1
|
Maier PM, Iggena D, Ploner CJ, Finke C. Memory consolidation affects the interplay of place and response navigation. Cortex 2024; 175:12-27. [PMID: 38701643 DOI: 10.1016/j.cortex.2024.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 02/11/2024] [Accepted: 04/12/2024] [Indexed: 05/05/2024]
Abstract
Navigation through space is based on memory representations of landmarks ('place') or movement sequences ('response'). Over time, memory representations transform through consolidation. However, it is unclear how the transformation affects place and response navigation in humans. In the present study, healthy adults navigated to target locations in a virtual maze. The preference for using place and response strategies and the ability to recall place and response memories were tested after a delay of one hour (n = 31), one day (n = 30), or two weeks (n = 32). The different delays captured early-phase synaptic changes, changes after one night of sleep, and long-delay changes due to the reorganization of navigation networks. Our results show that the relative contributions of place and response navigation changed as a function of time. After a short delay of up to one day, participants preferentially used a place strategy and exhibited a high degree of visual landmark exploration. After a longer delay of two weeks, place strategy use decreased significantly. Participants now equally relied on place and response strategy use and increasingly repeated previously taken paths. Further analyses indicate that response strategy use predominantly occurred as a compensatory strategy in the absence of sufficient place memory. Over time, place memory faded before response memory. We suggest that the observed shift from place to response navigation is context-dependent since detailed landmark information, which strongly relied on hippocampal function, decayed faster than sequence information, which required less detail and depended on extra-hippocampal areas. We conclude that changes in place and response navigation likely reflect the reorganization of navigation networks during systems consolidation.
Collapse
Affiliation(s)
- Patrizia M Maier
- Charité - Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany; Humboldt-Universität zu Berlin, Faculty of Philosophy, Berlin School of Mind and Brain, Berlin, Germany
| | - Deetje Iggena
- Charité - Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany; Humboldt-Universität zu Berlin, Faculty of Philosophy, Berlin School of Mind and Brain, Berlin, Germany
| | - Christoph J Ploner
- Charité - Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany
| | - Carsten Finke
- Charité - Universitätsmedizin Berlin, Department of Neurology, Berlin, Germany; Humboldt-Universität zu Berlin, Faculty of Philosophy, Berlin School of Mind and Brain, Berlin, Germany.
| |
Collapse
|
2
|
Xue J, Li B, Huang B, Feng H, Li X, Liang S, Yuan F, Wang S, Shi H, Shao J, Shi Y. Sex-dependent and long-lasting effects of adolescent sleep deprivation on social behaviors in adult mice. Pharmacol Biochem Behav 2023; 232:173657. [PMID: 37804868 DOI: 10.1016/j.pbb.2023.173657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/01/2023] [Accepted: 10/04/2023] [Indexed: 10/09/2023]
Abstract
Increasing evidence indicates that sleep deprivation (SD) can exert multiple negative effects on neuronal circuits, resulting in memory impairment, depression, and anxiety, among other consequences. The long-term effects of SD during early life on behavioral phenotypes in adulthood are still poorly understood. In this study, we investigated the long-lasting effects of SD in adolescence on social behaviors, including empathic ability and social dominance, and the role of the gut microbiota in these processes, using a series of behavioral paradigms in mice combined with 16S rRNA gene pyrosequencing. Behavioral assay results showed that SD in adolescence significantly reduced the frequency of licking, the total time spent licking, and the time spent sniffing during the emotional contagion test in male mice, effects that were not observed in female mice. These findings indicated that SD in adolescence exerts long-term, negative effects on empathic ability in mice and that this effect is sex-dependent. In contrast, SD in adolescence had no significant effect on locomotor activities, social dominance but decreased social interaction in male mice in adulthood. Meanwhile, 16S rRNA gene pyrosequencing results showed that gut microbial richness and diversity were significantly altered in adult male mice subjected to SD in adolescence. Our data provide direct evidence that SD in youth can induce alterations in empathic ability in adult male mice, which may be associated with changes in the gut microbiota. These findings highlight the long-lasting effects of sleep loss in adolescence on social behaviors in adulthood and the role played by the brain-gut axis.
