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Tompary A, Davachi L. Integration of overlapping sequences emerges with consolidation through medial prefrontal cortex neural ensembles and hippocampal-cortical connectivity. eLife 2024; 13:e84359. [PMID: 39545928 PMCID: PMC11567667 DOI: 10.7554/elife.84359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 09/18/2024] [Indexed: 11/17/2024] Open
Abstract
Systems consolidation theories propose two mechanisms that enable the behavioral integration of related memories: coordinated reactivation between hippocampus and cortex, and the emergence of cortical traces that reflect overlap across memories. However, there is limited empirical evidence that links these mechanisms to the emergence of behavioral integration over time. In two experiments, participants implicitly encoded sequences of objects with overlapping structure. Assessment of behavioral integration showed that response times during a recognition task reflected behavioral priming between objects that never occurred together in time but belonged to overlapping sequences. This priming was consolidation-dependent and only emerged for sequences learned 24 hr prior to the test. Critically, behavioral integration was related to changes in neural pattern similarity in the medial prefrontal cortex and increases in post-learning rest connectivity between the posterior hippocampus and lateral occipital cortex. These findings suggest that memories with a shared predictive structure become behaviorally integrated through a consolidation-related restructuring of the learned sequences, providing insight into the relationship between different consolidation mechanisms that support behavioral integration.
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2
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Distinct multivariate structural brain profiles are related to variations in short- and long-delay memory consolidation across children and young adults. Dev Cogn Neurosci 2022; 59:101192. [PMID: 36566622 PMCID: PMC9803921 DOI: 10.1016/j.dcn.2022.101192] [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: 07/06/2022] [Revised: 12/12/2022] [Accepted: 12/21/2022] [Indexed: 12/24/2022] Open
Abstract
From early to middle childhood, brain regions that underlie memory consolidation undergo profound maturational changes. However, there is little empirical investigation that directly relates age-related differences in brain structural measures to memory consolidation processes. The present study examined memory consolidation of intentionally studied object-location associations after one night of sleep (short delay) and after two weeks (long delay) in normally developing 5-to-7-year-old children (n = 50) and young adults (n = 39). Behavioural differences in memory retention rate were related to structural brain measures. Our results showed that children, in comparison to young adults, retained correctly learnt object-location associations less robustly over short and long delay. Moreover, using partial least squares correlation method, a unique multivariate profile comprised of specific neocortical (prefrontal, parietal, and occipital), cerebellar, and hippocampal head and subfield structures in the body was found to be associated with variation in short-delay memory retention. A different multivariate profile comprised of a reduced set of brain structures, mainly consisting of neocortical (prefrontal, parietal, and occipital), hippocampal head, and selective hippocampal subfield structures (CA1-2 and subiculum) was associated with variation in long-delay memory retention. Taken together, the results suggest that multivariate structural pattern of unique sets of brain regions are related to variations in short- and long-delay memory consolidation across children and young adults.
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3
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Talamini LM, van Moorselaar D, Bakker R, Bulath M, Szegedi S, Sinichi M, De Boer M. No evidence for a preferential role of sleep in episodic memory abstraction. Front Neurosci 2022; 16:871188. [PMID: 36570837 PMCID: PMC9780604 DOI: 10.3389/fnins.2022.871188] [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: 02/07/2022] [Accepted: 11/21/2022] [Indexed: 12/13/2022] Open
Abstract
Substantial evidence suggests that sleep has a role in declarative memory consolidation. An influential notion holds that such sleep-related memory consolidation is associated with a process of abstraction. The neural underpinnings of this putative process are thought to involve a hippocampo-neocortical dialogue. Specifically, the idea is that, during sleep, the statistical contingencies across episodes are re-coded to a less hippocampus-dependent format, while at the same time losing configural information. Two previous studies from our lab, however, failed to show a preferential role of sleep in either episodic memory decontextualisation or the formation of abstract knowledge across episodic exemplars. Rather these processes occurred over sleep and wake time alike. Here, we present two experiments that replicate and extend these previous studies and exclude some alternative interpretations. The combined data show that sleep has no preferential function in this respect. Rather, hippocampus-dependent memories are generalised to an equal extent across both wake and sleep time. The one point on which sleep outperforms wake is actually the preservation of episodic detail of memories stored prior to sleep.
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Affiliation(s)
- Lucia M. Talamini
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
- University of Amsterdam—Amsterdam Brain and Cognition, Amsterdam, Netherlands
| | - Dirk van Moorselaar
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Richard Bakker
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Máté Bulath
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Steffie Szegedi
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Mohammadamin Sinichi
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
| | - Marieke De Boer
- Brain and Cognition, Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
- University of Amsterdam—Amsterdam Brain and Cognition, Amsterdam, Netherlands
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4
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Baena D, Cantero JL, Atienza M. Stability of neural encoding moderates the contribution of sleep and repeated testing to memory consolidation. Neurobiol Learn Mem 2021; 185:107529. [PMID: 34597816 DOI: 10.1016/j.nlm.2021.107529] [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: 05/03/2021] [Revised: 09/03/2021] [Accepted: 09/24/2021] [Indexed: 10/20/2022]
Abstract
There is evidence suggesting that online consolidation during retrieval-mediated learning interacts with offline consolidation during subsequent sleep to transform memory. Here we investigate whether this interaction persists when retrieval-mediated learning follows post-training sleep and whether the direction of this interaction is conditioned by the quality of encoding resulting from manipulation of the amount of sleep on the previous night. The quality of encoding was determined by computing the degree of similarity between EEG-activity patterns across restudy of face pairs in two groups of young participants, one who slept the last 4 h of the pre-training night, and another who slept 8 h. The offline consolidation was assessed by computing the degree of coupling between slow oscillations (SOs) and spindles (SPs) during post-training sleep, while the online consolidation was evaluated by determining the degree of similarity between EEG-activity patterns recorded during the study phase and during repeated recognition of either the same face pair (i.e., specific similarity) or face pairs sharing sex and profession (i.e., categorical similarity) to evaluate differentiation and generalization, respectively. The study and recognition phases were separated by a night of normal sleep duration. Mixed-effects models revealed that the stability of neural encoding moderated the relationship between sleep- and retrieval-mediated consolidation processes over left frontal regions. For memories showing lower encoding stability, the enhanced SO-SP coupling was associated with increased reinstatement of category-specific encoding-related activity at the expense of content-specific activity, whilst the opposite occurred for memories showing greater encoding stability. Overall, these results suggest that offline consolidation during post-training sleep interacts with online consolidation during retrieval the next day to favor the reorganization of memory contents, by increasing specificity of stronger memories and generalization of the weaker ones.
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Affiliation(s)
- Daniel Baena
- Laboratory of Functional Neuroscience, Universidad Pablo de Olavide, Seville 41013, Spain
| | - Jose L Cantero
- Laboratory of Functional Neuroscience, Universidad Pablo de Olavide, Seville 41013, Spain; CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, Spain
| | - Mercedes Atienza
- Laboratory of Functional Neuroscience, Universidad Pablo de Olavide, Seville 41013, Spain; CIBERNED, Network Center for Biomedical Research in Neurodegenerative Diseases, Spain.
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5
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Abstract
We rely on our long-term memories to guide future behaviors, making it adaptive to prioritize the retention of goal-relevant, salient information in memory. In this review, we discuss findings from rodent and human research to demonstrate that active processes during post-encoding consolidation support the selective stabilization of recent experience into adaptive, long-term memories. Building upon literatures focused on dynamics at the cellular level, we highlight that consolidation also transforms memories at the systems level to support future goal-relevant behavior, resulting in more generalized memory traces in the brain and behavior. We synthesize previous literatures spanning animal research, human cognitive neuroscience, and cognitive psychology to propose an integrative framework for adaptive consolidation by which goal-relevant memoranda are "tagged" for subsequent consolidation, resulting in selective transformations to the structure of memories that support flexible, goal-relevant behaviors.
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6
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Goldthorpe RA, Rapley JM, Violante IR. A Systematic Review of Non-invasive Brain Stimulation Applications to Memory in Healthy Aging. Front Neurol 2020; 11:575075. [PMID: 33193023 PMCID: PMC7604325 DOI: 10.3389/fneur.2020.575075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/11/2020] [Indexed: 12/15/2022] Open
Abstract
It has long been acknowledged that memory changes over the course of one's life, irrespective of diseases like dementia. Approaches to mitigate these changes have however yielded mixed results. Brain stimulation has been identified as one novel approach of augmenting older adult's memory. Thus far, such approaches have however been nuanced, targeting different memory domains with different methodologies. This has produced an amalgam of research with an unclear image overall. This systematic review therefore aims to clarify this landscape, evaluating, and interpreting available research findings in a coherent manner. A systematic search of relevant literature was conducted across Medline, PsycInfo, Psycarticles and the Psychology and Behavioral Sciences Collection, which uncovered 44 studies employing non-invasive electrical brain stimulation in healthy older adults. All studies were of generally good quality spanning numerous memory domains. Within these, evidence was found for non-invasive brain stimulation augmenting working, episodic, associative, semantic, and procedural memory, with the first three domains having the greatest evidence base. Key sites for stimulation included the left dorsolateral prefrontal cortex (DLPFC), temporoparietal region, and primary motor cortex, with transcranial direct current stimulation (tDCS) holding the greatest literature base. Inconsistencies within the literature are highlighted and interpreted, however this discussion was constrained by potential confounding variables within the literature, a risk of bias, and challenges defining research aims and results. Non-invasive brain stimulation often did however have a positive and predictable impact on older adult's memory, and thus warrants further research to better understand these effects.
