1
|
Tallman CW, Luo Z, Smith CN. Human brain activity and functional connectivity associated with verbal long-term memory consolidation across 1 month. Front Hum Neurosci 2024; 18:1342552. [PMID: 38450223 PMCID: PMC10915245 DOI: 10.3389/fnhum.2024.1342552] [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: 11/22/2023] [Accepted: 01/22/2024] [Indexed: 03/08/2024] Open
Abstract
Introduction Declarative memories are initially dependent on the hippocampus and become stabilized through the neural reorganization of connections between the medial temporal lobe and neocortex. The exact time-course of these neural changes is not well established, although time-dependent changes in retrieval-related brain function can be detected across relatively short time periods in humans (e.g., hours to months). Methods In a study involving older adults with normal cognition (N = 24), we investigated changes in brain activity and functional connectivity associated with the long-term memory consolidation of verbal material over one month. Participants studied fact-like, three-word sentences at 1-month, 1-week, 1-day, and 1-hour intervals before a recognition memory test inside an MRI scanner. Old/new recognition with confidence ratings and response times were recorded. We examined whole-brain changes in retrieval-related brain activity, as well as functional connectivity of the hippocampus and ventromedial prefrontal cortex (vmPFC), as memories aged from 1 hour to 1 month. Secondary analyses minimized the effect of confounding factors affected by memory age (i.e., changes in confidence and response time or re-encoding of targets). Results Memory accuracy, confidence ratings, and response times changed with memory age. A memory age network was identified where retrieval-related brain activity in cortical regions increased or decreased as a function of memory age. Hippocampal brain activity in an anatomical region of interest decreased with memory age. Importantly, these changes in retrieval-related activity were not confounded with changes in activity related to concomitant changes in behavior or encoding. Exploratory analyses of vmPFC functional connectivity as a function of memory age revealed increased connectivity with the posterior parietal cortex, as well as with the vmPFC itself. In contrast, hippocampal functional connectivity with the vmPFC and orbitofrontal cortex decreased with memory age. Discussion The observed changes in retrieval-related brain activity and functional connectivity align with the predictions of standard systems consolidation theory. These results suggest that processes consistent with long-term memory consolidation can be identified over short time periods using fMRI, particularly for verbal material.
Collapse
Affiliation(s)
- Catherine W. Tallman
- Department of Psychology, University of California, San Diego, San Diego, CA, United States
- Veterans Affairs San Diego Healthcare System, Department of Research Service, San Diego, CA, United States
| | - Zhishang Luo
- Veterans Affairs San Diego Healthcare System, Department of Research Service, San Diego, CA, United States
- Halıcıoğlu Data Science Institute, University of California, San Diego, San Diego, CA, United States
| | - Christine N. Smith
- Veterans Affairs San Diego Healthcare System, Department of Research Service, San Diego, CA, United States
- Department of Psychiatry, University of California, San Diego, San Diego, CA, United States
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States
| |
Collapse
|
2
|
Tambini A, Miller J, Ehlert L, Kiyonaga A, D’Esposito M. Structured memory representations develop at multiple time scales in hippocampal-cortical networks. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.06.535935. [PMID: 37066263 PMCID: PMC10104124 DOI: 10.1101/2023.04.06.535935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Influential views of systems memory consolidation posit that the hippocampus rapidly forms representations of specific events, while neocortical networks extract regularities across events, forming the basis of schemas and semantic knowledge. Neocortical extraction of schematic memory representations is thought to occur on a protracted timescale of months, especially for information that is unrelated to prior knowledge. However, this theorized evolution of memory representations across extended timescales, and differences in the temporal dynamics of consolidation across brain regions, lack reliable empirical support. To examine the temporal dynamics of memory representations, we repeatedly exposed human participants to structured information via sequences of fractals, while undergoing longitudinal fMRI for three months. Sequence-specific activation patterns emerged in the hippocampus during the first 1-2 weeks of learning, followed one week later by high-level visual cortex, and subsequently the medial prefrontal and parietal cortices. Schematic, sequence-general representations emerged in the prefrontal cortex after 3 weeks of learning, followed by the medial temporal lobe and anterior temporal cortex. Moreover, hippocampal and most neocortical representations showed sustained rather than time-limited dynamics, suggesting that representations tend to persist across learning. These results show that specific hippocampal representations emerge early, followed by both specific and schematic representations at a gradient of timescales across hippocampal-cortical networks as learning unfolds. Thus, memory representations do not exist only in specific brain regions at a given point in time, but are simultaneously present at multiple levels of abstraction across hippocampal-cortical networks.
Collapse
Affiliation(s)
- Arielle Tambini
- Center for Biomedical Imaging and Neuromodulation, Nathan Kline Institute for Psychiatric Research, Orangeburg, NY
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY
| | - Jacob Miller
- Wu Tsai Institute, Department of Psychiatry, Yale University, New Haven, CT
| | - Luke Ehlert
- Department of Neurobiology and Behavior, University of California. Irvine, CA
| | - Anastasia Kiyonaga
- Department of Cognitive Science, University of California, San Diego, CA
| | - Mark D’Esposito
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA
- Department of Psychology, University of California, Berkeley, CA
| |
Collapse
|
3
|
Multiple traces and altered signal-to-noise in systems consolidation: Evidence from the 7T fMRI Natural Scenes Dataset. Proc Natl Acad Sci U S A 2022; 119:e2123426119. [PMID: 36279446 PMCID: PMC9636924 DOI: 10.1073/pnas.2123426119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
How do the neural correlates of recognition change over time? We study natural scene image recognition spanning a year with 7-Tesla functional magnetic resonance imaging (fMRI) of the human brain. We find that the medial temporal lobe (MTL) contribution to recognition persists over 200 d, supporting multiple-trace theory and contradicting a trace transfer (from MTL to cortex) point of view. We then test the hypothesis that the signal-to-noise ratio of traces increases over time, presumably a consequence of synaptic “desaturation” in the weeks following learning. The fMRI trace signature associates with the rate of removal of competing traces and reflects a time-related enhancement of image-feature selectivity. We conclude that multiple MTL traces and improved signal-to-noise may underlie systems-level memory consolidation. The brain mechanisms of memory consolidation remain elusive. Here, we examine blood-oxygen-level-dependent (BOLD) correlates of image recognition through the scope of multiple influential systems consolidation theories. We utilize the longitudinal Natural Scenes Dataset, a 7-Tesla functional magnetic resonance imaging human study in which ∼135,000 trials of image recognition were conducted over the span of a year among eight subjects. We find that early- and late-stage image recognition associates with both medial temporal lobe (MTL) and visual cortex when evaluating regional activations and a multivariate classifier. Supporting multiple-trace theory (MTT), parts of the MTL activation time course show remarkable fit to a 20-y-old MTT time-dynamical model predicting early trace intensity increases and slight subsequent interference (R2 > 0.90). These findings contrast a simplistic, yet common, view that memory traces are transferred from MTL to cortex. Next, we test the hypothesis that the MTL trace signature of memory consolidation should also reflect synaptic “desaturation,” as evidenced by an increased signal-to-noise ratio. We find that the magnitude of relative BOLD enhancement among surviving memories is positively linked to the rate of removal (i.e., forgetting) of competing traces. Moreover, an image-feature and time interaction of MTL and visual cortex functional connectivity suggests that consolidation mechanisms improve the specificity of a distributed trace. These neurobiological effects do not replicate on a shorter timescale (within a session), implicating a prolonged, offline process. While recognition can potentially involve cognitive processes outside of memory retrieval (e.g., re-encoding), our work largely favors MTT and desaturation as perhaps complementary consolidative memory mechanisms.
Collapse
|
4
|
Prior fear learning enables the rapid assimilation of new fear memories directly into cortical networks. PLoS Biol 2022; 20:e3001789. [PMID: 36178983 PMCID: PMC9555644 DOI: 10.1371/journal.pbio.3001789] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 10/12/2022] [Accepted: 08/08/2022] [Indexed: 11/20/2022] Open
Abstract
Long-term memory formation involves the reorganization of brain circuits, termed system consolidation. Whether and how a prior fear experience influences system consolidation of new memories is poorly understood. In rats, we found that prior auditory fear learning allows the secondary auditory cortex to immediately encode new auditory memories, with these new memories purely requiring the activation of cellular mechanisms of synaptic consolidation within secondary auditory cortex. Similar results were obtained in the anterior cingulate cortex for contextual fear memories. Moreover, prior learning enabled connections from these cortices to the basolateral amygdala (BLA) to support recent memory retention. We propose that the reorganization of circuits that characterizes system consolidation occurs only in the first instance that an event is learned, subsequently allowing the immediate assimilation of new analogous events in final storage sites.