Collapse
Affiliation(s)
- Jiping Xue
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Bingyu Li
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Boya Huang
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China
| | - Hao Feng
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Xinrui Li
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Shihao Liang
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Fang Yuan
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Sheng Wang
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China
| | - Haishui Shi
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China; Hebei Key Laboratory of Neurophysiology, Hebei Medicinal University, Shijiazhuang 050017, China; Nursing School, Hebei Medicinal University, Shijiazhuang 050031, China.
| | - Juan Shao
- Department of Senile Disease, The Third Hospital of Hebei Medical University, Shijiazhuang 050051, China.
| | - Yun Shi
- Neuroscience Research Center, Institute of Medical and Health Science, Hebei Medical University, Shijiazhuang 050017, China.
| |
Collapse
|
3
|
Villemonteix T, Guerreri M, Deantoni M, Balteau E, Schmidt C, Stee W, Zhang H, Peigneux P. Sleep-dependent structural neuroplasticity after a spatial navigation task: A diffusion imaging study. J Neurosci Res 2023; 101:1031-1043. [PMID: 36787426 DOI: 10.1002/jnr.25176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 12/30/2022] [Accepted: 01/20/2023] [Indexed: 02/16/2023]
Abstract
Evidence for sleep-dependent changes in microstructural neuroplasticity remains scarce, despite the fact that it is a mandatory correlate of the reorganization of learning-related functional networks. We investigated the effects of post-training sleep on structural neuroplasticity markers measuring standard diffusion tensor imaging (DTI), mean diffusivity (MD), and the revised biophysical neurite orientation dispersion and density imaging (NODDI), free water fraction (FWF), and neurite density (NDI) parameters that enable disentangling whether MD changes result from modifications in neurites or in other cellular components (e.g., glial cells). Thirty-four healthy young adults were scanned using diffusion-weighted imaging (DWI) on Day1 before and after 40-min route learning (navigation) in a virtual environment, then were sleep deprived (SD) or slept normally (RS) for the night. After recovery sleep for 2 nights, they were scanned again (Day4) before and after 40-min route learning (navigation) in an extended environment. Sleep-related microstructural changes were computed on DTI (MD) and NODDI (NDI and FWF) parameters in the cortical ribbon and subcortical hippocampal and striatal regions of interest (ROIs). Results disclosed navigation learning-related decreased DWI parameters in the cortical ribbon (MD, FWF) and subcortical (MD, FWF, NDI) areas. Post-learning sleep-related changes were found at Day4 in the extended learning session (pre- to post-relearning percentage changes), suggesting a rapid sleep-related remodeling of neurites and glial cells subtending learning and memory processes in basal ganglia and hippocampal structures.
Collapse
Affiliation(s)
- Thomas Villemonteix
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Laboratoire Psychopathologie et Processus de Changement, EA2027, Paris 8 University, Saint-Denis, France
| | - Michele Guerreri
- Department of Computer Science & Centre for Medical Image Computing, University College London, London, UK
| | - Michele Deantoni
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Evelyne Balteau
- Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Christina Schmidt
- Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Whitney Stee
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| | - Hui Zhang
- Department of Computer Science & Centre for Medical Image Computing, University College London, London, UK
| | - Philippe Peigneux
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit affiliated at CRCN - Centre for Research in Cognition and Neurosciences and UNI - ULB Neuroscience Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium.,Sleep & Chronobiology Group, GIGA-CRC-In Vivo Imaging Research Unit, University of Liège, Liège, Belgium
| |
Collapse
|
4
|
Reggente N. VR for Cognition and Memory. Curr Top Behav Neurosci 2023; 65:189-232. [PMID: 37440126 DOI: 10.1007/7854_2023_425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
This chapter will provide a review of research into human cognition through the lens of VR-based paradigms for studying memory. Emphasis is placed on why VR increases the ecological validity of memory research and the implications of such enhancements.