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Affiliation(s)
| | | | - Ines R. Violante
- School of Psychology, University of Surrey, Guildford, United Kingdom
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7
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Pelekanos V, Premereur E, Mitchell DJ, Chakraborty S, Mason S, Lee ACH, Mitchell AS. Corticocortical and Thalamocortical Changes in Functional Connectivity and White Matter Structural Integrity after Reward-Guided Learning of Visuospatial Discriminations in Rhesus Monkeys. J Neurosci 2020; 40:7887-7901. [PMID: 32900835 PMCID: PMC7548693 DOI: 10.1523/jneurosci.0364-20.2020] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 06/30/2020] [Accepted: 07/25/2020] [Indexed: 12/14/2022] Open
Abstract
The frontal cortex and temporal lobes together regulate complex learning and memory capabilities. Here, we collected resting-state functional and diffusion-weighted MRI data before and after male rhesus macaque monkeys received extensive training to learn novel visuospatial discriminations (reward-guided learning). We found functional connectivity changes in orbitofrontal, ventromedial prefrontal, inferotemporal, entorhinal, retrosplenial, and anterior cingulate cortices, the subicular complex, and the dorsal, medial thalamus. These corticocortical and thalamocortical changes in functional connectivity were accompanied by related white matter structural alterations in the uncinate fasciculus, fornix, and ventral prefrontal tract: tracts that connect (sub)cortical networks and are implicated in learning and memory processes in monkeys and humans. After the well-trained monkeys received fornix transection, they were impaired in learning new visuospatial discriminations. In addition, the functional connectivity profile that was observed after the training was altered. These changes were accompanied by white matter changes in the ventral prefrontal tract, although the integrity of the uncinate fasciculus remained unchanged. Our experiments highlight the importance of different communication relayed among corticocortical and thalamocortical circuitry for the ability to learn new visuospatial associations (learning-to-learn) and to make reward-guided decisions.SIGNIFICANCE STATEMENT Frontal neural networks and the temporal lobes contribute to reward-guided learning in mammals. Here, we provide novel insight by showing that specific corticocortical and thalamocortical functional connectivity is altered after rhesus monkeys received extensive training to learn novel visuospatial discriminations. Contiguous white matter fiber pathways linking these gray matter structures, namely, the uncinate fasciculus, fornix, and ventral prefrontal tract, showed structural changes after completing training in the visuospatial task. Additionally, different patterns of functional and structural connectivity are reported after removal of subcortical connections within the extended hippocampal system, via fornix transection. These results highlight the importance of both corticocortical and thalamocortical interactions in reward-guided learning in the normal brain and identify brain structures important for memory capabilities after injury.
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Affiliation(s)
- Vassilis Pelekanos
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3SR, United Kingdom
| | - Elsie Premereur
- Laboratory for Neuro- and Psychophysiology, KU Leuven, 3000 Leuven, Belgium
| | - Daniel J Mitchell
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, United Kingdom
| | - Subhojit Chakraborty
- Department of Neuroinflammation, Queen Square Multiple Sclerosis Centre, Institute of Neurology, University College London, London WC1N 3BG, United Kingdom
| | - Stuart Mason
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3SR, United Kingdom
| | - Andy C H Lee
- Department of Psychology (Scarborough), University of Toronto, Toronto, Ontario M1C 1A4, Canada
- Rotman Research Institute, Baycrest Centre, Toronto, Ontario M6A 2E1, Canada
| | - Anna S Mitchell
- Department of Experimental Psychology, University of Oxford, Oxford OX1 3SR, United Kingdom
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Prior cortical activity differences during an action observation plus motor imagery task related to motor adaptation performance of a coordinated multi-limb complex task. Cogn Neurodyn 2020; 14:769-779. [PMID: 33101530 DOI: 10.1007/s11571-020-09633-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 08/24/2020] [Accepted: 09/01/2020] [Indexed: 12/16/2022] Open
Abstract
Motor adaptation is the ability to develop new motor skills that makes performing a consolidated motor task under different psychophysical conditions possible. There exists a proven relationship between prior brain activity at rest and motor adaptation. However, the brain activity at rest is highly variable both between and within subjects. Here we hypothesize that the cortical activity during the original task to be later adapted is a more reliable and stronger determinant of motor adaptation. Consequently, we present a study to find cortical areas whose activity, both at rest and during first-person virtual reality simulation of bicycle riding, characterizes the subjects who did and did not adapt to ride a reverse steering bicycle, a complex motor adaptation task involving all limbs and balance. The results showed that cortical activity differences during the simulated task were higher, more significant, spatially larger, and spectrally wider than at rest for good performers. In this sense, the activity of the left anterior insula, left dorsolateral and ventrolateral inferior prefrontal areas, and left inferior premotor cortex (action understanding hub of the mirror neuron circuit) during simulated bicycle riding are the areas with the most descriptive power for the ability of adapting the motor task. Trials registration Trial was registered with the NIH Clinical Trials Registry (clinicaltrials.gov), with the registration number NCT02999516 (21/12/2016).
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9
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Elshiekh A, Subramaniapillai S, Rajagopal S, Pasvanis S, Ankudowich E, Rajah MN. The association between cognitive reserve and performance-related brain activity during episodic encoding and retrieval across the adult lifespan. Cortex 2020; 129:296-313. [DOI: 10.1016/j.cortex.2020.05.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/26/2020] [Accepted: 05/02/2020] [Indexed: 01/23/2023]
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10
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Gerver CR, Overman AA, Babu HJ, Hultman CE, Dennis NA. Examining the Neural Basis of Congruent and Incongruent Configural Contexts during Associative Retrieval. J Cogn Neurosci 2020; 32:1796-1812. [PMID: 32530379 DOI: 10.1162/jocn_a_01593] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Disrupting the configural context, or relative organization and orientation of paired stimuli, between encoding and retrieval negatively impacts memory. Using univariate and multivariate fMRI analyses, we examined the effect of retaining and manipulating the configural context on neural mechanisms supporting associative retrieval. Behavioral results showed participants had significantly higher hit rates for recollecting pairs in a contextually congruent, versus incongruent, configuration. In addition, contextual congruency between memory phases was a critical determinant to characterizing both the magnitude and patterns of neural activation within visual and parietal cortices. Regions within visual cortices also exhibited higher correlations between patterns of activity at encoding and retrieval when configural context was congruent across memory phases than incongruent. Collectively, these findings shed light on how manipulating configural context between encoding and retrieval affects associative recognition, with changes in the configural context leading to reductions in information transfer and increases in task difficulty.
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11
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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.
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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
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12
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Sleep Spindles Promote the Restructuring of Memory Representations in Ventromedial Prefrontal Cortex through Enhanced Hippocampal-Cortical Functional Connectivity. J Neurosci 2020; 40:1909-1919. [PMID: 31959699 DOI: 10.1523/jneurosci.1946-19.2020] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 01/06/2020] [Accepted: 01/08/2020] [Indexed: 11/21/2022] Open
Abstract
Memory consolidation is hypothesized to involve the distribution and restructuring of memory representations across hippocampal and cortical regions. Theories suggest that, through extended hippocampal-cortical interactions, cortical ensembles come to represent more integrated, or overlapping, memory traces that prioritize commonalities across related memories. Sleep processes, particularly fast sleep spindles, are thought to support consolidation, but evidence for this relationship has been mostly limited to memory retention benefits. Whether fast spindles provide a mechanism for neural changes hypothesized to support consolidation, including the strengthening of hippocampal-cortical networks and integration across memory representations, remains unclear, as does the specificity of regions involved. Using functional connectivity analyses of human fMRI data (both sexes), we show that fast spindle density during overnight sleep is related to enhanced hippocampal-cortical functional connectivity the next day, when restudying information learned before sleep. Spindle density modulated connectivity in distinct hippocampal-cortical networks depending on the category of the consolidated stimuli. Specifically, spindle density correlated with functional connectivity between anterior hippocampus and ventromedial prefrontal cortex (vmPFC) for object-word pairs, and posterior hippocampus and posteromedial cortex for scene-word pairs. Using multivariate pattern analyses, we also show that fast spindle density during postlearning sleep is associated with greater pattern similarity, or representational overlap, across individual object-word memories in vmPFC the next day. Further, the relationship between fast spindle density and representational overlap in vmPFC was mediated by the degree of anterior hippocampal-vmPFC functional connectivity. Together, these results suggest that fast spindles support the network distribution of memory traces, potentially restructuring memory representations in vmPFC.SIGNIFICANCE STATEMENT How new experiences are transformed into long-term memories remains a fundamental question for neuroscience research. Theories suggest that memories are stabilized as they are reorganized in the brain, a process thought to be supported by sleep oscillations, particularly sleep spindles. Although sleep spindles have been associated with benefits in memory retention, it is not well understood how spindles modify neural memory traces. This study found that spindles during overnight sleep correlate with changes in neural memory traces, including enhanced functional connectivity in distinct hippocampal-cortical networks and increased pattern similarity among memories in the cortex. The results provide critical evidence that spindles during overnight sleep may act as a physiological mechanism for the restructuring of neural memory traces.
