In contrast, in the dentate gyrus (DG), temporally proximal items that belonged to the same event became associated with more differentiated neural patterns. A computational model explained these results by dynamic inhibition in the DG. Additional similarity measures support the notion that CA3 clustered representations reflect shared voxel populations, while DG's distinct item representations reflect different voxel populations. These findings suggest an interplay between temporal differentiation in the DG and attractor dynamics in CA3. They advance our understanding of how knowledge is structured through integration and separation across time and context.
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Affiliation(s)
- Oded Bein
- Princeton Neuroscience Institute, Princeton University, Princeton, New Jersey 08540
| | - Lila Davachi
- Department of Psychology, Columbia University, New York, New York 10027
- Center for Clinical Research, The Nathan S. Kline Institute for Psychiatric Research, Orangeburg, New York 10962
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13
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Spens E, Burgess N. A generative model of memory construction and consolidation. Nat Hum Behav 2024; 8:526-543. [PMID: 38242925 PMCID: PMC10963272 DOI: 10.1038/s41562-023-01799-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: 05/30/2023] [Accepted: 12/05/2023] [Indexed: 01/21/2024]
Abstract
Episodic memories are (re)constructed, share neural substrates with imagination, combine unique features with schema-based predictions and show schema-based distortions that increase with consolidation. Here we present a computational model in which hippocampal replay (from an autoassociative network) trains generative models (variational autoencoders) to (re)create sensory experiences from latent variable representations in entorhinal, medial prefrontal and anterolateral temporal cortices via the hippocampal formation. Simulations show effects of memory age and hippocampal lesions in agreement with previous models, but also provide mechanisms for semantic memory, imagination, episodic future thinking, relational inference and schema-based distortions including boundary extension. The model explains how unique sensory and predictable conceptual elements of memories are stored and reconstructed by efficiently combining both hippocampal and neocortical systems, optimizing the use of limited hippocampal storage for new and unusual information. Overall, we believe hippocampal replay training generative models provides a comprehensive account of memory construction, imagination and consolidation.
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Affiliation(s)
- Eleanor Spens
- UCL Institute of Cognitive Neuroscience, University College London, London, UK.
| | - Neil Burgess
- UCL Institute of Cognitive Neuroscience, University College London, London, UK.
- UCL Queen Square Institute of Neurology, University College London, London, UK.
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14
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Strickland JA, Austen JM, Sprengel R, Sanderson DJ. Knockout of NMDARs in CA1 and dentate gyrus fails to impair temporal control of conditioned behavior in mice. Hippocampus 2024; 34:126-140. [PMID: 38140716 DOI: 10.1002/hipo.23593] [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: 01/15/2023] [Revised: 11/10/2023] [Accepted: 11/25/2023] [Indexed: 12/24/2023]
Abstract
The hippocampus has been implicated in temporal learning. Plasticity within the hippocampus requires NMDA receptor-dependent glutamatergic neurotransmission. We tested the prediction that hippocampal NMDA receptors are required for learning about time by testing mice that lack postembryonal NMDARs in the CA1 and dentate gyrus (DG) hippocampal subfields on three different appetitive temporal learning procedures. The conditional knockout mice (Grin1ΔDCA1 ) showed normal sensitivity to cue duration, responding at a higher level to a short duration cue than compared to a long duration cue. Knockout mice also showed normal precision and accuracy of response timing in the peak procedure in which reinforcement occurred after 10 s delay within a 30 s cue presentation. Mice were tested on the matching of response rates to reinforcement rates on instrumental conditioning with two levers reinforced on a concurrent variable interval schedule. Pressing on one lever was reinforced at a higher rate than the other lever. Grin1ΔDGCA1 mice showed normal sensitivity to the relative reinforcement rates of the levers. In contrast to the lack of effect of hippocampal NMDAR deletion on measures of temporal sensitivity, Grin1ΔDGCA1 mice showed increased baseline measures of magazine activity and lever pressing. Furthermore, reversal learning was enhanced when the reward contingencies were switched in the lever pressing task, but this was true only for mice trained with a large difference between relative reinforcement rates between the levers. The results failed to demonstrate a role for NMDARs in excitatory CA1 and DG neurons in learning about temporal information.
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Affiliation(s)
| | | | - Rolf Sprengel
- Departments of Molecular Neurobiology and Physiology, Max Planck Institute for Medical Research, Heidelberg, Germany
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15
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Sosa M, Plitt MH, Giocomo LM. Hippocampal sequences span experience relative to rewards. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.27.573490. [PMID: 38234842 PMCID: PMC10793396 DOI: 10.1101/2023.12.27.573490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Hippocampal place cells fire in sequences that span spatial environments and non-spatial modalities, suggesting that hippocampal activity can anchor to the most behaviorally salient aspects of experience. As reward is a highly salient event, we hypothesized that sequences of hippocampal activity can anchor to rewards. To test this, we performed two-photon imaging of hippocampal CA1 neurons as mice navigated virtual environments with changing hidden reward locations. When the reward moved, the firing fields of a subpopulation of cells moved to the same relative position with respect to reward, constructing a sequence of reward-relative cells that spanned the entire task structure. The density of these reward-relative sequences increased with task experience as additional neurons were recruited to the reward-relative population. Conversely, a largely separate subpopulation maintained a spatially-based place code. These findings thus reveal separate hippocampal ensembles can flexibly encode multiple behaviorally salient reference frames, reflecting the structure of the experience.
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Affiliation(s)
- Marielena Sosa
- Department of Neurobiology, Stanford University School of Medicine; Stanford, CA, USA
| | - Mark H. Plitt
- Department of Neurobiology, Stanford University School of Medicine; Stanford, CA, USA
- Present address: Department of Molecular and Cell Biology, University of California Berkeley; Berkeley, CA, USA
| | - Lisa M. Giocomo
- Department of Neurobiology, Stanford University School of Medicine; Stanford, CA, USA
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16
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Torres-Morales C, Cansino S. Brain representations of space and time in episodic memory: A systematic review and meta-analysis. COGNITIVE, AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2024; 24:1-18. [PMID: 38030912 PMCID: PMC10827973 DOI: 10.3758/s13415-023-01140-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 11/06/2023] [Indexed: 12/01/2023]
Abstract
All experiences preserved within episodic memory contain information on the space and time of events. The hippocampus is the main brain region involved in processing spatial and temporal information for incorporation within episodic memory representations. However, the other brain regions involved in the encoding and retrieval of spatial and temporal information within episodic memory are unclear, because a systematic review of related studies is lacking and the findings are scattered. The present study was designed to integrate the results of functional magnetic resonance imaging and positron emission tomography studies by means of a systematic review and meta-analysis to provide converging evidence. In particular, we focused on identifying the brain regions involved in the retrieval of spatial and temporal information. We identified a spatial retrieval network consisting of the inferior temporal gyrus, parahippocampal gyrus, superior parietal lobule, angular gyrus, and precuneus. Temporal context retrieval was supported by the dorsolateral prefrontal cortex. Thus, the retrieval of spatial and temporal information is supported by different brain regions, highlighting their different natures within episodic memory.
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Affiliation(s)
- César Torres-Morales
- Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico
| | - Selene Cansino
- Laboratory of NeuroCognition, Faculty of Psychology, National Autonomous University of Mexico, Mexico City, Mexico.
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17
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Cao R, Wang J, Brunner P, Willie JT, Li X, Rutishauser U, Brandmeir NJ, Wang S. Neural mechanisms of face familiarity and learning in the human amygdala and hippocampus. Cell Rep 2024; 43:113520. [PMID: 38151023 PMCID: PMC10834150 DOI: 10.1016/j.celrep.2023.113520] [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: 09/19/2022] [Revised: 09/12/2023] [Accepted: 11/14/2023] [Indexed: 12/29/2023] Open
Abstract
Recognizing familiar faces and learning new faces play an important role in social cognition. However, the underlying neural computational mechanisms remain unclear. Here, we record from single neurons in the human amygdala and hippocampus and find a greater neuronal representational distance between pairs of familiar faces than unfamiliar faces, suggesting that neural representations for familiar faces are more distinct. Representational distance increases with exposures to the same identity, suggesting that neural face representations are sharpened with learning and familiarization. Furthermore, representational distance is positively correlated with visual dissimilarity between faces, and exposure to visually similar faces increases representational distance, thus sharpening neural representations. Finally, we construct a computational model that demonstrates an increase in the representational distance of artificial units with training. Together, our results suggest that the neuronal population geometry, quantified by the representational distance, encodes face familiarity, similarity, and learning, forming the basis of face recognition and memory.
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Affiliation(s)
- Runnan Cao
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA; Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA.
| | - Jinge Wang
- Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Peter Brunner
- Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Jon T Willie
- Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO 63110, USA
| | - Xin Li
- Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA
| | - Ueli Rutishauser
- Departments of Neurosurgery and Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | | | - Shuo Wang
- Department of Radiology, Washington University in St. Louis, St. Louis, MO 63110, USA; Lane Department of Computer Science and Electrical Engineering, West Virginia University, Morgantown, WV 26506, USA; Department of Neurosurgery, Washington University in St. Louis, St. Louis, MO 63110, USA.