Collapse
Affiliation(s)
- Nicco Reggente
- Institute for Advanced Consciousness Studies, Santa Monica, CA, USA.
| |
Collapse
|
5
|
Simon KC, Clemenson GD, Zhang J, Sattari N, Shuster AE, Clayton B, Alzueta E, Dulai T, de Zambotti M, Stark C, Baker FC, Mednick SC. Sleep facilitates spatial memory but not navigation using the Minecraft Memory and Navigation task. Proc Natl Acad Sci U S A 2022; 119:e2202394119. [PMID: 36252023 PMCID: PMC9618094 DOI: 10.1073/pnas.2202394119] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Accepted: 08/04/2022] [Indexed: 11/18/2022] Open
Abstract
Sleep facilitates hippocampal-dependent memories, supporting the acquisition and maintenance of internal representation of spatial relations within an environment. In humans, however, findings have been mixed regarding sleep's contribution to spatial memory and navigation, which may be due to task designs or outcome measurements. We developed the Minecraft Memory and Navigation (MMN) task for the purpose of disentangling how spatial memory accuracy and navigation change over time, and to study sleep's independent contributions to each. In the MMN task, participants learned the locations of objects through free exploration of an open field computerized environment. At test, they were teleported to random positions around the environment and required to navigate to the remembered location of each object. In study 1, we developed and validated four unique MMN environments with the goal of equating baseline learning and immediate test performance. A total of 86 participants were administered the training phases and immediate test. Participants' baseline performance was equivalent across all four environments, supporting the use of the MMN task. In study 2, 29 participants were trained, tested immediately, and again 12 h later after a period of sleep or wake. We found that the metric accuracy of object locations, i.e., spatial memory, was maintained over a night of sleep, while after wake, metric accuracy declined. In contrast, spatial navigation improved over both sleep and wake delays. Our findings support the role of sleep in retaining the precise spatial relationships within a cognitive map; however, they do not support a specific role of sleep in navigation.
Collapse
Affiliation(s)
- Katharine C. Simon
- Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine, CA 92697
| | - Gregory D. Clemenson
- Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA 92697
| | - Jing Zhang
- Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine, CA 92697
| | - Negin Sattari
- Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine, CA 92697
| | - Alessandra E. Shuster
- Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine, CA 92697
| | - Brandon Clayton
- Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine, CA 92697
| | - Elisabet Alzueta
- Center for Health Sciences, SRI International, Menlo Park, CA 94025
| | - Teji Dulai
- Center for Health Sciences, SRI International, Menlo Park, CA 94025
| | | | - Craig Stark
- Department of Neurobiology and Behavior, School of Biological Sciences, University of California, Irvine, CA 92697
| | - Fiona C. Baker
- Center for Health Sciences, SRI International, Menlo Park, CA 94025
- Brain Function Research Group, School of Physiology, University of the Witwatersrand, Johannesburg, 2193, South Africa
| | - Sara C. Mednick
- Department of Cognitive Sciences, School of Social Sciences, University of California, Irvine, CA 92697
| |
Collapse
|
6
|
Piber D. The role of sleep disturbance and inflammation for spatial memory. Brain Behav Immun Health 2021; 17:100333. [PMID: 34589818 PMCID: PMC8474561 DOI: 10.1016/j.bbih.2021.100333] [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: 03/26/2021] [Revised: 08/19/2021] [Accepted: 08/20/2021] [Indexed: 11/09/2022] Open
Abstract
Spatial memory is a brain function involved in multiple behaviors such as planning a route or recalling an object's location. The formation of spatial memory relies on the homeostasis of various biological systems, including healthy sleep and a well-functioning immune system. While sleep is thought to promote the stabilization and storage of spatial memories, considerable evidence shows that the immune system modulates neuronal processes underlying spatial memory such as hippocampal neuroplasticity, long-term potentiation, and neurogenesis. Conversely, when sleep is disturbed and/or states of heightened immune activation occur, hippocampal regulatory pathways are altered, which - on a behavioral level - may result in spatial memory impairments. In this Brief Review, I summarize how sleep and the immune system contribute to spatial memory processes. In addition, I present emerging evidence suggesting that sleep disturbance and inflammation might jointly impair spatial memory. Finally, potentials of integrated strategies that target sleep disturbance and inflammation to possibly mitigate risk for spatial memory impairment are discussed.