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13
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Wagner IC, van Buuren M, Fernández G. Thalamo-cortical coupling during encoding and consolidation is linked to durable memory formation. Neuroimage 2019; 197:80-92. [DOI: 10.1016/j.neuroimage.2019.04.055] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Accepted: 04/19/2019] [Indexed: 01/08/2023] Open
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14
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Mancuso L, Costa T, Nani A, Manuello J, Liloia D, Gelmini G, Panero M, Duca S, Cauda F. The homotopic connectivity of the functional brain: a meta-analytic approach. Sci Rep 2019; 9:3346. [PMID: 30833662 PMCID: PMC6399443 DOI: 10.1038/s41598-019-40188-3] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 02/05/2019] [Indexed: 01/21/2023] Open
Abstract
Homotopic connectivity (HC) is the connectivity between mirror areas of the brain hemispheres. It can exhibit a marked and functionally relevant spatial variability, and can be perturbed by several pathological conditions. The voxel-mirrored homotopic connectivity (VMHC) is a technique devised to enquire this pattern of brain organization, based on resting state functional connectivity. Since functional connectivity can be revealed also in a meta-analytical fashion using co-activations, here we propose to calculate the meta-analytic homotopic connectivity (MHC) as the meta-analytic counterpart of the VMHC. The comparison between the two techniques reveals their general similarity, but also highlights regional differences associated with how HC varies from task to rest. Two main differences were found from rest to task: (i) regions known to be characterized by global hubness are more similar than regions displaying local hubness; and (ii) medial areas are characterized by a higher degree of homotopic connectivity, while lateral areas appear to decrease their degree of homotopic connectivity during task performance. These findings show that MHC can be an insightful tool to study how the hemispheres functionally interact during task and rest conditions.
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Affiliation(s)
- Lorenzo Mancuso
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
| | - Tommaso Costa
- GCS-fMRI, Koelliker Hospital and Department of Psychology, University of Turin, Turin, Italy.
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy.
| | - Andrea Nani
- GCS-fMRI, Koelliker Hospital and Department of Psychology, University of Turin, Turin, Italy
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
| | - Jordi Manuello
- GCS-fMRI, Koelliker Hospital and Department of Psychology, University of Turin, Turin, Italy
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
| | - Donato Liloia
- GCS-fMRI, Koelliker Hospital and Department of Psychology, University of Turin, Turin, Italy
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
| | - Gabriele Gelmini
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
| | - Melissa Panero
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
| | - Sergio Duca
- GCS-fMRI, Koelliker Hospital and Department of Psychology, University of Turin, Turin, Italy
| | - Franco Cauda
- GCS-fMRI, Koelliker Hospital and Department of Psychology, University of Turin, Turin, Italy
- Focus Lab, Department of Psychology, University of Turin, Turin, Italy
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15
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Córcoles-Parada M, Ubero-Martínez M, Morris RGM, Insausti R, Mishkin M, Muñoz-López M. Frontal and Insular Input to the Dorsolateral Temporal Pole in Primates: Implications for Auditory Memory. Front Neurosci 2019; 13:1099. [PMID: 31780878 PMCID: PMC6861303 DOI: 10.3389/fnins.2019.01099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 09/30/2019] [Indexed: 01/25/2023] Open
Abstract
The temporal pole (TP) has been involved in multiple functions from emotional and social behavior, semantic processing, memory, language in humans and epilepsy surgery, to the fronto-temporal neurodegenerative disorder (semantic) dementia. However, the role of the TP subdivisions is still unclear, in part due to the lack of quantitative data about TP connectivity. This study focuses in the dorsolateral subdivision of the TP: area 38DL. Area 38DL main input originates in the auditory processing areas of the rostral superior temporal gyrus. Among other connections, area 38DL conveys this auditory highly processed information to the entorhinal, rostral perirhinal, and posterior parahippocampal cortices, presumably for storage in long-term memory (Muñoz-López et al., 2015). However, the connections of the TP with cortical areas beyond the temporal cortex suggest that this area is part of a wider network. With the aim to quantitatively determine the topographical, laminar pattern and weighting of the lateral TP afferents from the frontal and insular cortices, we placed a total of 11 tracer injections of the fluorescent retrograde neuronal tracers Fast Blue and Diamidino Yellow at different levels of the lateral TP in rhesus monkeys. The results showed that circa 50% of the total cortical input to area 38DL originates in medial frontal areas 14, 25, 32, and 24 (25%); orbitofrontal areas Pro and PAll (15%); and the agranular, parainsular and disgranular insula (10%). This study sets the anatomical bases to better understand the function of the dorsolateral division of the TP. More specifically, these results suggest that area 38DL forms part of the wider limbic circuit that might contribute, among other functions, with an auditory component to multimodal memory processing.
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Affiliation(s)
- Marta Córcoles-Parada
- Human Neuroanatomy Laboratory, School of Medicine, University of Castilla-La Mancha, Albacete, Spain
| | - Mar Ubero-Martínez
- Human Neuroanatomy Laboratory, School of Medicine, University of Castilla-La Mancha, Albacete, Spain.,Department of Anatomy, Catholic University, Murcia, Spain
| | - Richard G M Morris
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Ricardo Insausti
- Human Neuroanatomy Laboratory, School of Medicine, University of Castilla-La Mancha, Albacete, Spain
| | - Mortimer Mishkin
- Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, ML, United States
| | - Mónica Muñoz-López
- Human Neuroanatomy Laboratory, School of Medicine, University of Castilla-La Mancha, Albacete, Spain.,Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, United Kingdom.,Laboratory of Neuropsychology, National Institute of Mental Health, Bethesda, ML, United States
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16
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Shanahan LK, Gjorgieva E, Paller KA, Kahnt T, Gottfried JA. Odor-evoked category reactivation in human ventromedial prefrontal cortex during sleep promotes memory consolidation. eLife 2018; 7:e39681. [PMID: 30560782 PMCID: PMC6298770 DOI: 10.7554/elife.39681] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/21/2018] [Indexed: 01/08/2023] Open
Abstract
Slow-wave sleep is an optimal opportunity for memory consolidation: when encoding occurs in the presence of a sensory cue, delivery of that cue during sleep enhances retrieval of associated memories. Recent studies suggest that cues might promote consolidation by inducing neural reinstatement of cue-associated content during sleep, but direct evidence for such mechanisms is scant, and the relevant brain areas supporting these processes are poorly understood. Here, we address these gaps by combining a novel olfactory cueing paradigm with an object-location memory task and simultaneous EEG-fMRI recording in human subjects. Using pattern analysis of fMRI ensemble activity, we find that presentation of odor cues during sleep promotes reactivation of category-level information in ventromedial prefrontal cortex that significantly correlates with post-sleep memory performance. In identifying the potential mechanisms by which odor cues selectively modulate memory in the sleeping brain, these findings bring unique insights into elucidating how and what we remember.
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Affiliation(s)
- Laura K Shanahan
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoUnited States
| | - Eva Gjorgieva
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoUnited States
| | - Ken A Paller
- Department of Psychology, Weinberg College of Arts and SciencesNorthwestern UniversityEvanstonUnited States
| | - Thorsten Kahnt
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoUnited States
- Department of Psychology, Weinberg College of Arts and SciencesNorthwestern UniversityEvanstonUnited States
| | - Jay A Gottfried
- Department of Neurology, Feinberg School of MedicineNorthwestern UniversityChicagoUnited States
- Department of Neurology, Perelman School of MedicineUniversity of PennsylvaniaPhiladelphiaUnited States
- Department of Psychology, School of Arts and SciencesUniversity of PennsylvaniaPhiladelphiaUnited States
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17
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Ezzyat Y, Inhoff MC, Davachi L. Differentiation of Human Medial Prefrontal Cortex Activity Underlies Long-Term Resistance to Forgetting in Memory. J Neurosci 2018; 38:10244-10254. [PMID: 30012697 PMCID: PMC6262147 DOI: 10.1523/jneurosci.2290-17.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 06/12/2018] [Accepted: 06/12/2018] [Indexed: 11/21/2022] Open
Abstract
It is well known that distributing study events over time leads to better memory over long time scales, compared with massing study events together. One explanation for such long-term resistance to forgetting is that distributed study leads to neural differentiation in memory, which supports retrieval of past experiences by disambiguating highly similar memory representations. Neuroanatomical models of episodic memory retrieval propose that the hippocampus and medial prefrontal cortex (MPFC) work together to enable retrieval of behaviorally appropriate memories. However, it is not known how representations in these regions jointly support resistance to forgetting long after initial learning. Using fMRI, we measured differentiation in retrieved memory representations following an extended delay in male and female human participants. After 1 week, word-object associations were better remembered if studied across 2 d (overnight), allowing associations to be learned in distinct temporal contexts, compared with learning within a single day (same day). MPFC retrieval patterns showed differentiation for overnight relative to same day memories, whereas hippocampal patterns reflected associative retrieval success. Overnight memory differentiation in MPFC was higher for associative than item memories and higher than differentiation assessed over a brain-wide set of retrieval-active voxels. The memory-related difference in MPFC pattern differentiation correlated with memory success for overnight learning and with hippocampal-MPFC functional connectivity. These results show that learning information across days leads to differentiated MPFC memory representations, reducing forgetting after 1 week, and suggest this arises from persistent interactions between MPFC and hippocampus.SIGNIFICANCE STATEMENT Neural activity in both the hippocampus and medial prefrontal cortex (MPFC) has been linked to memory-related representations, but prior work has not examined how these representations support episodic memory retrieval over extended time scales that are characteristic of everyday retrieval. We show that differentiation in MPFC activity 1 week after encoding is higher for retrieved information learned across 2 d compared with within a single day. In hippocampus, differentiation was greater for detailed memory retrieval but was not influenced by whether information had been learned over 1 or 2 d. Differentiation in MPFC predicted behavioral robustness to forgetting and was correlated with hippocampal-MPFC connectivity. The results suggest that context-based differentiation supports robust long-term memory via persistent MPFC-hippocampal interactions.