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18
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Liao J, Li J, Qiu Y, Wu X, Liu B, Zhang L, Zhang Y, Peng X, Huang R. Dissociable contributions of the hippocampus and orbitofrontal cortex to representing task space in a social context. Cereb Cortex 2024; 34:bhad447. [PMID: 38011099 PMCID: PMC10793565 DOI: 10.1093/cercor/bhad447] [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: 06/12/2023] [Revised: 10/30/2023] [Accepted: 11/08/2023] [Indexed: 11/29/2023] Open
Abstract
The hippocampus (HC) and the orbitofrontal cortex (OFC) jointly encode a map-like representation of a task space to guide behavior. It remains unclear how the OFC and HC interact in encoding this map-like representation, though previous studies indicated that both regions have different functions. We acquired the functional magnetic resonance imaging data under a social navigation task in which participants interacted with characters in a two-dimensional "social space." We calculate the social relationships between the participants and characters and used a drift-diffusion model to capture the inner process of social interaction. Then we used multivoxel pattern analysis to explore the brain-behavior relationship. We found that (i) both the HC and the OFC showed higher activations during the selective trial than the narrative trial; (ii) the neural pattern of the right HC was associated with evidence accumulation during social interaction, and the pattern of the right lateral OFC was associated with the social relationship; (iii) the neural pattern of the HC can decode the participants choices, while the neural pattern of the OFC can decode the task information about trials. The study provided evidence for distinct roles of the HC and the OFC in encoding different information when representing social space.
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Affiliation(s)
- Jiajun Liao
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Jinhui Li
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Yidan Qiu
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Xiaoyan Wu
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Bingyi Liu
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Lu Zhang
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Yuting Zhang
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Xiaoqi Peng
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
| | - Ruiwang Huang
- School of Psychology, Center for Studies of Psychological Application, Guangdong Key Laboratory of Mental Health and Cognitive Science, South China Normal University, Guangzhou 510631, Guangdong, China
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19
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Rolando F, Kononowicz TW, Duhamel JR, Doyère V, Wirth S. Distinct neural adaptations to time demand in the striatum and the hippocampus. Curr Biol 2024; 34:156-170.e7. [PMID: 38141617 DOI: 10.1016/j.cub.2023.11.066] [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: 04/12/2023] [Revised: 10/18/2023] [Accepted: 11/30/2023] [Indexed: 12/25/2023]
Abstract
How do neural codes adjust to track time across a range of resolutions, from milliseconds to multi-seconds, as a function of the temporal frequency at which events occur? To address this question, we studied time-modulated cells in the striatum and the hippocampus, while macaques categorized three nested intervals within the sub-second or the supra-second range (up to 1, 2, 4, or 8 s), thereby modifying the temporal resolution needed to solve the task. Time-modulated cells carried more information for intervals with explicit timing demand, than for any other interval. The striatum, particularly the caudate, supported the most accurate temporal prediction throughout all time ranges. Strikingly, its temporal readout adjusted non-linearly to the time range, suggesting that the striatal resolution shifted from a precise millisecond to a coarse multi-second range as a function of demand. This is in line with monkey's behavioral latencies, which indicated that they tracked time until 2 s but employed a coarse categorization strategy for durations beyond. By contrast, the hippocampus discriminated only the beginning from the end of intervals, regardless of the range. We propose that the hippocampus may provide an overall poor signal marking an event's beginning, whereas the striatum optimizes neural resources to process time throughout an interval adapting to the ongoing timing necessity.
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Affiliation(s)
- Felipe Rolando
- Institut des Sciences Cognitives Marc Jeannerod, CNRS, Université Lyon 1, 67 boulevard Pinel, 69500 Bron, France
| | - Tadeusz W Kononowicz
- Institut des Sciences Cognitives Marc Jeannerod, CNRS, Université Lyon 1, 67 boulevard Pinel, 69500 Bron, France; Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay (NeuroPSI), 91400 Saclay, France; Institute of Psychology, The Polish Academy of Sciences, ul. Jaracza 1, 00-378 Warsaw, Poland
| | - Jean-René Duhamel
- Institut des Sciences Cognitives Marc Jeannerod, CNRS, Université Lyon 1, 67 boulevard Pinel, 69500 Bron, France
| | - Valérie Doyère
- Université Paris-Saclay, CNRS, Institut des Neurosciences Paris-Saclay (NeuroPSI), 91400 Saclay, France
| | - Sylvia Wirth
- Institut des Sciences Cognitives Marc Jeannerod, CNRS, Université Lyon 1, 67 boulevard Pinel, 69500 Bron, France.
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20
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White E, Dalley JW. Brain mechanisms of temporal processing in impulsivity: Relevance to attention-deficit hyperactivity disorder. Brain Neurosci Adv 2024; 8:23982128241272234. [PMID: 39148691 PMCID: PMC11325328 DOI: 10.1177/23982128241272234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 06/25/2024] [Indexed: 08/17/2024] Open
Abstract
In this article, we critique the hypothesis that different varieties of impulsivity, including impulsiveness present in attention-deficit hyperactivity disorder, encompass an accelerated perception of time. This conceptualisation provides insights into how individuals with attention-deficit hyperactivity disorder have the capacity to maximise cognitive capabilities by more closely aligning themselves with appropriate environmental contexts (e.g. fast paced tasks that prevent boredom). We discuss the evidence for altered time perception in attention-deficit hyperactivity disorder alongside putative underlying neurobiological substrates, including a distributed brain network mediating time perception over multiple timescales. In particular, we explore the importance of temporal representations across the brain for time perception and symptom manifestation in attention-deficit hyperactivity disorder, including a prominent role of the hippocampus and other temporal lobe regions. We also reflect on how abnormalities in the perception of time may be relevant for understanding the aetiology of attention-deficit hyperactivity disorder and mechanism of action of existing medications.
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Affiliation(s)
- Eleanor White
- Department of Psychology, University of Cambridge, Cambridge, UK
| | - Jeffrey W Dalley
- Department of Psychology, University of Cambridge, Cambridge, UK
- Department of Psychiatry, Herschel Smith Building for Brain and Mind Sciences, Cambridge, UK
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21
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Soldado-Magraner S, Buonomano DV. Neural Sequences and the Encoding of Time. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2024; 1455:81-93. [PMID: 38918347 DOI: 10.1007/978-3-031-60183-5_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2024]
Abstract
Converging experimental and computational evidence indicate that on the scale of seconds the brain encodes time through changing patterns of neural activity. Experimentally, two general forms of neural dynamic regimes that can encode time have been observed: neural population clocks and ramping activity. Neural population clocks provide a high-dimensional code to generate complex spatiotemporal output patterns, in which each neuron exhibits a nonlinear temporal profile. A prototypical example of neural population clocks are neural sequences, which have been observed across species, brain areas, and behavioral paradigms. Additionally, neural sequences emerge in artificial neural networks trained to solve time-dependent tasks. Here, we examine the role of neural sequences in the encoding of time, and how they may emerge in a biologically plausible manner. We conclude that neural sequences may represent a canonical computational regime to perform temporal computations.
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Affiliation(s)
| | - Dean V Buonomano
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, USA.
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, USA.
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22
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Sadeh T, Moscovitch M. Retrieval of temporal structure at recall can occur automatically. Cognition 2024; 242:105647. [PMID: 37857055 DOI: 10.1016/j.cognition.2023.105647] [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: 04/06/2023] [Revised: 10/06/2023] [Accepted: 10/10/2023] [Indexed: 10/21/2023]
Abstract
Temporal-structure, namely, the order in which events unfold over time, is one of the fundamental principles of episodic memory organization. A seminal empirical demonstration of the prominence of temporal structure in memory organization is the Temporal Contiguity Effect (TCE), whereby the proximity between two items at encoding predicts the likelihood of those two items being retrieved consecutively during recall. Recent studies have found that TCE occurs under a wide variety of conditions in which strategic control processes at encoding are reduced or even eliminated. This suggests that the encoding of temporal structure occurs automatically. Extending these findings, in the current study we asked whether the retrieval of temporal structure, as reflected by indices of the TCE, is influenced by strategic control processes at retrieval. To manipulate participants' ability to rely on strategic control processes, we compared standard recall performance (Full Attention condition) to a condition in which attention was divided between recall and a concurrent task (Divided Attention condition), which has been shown to disrupt such control processes. Across two experiments-one with standard encoding conditions and one with continual distraction during encoding-we found no differences in any index of the TCE between the two conditions. These results are all the more striking considering that in both experiments, dividing attention negatively affected overall recall performance compared to the Full Attention condition. Thus, while recall performance is reduced when disrupting strategic processes, the ability to use temporal structure to drive recall is not affected.