Collapse
Affiliation(s)
- Dominique Piber
- Department of Psychiatry, Charité – Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Hindenburgdamm 30, 12203, Berlin, Germany
- Berlin Institute of Health (BIH), Berlin, Germany
- Cousins Center for Psychoneuroimmunology, Semel Institute for Neuroscience and Human Behavior, Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California Los Angeles (UCLA), Los Angeles, USA
| |
Collapse
|
7
|
Noack H, Doeller CF, Born J. Sleep strengthens integration of spatial memory systems. ACTA ACUST UNITED AC 2021; 28:162-170. [PMID: 33858969 PMCID: PMC8054676 DOI: 10.1101/lm.053249.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 02/21/2021] [Indexed: 11/24/2022]
Abstract
Spatial memory comprises different representational systems that are sensitive to different environmental cues, like proximal landmarks or local boundaries. Here we examined how sleep affects the formation of a spatial representation integrating landmark-referenced and boundary-referenced representations. To this end, participants (n = 42) were familiarized with an environment featuring both a proximal landmark and a local boundary. After nocturnal periods of sleep or wakefulness and another night of sleep, integration of the two representational systems was tested by testing the participant's flexibility to switch from landmark-based to boundary-based navigation in the environment, and vice versa. Results indicate a distinctly increased flexibility in relying on either landmarks or boundaries for navigation, when familiarization to the environment was followed by sleep rather than by wakefulness. A second control study (n = 45) did not reveal effects of sleep (vs. wakefulness) on navigation in environments featuring only landmarks or only boundaries. Thus, rather than strengthening isolated representational systems per se, sleep presumably through forming an integrative representation, enhances flexible coordination of representational subsystems.
Collapse
Affiliation(s)
- Hannes Noack
- Institute for Medical Psychology and Behavioral Neurobiology, University Tübingen, 72076 Tübingen, Germany.,Department of Psychiatry and Psychotherapy, Medical School, University Tübingen, 72076 Tübingen, Germany
| | - Christian F Doeller
- Kavli Institute for Systems Neuroscience, Centre for Neural Computation, The Egil and Pauline Braathen and Fred Kavli Centre for Cortical Microcircuits, Norwegian University of Science and Technology and St. Olavs Hospital, Trondheim University Hospital, Trondheim NO-7491, Norway.,Department of Psychology, Max Planck Institute for Cognitive and Brain Sciences, 04103 Leipzig, Germany
| | - Jan Born
- Institute for Medical Psychology and Behavioral Neurobiology, University Tübingen, 72076 Tübingen, Germany
| |
Collapse
|
8
|
Deantoni M, Villemonteix T, Balteau E, Schmidt C, Peigneux P. Post-Training Sleep Modulates Topographical Relearning-Dependent Resting State Activity. Brain Sci 2021; 11:brainsci11040476. [PMID: 33918574 PMCID: PMC8069225 DOI: 10.3390/brainsci11040476] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 03/30/2021] [Accepted: 04/07/2021] [Indexed: 11/16/2022] Open
Abstract
Continuation of experience-dependent neural activity during offline sleep and wakefulness episodes is a critical component of memory consolidation. Using functional magnetic resonance imaging (fMRI), offline consolidation effects have been evidenced probing behavioural and neurophysiological changes during memory retrieval, i.e., in the context of task practice. Resting state fMRI (rsfMRI) further allows investigating the offline evolution of recently learned information without the confounds of online task-related effects. We used rsfMRI to investigate sleep-related changes in seed-based resting functional connectivity (FC) and amplitude of low frequency fluctuations (ALFF) after spatial navigation learning and relearning. On Day 1, offline resting state activity was measured immediately before and after topographical learning in a virtual town. On Day 4, it was measured again before and after relearning in an extended version of the town. Navigation-related activity was also recorded during target retrieval, i.e., online. Participants spent the first post-training night under regular sleep (RS) or sleep deprivation (SD) conditions. Results evidence FC and ALFF changes in task-related neural networks, indicating the continuation of navigation-related activity in the resting state. Although post-training sleep did not modulate behavioural performance, connectivity analyses evidenced increased FC after post-training SD between navigation-related brain structures during relearning in the extended environment. These results suggest that memory traces were less efficiently consolidated after post-learning SD, eventually resulting in the use of compensatory brain resources to link previously stored spatial elements with the newly presented information.