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Affiliation(s)
- Youssef Ezzyat
- Department of Psychology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Marika C Inhoff
- Department of Psychology, University of California, Davis, California 95616, and
| | - Lila Davachi
- Department of Psychology, Columbia University, New York, New York 10027
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18
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Schott BH, Wüstenberg T, Lücke E, Pohl IM, Richter A, Seidenbecher CI, Pollmann S, Kizilirmak JM, Richardson-Klavehn A. Gradual acquisition of visuospatial associative memory representations via the dorsal precuneus. Hum Brain Mapp 2018; 40:1554-1570. [PMID: 30430687 DOI: 10.1002/hbm.24467] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/18/2018] [Accepted: 10/31/2018] [Indexed: 12/20/2022] Open
Abstract
Activation of parietal cortex structures like the precuneus is commonly observed during explicit memory retrieval, but the role of parietal cortices in encoding has only recently been appreciated and is still poorly understood. Considering the importance of the precuneus in human visual attention and imagery, we aimed to assess a potential role for the precuneus in the encoding of visuospatial representations into long-term memory. We therefore investigated the acquisition of constant versus repeatedly shuffled configurations of icons on background images over five subsequent days in 32 young, healthy volunteers. Functional magnetic resonance imaging was conducted on Days 1, 2, and 5, and persistent memory traces were assessed by a delayed memory test after another 5 days. Constant compared to shuffled configurations were associated with significant improvement of position recognition from Day 1 to 5 and better delayed memory performance. Bilateral dorsal precuneus activations separated constant from shuffled configurations from Day 2 onward, and coactivation of the precuneus and hippocampus dissociated recognized and forgotten configurations, irrespective of condition. Furthermore, learning of constant configurations elicited increased functional coupling of the precuneus with dorsal and ventral visual stream structures. Our results identify the precuneus as a key brain structure in the acquisition of detailed visuospatial information by orchestrating a parieto-occipito-temporal network.
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Affiliation(s)
- Björn H Schott
- Leibniz Institute for Neurobiology, Magdeburg, Germany.,Department of Psychiatry and Psychotherapy, Charité University Medicine, Berlin, Germany.,Department of Neurology, Otto von Guericke University Magdeburg, Magdeburg, Germany.,Department of Psychiatry and Psychotherapy, University Medicine Göttingen, Göttingen, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Torsten Wüstenberg
- Department of Psychiatry and Psychotherapy, Charité University Medicine, Berlin, Germany.,Systems Neuroscience in Psychiatry (SNiP), Central Institute of Mental Health, Mannheim, Germany
| | - Eva Lücke
- Department of Pulmonary Medicine, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Ina-Maria Pohl
- Institute of Psychology, Otto von Guericke University Magdeburg, Magdeburg, Germany
| | - Anni Richter
- Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Constanze I Seidenbecher
- Leibniz Institute for Neurobiology, Magdeburg, Germany.,Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany
| | - Stefan Pollmann
- Center for Behavioral Brain Sciences (CBBS), Magdeburg, Germany.,Institute of Psychology, Otto von Guericke University Magdeburg, Magdeburg, Germany
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19
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Rabellino D, Densmore M, Théberge J, McKinnon MC, Lanius RA. The cerebellum after trauma: Resting-state functional connectivity of the cerebellum in posttraumatic stress disorder and its dissociative subtype. Hum Brain Mapp 2018; 39:3354-3374. [PMID: 29667267 PMCID: PMC6866303 DOI: 10.1002/hbm.24081] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/28/2018] [Accepted: 04/04/2018] [Indexed: 12/25/2022] Open
Abstract
The cerebellum plays a key role not only in motor function but also in affect and cognition. Although several psychopathological disorders have been associated with overall cerebellar dysfunction, it remains unclear whether different regions of the cerebellum contribute uniquely to psychopathology. Accordingly, we compared seed-based resting-state functional connectivity of the anterior cerebellum (lobule IV-V), of the posterior cerebellum (Crus I), and of the anterior vermis across posttraumatic stress disorder (PTSD; n = 65), its dissociative subtype (PTSD + DS; n = 37), and non-trauma-exposed healthy controls (HC; n = 47). Here, we observed decreased functional connectivity of the anterior cerebellum and anterior vermis with brain regions involved in somatosensory processing, multisensory integration, and bodily self-consciousness (temporo-parietal junction, postcentral gyrus, and superior parietal lobule) in PTSD + DS as compared to PTSD and HC. Moreover, the PTSD + DS group showed increased functional connectivity of the posterior cerebellum with cortical areas related to emotion regulation (ventromedial prefrontal and orbito-frontal cortex, subgenual anterior cingulum) as compared to PTSD. By contrast, PTSD showed increased functional connectivity of the anterior cerebellum with cortical areas associated with visual processing (fusiform gyrus), interoceptive awareness (posterior insula), memory retrieval, and contextual processing (hippocampus) as compared to HC. Finally, we observed decreased functional connectivity between the posterior cerebellum and prefrontal regions involved in emotion regulation, in PTSD as compared to HC. These findings not only highlight the crucial role of each cerebellar region examined in the psychopathology of PTSD but also reveal unique alterations in functional connectivity distinguishing the dissociative subtype of PTSD versus PTSD.
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Affiliation(s)
- Daniela Rabellino
- Department of PsychiatryUniversity of Western OntarioLondonOntarioCanada
- Imaging DivisionLawson Health Research InstituteLondonOntarioCanada
| | - Maria Densmore
- Department of PsychiatryUniversity of Western OntarioLondonOntarioCanada
- Imaging DivisionLawson Health Research InstituteLondonOntarioCanada
| | - Jean Théberge
- Department of PsychiatryUniversity of Western OntarioLondonOntarioCanada
- Imaging DivisionLawson Health Research InstituteLondonOntarioCanada
- Department of Medical BiophysicsUniversity of Western OntarioLondonOntarioCanada
| | - Margaret C. McKinnon
- Mood Disorders Program, St. Joseph's HealthcareHamiltonOntarioCanada
- Department of Psychiatry and Behavioural NeurosciencesMcMaster UniversityHamiltonOntarioCanada
- Homewood Research InstituteGuelphOntarioCanada
| | - Ruth A. Lanius
- Department of PsychiatryUniversity of Western OntarioLondonOntarioCanada
- Imaging DivisionLawson Health Research InstituteLondonOntarioCanada
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20
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Abstract
Attentional blink (AB) refers to the situation where correctly identifying a target impairs the processing of a subsequent probe in a sequence of stimuli. Although the AB often coincides with a modulation of scalp-recorded cognitive event-related potentials (ERPs), the neural sources of this effect remain unclear. In two separate experiments, we used classical LORETA analysis recursively applied (CLARA) to estimate the neural sources of ERPs elicited by an auditory probe when it immediately followed an auditory target (i.e., AB condition), when no auditory target was present (i.e., no-AB condition), and when the probe followed an auditory target but occurred outside of the AB time window (i.e., no-AB condition). We observed a processing deficit when the probe immediately followed the target, and this auditory AB was accompanied by reduced P3b amplitude. Contrasting brain electrical source activity from the AB and no-AB conditions revealed reduced source activity in the medial temporal region as well as in the temporoparietal junction (extending into inferior parietal lobe), ventromedial prefrontal cortex, left anterior thalamic nuclei, mammillary body, and left cerebellum. The results indicate that successful probe identification following a target relies on a widely distributed brain network and further support the suggestion that the auditory AB reflects the failure of the probe to reach short-term consolidation. NEW & NOTEWORTHY Within a rapid succession of auditory stimuli, the perception of a predefined target sound often impedes listeners' ability to detect another target sound that is presented close in succession. This attentional blink may be related to activity in brain areas supporting attention and memory. We show that the auditory attentional blink is associated with brain activity changes in a network including the medial temporal lobe, parietal cortex, and prefrontal cortex. This study suggests that a problem in the interaction between attention and memory underlies the auditory attentional blink.
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Affiliation(s)
- Dawei Shen
- Rotman Research Institute, Baycrest Centre for Geriatric Care , Toronto, Ontario , Canada
| | - Dominique T Vuvan
- Department of Psychology, Skidmore College , Saratoga Springs, New York
| | - Claude Alain
- Rotman Research Institute, Baycrest Centre for Geriatric Care , Toronto, Ontario , Canada.,Department of Psychology, University of Toronto , Toronto, Ontario , Canada.,Institute of Medical Sciences, University of Toronto , Toronto, Ontario , Canada
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21
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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: 127] [Impact Index Per Article: 18.1] [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.