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Affiliation(s)
- Talya Sadeh
- The Department of Cognitive and Brain Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel; Department of Psychology, Ben-Gurion University of the Negev, Beer Sheva, Israel; The School of Brain Sciences and Cognition, Ben-Gurion University of the Negev, Beer Sheva, Israel.
| | - Morris Moscovitch
- Rotman Research Institute, Baycrest Centre, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Canada
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23
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Lin D, Huang AZ, Richards BA. Temporal encoding in deep reinforcement learning agents. Sci Rep 2023; 13:22335. [PMID: 38102369 PMCID: PMC10724179 DOI: 10.1038/s41598-023-49847-y] [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: 07/14/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023] Open
Abstract
Neuroscientists have observed both cells in the brain that fire at specific points in time, known as "time cells", and cells whose activity steadily increases or decreases over time, known as "ramping cells". It is speculated that time and ramping cells support temporal computations in the brain and carry mnemonic information. However, due to the limitations in animal experiments, it is difficult to determine how these cells really contribute to behavior. Here, we show that time cells and ramping cells naturally emerge in the recurrent neural networks of deep reinforcement learning models performing simulated interval timing and working memory tasks, which have learned to estimate expected rewards in the future. We show that these cells do indeed carry information about time and items stored in working memory, but they contribute to behavior in large part by providing a dynamic representation on which policy can be computed. Moreover, the information that they do carry depends on both the task demands and the variables provided to the models. Our results suggest that time cells and ramping cells could contribute to temporal and mnemonic calculations, but the way in which they do so may be complex and unintuitive to human observers.
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Affiliation(s)
- Dongyan Lin
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3A 0G4, Canada.
- Mila, Montreal, QC, H2S 3H1, Canada.
| | - Ann Zixiang Huang
- Mila, Montreal, QC, H2S 3H1, Canada
- School of Computer Science, McGill University, Montreal, QC, H3A 0G4, Canada
| | - Blake Aaron Richards
- Integrated Program in Neuroscience, McGill University, Montreal, QC, H3A 0G4, Canada
- Mila, Montreal, QC, H2S 3H1, Canada
- School of Computer Science, McGill University, Montreal, QC, H3A 0G4, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, H3A 0G4, Canada
- Learning in Machines and Brains Program, Canadian Institute for Advanced Research, Toronto, ON, M5G 1M1, Canada
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24
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Smith TR, Southern R, Kirkpatrick K. Mechanisms of impulsive choice: Experiments to explore and models to map the empirical terrain. Learn Behav 2023; 51:355-391. [PMID: 36913144 PMCID: PMC10497727 DOI: 10.3758/s13420-023-00577-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2023] [Indexed: 03/14/2023]
Abstract
Impulsive choice is preference for a smaller-sooner (SS) outcome over a larger-later (LL) outcome when LL choices result in greater reinforcement maximization. Delay discounting is a model of impulsive choice that describes the decaying value of a reinforcer over time, with impulsive choice evident when the empirical choice-delay function is steep. Steep discounting is correlated with multiple diseases and disorders. Thus, understanding the processes underlying impulsive choice is a popular topic for investigation. Experimental research has explored the conditions that moderate impulsive choice, and quantitative models of impulsive choice have been developed that elegantly represent the underlying processes. This review spotlights experimental research in impulsive choice covering human and nonhuman animals across the domains of learning, motivation, and cognition. Contemporary models of delay discounting designed to explain the underlying mechanisms of impulsive choice are discussed. These models focus on potential candidate mechanisms, which include perception, delay and/or reinforcer sensitivity, reinforcement maximization, motivation, and cognitive systems. Although the models collectively explain multiple mechanistic phenomena, there are several cognitive processes, such as attention and working memory, that are overlooked. Future research and model development should focus on bridging the gap between quantitative models and empirical phenomena.
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25
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Wang X, Salminen LE, Petkus AJ, Driscoll I, Millstein J, Beavers DP, Espeland MA, Erus G, Braskie MN, Thompson PM, Gatz M, Chui HC, Resnick SM, Kaufman JD, Rapp SR, Shumaker S, Brown M, Younan D, Chen JC. Association between late-life air pollution exposure and medial temporal lobe atrophy in older women. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.11.28.23298708. [PMID: 38077091 PMCID: PMC10705610 DOI: 10.1101/2023.11.28.23298708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Background Ambient air pollution exposures increase risk for Alzheimer's disease (AD) and related dementias, possibly due to structural changes in the medial temporal lobe (MTL). However, existing MRI studies examining exposure effects on the MTL were cross-sectional and focused on the hippocampus, yielding mixed results. Method To determine whether air pollution exposures were associated with MTL atrophy over time, we conducted a longitudinal study including 653 cognitively unimpaired community-dwelling older women from the Women's Health Initiative Memory Study with two MRI brain scans (MRI-1: 2005-6; MRI-2: 2009-10; Mage at MRI-1=77.3±3.5years). Using regionalized universal kriging models, exposures at residential locations were estimated as 3-year annual averages of fine particulate matter (PM2.5) and nitrogen dioxide (NO2) prior to MRI-1. Bilateral gray matter volumes of the hippocampus, amygdala, parahippocampal gyrus (PHG), and entorhinal cortex (ERC) were summed to operationalize the MTL. We used linear regressions to estimate exposure effects on 5-year volume changes in the MTL and its subregions, adjusting for intracranial volume, sociodemographic, lifestyle, and clinical characteristics. Results On average, MTL volume decreased by 0.53±1.00cm3 over 5 years. For each interquartile increase of PM2.5 (3.26μg/m3) and NO2 (6.77ppb), adjusted MTL volume had greater shrinkage by 0.32cm3 (95%CI=[-0.43, -0.21]) and 0.12cm3 (95%CI=[-0.22, -0.01]), respectively. The exposure effects did not differ by APOE ε4 genotype, sociodemographic, and cardiovascular risk factors, and remained among women with low-level PM2.5 exposure. Greater PHG atrophy was associated with higher PM2.5 (b=-0.24, 95%CI=[-0.29, -0.19]) and NO2 exposures (b=-0.09, 95%CI=[-0.14, -0.04]). Higher exposure to PM2.5 but not NO2 was also associated with greater ERC atrophy. Exposures were not associated with amygdala or hippocampal atrophy. Conclusion In summary, higher late-life PM2.5 and NO2 exposures were associated with greater MTL atrophy over time in cognitively unimpaired older women. The PHG and ERC - the MTL cortical subregions where AD neuropathologies likely begin, may be preferentially vulnerable to air pollution neurotoxicity.
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Affiliation(s)
- Xinhui Wang
- Department of Neurology, University of Southern California, Los Angeles, California
| | - Lauren E Salminen
- Department of Neurology, University of Southern California, Los Angeles, California
- Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Andrew J Petkus
- Department of Neurology, University of Southern California, Los Angeles, California
| | - Ira Driscoll
- Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Joshua Millstein
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California
| | - Daniel P Beavers
- Departments of Statistical Sciences, Wake Forest University, Winston-Salem, North Carolina
| | - Mark A Espeland
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
- Department of Biostatistics and Data Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Guray Erus
- Center for Biomedical Image Computing and Analytics (CBICA), University of Pennsylvania, Philadelphia, Pennsylvania
| | - Meredith N Braskie
- Department of Neurology, University of Southern California, Los Angeles, California
- Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Paul M Thompson
- Department of Neurology, University of Southern California, Los Angeles, California
- Mark and Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, California
| | - Margaret Gatz
- Center for Economic and Social Research, University of Southern California, Los Angeles, California
| | - Helena C Chui
- Department of Neurology, University of Southern California, Los Angeles, California
| | - Susan M Resnick
- The Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland
| | - Joel D Kaufman
- Departments of Environmental & Occupational Health Sciences, Medicine (General Internal Medicine), and Epidemiology, University of Washington, Seattle, Washington
| | - Stephen R Rapp
- Departments of Psychiatry and Behavioral Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Sally Shumaker
- Department of Social Sciences and Health Policy, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Mark Brown
- Department of Biostatistics and Data Sciences, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Diana Younan
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California
| | - Jiu-Chiuan Chen
- Department of Neurology, University of Southern California, Los Angeles, California
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, California
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26
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M Aghajan Z, Kreiman G, Fried I. Minute-scale periodicity of neuronal firing in the human entorhinal cortex. Cell Rep 2023; 42:113271. [PMID: 37906591 DOI: 10.1016/j.celrep.2023.113271] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2023] [Revised: 07/09/2023] [Accepted: 09/28/2023] [Indexed: 11/02/2023] Open
Abstract
Grid cells in the entorhinal cortex demonstrate spatially periodic firing, thought to provide a spatial map on behaviorally relevant length scales. Whether such periodicity exists for behaviorally relevant time scales in the human brain remains unclear. We investigate neuronal firing during a temporally continuous experience by presenting 14 neurosurgical patients with a video while recording neuronal activity from multiple brain regions. We report on neurons that modulate their activity in a periodic manner across different time scales-from seconds to many minutes, most prevalently in the entorhinal cortex. These neurons remap their dominant periodicity to shorter time scales during a subsequent recognition memory task. When the video is presented at two different speeds, a significant percentage of these temporally periodic cells (TPCs) maintain their time scales, suggesting a degree of invariance. The TPCs' temporal periodicity might complement the spatial periodicity of grid cells and together provide scalable spatiotemporal metrics for human experience.
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Affiliation(s)
- Zahra M Aghajan
- Department of Neurosurgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Gabriel Kreiman
- Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Center for Brains, Minds and Machines, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Jane and Terry Semel Institute for Neuroscience and Human Behavior, University of California Los Angeles, Los Angeles, CA 90095, USA; Faculty of Medicine, Tel Aviv University, Tel-Aviv 69978, Israel.