Collapse
Affiliation(s)
- Michele Deantoni
- Neuropsychology and Functional Neuroimaging Research Unit (UR2NF) at CRCN—Centre for Research in Cognition and Neurosciences and UNI—ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), CP191 Av. F. Roosevelt 50, 1050 Bruxelles, Belgium; (M.D.); (T.V.)
- CRC-GIGA In Vivo Imaging, Université de Liège, Allée du 6 Août, Bâtiment B30, Sart Tilman, 4000 Liège, Belgium; (E.B.); (C.S.)
| | - Thomas Villemonteix
- Neuropsychology and Functional Neuroimaging Research Unit (UR2NF) at CRCN—Centre for Research in Cognition and Neurosciences and UNI—ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), CP191 Av. F. Roosevelt 50, 1050 Bruxelles, Belgium; (M.D.); (T.V.)
- Psychopathology and Neuropsychology Lab, Paris 8 University, Rue de la Liberté 2, 93,526 Saint-Denis, France
| | - Evelyne Balteau
- CRC-GIGA In Vivo Imaging, Université de Liège, Allée du 6 Août, Bâtiment B30, Sart Tilman, 4000 Liège, Belgium; (E.B.); (C.S.)
| | - Christina Schmidt
- CRC-GIGA In Vivo Imaging, Université de Liège, Allée du 6 Août, Bâtiment B30, Sart Tilman, 4000 Liège, Belgium; (E.B.); (C.S.)
- Psychology and Neurosciences of Cognition (PsyNCog), Université de Liège, Quartier Agora, Place des Orateurs, 3, Bâtiment B33, 4000 Liège, Belgium
| | - Philippe Peigneux
- Neuropsychology and Functional Neuroimaging Research Unit (UR2NF) at CRCN—Centre for Research in Cognition and Neurosciences and UNI—ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), CP191 Av. F. Roosevelt 50, 1050 Bruxelles, Belgium; (M.D.); (T.V.)
- CRC-GIGA In Vivo Imaging, Université de Liège, Allée du 6 Août, Bâtiment B30, Sart Tilman, 4000 Liège, Belgium; (E.B.); (C.S.)
- Correspondence:
| |
Collapse
|
9
|
Toscano-Hermoso MD, Arbinaga F, Fernández-Ozcorta EJ, Gómez-Salgado J, Ruiz-Frutos C. Influence of Sleeping Patterns in Health and Academic Performance Among University Students. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E2760. [PMID: 32316249 PMCID: PMC7215924 DOI: 10.3390/ijerph17082760] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/12/2020] [Accepted: 04/14/2020] [Indexed: 01/20/2023]
Abstract
Sleep problems in university students are important and have implications for health, quality of life, and academic performance. Using an ex post facto design, a total sample of 855 students (55.7% women) participated in the study. Sleep assessment was conducted using the Pittsburgh Sleep Quality Index, the Nightmare Frequency Scale, the Nightmare Proneness Scale, and the Composite Morningness Scale. Women show a higher risk [OR = 2.61] of presenting poor sleep quality (> 5 points on the PSQI) compared with men (p < 0.001). Similarly, women reported a greater frequency of nightmares (p < 0.001, d = 0.60), greater propensity for nightmares (p < 0.001, d = 0.70) and a higher score on Item-5h of the PSQI regarding nightmares (p < 0.001, d = 0.59). Women, compared with men, show higher risk [OR = 2.84] for a sleep disorder related to nightmares (p = 0.012). Women need more time to reach a state of alertness after getting up (p = 0.022), and there was an interaction between sex and the alertness factor when evaluating the subjective quality of sleep (p = 0.030). Women show worse sleep quality and a higher frequency and propensity for suffering nightmares. When considering the relationship between sleep quality and academic performance, it is observed that students with poor sleep quality obtain lower academic scores (M = 7.21, SD = 0.805) than those with good sleep quality (M = 7.32, SD = 0.685), an effect that reaches significance (t = 2.116, p = 0.035). Regarding the relationship between the categorized chronotype and academic performance, students with a morning chronotype achieve better academic results (M = 7.41, SD = 0.89) than their evening counterparts (M = 7.15, SD = 0.76), although these differences have a small effect size (d = 0.31).