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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.
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22
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Vitorino R, Hojjat SP, Cantrell CG, Feinstein A, Zhang L, Lee L, O'Connor P, Carroll TJ, Aviv RI. Regional Frontal Perfusion Deficits in Relapsing-Remitting Multiple Sclerosis with Cognitive Decline. AJNR Am J Neuroradiol 2016; 37:1800-1807. [PMID: 27197989 DOI: 10.3174/ajnr.a4824] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Accepted: 03/17/2016] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND PURPOSE Cortical dysfunction, quantifiable by cerebral perfusion techniques, is prevalent in patients with MS, contributing to cognitive impairment. We sought to localize perfusion distribution differences in patients with relapsing-remitting MS with and without cognitive impairment and healthy controls. MATERIALS AND METHODS Thirty-nine patients with relapsing-remitting MS (20 cognitively impaired, 19 nonimpaired) and 19 age- and sex-matched healthy controls underwent a neurocognitive battery and MR imaging. Voxel-based analysis compared regional deep and cortical GM perfusion and volume among the cohorts. RESULTS After we adjusted for localized volumetric differences in the right frontal, temporal, and occipital lobes, progressive CBF and CBV deficits were present in the left middle frontal cortex for all cohorts and in the left superior frontal gyrus for patients with cognitive impairment compared with patients without impairment and controls. Compared with healthy controls, reduced CBF was present in the limbic regions of patients with cognitive impairment, and reduced CBV was present in the right middle frontal gyrus in patients with cognitive impairment and in the temporal gyrus of relapsing-remitting MS patients without cognitive impairment. CONCLUSIONS Consistent regional frontal cortical perfusion deficits are present in patients with relapsing-remitting MS, with more widespread hypoperfusion in those with cognitive impairment, independent of structural differences, indicating that cortical perfusion may be a useful biomarker of cortical dysfunction and cognitive impairment in MS.
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Affiliation(s)
- R Vitorino
- Medical Imaging (R.V., S.-P.H., L.Z., R.I.A.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - S-P Hojjat
- Medical Imaging (R.V., S.-P.H., L.Z., R.I.A.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
- Medical Imaging (S.-P.H., R.I.A.), University of Toronto, Toronto, Ontario, Canada
| | - C G Cantrell
- Departments of Biomedical Engineering (C.G.C., T.J.C)
| | - A Feinstein
- From the Departments of Psychiatry (A.F.)
- Psychiatry (A.F.)
| | - L Zhang
- Medical Imaging (R.V., S.-P.H., L.Z., R.I.A.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
| | - L Lee
- Neurology (L.L.)
- Departments of Medicine (L.L., P.O.)
| | | | - T J Carroll
- Departments of Biomedical Engineering (C.G.C., T.J.C)
- Radiology (T.J.C.), Northwestern University, Chicago, Illinois
| | - R I Aviv
- Medical Imaging (R.V., S.-P.H., L.Z., R.I.A.), Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada
- Medical Imaging (S.-P.H., R.I.A.), University of Toronto, Toronto, Ontario, Canada
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23
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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: 26] [Impact Index Per Article: 3.3] [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.
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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
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24
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Sneve MH, Grydeland H, Amlien IK, Langnes E, Walhovd KB, Fjell AM. Decoupling of large-scale brain networks supports the consolidation of durable episodic memories. Neuroimage 2016; 153:336-345. [PMID: 27215795 DOI: 10.1016/j.neuroimage.2016.05.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 05/18/2016] [Indexed: 01/24/2023] Open
Abstract
At a large scale, the human brain is organized into modules of interconnected regions, some of which play opposing roles in supporting cognition. In particular, the Default-Mode Network (DMN) has been linked to operations on internal representations, while task-positive networks are recruited during interactions with the external world. Here, we test the hypothesis that the generation of durable long-term memories depends on optimal recruitment of such antagonistic large-scale networks. As long-term memory consolidation is a process ongoing for days and weeks after an experience, we propose that individuals characterized by strong decoupling of the DMN and task-positive networks at rest operate in a mode beneficial for the long-term stabilization of episodic memories. To capture network connectivity unaffected by transient task demands and representative of brain behavior outside an experimental setting, 87 participants were scanned during rest before performing an associative encoding task. To link individual resting-state functional connectivity patterns to time-dependent memory consolidation processes, participants were given an unannounced memory test, either after a brief interval or after a retention period of ~6 weeks. We found that participants with a resting state characterized by high synchronicity in a DMN-centered network system and low synchronicity between task-positive networks showed superior recollection weeks after encoding. These relationships were not observed for information probed only hours after encoding. Furthermore, the two network systems were found to be anticorrelated. Our results suggest that this memory-relevant antagonism between DMN and task-positive networks is maintained through complex regulatory interactions between the systems.
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Affiliation(s)
- Markus H Sneve
- Center for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway.
| | - Håkon Grydeland
- Center for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
| | - Inge K Amlien
- Center for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
| | - Espen Langnes
- Center for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway
| | - Kristine B Walhovd
- Center for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway; Department of Physical medicine and rehabilitation, Unit of neuropsychology, Oslo University Hospital, Norway
| | - Anders M Fjell
- Center for Lifespan Changes in Brain and Cognition, Department of Psychology, University of Oslo, Norway; Department of Physical medicine and rehabilitation, Unit of neuropsychology, Oslo University Hospital, Norway
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25
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Dede AJO, Smith CN. The Functional and Structural Neuroanatomy of Systems Consolidation for Autobiographical and Semantic Memory. Curr Top Behav Neurosci 2016; 37:119-150. [PMID: 27677778 DOI: 10.1007/7854_2016_452] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It is well established that patients with memory impairment have more difficulty retrieving memories from the recent past relative to the remote past and that damage to the medial temporal lobe (MTL) plays a key role in this pattern of impairment. The precise role of the MTL and how it may interact with other brain regions remains an area of active research. We investigated the role of structures in a memory network that supports remembering. Our chapter focuses on two types of memory: episodic memory and semantic memory. Findings from studies of patients with brain damage and neuroimaging studies in patients and healthy individuals were considered together to identify the functional and structural neuroanatomy of past remembrance.
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Affiliation(s)
- Adam J O Dede
- Department of Psychology, University of California San Diego, San Diego, CA, 92093, USA
- Veteran Affairs San Diego Healthcare System, 3350 La Jolla Village Drive (116A), San Diego, CA, 92161, USA
| | - Christine N Smith
- Department of Psychiatry, University of California San Diego, San Diego, CA, 92093, USA.
- Veteran Affairs San Diego Healthcare System, 3350 La Jolla Village Drive (116A), San Diego, CA, 92161, USA.
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26
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Lesser Neural Pattern Similarity across Repeated Tests Is Associated with Better Long-Term Memory Retention. J Neurosci 2015; 35:9595-602. [PMID: 26134642 DOI: 10.1523/jneurosci.3550-14.2015] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Encoding and retrieval processes enhance long-term memory performance. The efficiency of encoding processes has recently been linked to representational consistency: the reactivation of a representation that gets more specific each time an item is further studied. Here we examined the complementary hypothesis of whether the efficiency of retrieval processes also is linked to representational consistency. Alternatively, recurrent retrieval might foster representational variability--the altering or adding of underlying memory representations. Human participants studied 60 Swahili-Swedish word pairs before being scanned with fMRI the same day and 1 week later. On Day 1, participants were tested three times on each word pair, and on Day 7 each pair was tested once. A BOLD signal change in right superior parietal cortex was associated with subsequent memory on Day 1 and with successful long-term retention on Day 7. A representational similarity analysis in this parietal region revealed that beneficial recurrent retrieval was associated with representational variability, such that the pattern similarity on Day 1 was lower for retrieved words subsequently remembered compared with those subsequently forgotten. This was mirrored by a monotonically decreased BOLD signal change in dorsolateral prefrontal cortex on Day 1 as a function of repeated successful retrieval for words subsequently remembered, but not for words subsequently forgotten. This reduction in prefrontal response could reflect reduced demands on cognitive control. Collectively, the results offer novel insights into why memory retention benefits from repeated retrieval, and they suggest fundamental differences between repeated study and repeated testing. SIGNIFICANCE STATEMENT Repeated testing is known to produce superior long-term retention of the to-be-learned material compared with repeated encoding and other learning techniques, much because it fosters repeated memory retrieval. This study demonstrates that repeated memory retrieval might strengthen memory by inducing more differentiated or elaborated memory representations in the parietal cortex, and at the same time reducing demands on prefrontal-cortex-mediated cognitive control processes during retrieval. The findings contrast with recent demonstrations that repeated encoding induces less differentiated or elaborated memory representations. Together, this study suggests a potential neurocognitive explanation of why repeated retrieval is more beneficial for long-term retention than repeated encoding, a phenomenon known as the testing effect.