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Schonhaut DR, Aghajan ZM, Kahana MJ, Fried I. A neural code for time and space in the human brain. Cell Rep 2023; 42:113238. [PMID: 37906595 DOI: 10.1016/j.celrep.2023.113238] [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: 12/20/2022] [Revised: 08/14/2023] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
Time and space are primary dimensions of human experience. Separate lines of investigation have identified neural correlates of time and space, yet little is known about how these representations converge during self-guided experience. Here, 10 subjects with intracranially implanted microelectrodes play a timed, virtual navigation game featuring object search and retrieval tasks separated by fixed delays. Time cells and place cells activate in parallel during timed navigation intervals, whereas a separate time cell sequence spans inter-task delays. The prevalence, firing rates, and behavioral coding strengths of time cells and place cells are indistinguishable-yet time cells selectively remap between search and retrieval tasks, while place cell responses remain stable. Thus, the brain can represent time and space as overlapping but dissociable dimensions. Time cells and place cells may constitute a biological basis for the cognitive map of spatiotemporal context onto which memories are written.
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Affiliation(s)
- Daniel R Schonhaut
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Zahra M Aghajan
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Michael J Kahana
- Department of Psychology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Itzhak Fried
- Department of Neurosurgery, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA; Department of Psychiatry and Biobehavioral Sciences, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA 90024, USA; Faculty of Medicine, Tel-Aviv University, Tel-Aviv 69978, Israel.
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28
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Kolibius LD, Roux F, Parish G, Ter Wal M, Van Der Plas M, Chelvarajah R, Sawlani V, Rollings DT, Lang JD, Gollwitzer S, Walther K, Hopfengärtner R, Kreiselmeyer G, Hamer H, Staresina BP, Wimber M, Bowman H, Hanslmayr S. Hippocampal neurons code individual episodic memories in humans. Nat Hum Behav 2023; 7:1968-1979. [PMID: 37798368 PMCID: PMC10663153 DOI: 10.1038/s41562-023-01706-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/23/2023] [Indexed: 10/07/2023]
Abstract
The hippocampus is an essential hub for episodic memory processing. However, how human hippocampal single neurons code multi-element associations remains unknown. In particular, it is debated whether each hippocampal neuron represents an invariant element within an episode or whether single neurons bind together all the elements of a discrete episodic memory. Here we provide evidence for the latter hypothesis. Using single-neuron recordings from a total of 30 participants, we show that individual neurons, which we term episode-specific neurons, code discrete episodic memories using either a rate code or a temporal firing code. These neurons were observed exclusively in the hippocampus. Importantly, these episode-specific neurons do not reflect the coding of a particular element in the episode (that is, concept or time). Instead, they code for the conjunction of the different elements that make up the episode.
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Affiliation(s)
- Luca D Kolibius
- Department of Biomedical Engineering, Columbia University, New York, NY, USA.
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK.
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK.
| | - Frederic Roux
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - George Parish
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Marije Ter Wal
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Mircea Van Der Plas
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Ramesh Chelvarajah
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
- Complex Epilepsy and Surgery Service, Neurosciences Centre, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | - Vijay Sawlani
- Complex Epilepsy and Surgery Service, Neurosciences Centre, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | - David T Rollings
- Complex Epilepsy and Surgery Service, Neurosciences Centre, Queen Elizabeth Hospital Birmingham, Birmingham, UK
| | - Johannes D Lang
- Epilepsy Center, Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Stephanie Gollwitzer
- Epilepsy Center, Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Katrin Walther
- Epilepsy Center, Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Rüdiger Hopfengärtner
- Epilepsy Center, Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Gernot Kreiselmeyer
- Epilepsy Center, Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Hajo Hamer
- Epilepsy Center, Department of Neurology, University Hospital Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Bernhard P Staresina
- Department of Experimental Psychology, University of Oxford, Oxford, UK
- Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, Department of Psychiatry, University of Oxford, Oxford, UK
| | - Maria Wimber
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
| | - Howard Bowman
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK
- Centre for Cognitive Neuroscience and Cognitive Systems and the School of Computing, University of Kent, Canterbury, UK
| | - Simon Hanslmayr
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, University of Glasgow, Glasgow, UK.
- Centre for Human Brain Health, School of Psychology, University of Birmingham, Birmingham, UK.
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29
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Azizi L, Polti I, van Wassenhove V. Spontaneous α Brain Dynamics Track the Episodic "When". J Neurosci 2023; 43:7186-7197. [PMID: 37704373 PMCID: PMC10601376 DOI: 10.1523/jneurosci.0816-23.2023] [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: 04/27/2023] [Revised: 07/14/2023] [Accepted: 08/06/2023] [Indexed: 09/15/2023] Open
Abstract
Across species, neurons track time over the course of seconds to minutes, which may feed the sense of time passing. Here, we asked whether neural signatures of time-tracking could be found in humans. Participants stayed quietly awake for a few minutes while being recorded with magnetoencephalography (MEG). They were unaware they would be asked how long the recording lasted (retrospective time) or instructed beforehand to estimate how long it will last (prospective timing). At rest, rhythmic brain activity is nonstationary and displays bursts of activity in the alpha range (α: 7-14 Hz). When participants were not instructed to attend to time, the relative duration of α bursts linearly predicted individuals' retrospective estimates of how long their quiet wakefulness lasted. The relative duration of α bursts was a better predictor than α power or burst amplitude. No other rhythmic or arrhythmic activity predicted retrospective duration. However, when participants timed prospectively, the relative duration of α bursts failed to predict their duration estimates. Consistent with this, the amount of α bursts was discriminant between prospective and retrospective timing. Last, with a control experiment, we demonstrate that the relation between α bursts and retrospective time is preserved even when participants are engaged in a visual counting task. Thus, at the time scale of minutes, we report that the relative time of spontaneous α burstiness predicts conscious retrospective time. We conclude that in the absence of overt attention to time, α bursts embody discrete states of awareness constitutive of episodic timing.SIGNIFICANCE STATEMENT The feeling that time passes is a core component of consciousness and episodic memory. A century ago, brain rhythms called "α" were hypothesized to embody an internal clock. However, rhythmic brain activity is nonstationary and displays on-and-off oscillatory bursts, which would serve irregular ticks to the hypothetical clock. Here, we discovered that in a given lapse of time, the relative bursting time of α rhythms is a good indicator of how much time an individual will report to have elapsed. Remarkably, this relation only holds true when the individual does not attend to time and vanishes when attending to it. Our observations suggest that at the scale of minutes, α brain activity tracks episodic time.
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Affiliation(s)
- Leila Azizi
- Cognitive Neuroimaging Unit, NeuroSpin, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Gif/Yvette 91191, France
| | - Ignacio Polti
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway 7030
- Department of Psychology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany D-04103
| | - Virginie van Wassenhove
- Cognitive Neuroimaging Unit, NeuroSpin, Commissariat à l'énergie atomique et aux énergies alternatives, Institut National de la Santé et de la Recherche Médicale, Université Paris-Saclay, Gif/Yvette 91191, France
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30
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Woo SH, Hahm J, Kyong JS, Kim HR, Kim KK. Time Perception and Memory in Mild Cognitive Impairment and Alzheimer's Disease: A Preliminary Study. Dement Neurocogn Disord 2023; 22:148-157. [PMID: 38025407 PMCID: PMC10654483 DOI: 10.12779/dnd.2023.22.4.148] [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: 09/19/2023] [Revised: 11/02/2023] [Accepted: 11/06/2023] [Indexed: 12/01/2023] Open
Abstract
Background and Purpose Episodic memory is a system that receives and stores information about temporally dated episodes and their interrelations. Our study aimed to investigate the relevance of episodic memory to time perception, with a specific focus on simultaneity/order judgment. Methods Experiment 1 employed the simultaneity judgment task to discern differences in time perception between patients with mild cognitive impairment or dementia, and age-matched normals. A mathematical analysis capable of estimating subjects' time processing was utilized to identify the sensory and decisional components of temporal order and simultaneity judgment. Experiment 2 examined how differences in temporal perception relate to performance in temporal order memory, in which time delays play a critical role. Results The temporal decision windows for both temporal order and simultaneity judgments exhibited marginal differences between patients with episodic memory impairment, and their healthy counterparts (p = 0.15, t(22) = 1.34). These temporal decision windows may be linked to the temporal separation of events in episodic memory (Pearson's ρ = -0.53, p = 0.05). Conclusions Based on our findings, the frequency of visual events accumulated and encoded in the working memory system in the patients' and normal group appears to be approximately (5.7 and 11.2) Hz, respectively. According to the internal clock model, a lower frequency of event pulses tends to result in underestimation of event duration, which phenomenon might be linked to the observed time distortions in patients with dementia.