Collapse
Affiliation(s)
| | - Félix Arbinaga
- Faculty of Education, Psychology and Sports Science, Department of Clinical and Experimental Psychology, University of Huelva, 21007 Huelva, Spain
| | - Eduardo J. Fernández-Ozcorta
- Department of Physical Activity and Sports, Center for University Studies Cardenal Spínola CEU, University of Seville attached centre, 41930 Bormujos, Spain;
| | - Juan Gómez-Salgado
- School of Labour Sciences, Department of Sociology, Social Work and Public Health, University of Huelva, 21007 Huelva, Spain;
- Safety and Health Posgrade Program, University Espiritu Santo, 092301 Guayaquil, Ecuador
| | - Carlos Ruiz-Frutos
- School of Labour Sciences, Department of Sociology, Social Work and Public Health, University of Huelva, 21007 Huelva, Spain;
- Safety and Health Posgrade Program, University Espiritu Santo, 092301 Guayaquil, Ecuador
| |
Collapse
|
10
|
Shin JC, Parab KV, An R, Grigsby-Toussaint DS. Greenspace exposure and sleep: A systematic review. ENVIRONMENTAL RESEARCH 2020; 182:109081. [PMID: 31891829 DOI: 10.1016/j.envres.2019.109081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 12/18/2019] [Accepted: 12/21/2019] [Indexed: 05/23/2023]
Abstract
Green space is considered a critical environmental factor for sleep quality and quantity. However, no systematic review exploring this relationship exists. The purpose of this systematic review was to 1) explore research related to green space and sleep, and 2) examine the impact of green space exposure on sleep quality and quantity. Papers from eight electronic databases were eligible for inclusion if they met the following criteria: well-designed, any analysis exploring green space and sleep, provided sleep and green space measurement, published in peer-reviewed journals, and written in English. Thirteen eligible studies related to green space and sleep were selected after peer-review procedures. Cross-sectional studies (n = 7) used either a questionnaire or the combination of Geographic Information Systems and remote sensing images for green space measurement, while questionnaires were primarily used to measure both sleep quality and quantity. Intervention studies (n = 5) were categorized into three types: walking program, gardening, and working in a forest. Eleven out of thirteen studies concluded that green space exposure was associated with improvement in both sleep quality and quantity. The findings support the evidence of a positive association between green space exposures and sleep quality and quantity, and also suggest green exercise and therapeutic gardening as possible intervention methods to improve sleep outcomes.
Collapse
Affiliation(s)
- Jong Cheol Shin
- Department Behavioral and Social Sciences, Center for Health Equity Research, Department of Behavioral and Social Science, School of Public Health, Brown University, Providence, RI, USA.
| | - Kaustubh Vijay Parab
- Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
| | - Ruopeng An
- Brown School, Washington University in St. Louis, St. Louis, MO, USA.
| | - Diana S Grigsby-Toussaint
- Department Behavioral and Social Sciences, Center for Health Equity Research, Department of Behavioral and Social Science, School of Public Health, Brown University, Providence, RI, USA.