Collapse
|
5
|
Gobbo F, Mitchell-Heggs R, Tse D. Changes in brain activity and connectivity as memories age. Cogn Neurosci 2022; 13:141-143. [PMID: 35695056 DOI: 10.1080/17588928.2022.2076076] [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: 04/21/2022] [Indexed: 11/03/2022]
Abstract
The role of the hippocampus during memory consolidation is not fully understood, with human and animal experiments producing conflicting conclusions. In particular, human lesion studies tend to indicate that the hippocampus gradually becomes independent from memory over years, whilst animal studies suggest that this can happen over days. Tallman et al. (this issue) used fMRI to investigate activity and functional connectivity in the brain at four different time points following memory encoding. Their findings include a decrease in functional connectivity between the hippocampus and parahippocampal cortex with memory age, which supports the system consolidation theory, but also argues against the reduced involvement of the hippocampus over time. This study sheds new light on the neurobiology of memory.
Collapse
Affiliation(s)
- Francesco Gobbo
- Centre for Discover Brain Sciences, Deanery of Biomedical Sciences, University of Edinburgh, UK
| | - Rufus Mitchell-Heggs
- Centre for Discover Brain Sciences, Deanery of Biomedical Sciences, University of Edinburgh, UK
- Department of Bioengineering and Centre for Neurotechnology, Imperial College London, London, UK
| | - Dorothy Tse
- Department of Psychology, Edge Hill University, Ormskirk, UK
| |
Collapse
|
6
|
Tallman CW, Clark RE, Smith CN. A way forward for design and analysis of neuroimaging studies of memory consolidation. Cogn Neurosci 2022; 13:158-164. [PMID: 36112016 PMCID: PMC9673460 DOI: 10.1080/17588928.2022.2121274] [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: 08/26/2022] [Indexed: 11/03/2022]
Abstract
Several novel ideas and suggestions were made in response to our discussion paper (Tallman et al., this issue). Careful consideration of the content and context of memory while accounting for the neuroanatomy and functional specialization of the hippocampus may reveal more consistent patterns in fMRI studies of memory consolidation. Below we address these ideas as well as issues that arise when interpreting the fMRI signal in memory consolidation studies. In addition, we describe new analyses suggested by the commentators that clarify our findings with respect to current theories.
Collapse
Affiliation(s)
- Catherine W. Tallman
- Department of Psychology, UCSD, San Diego, CA, USA
- Veterans Affairs San Diego Healthcare System, Research Service, San Diego, CA, USA
| | - Robert E. Clark
- Department of Psychiatry, UCSD, San Diego, CA, USA
- Center for the Neurobiology of Learning and Memory, UCI, Irvine, CA, USA
| | - Christine N. Smith
- Veterans Affairs San Diego Healthcare System, Research Service, San Diego, CA, USA
- Department of Psychiatry, UCSD, San Diego, CA, USA
- Center for the Neurobiology of Learning and Memory, UCI, Irvine, CA, USA
| |
Collapse
|
7
|
The Distinctive Pattern of Declarative Memories in Autism Spectrum Disorder: Further Evidence of Episodic Memory Constraints. J Autism Dev Disord 2022:10.1007/s10803-022-05579-y. [PMID: 35616819 DOI: 10.1007/s10803-022-05579-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/16/2022] [Indexed: 10/18/2022]
Abstract
This study examines declarative memory retrieval in ASD depending on the availability and access to stored conceptual knowledge. Fifteen autistic participants and a matched control group of 18 typically-developed (TD) volunteers completed a Remember-Know paradigm manipulated by encoding-type (categorical, perceptual) and item-typicality (high-typical, low-typical). The autistic group showed worse and slower recognition and less recollection but equivalent familiarity-based memories compared to TDs. Notably, low-typical items did not improve their memories as they did for TDs, likely due to difficulties in matching low-fit information to the stored schema. Results suggest that memory decline in ASD may derive from the episodic system and its dynamics with the semantic system. These findings may inform interventional strategies for enhancing learning abilities in ASD.
Collapse
|
8
|
Gellersen HM, Simons JS. The devil may be in the details: The need for contextually rich stimuli in memory consolidation research. Cogn Neurosci 2022; 13:139-140. [PMID: 35587688 DOI: 10.1080/17588928.2022.2076077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Systems consolidation theory (SCT) proposes that the hippocampus is not required for retrieval of remote memories. In this issue, Tallman and colleagues observe reduced hippocampal-cortical connectivity in recognition memory as a function of memory age, which they interpret as supportive of SCT. We suggest that research seeking to inform this debate would benefit from using perceptually rich stimuli that promote the recollection of high-fidelity contextual details. Tests of recognition alone may not be capable of discerning whether reductions in hippocampal activity or connectivity reflect remote memory retrieval independent of hippocampus (consistent with SCT) or a time-dependent decline in episodic detail.
Collapse
Affiliation(s)
| | - Jon S Simons
- Department of Psychology, University of Cambridge, Cambridge, UK
| |
Collapse
|
9
|
Examining the relationship between working memory consolidation and long-term consolidation. Psychon Bull Rev 2022; 29:1625-1648. [PMID: 35357669 DOI: 10.3758/s13423-022-02084-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/04/2022] [Indexed: 11/08/2022]
Abstract
An emerging area of research is focused on the relationship between working memory and long-term memory and the likely overlap between these processes. Of particular interest is how some information first maintained in working memory is retained for longer periods and eventually preserved in long-term memory. The process of stabilizing transient memory representations for lasting retention is referred to as consolidation in both the working memory and long-term memory literature, although these have historically been viewed as independent constructs. The present review aims to investigate the relationship between working memory consolidation and long-term memory consolidation, which both have rich, but distinct, histories. This review provides an overview of the proposed models and neural mechanisms of both types of consolidation, as well as clinical findings related to consolidation and potential approaches for the manipulation of consolidation. Finally, two hypotheses are proposed to explain the relationship between working memory consolidation and long-term memory consolidation.
Collapse
|
10
|
Tallman CW, Clark RE, Smith CN. Human brain activity and functional connectivity as memories age from one hour to one month. Cogn Neurosci 2022; 13:115-133. [DOI: 10.1080/17588928.2021.2021164] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Catherine W. Tallman
- Department of Psychology, UCSD, San Diego, CA, USA
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
| | - Robert E. Clark
- Department of Psychiatry, UCSD, San Diego, CA, USA
- Center for the Neurobiology of Learning and Memory, UCI, San Diego, CA, USA
| | - Christine N. Smith
- Research Service, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
- Department of Psychiatry, UCSD, San Diego, CA, USA
- Center for the Neurobiology of Learning and Memory, UCI, San Diego, CA, USA
| |
Collapse
|
11
|
Hu Z, Zhou W, Yang J. The effect of encoding task on the forgetting of object gist and details. PLoS One 2021; 16:e0255474. [PMID: 34550983 PMCID: PMC8457468 DOI: 10.1371/journal.pone.0255474] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 07/18/2021] [Indexed: 11/19/2022] Open
Abstract
One important feature of episodic memory is that it contains fine-grained and vividly recollected details. How to improve and maintain detailed information over time has been one of the central issues in memory research. Previous studies have inconsistent findings on whether detailed memory is forgotten more rapidly than gist memory. In this study, we investigated to what extent different encoding tasks modulated forgetting of gist and detailed information. In three experiments, participants were presented pictures of common objects and were asked to name them (Experiment 1), describe the details about them (Experiment 2) or imagine scenes associated with them (Experiment 3). After intervals of 10 minutes, one day, one week and one month, gist and detailed memories of the pictures were tested and assessed using a remember/know/guess judgement. The results showed that after the naming task, gist and detailed memories were forgotten at a similar rate, but after the description and the imagination tasks, detailed memory was forgotten at a slower rate than gist memory. The forgetting rate of gist memory was the slowest after the naming task, while that of detailed memory was the slowest after the description task. In addition, when three experiments were compared, the naming task enhanced the contributions of recollection and familiarity for gist memory, while the description task enhanced the contribution of familiarity for detailed memory. These results reveal the importance of the encoding task in the forgetting of gist and detailed information, and suggest a possible way to maintain perceptual details of objects at longer intervals.