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Affiliation(s)
- Sung-Ho Woo
- Institute of Interdisciplinary Brain Science, Dongguk University College of Medicine, Goyang, Korea
| | - Jarang Hahm
- Department of Neurology, Dongguk University Ilsan Hospital, Goyang, Korea
| | - Jeong-Sug Kyong
- Institute of Interdisciplinary Brain Science, Dongguk University College of Medicine, Goyang, Korea
| | - Hang-Rai Kim
- Institute of Interdisciplinary Brain Science, Dongguk University College of Medicine, Goyang, Korea
- Department of Neurology, Dongguk University Ilsan Hospital, Goyang, Korea
| | - Kwang Ki Kim
- Institute of Interdisciplinary Brain Science, Dongguk University College of Medicine, Goyang, Korea
- Department of Neurology, Dongguk University Ilsan Hospital, Goyang, Korea
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31
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Venkatesh P, Wolfe C, Lega B. Neuromodulation of the anterior thalamus: Current approaches and opportunities for the future. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 5:100109. [PMID: 38020810 PMCID: PMC10663132 DOI: 10.1016/j.crneur.2023.100109] [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: 05/14/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 12/01/2023] Open
Abstract
The role of thalamocortical circuits in memory has driven a recent burst of scholarship, especially in animal models. Investigating this circuitry in humans is more challenging. And yet, the development of new recording and stimulation technologies deployed for clinical indications has created novel opportunities for data collection to elucidate the cognitive roles of thalamic structures. These technologies include stereoelectroencephalography (SEEG), deep brain stimulation (DBS), and responsive neurostimulation (RNS), all of which have been applied to memory-related thalamic regions, specifically for seizure localization and treatment. This review seeks to summarize the existing applications of neuromodulation of the anterior thalamic nuclei (ANT) and highlight several devices and their capabilities that can allow cognitive researchers to design experiments to assay its functionality. Our goal is to introduce to investigators, who may not be familiar with these clinical devices, the capabilities, and limitations of these tools for understanding the neurophysiology of the ANT as it pertains to memory and other behaviors. We also briefly cover the targeting of other thalamic regions including the centromedian (CM) nucleus, dorsomedial (DM) nucleus, and pulvinar, with associated potential avenues of experimentation.
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Affiliation(s)
- Pooja Venkatesh
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Cody Wolfe
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Bradley Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
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32
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Mehrotra D, Dubé L. Accounting for multiscale processing in adaptive real-world decision-making via the hippocampus. Front Neurosci 2023; 17:1200842. [PMID: 37732307 PMCID: PMC10508350 DOI: 10.3389/fnins.2023.1200842] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 08/25/2023] [Indexed: 09/22/2023] Open
Abstract
For adaptive real-time behavior in real-world contexts, the brain needs to allow past information over multiple timescales to influence current processing for making choices that create the best outcome as a person goes about making choices in their everyday life. The neuroeconomics literature on value-based decision-making has formalized such choice through reinforcement learning models for two extreme strategies. These strategies are model-free (MF), which is an automatic, stimulus-response type of action, and model-based (MB), which bases choice on cognitive representations of the world and causal inference on environment-behavior structure. The emphasis of examining the neural substrates of value-based decision making has been on the striatum and prefrontal regions, especially with regards to the "here and now" decision-making. Yet, such a dichotomy does not embrace all the dynamic complexity involved. In addition, despite robust research on the role of the hippocampus in memory and spatial learning, its contribution to value-based decision making is just starting to be explored. This paper aims to better appreciate the role of the hippocampus in decision-making and advance the successor representation (SR) as a candidate mechanism for encoding state representations in the hippocampus, separate from reward representations. To this end, we review research that relates hippocampal sequences to SR models showing that the implementation of such sequences in reinforcement learning agents improves their performance. This also enables the agents to perform multiscale temporal processing in a biologically plausible manner. Altogether, we articulate a framework to advance current striatal and prefrontal-focused decision making to better account for multiscale mechanisms underlying various real-world time-related concepts such as the self that cumulates over a person's life course.
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Affiliation(s)
- Dhruv Mehrotra
- Integrated Program in Neuroscience, McGill University, Montréal, QC, Canada
- Montréal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Laurette Dubé
- Desautels Faculty of Management, McGill University, Montréal, QC, Canada
- McGill Center for the Convergence of Health and Economics, McGill University, Montréal, QC, Canada
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33
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Davis CP, Yee E. Is time an embodied property of concepts? PLoS One 2023; 18:e0290997. [PMID: 37669298 PMCID: PMC10479924 DOI: 10.1371/journal.pone.0290997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 08/18/2023] [Indexed: 09/07/2023] Open
Abstract
A haircut usually lasts under an hour. But how long does it take to recognize that something is an instance of a haircut? And is this "time-to-perceive" a part of the representation of concepts like haircut? Across three experiments testing lexical decision, word recognition, and semantic decision, we show that the amount of time people say it takes to perceive a concept in the world (e.g., haircut, dandelion, or merit) predicts how long it takes for them to respond to a word referring to that thing, over and above the effects of other lexical-semantic variables (e.g., word frequency, concreteness) and other variables related to conceptual complexity (e.g., how confusable a concept is with other, similar concepts, or the diversity of the contexts in which a concept appears). These results suggest that our experience of how long it takes to recognize an instance of a concept can become a part of its representation, and that we simulate this information when reading words. Consequently, we suggest that time may be an embodied property of concepts.
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Affiliation(s)
- Charles P. Davis
- Department of Psychology & Neuroscience, Duke University, Durham, North Carolina, United States of America
- CT Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, Connecticut, United States of America
| | - Eiling Yee
- CT Institute for the Brain and Cognitive Sciences, University of Connecticut, Storrs, Connecticut, United States of America
- Department of Psychological Sciences, University of Connecticut, Storrs, Connecticut, United States of America
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34
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Knowles TC, Summerton AG, Whiting JGH, Pearson MJ. Ring Attractors as the Basis of a Biomimetic Navigation System. Biomimetics (Basel) 2023; 8:399. [PMID: 37754150 PMCID: PMC10526409 DOI: 10.3390/biomimetics8050399] [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: 07/03/2023] [Revised: 08/14/2023] [Accepted: 08/15/2023] [Indexed: 09/28/2023] Open
Abstract
The ability to navigate effectively in a rich and complex world is crucial for the survival of all animals. Specialist neural structures have evolved that are implicated in facilitating this ability, one such structure being the ring attractor network. In this study, we model a trio of Spiking Neural Network (SNN) ring attractors as part of a bio-inspired navigation system to maintain an internal estimate of planar translation of an artificial agent. This estimate is dynamically calibrated using a memory recall system of landmark-free allotheic multisensory experiences. We demonstrate that the SNN-based ring attractor system can accurately model motion through 2D space by integrating ideothetic velocity information and use recalled allothetic experiences as a positive corrective mechanism. This SNN based navigation system has potential for use in mobile robotics applications where power supply is limited and external sensory information is intermittent or unreliable.
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Affiliation(s)
- Thomas C. Knowles
- Bristol Robotics Laboratory, University of the West of England, Bristol BS16 1QY, UK;
| | - Anna G. Summerton
- School of Engineering, University of the West of England, Bristol BS16 1QY, UK; (A.G.S.); (J.G.H.W.)
| | - James G. H. Whiting
- School of Engineering, University of the West of England, Bristol BS16 1QY, UK; (A.G.S.); (J.G.H.W.)
| | - Martin J. Pearson
- Bristol Robotics Laboratory, University of the West of England, Bristol BS16 1QY, UK;
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35
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Skye J, Bruss J, Herbet G, Tranel D, Boes AD. Localization of a Medial Temporal Lobe-Precuneus Network for Time Orientation. Ann Neurol 2023; 94:421-433. [PMID: 37183996 PMCID: PMC10524450 DOI: 10.1002/ana.26681] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 04/26/2023] [Accepted: 05/02/2023] [Indexed: 05/16/2023]
Abstract
OBJECTIVE Time orientation is a fundamental cognitive process in which one's personal sense of time is matched with a universal reference. Time orientation is commonly assessed through mental status examination, yet its neural correlates remain unclear. Large lesions have been associated with deficits in time orientation, but the regional anatomy implicated in time disorientation is not well established. The current study investigates the anatomy of time disorientation and its network correlates in patients with focal brain lesions. METHODS Time orientation was assessed 3 months or more after lesion onset using the Benton Temporal Orientation Test (BTOT) in 550 patients with acquired, focal brain lesions, 39 of whom were impaired. Multivariate lesion-symptom mapping and lesion network mapping were used to evaluate the anatomy and networks associated with time disorientation. Performance on a variety of neuropsychological tests was compared between the time oriented and time disoriented group. RESULTS Lesion-symptom mapping showed that lesions of the precuneus, medial temporal lobes (MTL), and occipito-temporal cortex were associated with time disorientation (r = 0.264, p < 0.001). Lesion network mapping using normative connectome data demonstrated that these regional findings occurred along a network that includes white and gray matter connecting the precuneus and MTL. There was a strong behavioral and anatomical association of time disorientation with memory impairment, such that the 2 processes could not be fully disentangled. INTERPRETATION We interpret these findings as novel evidence for a network involving the precuneus and the medial temporal lobe in supporting time orientation. ANN NEUROL 2023;94:421-433.