| |
Collapse
|
11
|
Javaheripour N, Shahdipour N, Noori K, Zarei M, Camilleri JA, Laird AR, Fox PT, Eickhoff SB, Eickhoff CR, Rosenzweig I, Khazaie H, Tahmasian M. Functional brain alterations in acute sleep deprivation: An activation likelihood estimation meta-analysis. Sleep Med Rev 2019; 46:64-73. [PMID: 31063939 PMCID: PMC7279069 DOI: 10.1016/j.smrv.2019.03.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 03/18/2019] [Accepted: 03/21/2019] [Indexed: 12/26/2022]
Abstract
Sleep deprivation (SD) is a common problem in modern societies, which leads to cognitive dysfunctions including attention lapses, impaired working memory, hindering decision making, impaired emotional processing, and motor vehicle accidents. Numerous neuroimaging studies have investigated the neural correlates of SD, but these studies have reported inconsistent results. Thus, we aimed to identify convergent patterns of abnormal brain functions due to acute SD. Based on the preferred reporting for systematic reviews and meta-analyses statement, we searched the PubMed database and performed reference tracking and finally retrieved 31 eligible functional neuroimaging studies. Then, we applied activation estimation likelihood meta-analysis and found reduced activity mainly in the right intraparietal sulcus and superior parietal lobule. The functional decoding analysis using the BrainMap database indicated that this region is mostly related to visuospatial perception, memory and reasoning. The significant co-activation of this region using the BrainMap database were found in the left superior parietal lobule, intraparietal sulcus, bilateral occipital cortex, left fusiform gyrus and thalamus. This region also connected with the superior parietal lobule, intraparietal sulcus, insula, inferior frontal gyrus, precentral, occipital and cerebellum through resting-state functional connectivity in healthy subjects. Taken together, our findings highlight the role of superior parietal cortex in SD.
Collapse
Affiliation(s)
- Nooshin Javaheripour
- Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran
| | - Niloofar Shahdipour
- Sleep Disorders Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Khadijeh Noori
- Sleep Disorders Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Mojtaba Zarei
- Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran
| | - Julia A Camilleri
- Institute of Neuroscience and Medicine (INM-7), Research Center Jülich, Jülich, Germany; Institute of Systems Neuroscience, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Angela R Laird
- Department of Physics, Florida International University, Miami, FL, USA
| | - Peter T Fox
- Research Imaging Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA; South Texas Veterans Healthcare System University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Simon B Eickhoff
- Institute of Neuroscience and Medicine (INM-1; INM-7), Research Center Jülich, Jülich, Germany; Institute of Systems Neuroscience, Medical Faculty, Heinrich-Heine University, Düsseldorf, Germany
| | - Claudia R Eickhoff
- Institute of Neuroscience and Medicine (INM-1; INM-7), Research Center Jülich, Jülich, Germany; Institute of Clinical Neuroscience and Medical Psychology, Heinrich Heine University, Düsseldorf, Germany
| | - Ivana Rosenzweig
- Sleep Disorders Centre, Guy's and St Thomas' Hospital, GSTT NHS, London, UK; Sleep and Brain Plasticity Centre, Department of Neuroimaging, IOPPN, King's College London, London, UK
| | - Habibolah Khazaie
- Sleep Disorders Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran.
| | - Masoud Tahmasian
- Institute of Medical Science and Technology, Shahid Beheshti University, Tehran, Iran
| |
Collapse
|
12
|
Cousins JN, Fernández G. The impact of sleep deprivation on declarative memory. PROGRESS IN BRAIN RESEARCH 2019; 246:27-53. [PMID: 31072562 DOI: 10.1016/bs.pbr.2019.01.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Sleep plays a crucial role in memory stabilization and integration, yet many people obtain insufficient sleep. This review assesses what is known about the level of sleep deprivation that leads to impairments during encoding, consolidation and retrieval of declarative memories, and what can be determined about the underlying neurophysiological processes. Neuroimaging studies that deprived sleep after learning have provided some of the most compelling evidence for sleep's role in the long-term reorganization of memories in the brain (systems consolidation). However, the behavioral consequences of losing sleep after learning-shown by increased forgetting-appear to recover over time and are unaffected by more common forms of partial sleep restriction across several nights. The capacity to encode new memories is the most vulnerable to sleep loss, since long-term deficits have been observed after total and partial sleep deprivation, while retrieval mechanisms are relatively unaffected. The negative impact of sleep loss on memory has been explored extensively after a night of total sleep deprivation, but further research is needed on the consequences of partial sleep loss over many days so that impairments may be generalized to more common forms of sleep loss.