Collapse
Affiliation(s)
- Zhongyu Hu
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
| | - Wenxi Zhou
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
| | - Jiongjiong Yang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- * E-mail:
| |
Collapse
|
12
|
Phasuk S, Jasmin S, Pairojana T, Chang HK, Liang KC, Liu IY. Lack of the peroxiredoxin 6 gene causes impaired spatial memory and abnormal synaptic plasticity. Mol Brain 2021; 14:72. [PMID: 33874992 PMCID: PMC8056661 DOI: 10.1186/s13041-021-00779-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/06/2021] [Indexed: 02/07/2023] Open
Abstract
Peroxiredoxin 6 (PRDX6) is expressed dominantly in the astrocytes and exerts either neuroprotective or neurotoxic effects in the brain. Although PRDX6 can modulate several signaling cascades involving cognitive functions, its physiological role in spatial memory has not been investigated yet. This study aims to explore the function of the Prdx6 gene in spatial memory formation and synaptic plasticity. We first tested Prdx6-/- mice on a Morris water maze task and found that their memory performance was defective, along with reduced long-term potentiation (LTP) in CA3-CA1 hippocampal synapses recorded from hippocampal sections of home-caged mice. Surprisingly, after the probe test, these knockout mice exhibited elevated hippocampal LTP, higher phosphorylated ERK1/2 level, and decreased reactive astrocyte markers. We further reduced ERK1/2 phosphorylation by administering MEK inhibitor, U0126, into Prdx6-/- mice before the probe test, which reversed their spatial memory deficit. This study is the first one to report the role of PRDX6 in spatial memory and synaptic plasticity. Our results revealed that PRDX6 is necessary for maintaining spatial memory by modulating ERK1/2 phosphorylation and astrocyte activation.
Collapse
Affiliation(s)
- Sarayut Phasuk
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sureka Jasmin
- Department of Molecular Biology and Human Genetics, Tzu Chi University, Hualien, Taiwan
| | - Tanita Pairojana
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
| | - Hsueh-Kai Chang
- Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Kai-Chi Liang
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan
| | - Ingrid Y Liu
- Institute of Medical Sciences, Tzu Chi University, Hualien, Taiwan.
| |
Collapse
|
13
|
Goode TD, Tanaka KZ, Sahay A, McHugh TJ. An Integrated Index: Engrams, Place Cells, and Hippocampal Memory. Neuron 2020; 107:805-820. [PMID: 32763146 PMCID: PMC7486247 DOI: 10.1016/j.neuron.2020.07.011] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 06/17/2020] [Accepted: 07/13/2020] [Indexed: 01/10/2023]
Abstract
The hippocampus and its extended network contribute to encoding and recall of episodic experiences. Drawing from recent anatomical, physiological, and behavioral studies, we propose that hippocampal engrams function as indices to mediate memory recall. We broaden this idea to discuss potential relationships between engrams and hippocampal place cells, as well as the molecular, cellular, physiological, and circuit determinants of engrams that permit flexible routing of information to intra- and extrahippocampal circuits for reinstatement, a feature critical to memory indexing. Incorporating indexing into frameworks of memory function opens new avenues of study and even therapies for hippocampal dysfunction.
Collapse
Affiliation(s)
- Travis D Goode
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Kazumasa Z Tanaka
- Memory Research Unit, Okinawa Institute of Science and Technology Graduate University, Onna-son, Kunigami-gun, Okinawa, Japan
| | - Amar Sahay
- Center for Regenerative Medicine, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114 USA; Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.
| | - Thomas J McHugh
- Laboratory for Circuit and Behavioral Physiology, RIKEN Center for Brain Science, Wakoshi, Saitama, Japan.
| |
Collapse
|
14
|
Romanella SM, Roe D, Paciorek R, Cappon D, Ruffini G, Menardi A, Rossi A, Rossi S, Santarnecchi E. Sleep, Noninvasive Brain Stimulation, and the Aging Brain: Challenges and Opportunities. Ageing Res Rev 2020; 61:101067. [PMID: 32380212 PMCID: PMC8363192 DOI: 10.1016/j.arr.2020.101067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/26/2020] [Accepted: 04/04/2020] [Indexed: 02/06/2023]
Abstract
As we age, sleep patterns undergo severe modifications of their micro and macrostructure, with an overall lighter and more fragmented sleep structure. In general, interventions targeting sleep represent an excellent opportunity not only to maintain life quality in the healthy aging population, but also to enhance cognitive performance and, when pathology arises, to potentially prevent/slow down conversion from e.g. Mild Cognitive Impairment (MCI) to Alzheimer's Disease (AD). Sleep abnormalities are, in fact, one of the earliest recognizable biomarkers of dementia, being also partially responsible for a cascade of cortical events that worsen dementia pathophysiology, including impaired clearance systems leading to build-up of extracellular amyloid-β (Aβ) peptide and intracellular hyperphosphorylated tau proteins. In this context, Noninvasive Brain Stimulation (NiBS) techniques, such as transcranial electrical stimulation (tES) and transcranial magnetic stimulation (TMS), may help investigate the neural substrates of sleep, identify sleep-related pathology biomarkers, and ultimately help patients and healthy elderly individuals to restore sleep quality and cognitive performance. However, brain stimulation applications during sleep have so far not been fully investigated in healthy elderly cohorts, nor tested in AD patients or other related dementias. The manuscript discusses the role of sleep in normal and pathological aging, reviewing available evidence of NiBS applications during both wakefulness and sleep in healthy elderly individuals as well as in MCI/AD patients. Rationale and details for potential future brain stimulation studies targeting sleep alterations in the aging brain are discussed, including enhancement of cognitive performance, overall quality of life as well as protein clearance.
Collapse
Affiliation(s)
- Sara M Romanella
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy
| | - Daniel Roe
- Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Rachel Paciorek
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - Davide Cappon
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | | | - Arianna Menardi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Padova Neuroscience Center, Department of Neuroscience, University of Padova, Padova, Italy
| | - Alessandro Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - Simone Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy; Siena Robotics and Systems Lab (SIRS-Lab), Engineering and Mathematics Department, University of Siena, Siena, Italy
| | - Emiliano Santarnecchi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
15
|
Li C, Yang J. Role of the hippocampus in the spacing effect during memory retrieval. Hippocampus 2020; 30:703-714. [PMID: 32022387 DOI: 10.1002/hipo.23193] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 12/19/2019] [Accepted: 01/05/2020] [Indexed: 11/11/2022]
Abstract
It is well known that distributed learning (DL) leads to improved memory performance compared with massed learning (ML) (i.e., spacing effect). However, the extent to which the hippocampus is involved in the spacing effect at shorter and longer retention intervals remains unclear. To address this issue, two groups of participants were asked to encode face-scene pairs at 20-min, 1-day, and 1-month intervals before they were scanned using fMRI during an associative recognition task. The pairs were repeated six times in either a massed (i.e., six times in 1 day) or a distributed (i.e., six times over 3 days, twice per day) manner. The results showed that compared with that in the ML group, the activation of the left hippocampus was stronger in the DL group when the participants retrieved old pairs correctly and rejected new pairs correctly at different retention intervals. In addition, the posterior hippocampus was more strongly activated when the new associations were rejected correctly after DL than ML, especially at the 1-month interval. Hence, our results provide evidence that the hippocampus is involved in better memory performance after DL compared to ML at both shorter and longer retention intervals.
Collapse
Affiliation(s)
- Cuihong Li
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
| | - Jiongjiong Yang
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
| |
Collapse
|
16
|
Du X, Zhan L, Chen G, Guo D, Li C, Moscovitch M, Yang J. Differential activation of the medial temporal lobe during item and associative memory across time. Neuropsychologia 2019; 135:107252. [PMID: 31698009 DOI: 10.1016/j.neuropsychologia.2019.107252] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 10/26/2019] [Accepted: 11/01/2019] [Indexed: 11/26/2022]
Abstract
Studies have shown that the hippocampus plays a crucial role in associative memory. One central issue is whether the involvement of the hippocampus in associative memory remains stable or declines with the passage of time. In the majority of studies, memory performance declines with delay, confounding attempts at interpreting differences in hippocampal activation over time. To address this issue, we tried to equate behavioral performance as much as possible across time for memory of items and associations separately. After encoding words and word pairs, participants were tested for item and associative memories at four time intervals: 20-min, 1-day, 1-week, and 1-month. The results revealed that MTL activation differed over time for associative and item memories. For associative memory, the activation of the anterior hippocampus decreased from 20-min to 1-day then remained stable, whereas in the posterior hippocampus, the activation was comparable for different time intervals when old pairs were correctly retrieved. The hippocampal activation also remained stable when recombined pairs were correctly rejected. As this condition controls for familiarity of the individual items, correct performance depends only on associative memory. For item memory, hippocampal activation declined progressively from 20-min to 1-week and remained stable afterwards. By contrast, the activation in the perirhinal/entorhinal cortex increased over time irrespective of item and associative memories. Drawing on Tulving's distinction between recollection and familiarity, we interpret this pattern of results in accordance with Trace Transformation Theory, which states that as memories are transformed with time and experience, the neural structures mediating item and associative memories will vary according to the underlying representations to which the memories have been transformed.