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Affiliation(s)
- Jax Skye
- Department of Neurology, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Pediatrics, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Joel Bruss
- Department of Neurology, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Guillaume Herbet
- Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
- Department of Neurosurgery, Montpellier University Medical Center, Gui de Chauliac Hospital, Montpellier, France
| | - Daniel Tranel
- Department of Neurology, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Psychological and Brain Sciences, University of Iowa, Iowa City, Iowa, USA
| | - Aaron D. Boes
- Department of Neurology, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Pediatrics, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Psychiatry, University of Iowa Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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36
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Kim JS, Lee SA. Hippocampal orchestration of associative and sequential memory networks for episodic retrieval. Cell Rep 2023; 42:112989. [PMID: 37581985 DOI: 10.1016/j.celrep.2023.112989] [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: 02/16/2023] [Revised: 06/16/2023] [Accepted: 08/01/2023] [Indexed: 08/17/2023] Open
Abstract
Episodic memory involves the recollection of contextual details replayed mentally across time. Here, we propose the association-sequence network (ASN) model, characterizing complementary cortico-hippocampal networks underlying the retrieval of simultaneously associated and sequentially ordered events. Participants viewed objects, presented singly or in pairs, and later reported whether two objects were shown simultaneously, consecutively, or farther apart in time. Behavioral results and hippocampal activation reveal a correlation between the two sequential conditions but not the simultaneous condition, despite the temporal proximity of consecutive pairs. We also find that anterior hippocampal activity is modulated by temporal distance. Distinct cortical networks are engaged during simultaneous and sequential memory (prefrontal cortex and angular gyrus for association; supplementary motor cortex and precuneus for sequence); notably, these regions show differential connectivity with the hippocampus. The ASN model provides a comprehensive framework for how we reconstruct memories that are both rich in associative detail and temporally dynamic in nature.
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Affiliation(s)
- Ji Sun Kim
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul 08826, Korea
| | - Sang Ah Lee
- Department of Brain and Cognitive Sciences, Seoul National University, Seoul 08826, Korea.
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37
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Zou F, Wanjia G, Allen EJ, Wu Y, Charest I, Naselaris T, Kay K, Kuhl BA, Hutchinson JB, DuBrow S. Re-expression of CA1 and entorhinal activity patterns preserves temporal context memory at long timescales. Nat Commun 2023; 14:4350. [PMID: 37468489 DOI: 10.1038/s41467-023-40100-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 07/13/2023] [Indexed: 07/21/2023] Open
Abstract
Converging, cross-species evidence indicates that memory for time is supported by hippocampal area CA1 and entorhinal cortex. However, limited evidence characterizes how these regions preserve temporal memories over long timescales (e.g., months). At long timescales, memoranda may be encountered in multiple temporal contexts, potentially creating interference. Here, using 7T fMRI, we measured CA1 and entorhinal activity patterns as human participants viewed thousands of natural scene images distributed, and repeated, across many months. We show that memory for an image's original temporal context was predicted by the degree to which CA1/entorhinal activity patterns from the first encounter with an image were re-expressed during re-encounters occurring minutes to months later. Critically, temporal memory signals were dissociable from predictors of recognition confidence, which were carried by distinct medial temporal lobe expressions. These findings suggest that CA1 and entorhinal cortex preserve temporal memories across long timescales by coding for and reinstating temporal context information.
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Affiliation(s)
- Futing Zou
- Department of Psychology, University of Oregon, Eugene, OR, USA.
| | - Guo Wanjia
- Department of Psychology, University of Oregon, Eugene, OR, USA
| | - Emily J Allen
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA
| | - Yihan Wu
- Graduate Program in Cognitive Science, University of Minnesota, Minneapolis, MN, USA
| | - Ian Charest
- Department of Psychology, University of Montreal, Montreal, QC, Canada
| | - Thomas Naselaris
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| | - Kendrick Kay
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA
| | - Brice A Kuhl
- Department of Psychology, University of Oregon, Eugene, OR, USA
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
| | | | - Sarah DuBrow
- Department of Psychology, University of Oregon, Eugene, OR, USA
- Institute of Neuroscience, University of Oregon, Eugene, OR, USA
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38
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Lee EY. Memory Deficits in Parkinson's Disease Are Associated with Impaired Attentional Filtering and Memory Consolidation Processes. J Clin Med 2023; 12:4594. [PMID: 37510708 PMCID: PMC10380592 DOI: 10.3390/jcm12144594] [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: 04/17/2023] [Revised: 07/07/2023] [Accepted: 07/08/2023] [Indexed: 07/30/2023] Open
Abstract
The present study examined mechanisms underlying memory deficits in Parkinson's disease (PD) and their associations with brain structural metrics. Nineteen PD patients and twenty-two matched controls underwent two memory experiments. In Experiment 1 (delayed memory task), subjects were asked to remember an array of colored rectangles with varying memory set sizes (Low-Load (2 items), Low-Load (relevant 2 items) with Distractor (irrelevant 3 items), and High-Load (5 items)). After a 7 s delay period, they reported whether the orientation of any relevant figures had changed (test period). In Experiment 2 (working memory task), memory arrays were presented in varying set sizes (2 to 6 items) without distractors, followed by a 2 s delay period and a subsequent test period. Brain MRI data were acquired to assess structural differences (volumes and cortical thickness) in areas related to attention, working memory storage capacity, and episodic memory. Multivariate analyses of covariance revealed that, compared with controls, PD patients had lower memory capacity scores in all memory load conditions for Experiment 1 (p < 0.021), whereas there were no group differences in any memory load conditions for Experiment 2 (p > 0.06). In addition, PD patients had lower cortical thickness in the left superior temporal gyrus (p = 0.02), a region related to the ventral attentional system. Moreover, regression analyses revealed that lower cortical thickness values in the left superior temporal gyrus significantly predicted lower memory scores of Low-Load and Low-Load with Distractor conditions in Experiment 1 (p < 0.044) and lower scores of memory load conditions of 4 and 5 items in Experiment 2 (p < 0.012). These findings suggest that memory deficits in PD may partly be due to impaired attentional filtering and memory consolidation processes that may be related to superior temporal neurodegeneration. Future studies are warranted to confirm the current findings to guide the development of effective treatments for memory deficits in PD.
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Affiliation(s)
- Eun-Young Lee
- Department of Health Care and Science, Dong-A University, Busan 49315, Republic of Korea
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39
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Lohnas LJ, Healey MK, Davachi L. Neural temporal context reinstatement of event structure during memory recall. J Exp Psychol Gen 2023; 152:1840-1872. [PMID: 37036669 PMCID: PMC10293072 DOI: 10.1037/xge0001354] [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] [Indexed: 04/11/2023]
Abstract
The transformation of experiences into meaningful events and memories is intertwined with the notion of time. Temporal perception can influence, and be influenced by, segmenting continuous experience into meaningful events. Episodic memories formed from these events become associated with temporal information as well. However, it is less clear how temporal perception contributes to structuring events and organizing memory: whether it plays a more active or passive role, and whether this temporal information is encoded initially during perception or influenced by retrieval processes. To address these questions, we examined how event segmentation influences temporal representations during initial perception and memory retrieval, without testing temporal information explicitly. Using a neural measure of temporal context extracted from scalp electroencephalography in human participants (N = 170), we found reduced temporal context similarity between studied items separated by an event boundary when compared to items from the same event. Furthermore, while participants freely recalled list items, neural activity reflected reinstatement of temporal context representations from the study phase, including temporal disruption. A computational model of episodic memory, the context maintenance and retrieval (CMR) model, predicted these results, and made novel predictions regarding the influence of temporal disruption on recall order. These findings implicate the impact of event structure on memory organization via temporal representations, underscoring the role of temporal information in event segmentation and episodic memory. (PsycInfo Database Record (c) 2023 APA, all rights reserved).
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40
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Rozells J, Gavornik JP. Optogenetic manipulation of inhibitory interneurons can be used to validate a model of spatiotemporal sequence learning. Front Comput Neurosci 2023; 17:1198128. [PMID: 37362060 PMCID: PMC10288026 DOI: 10.3389/fncom.2023.1198128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/24/2023] [Indexed: 06/28/2023] Open
Abstract
The brain uses temporal information to link discrete events into memory structures supporting recognition, prediction, and a wide variety of complex behaviors. It is still an open question how experience-dependent synaptic plasticity creates memories including temporal and ordinal information. Various models have been proposed to explain how this could work, but these are often difficult to validate in a living brain. A recent model developed to explain sequence learning in the visual cortex encodes intervals in recurrent excitatory synapses and uses a learned offset between excitation and inhibition to generate precisely timed "messenger" cells that signal the end of an instance of time. This mechanism suggests that the recall of stored temporal intervals should be particularly sensitive to the activity of inhibitory interneurons that can be easily targeted in vivo with standard optogenetic tools. In this work we examined how simulated optogenetic manipulations of inhibitory cells modifies temporal learning and recall based on these mechanisms. We show that disinhibition and excess inhibition during learning or testing cause characteristic errors in recalled timing that could be used to validate the model in vivo using either physiological or behavioral measurements.
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Affiliation(s)
| | - Jeffrey P. Gavornik
- Center for Systems Neuroscience, Department of Biology, Boston University, Boston, MA, United States
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41
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Soma S, Ohara S, Nonomura S, Suematsu N, Yoshida J, Pastalkova E, Sakai Y, Tsutsui KI, Isomura Y. Rat hippocampal CA1 region represents learning-related action and reward events with shorter latency than the lateral entorhinal cortex. Commun Biol 2023; 6:584. [PMID: 37258700 DOI: 10.1038/s42003-023-04958-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 05/20/2023] [Indexed: 06/02/2023] Open
Abstract
The hippocampus and entorhinal cortex are deeply involved in learning and memory. However, little is known how ongoing events are processed in the hippocampal-entorhinal circuit. By recording from head-fixed rats during action-reward learning, here we show that the action and reward events are represented differently in the hippocampal CA1 region and lateral entorhinal cortex (LEC). Although diverse task-related activities developed after learning in both CA1 and LEC, phasic activities related to action and reward events differed in the timing of behavioral event representation. CA1 represented action and reward events almost instantaneously, whereas the superficial and deep layers of the LEC showed a delayed representation of the same events. Interestingly, we also found that ramping activity towards spontaneous action was correlated with waiting time in both regions and exceeded that in the motor cortex. Such functional activities observed in the entorhinal-hippocampal circuits may play a crucial role for animals in utilizing ongoing information to dynamically optimize their behaviors.