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27
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Initial investigation of the effects of an experimentally learned schema on spatial associative memory in humans. J Neurosci 2015; 34:16662-70. [PMID: 25505319 DOI: 10.1523/jneurosci.2365-14.2014] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Networks of interconnected neocortical representations of prior knowledge, "schemas," facilitate memory for congruent information. This facilitation is thought to be mediated by augmented encoding and accelerated consolidation. However, it is less clear how schema affects retrieval. Rodent and human studies to date suggest that schema-related memories are differently retrieved. However, these studies differ substantially as most human studies implement pre-experimental world-knowledge as schemas and tested item or nonspatial associative memory, whereas animal studies have used intraexperimental schemas based on item-location associations within a complex spatial layout that, in humans, could engage more strategic retrieval processes. Here, we developed a paradigm conceptually linked to rodent studies to examine the effects of an experimentally learned spatial associative schema on learning and retrieval of new object-location associations and to investigate the neural mechanisms underlying schema-related retrieval. Extending previous findings, we show that retrieval of schema-defining associations is related to activity along anterior and posterior midline structures and angular gyrus. The existence of such spatial associative schema resulted in more accurate learning and retrieval of new, related associations, and increased time allocated to retrieve these associations. This retrieval was associated with right dorsolateral prefrontal and lateral parietal activity, as well as interactions between the right dorsolateral prefrontal cortex and medial and lateral parietal regions, and between the medial prefrontal cortex and posterior midline regions, supporting the hypothesis that retrieval of new, schema-related object-location associations in humans also involves augmented monitoring and systematic search processes.
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28
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When you smile, you become happy: Evidence from resting state task-based fMRI. Biol Psychol 2014; 103:100-6. [DOI: 10.1016/j.biopsycho.2014.08.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 06/05/2014] [Accepted: 08/08/2014] [Indexed: 11/18/2022]
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Painold A, Faber PL, Milz P, Reininghaus EZ, Holl AK, Letmaier M, Pascual-Marqui RD, Reininghaus B, Kapfhammer HP, Lehmann D. Brain electrical source imaging in manic and depressive episodes of bipolar disorder. Bipolar Disord 2014; 16:690-702. [PMID: 24636537 DOI: 10.1111/bdi.12198] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 11/12/2013] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Bipolar disorder (BD) electroencephalographic (EEG) studies have reported varying results. The present study compared EEG in BD during manic and depressive episodes, using brain electrical source imaging [standardized low-resolution electromagnetic tomography (sLORETA)] to assess the cortical spatial distribution of the sources of EEG oscillation frequencies. METHODS Two independent datasets (a total of 95 patients with bipolar I disorder, of whom 59 were female) were analyzed. Dataset #1 comprised 14 patients in a manic as well as a depressive episode. Dataset #2 comprised 26 patients in a manic episode and 55 patients in a depressive episode. From the head surface-recorded EEG, sLORETA cortical activity was computed in eight EEG frequency bands, and compared between mood states in both datasets. The results from the two datasets were combined using conjunction analysis. RESULTS Conjunction analysis yielded significant differences between mood states: In manic compared to depressive states, patients had lesser theta frequency band activity (right-hemispheric lateral lower prefrontal and anterior temporal, mainly Brodmann areas 13, 38, and 47), and greater beta-2 and beta-3 frequency band activity (extended bilateral prefrontal-to-parietal, mainly Brodmann area 6, and the cingulate). CONCLUSIONS The spatial organization of the brain's electrical oscillations differed in patients with BD between manic and depressive mood states. The brain areas implementing the main functions that show opposing abnormalities during manic and depressive episodes were affected by unduly increased or decreased activity (beta or theta). The discussion considers that facilitating (beta) or inhibiting (theta) electrical activity can in either case result in behavioral facilitation or inhibition, depending on the function of the brain area.
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Cox R, Hofman WF, de Boer M, Talamini LM. Local sleep spindle modulations in relation to specific memory cues. Neuroimage 2014; 99:103-10. [DOI: 10.1016/j.neuroimage.2014.05.028] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/11/2014] [Indexed: 11/24/2022] Open
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31
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van Kesteren MTR, Rijpkema M, Ruiter DJ, Morris RGM, Fernández G. Building on Prior Knowledge: Schema-dependent Encoding Processes Relate to Academic Performance. J Cogn Neurosci 2014; 26:2250-61. [DOI: 10.1162/jocn_a_00630] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
The acquisition and retention of conceptual knowledge is more effective in well-structured curricula that provide an optimal conceptual framework for learning new material. However, the neural mechanisms by which preexisting conceptual schemas facilitate learning are not yet well understood despite their fundamental importance. A preexisting schema has been shown to enhance memory by influencing the balance between activity within the medial-temporal lobe and the medial pFC during mnemonic processes such as encoding, consolidation, and retrieval. Specifically, correctly encoding and retrieving information that is related to preexisting schemas appears rather related to medial prefrontal processing, whereas information unrelated or inconsistent with preexisting schemas rather relates to enhanced medial temporal processing and enhanced interaction between these structures. To further investigate interactions between these regions during conceptual encoding in a real-world university setting, we probed human brain activity and connectivity using fMRI during educationally relevant conceptual encoding carefully embedded within two course programs. Early second-year undergraduate biology and education students were scanned while encoding new facts that were either related or unrelated to the preexisting conceptual knowledge they had acquired during their first year of study. Subsequently, they were tested on their knowledge of these facts 24 hr later. Memory scores were better for course-related information, and this enhancement was associated with larger medial-prefrontal, but smaller medial-temporal subsequent memory effects. These activity differences went along with decreased functional interactions between these regions. Furthermore, schema-related medial-prefrontal subsequent memory effects measured during this experiment were found to be predictive of second-year course performance. These results, obtained in a real-world university setting, reveal brain mechanisms underlying acquisition of new knowledge that can be integrated into preexisting conceptual schemas and may indicate how relevant this process is for study success.
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Affiliation(s)
| | | | | | | | - Guillén Fernández
- 1Radboud University Nijmegen
- 2Radboud University Nijmegen Medical Centre
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de Fátima Oliveira-Silva I, Pereira SRC, Fernandes PA, Ribeiro AF, Pires RGW, Ribeiro AM. Mild thiamine deficiency and chronic ethanol consumption modulate acetylcholinesterase activity change and spatial memory performance in a water maze task. J Mol Neurosci 2014; 55:217-226. [PMID: 24770900 DOI: 10.1007/s12031-014-0306-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 04/08/2014] [Indexed: 11/25/2022]
Abstract
Chronic thiamine deficiency may be responsible for pathologic changes in the brains of alcoholics, and subclinical episodes of this vitamin deficiency may cause cumulative brain damage. In the present work, the chronic effects of ethanol and its association to a mild thiamine deficiency episode (subclinical model) on neocortical and hippocampal acetylcholinesterase activity were assessed along with their possible association to spatial cognitive dysfunction. The results indicate that in the beginning of the neurodegenerative process, before the appearance of brain lesions, chronic ethanol consumption reverses the effects of mild thiamine deficiency on both spatial cognitive performance and acetylcholinesterase activity without having significant effects on any morphometric parameter.
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Affiliation(s)
- Ieda de Fátima Oliveira-Silva
- Departamento de Análises Clínicas e Toxicológicas - Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Silvia R Castanheira Pereira
- Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Paula A Fernandes
- Departamento de Análises Clínicas e Toxicológicas - Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Andrea F Ribeiro
- Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Rita G W Pires
- Departamento de Ciências Fisiológicas/Centro Biomédico-Laboratório de Neurobiologia Molecular e Comportamental, Universidade Federal do Espírito Santo, Vitória, 29043-910, Brazil
| | - Angela Maria Ribeiro
- Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil.
- Departamento de Bioquímica e Imunologia, Laboratório de Neurociências Comportamental e Molecular, LaNeC, Faculdade de Filosofia e Ciências Humanas, FaFiCH, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil.
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33
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Neural mechanisms supporting the extraction of general knowledge across episodic memories. Neuroimage 2014; 87:138-46. [DOI: 10.1016/j.neuroimage.2013.10.063] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 09/22/2013] [Accepted: 10/28/2013] [Indexed: 11/17/2022] Open
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Abstract
To make adaptive choices, humans need to estimate the probability of future events. Based on a Bayesian approach, it is assumed that probabilities are inferred by combining a priori, potentially subjective, knowledge with factual observations, but the precise neurobiological mechanism remains unknown. Here, we study whether neural encoding centers on subjective posterior probabilities, and data merely lead to updates of posteriors, or whether objective data are encoded separately alongside subjective knowledge. During fMRI, young adults acquired prior knowledge regarding uncertain events, repeatedly observed evidence in the form of stimuli, and estimated event probabilities. Participants combined prior knowledge with factual evidence using Bayesian principles. Expected reward inferred from prior knowledge was encoded in striatum. BOLD response in specific nodes of the default mode network (angular gyri, posterior cingulate, and medial prefrontal cortex) encoded the actual frequency of stimuli, unaffected by prior knowledge. In this network, activity increased with frequencies and thus reflected the accumulation of evidence. In contrast, Bayesian posterior probabilities, computed from prior knowledge and stimulus frequencies, were encoded in bilateral inferior frontal gyrus. Here activity increased for improbable events and thus signaled the violation of Bayesian predictions. Thus, subjective beliefs and stimulus frequencies were encoded in separate cortical regions. The advantage of such a separation is that objective evidence can be recombined with newly acquired knowledge when a reinterpretation of the evidence is called for. Overall this study reveals the coexistence in the brain of an experience-based system of inference and a knowledge-based system of inference.