Collapse
Affiliation(s)
- Xiaoya Du
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, PR China
| | - Lexia Zhan
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, PR China
| | - Gang Chen
- Scientific and Statistical Computing Core, NIMH/NIH, Bethesda, MD, USA
| | - Dingrong Guo
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, PR China
| | - Cuihong Li
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, PR China
| | - Morris Moscovitch
- Department of Psychology, University of Toronto, Toronto, Canada; Rotman Research Institute, Baycrest Centre, Toronto, Canada.
| | - Jiongjiong Yang
- School of Psychological and Cognitive Sciences and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, PR China.
| |
Collapse
|
17
|
Larzabal C, Bacon-Macé N, Muratot S, Thorpe SJ. Tracking Your Mind's Eye during Recollection: Decoding the Long-Term Recall of Short Audiovisual Clips. J Cogn Neurosci 2019; 32:50-64. [PMID: 31560269 DOI: 10.1162/jocn_a_01468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Unlike familiarity, recollection involves the ability to reconstruct mentally previous events that results in a strong sense of reliving. According to the reinstatement hypothesis, this specific feature emerges from the reactivation of cortical patterns involved during information exposure. Over time, the retrieval of specific details becomes more difficult, and memories become increasingly supported by familiarity judgments. The multiple trace theory (MTT) explains the gradual loss of episodic details by a transformation in the memory representation, a view that is not shared by the standard consolidation model. In this study, we tested the MTT in light of the reinstatement hypothesis. The temporal dynamics of mental imagery from long-term memory were investigated and tracked over the passage of time. Participant EEG activity was recorded during the recall of short audiovisual clips that had been watched 3 weeks, 1 day, or a few hours beforehand. The recall of the audiovisual clips was assessed using a Remember/Know/New procedure, and snapshots of clips were used as recall cues. The decoding matrices obtained from the multivariate pattern analyses revealed sustained patterns that occurred at long latencies (>500 msec poststimulus onset) that faded away over the retention intervals and that emerged from the same neural processes. Overall, our data provide further evidence toward the MTT and give new insights into the exploration of our "mind's eye."
Collapse
|
18
|
Yonelinas AP, Ranganath C, Ekstrom AD, Wiltgen BJ. A contextual binding theory of episodic memory: systems consolidation reconsidered. Nat Rev Neurosci 2019; 20:364-375. [PMID: 30872808 PMCID: PMC7233541 DOI: 10.1038/s41583-019-0150-4] [Citation(s) in RCA: 201] [Impact Index Per Article: 40.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Episodic memory reflects the ability to recollect the temporal and spatial context of past experiences. Episodic memories depend on the hippocampus but have been proposed to undergo rapid forgetting unless consolidated during offline periods such as sleep to neocortical areas for long-term storage. Here, we propose an alternative to this standard systems consolidation theory (SSCT) - a contextual binding account - in which the hippocampus binds item-related and context-related information. We compare these accounts in light of behavioural, lesion, neuroimaging and sleep studies of episodic memory and contend that forgetting is largely due to contextual interference, episodic memory remains dependent on the hippocampus across time, contextual drift produces post-encoding activity and sleep benefits memory by reducing contextual interference.
Collapse
Affiliation(s)
| | - Charan Ranganath
- Center for Neuroscience, University of California, Davis, CA, USA
| | - Arne D Ekstrom
- Department of Psychology, University of Arizona, Tucson, AZ, USA
| | - Brian J Wiltgen
- Center for Neuroscience, University of California, Davis, CA, USA
| |
Collapse
|
19
|
Clewett D, DuBrow S, Davachi L. Transcending time in the brain: How event memories are constructed from experience. Hippocampus 2019; 29:162-183. [PMID: 30734391 PMCID: PMC6629464 DOI: 10.1002/hipo.23074] [Citation(s) in RCA: 89] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 01/07/2019] [Accepted: 01/09/2019] [Indexed: 11/06/2022]
Abstract
Our daily lives unfold continuously, yet when we reflect on the past, we remember those experiences as distinct and cohesive events. To understand this phenomenon, early investigations focused on how and when individuals perceive natural breakpoints, or boundaries, in ongoing experience. More recent research has examined how these boundaries modulate brain mechanisms that support long-term episodic memory. This work has revealed that a complex interplay between hippocampus and prefrontal cortex promotes the integration and separation of sequential information to help organize our experiences into mnemonic events. Here, we discuss how both temporal stability and change in one's thoughts, goals, and surroundings may provide scaffolding for these neural processes to link and separate memories across time. When learning novel or familiar sequences of information, dynamic hippocampal processes may work both independently from and in concert with other brain regions to bind sequential representations together in memory. The formation and storage of discrete episodic memories may occur both proactively as an experience unfolds. They may also occur retroactively, either during a context shift or when reactivation mechanisms bring the past into the present to allow integration. We also describe conditions and factors that shape the construction and integration of event memories across different timescales. Together these findings shed new light on how the brain transcends time to transform everyday experiences into meaningful memory representations.
Collapse
Affiliation(s)
| | - Sarah DuBrow
- Neuroscience Institute, Princeton University, USA
| | - Lila Davachi
- Department of Psychology, Columbia University, USA
- Nathan Kline Institute, Orangeburg, New York, USA
| |
Collapse
|
20
|
Züst MA, Ruch S, Wiest R, Henke K. Implicit Vocabulary Learning during Sleep Is Bound to Slow-Wave Peaks. Curr Biol 2019; 29:541-553.e7. [DOI: 10.1016/j.cub.2018.12.038] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 09/25/2018] [Accepted: 12/20/2018] [Indexed: 01/13/2023]
|
21
|
Barry DN, Chadwick MJ, Maguire EA. Nonmonotonic recruitment of ventromedial prefrontal cortex during remote memory recall. PLoS Biol 2018; 16:e2005479. [PMID: 29965966 PMCID: PMC6044544 DOI: 10.1371/journal.pbio.2005479] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 07/13/2018] [Accepted: 06/18/2018] [Indexed: 11/25/2022] Open
Abstract
Systems-level consolidation refers to the time-dependent reorganisation of memory traces in the neocortex, a process in which the ventromedial prefrontal cortex (vmPFC) has been implicated. Capturing the precise temporal evolution of this crucial process in humans has long proved elusive. Here, we used multivariate methods and a longitudinal functional magnetic resonance imaging (fMRI) design to detect, with high granularity, the extent to which autobiographical memories of different ages were represented in vmPFC and how this changed over time. We observed an unexpected time course of vmPFC recruitment during retrieval, rising and falling around an initial peak of 8–12 months, before reengaging for older 2- and 5-year-old memories. This pattern was replicated in 2 independent sets of memories. Moreover, it was further replicated in a follow-up study 8 months later with the same participants and memories, for which the individual memory representations had undergone their hypothesised strengthening or weakening over time. We conclude that the temporal engagement of vmPFC in memory retrieval seems to be nonmonotonic, revealing a complex relationship between systems-level consolidation and prefrontal cortex recruitment that is unaccounted for by current theories. Our past experiences are captured in autobiographical memories that allow us to recollect events from our lives long after they originally occurred. A part of the brain’s frontal lobe, called the ventromedial prefrontal cortex (vmPFC), is known to be important for supporting autobiographical memories, especially as memories become more remote. The precise temporal profile of the vmPFC’s involvement is unclear, yet this information is vital if we are to understand how memories change over time and the mechanisms involved. In this study, we sought to establish the time course of vmPFC engagement in the recollection of autobiographical memories while participants recalled memories of different ages during functional magnetic resonance imaging (fMRI). Using a method that detects the brain activity patterns associated with individual memories, we found that memory-specific neural patterns in vmPFC became more distinct over the first few months after a memory was formed, but then this initial involvement of vmPFC subsided after 1 year. However, more remote memories (2 years and older) appeared to reengage vmPFC once again. This temporal profile is difficult to accommodate within any single existing theory. Consequently, our results provoke a rethink about how memories evolve over time and the role played by the vmPFC.