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Affiliation(s)
- Shogo Soma
- Brain Science Institute, Tamagawa University, Tokyo, Japan.
- Department of Molecular Cell Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
| | - Shinya Ohara
- Laboratory of Systems Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
- PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Japan
| | - Satoshi Nonomura
- Brain Science Institute, Tamagawa University, Tokyo, Japan
- Department of Physiology and Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan
- Center for the Evolutionary Origins of Human Behavior, Kyoto University, Aichi, Japan
| | - Naofumi Suematsu
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA
| | - Junichi Yoshida
- Brain Science Institute, Tamagawa University, Tokyo, Japan
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Eva Pastalkova
- Department of Clinical Psychology, Pacifica Graduate Institute, Carpinteria, CA, USA
| | - Yutaka Sakai
- Brain Science Institute, Tamagawa University, Tokyo, Japan
| | - Ken-Ichiro Tsutsui
- Laboratory of Systems Neuroscience, Tohoku University Graduate School of Life Sciences, Sendai, Japan
| | - Yoshikazu Isomura
- Brain Science Institute, Tamagawa University, Tokyo, Japan.
- Department of Physiology and Cell Biology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
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42
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Herweg NA, Kunz L, Schonhaut D, Brandt A, Wanda PA, Sharan AD, Sperling MR, Schulze-Bonhage A, Kahana MJ. A Learned Map for Places and Concepts in the Human Medial Temporal Lobe. J Neurosci 2023; 43:3538-3547. [PMID: 37001991 PMCID: PMC10184731 DOI: 10.1523/jneurosci.0181-22.2023] [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: 01/24/2022] [Revised: 03/10/2023] [Accepted: 03/15/2023] [Indexed: 04/03/2023] Open
Abstract
Distinct lines of research in both humans and animals point to a specific role of the hippocampus in both spatial and episodic memory function. The discovery of concept cells in the hippocampus and surrounding medial temporal lobe (MTL) regions suggests that the MTL maps physical and semantic spaces with a similar neural architecture. Here, we studied the emergence of such maps using MTL microwire recordings from 20 patients (9 female, 11 male) navigating a virtual environment featuring salient landmarks with established semantic meaning. We present several key findings. The array of local field potentials in the MTL contains sufficient information for above-chance decoding of subjects' instantaneous location in the environment. Closer examination revealed that as subjects gain experience with the environment the field potentials come to represent both the subjects' locations in virtual space and in high-dimensional semantic space. Similarly, we observe a learning effect on temporal sequence coding. Over time, field potentials come to represent future locations, even after controlling for spatial proximity. This predictive coding of future states, more so than the strength of spatial representations per se, is linked to variability in subjects' navigation performance. Our results thus support the conceptualization of the MTL as a memory space, representing both spatial- and nonspatial information to plan future actions and predict their outcomes.SIGNIFICANCE STATEMENT Using rare microwire recordings, we studied the representation of spatial, semantic, and temporal information in the human MTL. Our findings demonstrate that subjects acquire a cognitive map that simultaneously represents the spatial and semantic relations between landmarks. We further show that the same learned representation is used to predict future states, implicating MTL cell assemblies as the building blocks of prospective memory functions.
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Affiliation(s)
- Nora A Herweg
- Computational Memory Lab, Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
- Department of Neuropsychology, Institute of Cognitive Neuroscience, Faculty of Psychology, Ruhr University Bochum, 44801 Bochum, Germany
| | - Lukas Kunz
- Department of Biomedical Engineering, Columbia University, New York, New York 10027
- Epilepsy Center, Medical Center, University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
| | - Daniel Schonhaut
- Computational Memory Lab, Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | - Armin Brandt
- Epilepsy Center, Medical Center, University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
| | - Paul A Wanda
- Computational Memory Lab, Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
| | | | - Michael R Sperling
- Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Andreas Schulze-Bonhage
- Epilepsy Center, Medical Center, University of Freiburg, Faculty of Medicine, 79106 Freiburg, Germany
| | - Michael J Kahana
- Computational Memory Lab, Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania, 19104
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43
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Markowitsch HJ, Staniloiu A. Behavioral, neurological, and psychiatric frailty of autobiographical memory. WILEY INTERDISCIPLINARY REVIEWS. COGNITIVE SCIENCE 2023; 14:e1617. [PMID: 35970754 DOI: 10.1002/wcs.1617] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 07/01/2022] [Accepted: 07/03/2022] [Indexed: 05/20/2023]
Abstract
Autobiographical-episodic memory is considered to be the most complex of the five long-term memory systems. It is autonoetic, which means, self-reflective, relies on emotional colorization, and needs the features of place and time; it allows mental time traveling. Compared to the other four long-term memory systems-procedural memory, priming, perceptual, and semantic memory-it develops the latest in phylogeny and ontogeny, and is the most vulnerable of the five systems, being easily impaired by brain damage and psychiatric disorders. Furthermore, it is characterized by its fragility and proneness to distortion due to environmental influences and subsequent information. On the brain level, a distinction has to be made between memory encoding and consolidating, memory storage, and memory retrieval. For encoding, structures of the limbic system, with the hippocampus in its center, are crucial, for storage of widespread cortical networks, and for retrieval again a distributed recollection network, in which the prefrontal cortex plays a crucial role, is engaged. Brain damage and psychiatric diseases can lead to what is called "focal retrograde amnesia." In this context, the clinical picture of dissociative or functional or psychogenic amnesia is central, as it may result in autobiographical-emotional amnesia of the total past with the consequence of an impairment of the self as well. The social environment therefore can have a major impact on the brain and on autobiographical-episodic memory processing. This article is categorized under: Psychology > Memory.
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Affiliation(s)
- Hans J Markowitsch
- Department of Physiological Psychology, University of Bielefeld, Bielefeld, Germany
| | - Angelica Staniloiu
- Department of Physiological Psychology, University of Bielefeld, Bielefeld, Germany
- Oberberg Clinic, Hornberg, Germany
- Department of Psychology, University of Bucharest, Bucharest, Romania
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44
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Rolls ET. Hippocampal spatial view cells for memory and navigation, and their underlying connectivity in humans. Hippocampus 2023; 33:533-572. [PMID: 36070199 PMCID: PMC10946493 DOI: 10.1002/hipo.23467] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/16/2022] [Accepted: 08/16/2022] [Indexed: 01/08/2023]
Abstract
Hippocampal and parahippocampal gyrus spatial view neurons in primates respond to the spatial location being looked at. The representation is allocentric, in that the responses are to locations "out there" in the world, and are relatively invariant with respect to retinal position, eye position, head direction, and the place where the individual is located. The underlying connectivity in humans is from ventromedial visual cortical regions to the parahippocampal scene area, leading to the theory that spatial view cells are formed by combinations of overlapping feature inputs self-organized based on their closeness in space. Thus, although spatial view cells represent "where" for episodic memory and navigation, they are formed by ventral visual stream feature inputs in the parahippocampal gyrus in what is the parahippocampal scene area. A second "where" driver of spatial view cells are parietal inputs, which it is proposed provide the idiothetic update for spatial view cells, used for memory recall and navigation when the spatial view details are obscured. Inferior temporal object "what" inputs and orbitofrontal cortex reward inputs connect to the human hippocampal system, and in macaques can be associated in the hippocampus with spatial view cell "where" representations to implement episodic memory. Hippocampal spatial view cells also provide a basis for navigation to a series of viewed landmarks, with the orbitofrontal cortex reward inputs to the hippocampus providing the goals for navigation, which can then be implemented by hippocampal connectivity in humans to parietal cortex regions involved in visuomotor actions in space. The presence of foveate vision and the highly developed temporal lobe for object and scene processing in primates including humans provide a basis for hippocampal spatial view cells to be key to understanding episodic memory in the primate and human hippocampus, and the roles of this system in primate including human navigation.
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Affiliation(s)
- Edmund T. Rolls
- Oxford Centre for Computational NeuroscienceOxfordUK
- Department of Computer ScienceUniversity of WarwickCoventryUK
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45
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Quian Quiroga R. An integrative view of human hippocampal function: Differences with other species and capacity considerations. Hippocampus 2023; 33:616-634. [PMID: 36965048 DOI: 10.1002/hipo.23527] [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: 08/30/2022] [Revised: 02/11/2023] [Accepted: 03/09/2023] [Indexed: 03/27/2023]
Abstract
We describe an integrative model that encodes associations between related concepts in the human hippocampal formation, constituting the skeleton of episodic memories. The model, based on partially overlapping assemblies of "concept cells," contrast markedly with the well-established notion of pattern separation, which relies on conjunctive, context dependent single neuron responses, instead of the invariant, context independent responses found in the human hippocampus. We argue that the model of partially overlapping assemblies is better suited to cope with memory capacity limitations, that the finding of different types of neurons and functions in this area is due to a flexible and temporary use of the extraordinary machinery of the hippocampus to deal with the task at hand, and that only information that is relevant and frequently revisited will consolidate into long-term hippocampal representations, using partially overlapping assemblies. Finally, we propose that concept cells are uniquely human and that they may constitute the neuronal underpinnings of cognitive abilities that are much further developed in humans compared to other species.