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35
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Behrendt RP. Conscious experience and episodic memory: hippocampus at the crossroads. Front Psychol 2013; 4:304. [PMID: 23755033 PMCID: PMC3667233 DOI: 10.3389/fpsyg.2013.00304] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Accepted: 05/13/2013] [Indexed: 12/21/2022] Open
Abstract
If an instance of conscious experience of the seemingly objective world around us could be regarded as a newly formed event memory, much as an instance of mental imagery has the content of a retrieved event memory, and if, therefore, the stream of conscious experience could be seen as evidence for ongoing formation of event memories that are linked into episodic memory sequences, then unitary conscious experience could be defined as a symbolic representation of the pattern of hippocampal neuronal firing that encodes an event memory – a theoretical stance that may shed light into the mind-body and binding problems in consciousness research. Exceedingly detailed symbols that describe patterns of activity rapidly self-organizing, at each cycle of the θ rhythm, in the hippocampus are instances of unitary conscious experience that jointly constitute the stream of consciousness. Integrating object information (derived from the ventral visual stream and orbitofrontal cortex) with contextual emotional information (from the anterior insula) and spatial environmental information (from the dorsal visual stream), the hippocampus rapidly forms event codes that have the informational content of objects embedded in an emotional and spatiotemporally extending context. Event codes, formed in the CA3-dentate network for the purpose of their memorization, are not only contextualized but also allocentric representations, similarly to conscious experiences of events and objects situated in a seemingly objective and observer-independent framework of phenomenal space and time. Conscious perception, creating the spatially and temporally extending world that we perceive around us, is likely to be evolutionarily related to more fleeting and seemingly internal forms of conscious experience, such as autobiographical memory recall, mental imagery, including goal anticipation, and to other forms of externalized conscious experience, namely dreaming and hallucinations; and evidence pointing to an important contribution of the hippocampus to these conscious phenomena will be reviewed.
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Affiliation(s)
- Ralf-Peter Behrendt
- Elderly Mental Health Team, Princess Elizabeth Hospital St Martin, Guernsey, UK
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36
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Anterior cingulate cortex and cognitive control: neuropsychological and electrophysiological findings in two patients with lesions to dorsomedial prefrontal cortex. Brain Cogn 2012; 80:237-49. [PMID: 22935543 DOI: 10.1016/j.bandc.2012.07.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2012] [Revised: 06/22/2012] [Accepted: 07/25/2012] [Indexed: 12/30/2022]
Abstract
Whereas neuroimaging studies of healthy subjects have demonstrated an association between the anterior cingulate cortex (ACC) and cognitive control functions, including response monitoring and error detection, lesion studies are sparse and have produced mixed results. Due to largely normal behavioral test results in two patients with medial prefrontal lesions, a hypothesis has been advanced claiming that the ACC is not involved in cognitive operations. In the current study, two comparably rare patients with unilateral lesions to dorsal medial prefrontal cortex (MPFC) encompassing the ACC were assessed with neuropsychological tests as well as Event-Related Potentials in two experimental paradigms known to engage prefrontal cortex (PFC). These included an auditory Novelty Oddball task and a visual Stop-signal task. Both patients performed normally on the Stroop test but showed reduced performance on tests of learning and memory. Moreover, altered attentional control was reflected in a diminished Novelty P3, whereas the posterior P3b to target stimuli was present in both patients. The error-related negativity, which has been hypothesized to be generated in the ACC, was present in both patients, but alterations of inhibitory behavior were observed. Although interpretative caution is generally called for in single case studies, and the fact that the lesions extended outside the ACC, the findings nevertheless suggest a role for MPFC in cognitive control that is not restricted to error monitoring.
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37
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Arsalidou M, Duerden EG, Taylor MJ. The centre of the brain: topographical model of motor, cognitive, affective, and somatosensory functions of the basal ganglia. Hum Brain Mapp 2012; 34:3031-54. [PMID: 22711692 DOI: 10.1002/hbm.22124] [Citation(s) in RCA: 146] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2012] [Revised: 04/09/2012] [Accepted: 04/20/2012] [Indexed: 01/11/2023] Open
Abstract
The basal ganglia have traditionally been viewed as motor processing nuclei; however, functional neuroimaging evidence has implicated these structures in more complex cognitive and affective processes that are fundamental for a range of human activities. Using quantitative meta-analysis methods we assessed the functional subdivisions of basal ganglia nuclei in relation to motor (body and eye movements), cognitive (working-memory and executive), affective (emotion and reward) and somatosensory functions in healthy participants. We document affective processes in the anterior parts of the caudate head with the most overlap within the left hemisphere. Cognitive processes showed the most widespread response, whereas motor processes occupied more central structures. On the basis of these demonstrated functional roles of the basal ganglia, we provide a new comprehensive topographical model of these nuclei and insight into how they are linked to a wide range of behaviors.
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Affiliation(s)
- Marie Arsalidou
- Diagnostic Imaging and Research Institute, Hospital for Sick Children, Toronto, Canada
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38
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Memory stabilization with targeted reactivation during human slow-wave sleep. Proc Natl Acad Sci U S A 2012; 109:10575-80. [PMID: 22691500 DOI: 10.1073/pnas.1201072109] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
It is believed that neural representations of recent experiences become reactivated during sleep, and that this process serves to stabilize associated memories in long-term memory. Here, we initiated this reactivation process for specific memories during slow-wave sleep. Participants studied 50 object-location associations with object-related sounds presented concurrently. For half of the associations, the related sounds were re-presented during subsequent slow-wave sleep while participants underwent functional MRI. Compared with control sounds, related sounds were associated with increased activation of right parahippocampal cortex. Postsleep memory accuracy was positively correlated with sound-related activation during sleep in various brain regions, including the thalamus, bilateral medial temporal lobe, and cerebellum. In addition, postsleep memory accuracy was also positively correlated with pre- to postsleep changes in parahippocampal-medial prefrontal connectivity during retrieval of reactivated associations. Our results suggest that the brain is differentially activated by studied and unstudied sounds during deep sleep and that the thalamus and medial temporal lobe are involved in establishing the mnemonic consequences of externally triggered reactivation of associative memories.
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39
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Nieuwenhuis ILC, Takashima A, Oostenveld R, McNaughton BL, Fernández G, Jensen O. The neocortical network representing associative memory reorganizes with time in a process engaging the anterior temporal lobe. ACTA ACUST UNITED AC 2011; 22:2622-33. [PMID: 22139815 DOI: 10.1093/cercor/bhr338] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
During encoding, the distributed neocortical representations of memory components are presumed to be associatively linked by the hippocampus. With time, a reorganization of brain areas supporting memory takes place, which can ultimately result in memories becoming independent of the hippocampus. While it is theorized that with time, the neocortical representations become linked by higher order neocortical association areas, this remains to be experimentally supported. In this study, 24 human participants encoded sets of face-location associations, which they retrieved 1 or 25 h later ("recent" and "remote" conditions, respectively), while their brain activity was recorded using whole-head magnetoencephalography. We investigated changes in the functional interactions between the neocortical representational areas emerging over time. To assess functional interactions, trial-by-trial high gamma (60-140 Hz) power correlations were calculated between the neocortical representational areas relevant to the encoded information, namely the fusiform face area (FFA) and posterior parietal cortex (PPC). With time, both the FFA and the PPC increased their functional interactions with the anterior temporal lobe (ATL). Given that the ATL is involved in semantic representation of paired associates, our results suggest that, already within 25 h after acquiring new memory associations, neocortical functional links are established via higher order semantic association areas.
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Affiliation(s)
- Ingrid L C Nieuwenhuis
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, 6500 HB Nijmegen, The Netherlands.
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40
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Rewiring the brain with repeated retrieval: A parametric fMRI study of the testing effect. Neurosci Lett 2011; 505:36-40. [DOI: 10.1016/j.neulet.2011.08.061] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2011] [Revised: 08/19/2011] [Accepted: 08/31/2011] [Indexed: 11/23/2022]
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41
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Neural enhancement and attenuation induced by repetitive recall. Neurobiol Learn Mem 2011; 96:143-9. [DOI: 10.1016/j.nlm.2011.03.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2010] [Revised: 03/22/2011] [Accepted: 03/28/2011] [Indexed: 11/18/2022]
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42
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Functional connectivity during light sleep is correlated with memory performance for face-location associations. Neuroimage 2011; 57:262-270. [PMID: 21514391 DOI: 10.1016/j.neuroimage.2011.04.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 03/31/2011] [Accepted: 04/07/2011] [Indexed: 11/24/2022] Open
Abstract
The consolidation of declarative memories benefits from sleep. The neural mechanisms involved in sleep-dependent consolidation, however, are largely unknown. Here, we used a combination of functional magnetic resonance imaging, polysomnography and a face-location associative memory task to target neural connectivity of a face sensitive area during an afternoon nap. Fusiform connectivity was substantially greater during sleep stage 1 than in wake in a network extending from early visual areas bilaterally to the fusiform gyrus, ventrally and into the posterior parietal cortices, dorsally. In sleep stage 2, fusiform connectivity was found to be larger in the precuneus, bilateral middle temporal gyrus and medial prefrontal cortex. Specific functional connectivity increases observed during light sleep were positively correlated with memory performance for face-location associations. A distinction could be made between fusiform-medial prefrontal connectivity during sleep stage 1 and 2 that was positively correlated with retention of associations learned prior to sleep and fusiform-hippocampal connectivity during sleep stage 1 that was correlated with better acquisition of new associations learned after sleep. Our results suggest that fusiform-medial prefrontal connectivity during sleep has a stabilizing effect on recently learned associative memories, possibly due to the existence of a task-related schema that allows rapid consolidation of related information. Our data further indicate that sleep-dependent connectivity between the fusiform gyrus and hippocampus correlated with new learning after sleep. Thus, our study provides correlational evidence for the behavioral relevance of specific medial prefrontal and hippocampal interactions with the fusiform gyrus during light sleep.