Collapse
Affiliation(s)
- Daniel N. Barry
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
| | - Martin J. Chadwick
- Institute of Behavioural Neuroscience, Department of Experimental Psychology, Division of Psychology and Language Sciences, University College London, London, United Kingdom
| | - Eleanor A. Maguire
- Wellcome Centre for Human Neuroimaging, Institute of Neurology, University College London, London, United Kingdom
- * E-mail:
| |
Collapse
|
22
|
Goodroe SC, Starnes J, Brown TI. The Complex Nature of Hippocampal-Striatal Interactions in Spatial Navigation. Front Hum Neurosci 2018; 12:250. [PMID: 29977198 PMCID: PMC6021746 DOI: 10.3389/fnhum.2018.00250] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/30/2018] [Indexed: 12/15/2022] Open
Abstract
Decades of research have established the importance of the hippocampus for episodic and spatial memory. In spatial navigation tasks, the role of the hippocampus has been classically juxtaposed with the role of the dorsal striatum, the latter of which has been characterized as a system important for implementing stimulus-response and action-outcome associations. In many neuroimaging paradigms, this has been explored through contrasting way finding and route-following behavior. The distinction between the contributions of the hippocampus and striatum to spatial navigation has been supported by extensive literature. Convergent research has also underscored the fact that these different memory systems can interact in dynamic ways and contribute to a broad range of navigational scenarios. For example, although familiar routes may often be navigable based on stimulus-response associations, hippocampal episodic memory mechanisms can also contribute to egocentric route-oriented memory, enabling recall of context-dependent sequences of landmarks or the actions to be made at decision points. Additionally, the literature has stressed the importance of subdividing the striatum into functional gradients—with more ventral and medial components being important for the behavioral expression of hippocampal-dependent spatial memories. More research is needed to reveal how networks involving these regions process and respond to dynamic changes in memory and control demands over the course of navigational events. In this Perspective article, we suggest that a critical direction for navigation research is to further characterize how hippocampal and striatal subdivisions interact in different navigational contexts.
Collapse
Affiliation(s)
- Sarah C Goodroe
- School of Psychology, Georgia Institute of Technology, Atlanta, GA, United States
| | - Jon Starnes
- School of Psychology, Georgia Institute of Technology, Atlanta, GA, United States
| | - Thackery I Brown
- School of Psychology, Georgia Institute of Technology, Atlanta, GA, United States
| |
Collapse
|
23
|
Cornell Kärnekull S, Arshamian A, Nilsson ME, Larsson M. The Effect of Blindness on Long-Term Episodic Memory for Odors and Sounds. Front Psychol 2018; 9:1003. [PMID: 29973898 PMCID: PMC6020764 DOI: 10.3389/fpsyg.2018.01003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 05/30/2018] [Indexed: 12/13/2022] Open
Abstract
We recently showed that compared with sighted, early blind individuals have better episodic memory for environmental sounds, but not odors, after a short retention interval (∼ 8 – 9 min). Few studies have investigated potential effects of blindness on memory across long time frames, such as months or years. Consequently, it was unclear whether compensatory effects may vary as a function of retention interval. In this study, we followed-up participants (N = 57 out of 60) approximately 1 year after the initial testing and retested episodic recognition for environmental sounds and odors, and identification ability. In contrast to our previous findings, the early blind participants (n = 14) performed at a similar level as the late blind (n = 13) and sighted (n = 30) participants for sound recognition. Moreover, the groups had similar recognition performance of odors and identification ability of odors and sounds. These findings suggest that episodic odor memory is unaffected by blindness after both short and long retention intervals. However, the effect of blindness on episodic memory for sounds may vary as a function of retention interval, such that early blind individuals have an advantage over sighted across short but not long time frames. We speculate that the finding of a differential effect of blindness on auditory episodic memory across retention intervals may be related to different memory strategies at initial and follow-up assessments. In conclusion, this study suggests that blindness does not influence auditory or olfactory episodic memory as assessed after a long retention interval.
Collapse
Affiliation(s)
| | - Artin Arshamian
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden.,Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.,Center for Language Studies, Donders Institute for Brain, Cognition and Behaviour, Radboud University, Nijmegen, Netherlands
| | - Mats E Nilsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| | - Maria Larsson
- Gösta Ekman Laboratory, Department of Psychology, Stockholm University, Stockholm, Sweden
| |
Collapse
|
24
|
Tompary A, Davachi L. Consolidation Promotes the Emergence of Representational Overlap in the Hippocampus and Medial Prefrontal Cortex. Neuron 2017; 96:228-241.e5. [PMID: 28957671 DOI: 10.1016/j.neuron.2017.09.005] [Citation(s) in RCA: 118] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 08/10/2017] [Accepted: 09/07/2017] [Indexed: 02/08/2023]
Abstract
Structured knowledge is thought to form, in part, through the extraction and representation of regularities across overlapping experiences. However, little is known about how consolidation processes may transform novel episodic memories to reflect such regularities. In a multi-day fMRI study, participants encoded trial-unique associations that shared features with other trials. Multi-variate pattern analyses were used to measure neural similarity across overlapping and non-overlapping memories during immediate and 1-week retrieval of these associations. We found that neural patterns in the hippocampus and medial prefrontal cortex represented the featural overlap across memories, but only after a week. Furthermore, after a week, the strength of a memory's unique episodic reinstatement during retrieval was inversely related to its representation of overlap, suggesting a trade-off between the integration of related memories and recovery of episodic details. These findings suggest that consolidation-related changes in neural representations support the gradual organization of discrete episodes into structured knowledge.
Collapse
Affiliation(s)
- Alexa Tompary
- Department of Psychology, New York University, New York, NY, 10003, USA
| | - Lila Davachi
- Department of Psychology, New York University, New York, NY, 10003, USA; Center for Neural Science, New York University, New York, NY, 10003, USA.
| |
Collapse
|
25
|
Marchewka A, Wypych M, Moslehi A, Riegel M, Michałowski JM, Jednoróg K. Arousal Rather than Basic Emotions Influence Long-Term Recognition Memory in Humans. Front Behav Neurosci 2016; 10:198. [PMID: 27818626 PMCID: PMC5073153 DOI: 10.3389/fnbeh.2016.00198] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/30/2016] [Indexed: 11/18/2022] Open
Abstract
Emotion can influence various cognitive processes, however its impact on memory has been traditionally studied over relatively short retention periods and in line with dimensional models of affect. The present study aimed to investigate emotional effects on long-term recognition memory according to a combined framework of affective dimensions and basic emotions. Images selected from the Nencki Affective Picture System were rated on the scale of affective dimensions and basic emotions. After 6 months, subjects took part in a surprise recognition test during an fMRI session. The more negative the pictures the better they were remembered, but also the more false recognitions they provoked. Similar effects were found for the arousal dimension. Recognition success was greater for pictures with lower intensity of happiness and with higher intensity of surprise, sadness, fear, and disgust. Consecutive fMRI analyses showed a significant activation for remembered (recognized) vs. forgotten (not recognized) images in anterior cingulate and bilateral anterior insula as well as in bilateral caudate nuclei and right thalamus. Further, arousal was found to be the only subjective rating significantly modulating brain activation. Higher subjective arousal evoked higher activation associated with memory recognition in the right caudate and the left cingulate gyrus. Notably, no significant modulation was observed for other subjective ratings, including basic emotion intensities. These results emphasize the crucial role of arousal for long-term recognition memory and support the hypothesis that the memorized material, over time, becomes stored in a distributed cortical network including the core salience network and basal ganglia.