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Affiliation(s)
- Rodrigo Quian Quiroga
- Hospital del Mar Medical Research Institute (IMIM), Barcelona, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
- Centre for Systems Neuroscience, University of Leicester, Leicester, UK
- Department of neurosurgery, clinical neuroscience center, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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46
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Aseyev N. Perception of color in primates: A conceptual color neurons hypothesis. Biosystems 2023; 225:104867. [PMID: 36792004 DOI: 10.1016/j.biosystems.2023.104867] [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: 11/09/2022] [Revised: 02/12/2023] [Accepted: 02/12/2023] [Indexed: 02/16/2023]
Abstract
Perception of color by humans and other primates is a complex problem, studied by neurophysiology, psychophysiology, psycholinguistics, and even philosophy. Being mostly trichromats, simian primates have three types of opsin proteins, expressed in cone neurons in the eye, which allow for the sensing of color as the physical wavelength of light. Further, in neural networks of the retina, the coding principle changes from three types of sensor proteins to two opponent channels: activity of one type of neuron encode the evolutionarily ancient blue-yellow axis of color stimuli, and another more recent evolutionary channel, encoding the axis of red-green color stimuli. Both color channels are distinctive in neural organization at all levels from the eye to the neocortex, where it is thought that the perception of color (as philosophical qualia) emerges from the activity of some neuron ensembles. Here, using data from neurophysiology as a starting point, we propose a hypothesis on how the perception of color can be encoded in the activity of certain neurons in the neocortex. These conceptual neurons, herein referred to as 'color neurons', code only the hue of the color of visual stimulus, similar to place cells and number neurons, already described in primate brains. A case study with preliminary, but direct, evidence for existing conceptual color neurons in the human brain was published in 2008. We predict that the upcoming studies in non-human primates will be more extensive and provide a more detailed description of conceptual color neurons.
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Affiliation(s)
- Nikolay Aseyev
- Institute Higher Nervous Activity and Neurophysiology, RAS, Moscow, 117485, Butlerova, 5A, Russian Federation.
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47
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Hines M, Poulter S, Douchamps V, Pibiri F, McGregor A, Lever C. Frequency matters: how changes in hippocampal theta frequency can influence temporal coding, anxiety-reduction, and memory. Front Syst Neurosci 2023; 16:998116. [PMID: 36817946 PMCID: PMC9936826 DOI: 10.3389/fnsys.2022.998116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 12/30/2022] [Indexed: 02/05/2023] Open
Abstract
Hippocampal theta frequency is a somewhat neglected topic relative to theta power, phase, coherence, and cross-frequency coupling. Accordingly, here we review and present new data on variation in hippocampal theta frequency, focusing on functional associations (temporal coding, anxiety reduction, learning, and memory). Taking the rodent hippocampal theta frequency to running-speed relationship as a model, we identify two doubly-dissociable frequency components: (a) the slope component of the theta frequency-to-stimulus-rate relationship ("theta slope"); and (b) its y-intercept frequency ("theta intercept"). We identify three tonic determinants of hippocampal theta frequency. (1) Hotter temperatures increase theta frequency, potentially consistent with time intervals being judged as shorter when hot. Initial evidence suggests this occurs via the "theta slope" component. (2) Anxiolytic drugs with widely-different post-synaptic and pre-synaptic primary targets share the effect of reducing the "theta intercept" component, supporting notions of a final common pathway in anxiety reduction involving the hippocampus. (3) Novelty reliably decreases, and familiarity increases, theta frequency, acting upon the "theta slope" component. The reliability of this latter finding, and the special status of novelty for learning, prompts us to propose a Novelty Elicits Slowing of Theta frequency (NEST) hypothesis, involving the following elements: (1) Theta frequency slowing in the hippocampal formation is a generalised response to novelty of different types and modalities; (2) Novelty-elicited theta slowing is a hippocampal-formation-wide adaptive response functioning to accommodate the additional need for learning entailed by novelty; (3) Lengthening the theta cycle enhances associativity; (4) Even part-cycle lengthening may boost associativity; and (5) Artificial theta stimulation aimed at enhancing learning should employ low-end theta frequencies.
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48
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Sherman BE, DuBrow S, Winawer J, Davachi L. Mnemonic Content and Hippocampal Patterns Shape Judgments of Time. Psychol Sci 2023; 34:221-237. [PMID: 36442582 PMCID: PMC10068509 DOI: 10.1177/09567976221129533] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/09/2022] [Indexed: 11/30/2022] Open
Abstract
Our experience of time can feel dilated or compressed, rather than reflecting true "clock time." Although many contextual factors influence the subjective perception of time, it is unclear how memory accessibility plays a role in constructing our experience of and memory for time. Here, we used a combination of behavioral and functional MRI measures in healthy young adults (N = 147) to ask the question of how memory is incorporated into temporal duration judgments. Behaviorally, we found that event boundaries, which have been shown to disrupt ongoing memory integration processes, result in the temporal compression of duration judgments. Additionally, using a multivoxel pattern similarity analysis of functional MRI data, we found that greater temporal pattern change in the left hippocampus within individual trials was associated with longer duration judgments. Together, these data suggest that mnemonic processes play a role in constructing representations of time.
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Affiliation(s)
| | | | - Jonathan Winawer
- Department of Psychology and Center for
Neural Science, New York University
| | - Lila Davachi
- Department of Psychology, Columbia
University
- Department of Clinical Research, Nathan
Kline Institute for Psychiatric Research
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49
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Omer DB, Las L, Ulanovsky N. Contextual and pure time coding for self and other in the hippocampus. Nat Neurosci 2023; 26:285-294. [PMID: 36585486 DOI: 10.1038/s41593-022-01226-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 10/31/2022] [Indexed: 12/31/2022]
Abstract
Navigation and episodic memory depend critically on representing temporal sequences. Hippocampal 'time cells' form temporal sequences, but it is unknown whether they represent context-dependent experience or time per se. Here we report on time cells in bat hippocampal area CA1, which, surprisingly, formed two distinct populations. One population of time cells generated different temporal sequences when the bat hung at different locations, thus conjunctively encoding spatial context and time-'contextual time cells'. A second population exhibited similar preferred times across different spatial contexts, thus purely encoding elapsed time. When examining neural responses after the landing moment of another bat, in a social imitation task, we found time cells that encoded temporal sequences aligned to the other's landing. We propose that these diverse time codes may support the perception of interval timing, episodic memory and temporal coordination between self and others.
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Affiliation(s)
- David B Omer
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Jerusalem, Israel.
| | - Liora Las
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Nachum Ulanovsky
- Department of Brain Sciences, Weizmann Institute of Science, Rehovot, Israel.
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50
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Teghil A, Bonavita A, Procida F, Giove F, Boccia M. Intrinsic hippocampal connectivity is associated with individual differences in retrospective duration processing. Brain Struct Funct 2023; 228:687-695. [PMID: 36695891 PMCID: PMC9944733 DOI: 10.1007/s00429-023-02612-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 01/13/2023] [Indexed: 01/26/2023]
Abstract
The estimation of incidentally encoded durations of time intervals (retrospective duration processing) is thought to rely on the retrieval of contextual information associated with a sequence of events, automatically encoded in medial temporal lobe regions. "Time cells" have been described in the hippocampus (HC), encoding the temporal progression of events and their duration. However, whether the HC supports explicit retrospective duration judgments in humans, and which neural dynamics are involved, is still poorly understood. Here we used resting-state fMRI to test the relation between variations in intrinsic connectivity patterns of the HC, and individual differences in retrospective duration processing, assessed using a novel task involving the presentation of ecological stimuli. Results showed that retrospective duration discrimination performance predicted variations in the intrinsic connectivity of the bilateral HC with the right precentral gyrus; follow-up exploratory analyses suggested a role of the CA1 and CA4/DG subfields in driving the observed pattern. Findings provide insights on neural networks associated with implicit processing of durations in the second range.
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Affiliation(s)
- Alice Teghil
- Department of Psychology, "Sapienza" University of Rome, Via dei Marsi 78, 00185, Rome, Italy. .,Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy.
| | - Alessia Bonavita
- Department of Psychology, “Sapienza” University of Rome, Via dei Marsi 78, 00185 Rome, Italy ,Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy ,PhD Program in Behavioral Neuroscience, Sapienza University of Rome, Rome, Italy
| | - Federica Procida
- Department of Psychology, “Sapienza” University of Rome, Via dei Marsi 78, 00185 Rome, Italy
| | - Federico Giove
- Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy ,MARBILab, Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, 00184 Rome, Italy
| | - Maddalena Boccia
- Department of Psychology, “Sapienza” University of Rome, Via dei Marsi 78, 00185 Rome, Italy ,Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy
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