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43
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Sleep effects on slow-brain-potential reflections of associative learning. Biol Psychol 2011; 86:219-29. [DOI: 10.1016/j.biopsycho.2010.12.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/12/2010] [Accepted: 12/12/2010] [Indexed: 10/18/2022]
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44
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Retrieval of associative information congruent with prior knowledge is related to increased medial prefrontal activity and connectivity. J Neurosci 2010; 30:15888-94. [PMID: 21106827 DOI: 10.1523/jneurosci.2674-10.2010] [Citation(s) in RCA: 158] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We remember information that is congruent instead of incongruent with prior knowledge better, but the underlying neural mechanisms related to this enhancement are still relatively unknown. Recently, this memory enhancement due to a prior schema has been suggested to be based on rapid neocortical assimilation of new information, related to optimized encoding and consolidation processes. The medial prefrontal cortex (mPFC) is thought to be important in mediating this process, but its role in retrieval of schema-consistent information is still unclear. In this study, we regarded multisensory congruency with prior knowledge as a schema and used this factor to probe retrieval of consolidated memories either consistent or inconsistent with prior knowledge. We conducted a visuotactile learning paradigm in which participants studied visual motifs randomly associated with word-fabric combinations that were either congruent or incongruent with common knowledge. The next day, participants were scanned using functional magnetic resonance imaging while their memory was tested. Congruent associations were remembered better than incongruent ones. This behavioral finding was parallelized by stronger retrieval-related activity in and connectivity between medial prefrontal and left somatosensory cortex. Moreover, we found a positive across-subject correlation between the connectivity enhancement and the behavioral congruency effect. These results show that successful retrieval of congruent compared to incongruent visuotactile associations is related to enhanced processing in an mPFC-somatosensory network, and support the hypothesis that new information that fits a preexisting schema is more rapidly assimilated in neocortical networks, a process that may be mediated, at least in part, by the mPFC.
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45
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Picchioni D, Horovitz SG, Fukunaga M, Carr WS, Meltzer JA, Balkin TJ, Duyn JH, Braun AR. Infraslow EEG oscillations organize large-scale cortical-subcortical interactions during sleep: a combined EEG/fMRI study. Brain Res 2010; 1374:63-72. [PMID: 21168395 DOI: 10.1016/j.brainres.2010.12.035] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Revised: 12/06/2010] [Accepted: 12/10/2010] [Indexed: 11/28/2022]
Abstract
Infraslow (<0.1 Hz) oscillations of brain activity, measured by EEG and other methods, have become a subject of increasing interest. While their prominence during sleep has been established, the functional significance of these oscillations for sleep physiology is unknown. To clarify this role, we examined correlations between infraslow EEG oscillations and BOLD fMRI during the course of natural sleep in healthy volunteers. Infraslow EEG oscillations appear to organize a broad dissociation of activity in cortical and subcortical regions: in general, correlations between power in the infraslow EEG band and BOLD were positive in subcortical regions and negative in the cortex. Robust negative correlations were found principally in paramedian heteromodal cortices whereas positive correlations were seen in cerebellum, thalamus, basal ganglia, lateral neocortices and hippocampus. This pattern of correlations suggests a mechanism by which infraslow oscillations may organize sleep-dependent neuroplastic processes including consolidation of episodic memory.
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Affiliation(s)
- Dante Picchioni
- Department of Behavioral Biology, Walter Reed Army Institute of Research, Silver Spring, MD 20910, USA.
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46
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Nieuwenhuis ILC, Takashima A. The role of the ventromedial prefrontal cortex in memory consolidation. Behav Brain Res 2010; 218:325-34. [PMID: 21147169 DOI: 10.1016/j.bbr.2010.12.009] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2010] [Accepted: 12/07/2010] [Indexed: 11/15/2022]
Abstract
"System-level memory consolidation theory" posits that the hippocampus an initially links the neocortical representations, followed by a shift to a hippocampus-independent neocortical network. With consolidation, an increase in activity in the human subgenual ventromedial prefrontal cortex (vmPFC) has repeatedly been shown. Previously we and others have proposed that this area might link the neocortical representational areas in remote memory, similarly as has been proposed for the rodent anterior cingulate cortex (ACC). Here, we review literature involving the human vmPFC to investigate if the results in other cognitive domains are in line with this proposal. We have taken into account reports on patients with lesions in this area, findings in reward and valuation, fear extinction, and confabulation studies, and integrated these with findings in consolidation studies. We conclude: Firstly, it is unlikely that the rodent ACC is homolog to the human subgenual vmPFC. It is more likely that the rodent infralimbic cortex is, as proposed in the fear extinction literature. Secondly, we propose that the function of the subgenual vmPFC is to integrate information which is represented in separate parts of the limbic system (the hippocampus, the amygdala, and the ventral striatum) and that the integrated representation in the subgenual vmPFC might subsequently be used to suppress irrelevant representations in the limbic system. With the progression of time, the importance of the integrated representation in the subgenual vmPFC increases, because it may replace some direct connectivity across the limbic areas which decays with time.
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Affiliation(s)
- Ingrid L C Nieuwenhuis
- Sleep and Neuroimaging Laboratory, Department of Psychology, University of California, Tolman Hall 3331, Berkeley, CA 94720-1650, USA
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47
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Abstract
The generalization of learning from trained to untrained conditions is of great potential value because it markedly increases the efficacy of practice. In principle, generalization and the learning itself could arise from either the same or distinct neural changes. Here, we assessed these two possibilities in the realm of human perceptual learning by comparing the time course of improvement on a trained condition (learning) to that on an untrained condition (generalization) for an auditory temporal-interval discrimination task. While significant improvement on the trained condition occurred within 2 d, generalization to the untrained condition lagged behind, only emerging after 4 d. The different time courses for learning and generalization suggest that these two types of perceptual improvement can arise from at least partially distinct neural changes. The notably longer time course for generalization than learning demonstrates that increasing the duration of training can be an effective means to increase the number of conditions to which learning generalizes on perceptual tasks.
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48
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Banai K, Ortiz JA, Oppenheimer JD, Wright BA. Learning two things at once: differential constraints on the acquisition and consolidation of perceptual learning. Neuroscience 2010; 165:436-44. [PMID: 19883735 DOI: 10.1016/j.neuroscience.2009.10.060] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2009] [Revised: 10/12/2009] [Accepted: 10/28/2009] [Indexed: 11/16/2022]
Abstract
Learning is often prevented by events that occur after training, an outcome that is usually attributed to the disruption of consolidation-the transfer of learning to long-term memory. Here, we provide evidence from perceptual learning that improvements in performance can also be blocked by intervening events that occur during the acquisition phase of learning-the period of active practice. Listeners improved on each of two conditions of auditory temporal-interval discrimination (100 and 350 ms) when the two were practiced consecutively, even though that is a classic disruption-of-consolidation regimen. However, when practice on these two conditions was interleaved, there was no learning on either condition. The failure to improve in the interleaved case indicates that, at least in some circumstances, learning can be prevented during acquisition by events that do not disrupt consolidation itself. These results thus suggest that acquisition and consolidation are distinct phases in human learning.
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Affiliation(s)
- K Banai
- Department of Communication Sciences and Disorders, University of Haifa, Haifa, Israel.
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49
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Abstract
Every day we store memories of innumerable new experiences. Our extraordinary ability to retrieve so many of them at a later time is due in no small part to the consolidation of these memories, a process that continues offline long after the experiences themselves are over.
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50
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Formation of long-term memory representation in human temporal cortex related to pictorial paired associates. J Neurosci 2009; 29:10335-40. [PMID: 19692607 DOI: 10.1523/jneurosci.1328-09.2009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
It is widely held that long-term memory gradually develops in the temporal neocortex after initial memory encoding into the hippocampus. However, little is known as to whether and where long-term memory can be newly created in the human temporal neocortex. In this functional magnetic resonance imaging study, we detected brain activity in the temporal neocortex that was developed approximately 8 weeks after study of unfamiliar pictorial paired associates. Two sets of paired Fourier figures were studied, one approximately 8 weeks before test and the other immediately before test, keeping the correct performance during the tests balanced across the two sets of stimuli. Significant signal increase was observed in the right hippocampus during retrieval of newly studied pairs relative to initially studied pairs. In contrast, significant signal increase was observed in the anterior temporal cortex during retrieval of initially studied pairs relative to newly studied pairs. The greater activity during retrieval of older memory developed in the temporal neocortex provides direct evidence of formation of temporal neocortical representation for stable long-term memory.
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