Collapse
Affiliation(s)
- Artur Marchewka
- Laboratory of Brain Imaging, Neurobiology Centre, Nencki Institute of Experimental Biology of Polish Academy of Sciences Warsaw, Poland
| | - Marek Wypych
- Laboratory of Brain Imaging, Neurobiology Centre, Nencki Institute of Experimental Biology of Polish Academy of Sciences Warsaw, Poland
| | - Abnoos Moslehi
- Laboratory of Brain Imaging, Neurobiology Centre, Nencki Institute of Experimental Biology of Polish Academy of Sciences Warsaw, Poland
| | - Monika Riegel
- Laboratory of Brain Imaging, Neurobiology Centre, Nencki Institute of Experimental Biology of Polish Academy of Sciences Warsaw, Poland
| | | | - Katarzyna Jednoróg
- Laboratory of Psychophysiology, Department of Neurophysiology, Nencki Institute of Experimental Biology of Polish Academy of Sciences Warsaw, Poland
| |
Collapse
|
26
|
Ruch S, Züst MA, Henke K. Subliminal messages exert long-term effects on decision-making. Neurosci Conscious 2016; 2016:niw013. [PMID: 30386634 PMCID: PMC6204644 DOI: 10.1093/nc/niw013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 07/01/2016] [Accepted: 07/22/2016] [Indexed: 01/02/2023] Open
Abstract
Subliminal manipulation is often considered harmless because its effects typically decay within a second. So far, subliminal long-term effects on behavior were only observed in studies which repeatedly presented highly familiar information such as single words. These studies suggest that subliminal messages are only slowly stored and might not be stored at all if they provide novel, unfamiliar information. We speculated that subliminal messages might affect delayed decision-making especially if messages contain several pieces of novel information that must be relationally bound in long-term memory. Relational binding engages the hippocampal memory system, which can rapidly encode and durably store novel relations. Here, we hypothesized that subliminally presented stimulus pairs would be relationally processed influencing the direction of delayed conscious decisions. In experiment 1, subliminal face–occupation pairs affected conscious decisions about the income of these individuals almost half an hour later. In experiment 2, subliminal presentation of vocabulary of a foreign language enabled participants to later decide whether these foreign words are presented with correct or incorrect translations. Subliminal influence did not significantly decay if probed after 25 versus 15 min. This is unprecedented evidence of the longevity and impact of subliminal messages on conscious, rational decision-making.
Collapse
Affiliation(s)
- Simon Ruch
- Department of Psychology, University of Bern, Switzerland and Center for Cognition, Learning and Memory, University of Bern, Switzerland
| | - Marc Alain Züst
- Department of Psychology, University of Bern, Switzerland and Center for Cognition, Learning and Memory, University of Bern, Switzerland
| | - Katharina Henke
- Department of Psychology, University of Bern, Switzerland and Center for Cognition, Learning and Memory, University of Bern, Switzerland
| |
Collapse
|
27
|
Yang J, Zhan L, Wang Y, Du X, Zhou W, Ning X, Sun Q, Moscovitch M. Effects of learning experience on forgetting rates of item and associative memories. Learn Mem 2016; 23:365-78. [PMID: 27317197 PMCID: PMC4918786 DOI: 10.1101/lm.041210.115] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Accepted: 04/22/2016] [Indexed: 12/02/2022]
Abstract
Are associative memories forgotten more quickly than item memories, and does the level of original learning differentially influence forgetting rates? In this study, we addressed these questions by having participants learn single words and word pairs once (Experiment 1), three times (Experiment 2), and six times (Experiment 3) in a massed learning (ML) or a distributed learning (DL) mode. Then they were tested for item and associative recognition separately after four retention intervals: 10 min, 1 d, 1 wk, and 1 mo. The contribution of recollection and familiarity processes were assessed by participants' remember/know judgments. The results showed that for both item and associative memories, across different degrees of learning, recollection decreased significantly and was the main source of forgetting over time, whereas familiarity remained relatively stable over time. Learning multiple times led to slower forgetting at shorter intervals, depending on recollection and familiarity processes. Compared with massed learning, distributed learning (six times) especially benefited associative memory by increasing recollection, leading to slower forgetting at longer intervals. This study highlighted the importance of process contribution and learning experiences in modulating the forgetting rates of item and associative memories. We interpret these results within the framework of a dual factor representational model of forgetting (as noted in a previous study) in which recollection is more prone to decay over time than familiarity.
Collapse
Affiliation(s)
- Jiongjiong Yang
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Lexia Zhan
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Yingying Wang
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Xiaoya Du
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Wenxi Zhou
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Xueling Ning
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Qing Sun
- Department of Psychology and Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing 100080, China
| | - Morris Moscovitch
- Department of Psychology, University of Toronto, Toronto, Ontario M5S 3G3, Canada Rotman Research Institute, Baycrest Centre, Toronto, Ontario M6A 2E1, Canada
| |
Collapse
|
28
|
Malle C, Eustache F, Rauchs G. [The role of sleep in memory consolidation: effects of age and Alzheimer's disease]. Biol Aujourdhui 2016; 209:261-272. [PMID: 26820832 DOI: 10.1051/jbio/2015024] [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: 10/08/2015] [Indexed: 06/05/2023]
Abstract
Sleep favors memory consolidation. Studies conducted in recent years allowed to reveal the neurobiological underpinnings underlying the beneficial effect of sleep on memory. They also have led to the proposal of two theoretical models: the "hippocampo-neocortical dialogue" and the "synaptic downscaling hypothesis". Normal ageing and, even more markedly Alzheimer's disease, are associated with sleep changes that may alter sleep-dependent memory consolidation. This paper presents a review of studies investigating the relationships between sleep and memory and how these links are affected by ageing and Alzheimer's disease.
Collapse
Affiliation(s)
- Carine Malle
- Inserm U1077, GIP Cyceron, Bd Becquerel, BP 5229, 14074 Caen Cedex 5, France - Université de Caen Normandie, UMR-S1077, Caen, France - École Pratique des Hautes Études, UMR-S1077, Caen, France - CHU de Caen, U1077, Caen, France
| | - Francis Eustache
- Inserm U1077, GIP Cyceron, Bd Becquerel, BP 5229, 14074 Caen Cedex 5, France - Université de Caen Normandie, UMR-S1077, Caen, France - École Pratique des Hautes Études, UMR-S1077, Caen, France - CHU de Caen, U1077, Caen, France
| | - Géraldine Rauchs
- Inserm U1077, GIP Cyceron, Bd Becquerel, BP 5229, 14074 Caen Cedex 5, France - Université de Caen Normandie, UMR-S1077, Caen, France - École Pratique des Hautes Études, UMR-S1077, Caen, France - CHU de Caen, U1077, Caen, France
| |
Collapse
|
29
|
Dissociating memory traces and scenario construction in mental time travel. Neurosci Biobehav Rev 2015; 60:82-9. [PMID: 26627866 DOI: 10.1016/j.neubiorev.2015.11.011] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/17/2015] [Accepted: 11/23/2015] [Indexed: 12/31/2022]
Abstract
There has been a persistent debate about how to define episodic memory and whether it is a uniquely human capacity. On the one hand, many animal cognition studies employ content-based criteria, such as the what-where-when criterion, and argue that nonhuman animals possess episodic memory. On the other hand, many human cognition studies emphasize the subjective experience during retrieval as an essential property of episodic memory and the distinctly human foresight it purportedly enables. We propose that both perspectives may examine distinct but complementary aspects of episodic memory by drawing a conceptual distinction between episodic memory traces and mental time travel. Episodic memory traces are sequential mnemonic representations of particular, personally experienced episodes. Mental time travel draws on these traces, but requires other components to construct scenarios and embed them into larger narratives. Various nonhuman animals may store episodic memory traces, and yet it is possible that only humans are able to construct and reflect on narratives of their lives - and flexibly compare alternative scenarios of the remote future.
Collapse
|
30
|
Tromp D, Dufour A, Lithfous S, Pebayle T, Després O. Episodic memory in normal aging and Alzheimer disease: Insights from imaging and behavioral studies. Ageing Res Rev 2015; 24:232-62. [PMID: 26318058 DOI: 10.1016/j.arr.2015.08.006] [Citation(s) in RCA: 201] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/20/2015] [Indexed: 12/30/2022]
Abstract
Age-related cognitive changes often include difficulties in retrieving memories, particularly those that rely on personal experiences within their temporal and spatial contexts (i.e., episodic memories). This decline may vary depending on the studied phase (i.e., encoding, storage or retrieval), according to inter-individual differences, and whether we are talking about normal or pathological (e.g., Alzheimer disease; AD) aging. Such cognitive changes are associated with different structural and functional alterations in the human neural network that underpins episodic memory. The prefrontal cortex is the first structure to be affected by age, followed by the medial temporal lobe (MTL), the parietal cortex and the cerebellum. In AD, however, the modifications occur mainly in the MTL (hippocampus and adjacent structures) before spreading to the neocortex. In this review, we will present results that attempt to characterize normal and pathological cognitive aging at multiple levels by integrating structural, behavioral, inter-individual and neuroimaging measures of episodic memory.
Collapse
Affiliation(s)
- D Tromp
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UDS) - 21 rue Becquerel, 67087 Strasbourg, France.
| | - A Dufour
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UDS) - 21 rue Becquerel, 67087 Strasbourg, France; Centre d'Investigations Neurocognitives et Neurophysiologiques (CI2N - UMS 3489 - CNRS/UDS) - 21 rue Becquerel, 67087 Strasbourg, France
| | - S Lithfous
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UDS) - 21 rue Becquerel, 67087 Strasbourg, France
| | - T Pebayle
- Centre d'Investigations Neurocognitives et Neurophysiologiques (CI2N - UMS 3489 - CNRS/UDS) - 21 rue Becquerel, 67087 Strasbourg, France
| | - O Després
- Laboratoire de Neurosciences Cognitives et Adaptatives (LNCA - UMR 7364 - CNRS/UDS) - 21 rue Becquerel, 67087 Strasbourg, France.
| |
Collapse
|
31
|
Ben-Yakov A, Dudai Y, Mayford MR. Memory Retrieval in Mice and Men. Cold Spring Harb Perspect Biol 2015; 7:cshperspect.a021790. [PMID: 26438596 DOI: 10.1101/cshperspect.a021790] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Retrieval, the use of learned information, was until recently mostly terra incognita in the neurobiology of memory, owing to shortage of research methods with the spatiotemporal resolution required to identify and dissect fast reactivation or reconstruction of complex memories in the mammalian brain. The development of novel paradigms, model systems, and new tools in molecular genetics, electrophysiology, optogenetics, in situ microscopy, and functional imaging, have contributed markedly in recent years to our ability to investigate brain mechanisms of retrieval. We review selected developments in the study of explicit retrieval in the rodent and human brain. The picture that emerges is that retrieval involves coordinated fast interplay of sparse and distributed corticohippocampal and neocortical networks that may permit permutational binding of representational elements to yield specific representations. These representations are driven largely by the activity patterns shaped during encoding, but are malleable, subject to the influence of time and interaction of the existing memory with novel information.
Collapse
Affiliation(s)
- Aya Ben-Yakov
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel
| | - Yadin Dudai
- Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Israel Center for Neural Science, New York University, New York, New York 10003
| | - Mark R Mayford
- Department of Molecular and Cellular Neuroscience, The Scripps Research Institute, La Jolla, California 92037
| |
Collapse
|
32
|
Persson J, Söderlund H. Hippocampal hemispheric and long-axis differentiation of stimulus content during episodic memory encoding and retrieval: An activation likelihood estimation meta-analysis. Hippocampus 2015; 25:1614-31. [DOI: 10.1002/hipo.22482] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 06/18/2015] [Accepted: 06/22/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Jonas Persson
- Department of Psychology; Uppsala University; Uppsala Sweden
| | | |
Collapse
|
33
|
Abstract
Conscious memory for a new experience is initially dependent on information stored in both the hippocampus and neocortex. Systems consolidation is the process by which the hippocampus guides the reorganization of the information stored in the neocortex such that it eventually becomes independent of the hippocampus. Early evidence for systems consolidation was provided by studies of retrograde amnesia, which found that damage to the hippocampus-impaired memories formed in the recent past, but typically spared memories formed in the more remote past. Systems consolidation has been found to occur for both episodic and semantic memories and for both spatial and nonspatial memories, although empirical inconsistencies and theoretical disagreements remain about these issues. Recent work has begun to characterize the neural mechanisms that underlie the dialogue between the hippocampus and neocortex (e.g., "neural replay," which occurs during sharp wave ripple activity). New work has also identified variables, such as the amount of preexisting knowledge, that affect the rate of consolidation. The increasing use of molecular genetic tools (e.g., optogenetics) can be expected to further improve understanding of the neural mechanisms underlying consolidation.
Collapse
Affiliation(s)
- Larry R Squire
- VA San Diego Healthcare System, San Diego, California 92161 Departments of Psychiatry and Neurosciences, University of California, San Diego, La Jolla, California 92093 Department of Psychology, University of California, San Diego, La Jolla, California 92093
| | - Lisa Genzel
- Centre for Cognitive and Neural Systems, The University of Edinburgh, Edinburgh EH8 9JZ, United Kingdom
| | - John T Wixted
- Department of Psychology, University of California, San Diego, La Jolla, California 92093
| | - Richard G Morris
- Centre for Cognitive and Neural Systems, The University of Edinburgh, Edinburgh EH8 9JZ, United Kingdom
| |
Collapse
|
34
|
Braun M, Jacobs AM, Richlan F, Hawelka S, Hutzler F, Kronbichler M. Many neighbors are not silent. fMRI evidence for global lexical activity in visual word recognition. Front Hum Neurosci 2015; 9:423. [PMID: 26257634 PMCID: PMC4510423 DOI: 10.3389/fnhum.2015.00423] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 07/10/2015] [Indexed: 12/03/2022] Open
Abstract
Many neurocognitive studies investigated the neural correlates of visual word recognition, some of which manipulated the orthographic neighborhood density of words and nonwords believed to influence the activation of orthographically similar representations in a hypothetical mental lexicon. Previous neuroimaging research failed to find evidence for such global lexical activity associated with neighborhood density. Rather, effects were interpreted to reflect semantic or domain general processing. The present fMRI study revealed effects of lexicality, orthographic neighborhood density and a lexicality by orthographic neighborhood density interaction in a silent reading task. For the first time we found greater activity for words and nonwords with a high number of neighbors. We propose that this activity in the dorsomedial prefrontal cortex reflects activation of orthographically similar codes in verbal working memory thus providing evidence for global lexical activity as the basis of the neighborhood density effect. The interaction of lexicality by neighborhood density in the ventromedial prefrontal cortex showed lower activity in response to words with a high number compared to nonwords with a high number of neighbors. In the light of these results the facilitatory effect for words and inhibitory effect for nonwords with many neighbors observed in previous studies can be understood as being due to the operation of a fast-guess mechanism for words and a temporal deadline mechanism for nonwords as predicted by models of visual word recognition. Furthermore, we propose that the lexicality effect with higher activity for words compared to nonwords in inferior parietal and middle temporal cortex reflects the operation of an identification mechanism based on local lexico-semantic activity.
Collapse
Affiliation(s)
- Mario Braun
- Neurocognition Lab, Centre for Cognitive Neuroscience, Universität SalzburgSalzburg, Austria
- Department of Experimental and Neurocognitive Psychology, Freie Universität BerlinBerlin, Germany
| | - Arthur M. Jacobs
- Department of Experimental and Neurocognitive Psychology, Freie Universität BerlinBerlin, Germany
- Center for Cognitive Neuroscience BerlinBerlin, Germany
- Dahlem Institute for Neuroimaging of Emotion, BerlinGermany
| | - Fabio Richlan
- Neurocognition Lab, Centre for Cognitive Neuroscience, Universität SalzburgSalzburg, Austria
| | - Stefan Hawelka
- Neurocognition Lab, Centre for Cognitive Neuroscience, Universität SalzburgSalzburg, Austria
| | - Florian Hutzler
- Neurocognition Lab, Centre for Cognitive Neuroscience, Universität SalzburgSalzburg, Austria
| | - Martin Kronbichler
- Neurocognition Lab, Centre for Cognitive Neuroscience, Universität SalzburgSalzburg, Austria
- Christian-Doppler-Klinik, Paracelsus Medical University, SalzburgAustria
| |
Collapse
|
35
|
Züst MA, Colella P, Reber TP, Vuilleumier P, Hauf M, Ruch S, Henke K. Hippocampus is place of interaction between unconscious and conscious memories. PLoS One 2015; 10:e0122459. [PMID: 25826338 PMCID: PMC4380440 DOI: 10.1371/journal.pone.0122459] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 02/11/2015] [Indexed: 11/18/2022] Open
Abstract
Recent evidence suggests that humans can form and later retrieve new semantic relations unconsciously by way of hippocampus-the key structure also recruited for conscious relational (episodic) memory. If the hippocampus subserves both conscious and unconscious relational encoding/retrieval, one would expect the hippocampus to be place of unconscious-conscious interactions during memory retrieval. We tested this hypothesis in an fMRI experiment probing the interaction between the unconscious and conscious retrieval of face-associated information. For the establishment of unconscious relational memories, we presented subliminal (masked) combinations of unfamiliar faces and written occupations ("actor" or "politician"). At test, we presented the former subliminal faces, but now supraliminally, as cues for the reactivation of the unconsciously associated occupations. We hypothesized that unconscious reactivation of the associated occupation-actor or politician-would facilitate or inhibit the subsequent conscious retrieval of a celebrity's occupation, which was also actor or politician. Depending on whether the reactivated unconscious occupation was congruent or incongruent to the celebrity's occupation, we expected either quicker or delayed conscious retrieval process. Conscious retrieval was quicker in the congruent relative to a neutral baseline condition but not delayed in the incongruent condition. fMRI data collected during subliminal face-occupation encoding confirmed previous evidence that the hippocampus was interacting with neocortical storage sites of semantic knowledge to support relational encoding. fMRI data collected at test revealed that the facilitated conscious retrieval was paralleled by deactivations in the hippocampus and neocortical storage sites of semantic knowledge. We assume that the unconscious reactivation has pre-activated overlapping relational representations in the hippocampus reducing the neural effort for conscious retrieval. This finding supports the notion of synergistic interactions between conscious and unconscious relational memories in a common, cohesive hippocampal-neocortical memory space.
Collapse
Affiliation(s)
- Marc Alain Züst
- Department of Psychology, Division of Experimental Psychology and Neuropsychology, University of Bern, Bern, Switzerland
- Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland
- * E-mail:
| | - Patrizio Colella
- Department of Psychology, Division of Experimental Psychology and Neuropsychology, University of Bern, Bern, Switzerland
- Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland
| | - Thomas Peter Reber
- Department of Psychology, Division of Experimental Psychology and Neuropsychology, University of Bern, Bern, Switzerland
- Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland
| | - Patrik Vuilleumier
- Department of Neurosciences and Clinical Neurology, University of Geneva, Geneva, Switzerland
| | - Martinus Hauf
- Institute of Diagnostic and Interventional Neuroradiology, University Hospital Bern, Bern, Switzerland
| | - Simon Ruch
- Department of Psychology, Division of Experimental Psychology and Neuropsychology, University of Bern, Bern, Switzerland
- Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland
| | - Katharina Henke
- Department of Psychology, Division of Experimental Psychology and Neuropsychology, University of Bern, Bern, Switzerland
- Center for Cognition, Learning and Memory, University of Bern, Bern, Switzerland
| |
Collapse
|
36
|
Rosa J, Myskiw JC, Furini CR, Sapiras GG, Izquierdo I. Fear extinction can be made state-dependent on peripheral epinephrine: Role of norepinephrine in the nucleus tractus solitarius. Neurobiol Learn Mem 2014; 113:55-61. [DOI: 10.1016/j.nlm.2013.09.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 09/11/2013] [Accepted: 09/18/2013] [Indexed: 11/16/2022]
|
37
|
Kim HJ, Ye BS, Yoon CW, Noh Y, Kim GH, Cho H, Jeon S, Lee JM, Kim JH, Seong JK, Kim CH, Choe YS, Lee KH, Kim ST, Kim JS, Park SE, Kim JH, Chin J, Cho J, Kim C, Lee JH, Weiner MW, Na DL, Seo SW. Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type. Eur J Neurol 2014; 21:744-51. [PMID: 24495089 DOI: 10.1111/ene.12376] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 12/27/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND AND PURPOSE The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized. METHODS Forty-five patients with svMCI and 46 patients with SVaD who were negative on Pittsburgh compound B (PiB) positron emission tomography imaging and 75 individuals with normal cognition (NC) were recruited. RESULTS Compared with NC, patients with PiB(-) svMCI exhibited frontal, language and retrieval type memory dysfunctions, which in patients with PiB(-) SVaD were further impaired and accompanied by visuospatial and recognition memory dysfunctions. Compared with NC, patients with PiB(-) svMCI exhibited cortical thinning in the frontal, perisylvian, basal temporal and posterior cingulate regions. This atrophy was more prominent and extended further toward the lateral parietal and medial temporal regions in patients with PiB(-) SVaD. Compared with NC subjects, patients with PiB(-) svMCI exhibited hippocampal shape deformities in the lateral body, whilst patients with PiB(-) SVaD exhibited additional deformities within the lateral head and inferior body. CONCLUSIONS Our findings suggest that patients with CVD in the absence of Alzheimer's disease pathology can be demented, showing cognitive impairment in multiple domains, which is consistent with the topography of cortical thinning and hippocampal shape deformity.
Collapse
Affiliation(s)
- H J Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Sadeh T, Ozubko JD, Winocur G, Moscovitch M. How we forget may depend on how we remember. Trends Cogn Sci 2014; 18:26-36. [DOI: 10.1016/j.tics.2013.10.008] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 12/17/2022]
|
39
|
Cheng S. The CRISP theory of hippocampal function in episodic memory. Front Neural Circuits 2013; 7:88. [PMID: 23653597 PMCID: PMC3644677 DOI: 10.3389/fncir.2013.00088] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2013] [Accepted: 04/19/2013] [Indexed: 12/12/2022] Open
Abstract
Over the past four decades, a "standard framework" has emerged to explain the neural mechanisms of episodic memory storage. This framework has been instrumental in driving hippocampal research forward and now dominates the design and interpretation of experimental and theoretical studies. It postulates that cortical inputs drive plasticity in the recurrent cornu ammonis 3 (CA3) synapses to rapidly imprint memories as attractor states in CA3. Here we review a range of experimental studies and argue that the evidence against the standard framework is mounting, notwithstanding the considerable evidence in its support. We propose CRISP as an alternative theory to the standard framework. CRISP is based on Context Reset by dentate gyrus (DG), Intrinsic Sequences in CA3, and Pattern completion in cornu ammonis 1 (CA1). Compared to previous models, CRISP uses a radically different mechanism for storing episodic memories in the hippocampus. Neural sequences are intrinsic to CA3, and inputs are mapped onto these intrinsic sequences through synaptic plasticity in the feedforward projections of the hippocampus. Hence, CRISP does not require plasticity in the recurrent CA3 synapses during the storage process. Like in other theories DG and CA1 play supporting roles, however, their function in CRISP have distinct implications. For instance, CA1 performs pattern completion in the absence of CA3 and DG contributes to episodic memory retrieval, increasing the speed, precision, and robustness of retrieval. We propose the conceptual theory, discuss its implications for experimental results and suggest testable predictions. It appears that CRISP not only accounts for those experimental results that are consistent with the standard framework, but also for results that are at odds with the standard framework. We therefore suggest that CRISP is a viable, and perhaps superior, theory for the hippocampal function in episodic memory.
Collapse
Affiliation(s)
- Sen Cheng
- Mercator Research Group "Structure of Memory", Ruhr-Universität Bochum Bochum, Germany ; Faculty of Psychology, Ruhr-Universität Bochum Bochum, Germany
| |
Collapse
|
40
|
Ganis G, Schendan HE. Concealed semantic and episodic autobiographical memory electrified. Front Hum Neurosci 2013; 6:354. [PMID: 23355816 PMCID: PMC3553422 DOI: 10.3389/fnhum.2012.00354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 12/20/2012] [Indexed: 11/25/2022] Open
Abstract
Electrophysiology-based concealed information tests (CIT) try to determine whether somebody possesses concealed information about a crime-related item (probe) by comparing event-related potentials (ERPs) between this item and comparison items (irrelevants). Although the broader field is sometimes referred to as “memory detection,” little attention has been paid to the precise type of underlying memory involved. This study begins addressing this issue by examining the key distinction between semantic and episodic memory in the autobiographical domain within a CIT paradigm. This study also addresses the issue of whether multiple repetitions of the items over the course of the session habituate the brain responses. Participants were tested in a 3-stimulus CIT with semantic autobiographical probes (their own date of birth) and episodic autobiographical probes (a secret date learned just before the study). Results dissociated these two memory conditions on several ERP components. Semantic probes elicited a smaller frontal N2 than episodic probes, consistent with the idea that the frontal N2 decreases with greater pre-existing knowledge about the item. Likewise, semantic probes elicited a smaller central N400 than episodic probes. Semantic probes also elicited a larger P3b than episodic probes because of their richer meaning. In contrast, episodic probes elicited a larger late positive complex (LPC) than semantic probes, because of the recent episodic memory associated with them. All these ERPs showed a difference between probes and irrelevants in both memory conditions, except for the N400, which showed a difference only in the semantic condition. Finally, although repetition affected the ERPs, it did not reduce the difference between probes and irrelevants. These findings show that the type of memory associated with a probe has both theoretical and practical importance for CIT research.
Collapse
Affiliation(s)
- Giorgio Ganis
- School of Psychology, Cognition Institute, University of Plymouth Plymouth, UK ; Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging Charlestown, MA, USA ; Department of Radiology, Harvard Medical School Boston, MA, USA
| | | |
Collapse
|