Collapse
Affiliation(s)
- James N Cousins
- Centre for Cognitive Neuroscience, Neuroscience and Behavioral Disorders Programme, Duke-NUS Medical School, Singapore, Singapore.
| | - Guillén Fernández
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, The Netherlands
| |
Collapse
|
13
|
Reggente N, Essoe JKY, Aghajan ZM, Tavakoli AV, McGuire JF, Suthana NA, Rissman J. Enhancing the Ecological Validity of fMRI Memory Research Using Virtual Reality. Front Neurosci 2018; 12:408. [PMID: 29962932 PMCID: PMC6013717 DOI: 10.3389/fnins.2018.00408] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/25/2018] [Indexed: 12/23/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) is a powerful research tool to understand the neural underpinnings of human memory. However, as memory is known to be context-dependent, differences in contexts between naturalistic settings and the MRI scanner environment may potentially confound neuroimaging findings. Virtual reality (VR) provides a unique opportunity to mitigate this issue by allowing memories to be formed and/or retrieved within immersive, navigable, visuospatial contexts. This can enhance the ecological validity of task paradigms, while still ensuring that researchers maintain experimental control over critical aspects of the learning and testing experience. This mini-review surveys the growing body of fMRI studies that have incorporated VR to address critical questions about human memory. These studies have adopted a variety of approaches, including presenting research participants with VR experiences in the scanner, asking participants to retrieve information that they had previously acquired in a VR environment, or identifying neural correlates of behavioral metrics obtained through VR-based tasks performed outside the scanner. Although most such studies to date have focused on spatial or navigational memory, we also discuss the promise of VR in aiding other areas of memory research and facilitating research into clinical disorders.
Collapse
Affiliation(s)
- Nicco Reggente
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Joey K-Y Essoe
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Zahra M Aghajan
- Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| | - Amir V Tavakoli
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States.,Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, United States.,Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA, United States
| | - Joseph F McGuire
- Division of Child and Adolescent Psychiatry, Johns Hopkins Children's Center, Johns Hopkins Medicine, Baltimore, MD, United States
| | - Nanthia A Suthana
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Neurosurgery, University of California, Los Angeles, Los Angeles, CA, United States
| | - Jesse Rissman
- Department of Psychology, University of California, Los Angeles, Los Angeles, CA, United States.,Department of Psychiatry & Biobehavioral Sciences, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
14
|
Ahuja S, Chen RK, Kam K, Pettibone WD, Osorio RS, Varga AW. Role of normal sleep and sleep apnea in human memory processing. Nat Sci Sleep 2018; 10:255-269. [PMID: 30214331 PMCID: PMC6128282 DOI: 10.2147/nss.s125299] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
A fundamental problem in the field of obstructive sleep apnea (OSA) and memory is that it has historically minimized the basic neurobiology of sleep's role in memory. Memory formation has been classically divided into phases of encoding, processing/consolidation, and retrieval. An abundance of evidence suggests that sleep plays a critical role specifically in the processing/consolidation phase, but may do so differentially for memories that were encoded using particular brain circuits. In this review, we discuss some of the more established evidence for sleep's function in the processing of declarative, spatial navigational, emotional, and motor/procedural memories and more emerging evidence highlighting sleep's importance in higher order functions such as probabilistic learning, transitive inference, and category/gist learning. Furthermore, we discuss sleep's capacity for memory augmentation through targeted/cued memory reactivation. OSA - by virtue of its associated sleep fragmentation, intermittent hypoxia, and potential brain structural effects - is well positioned to specifically impact the processing/consolidation phase, but testing this possibility requires experimental paradigms in which memory encoding and retrieval are separated by a period of sleep with and without the presence of OSA. We argue that such paradigms should focus on the specific types of memory tasks for which sleep has been shown to have a significant effect. We discuss the small number of studies in which this has been done, in which OSA nearly uniformly negatively impacts offline memory processing. When periods of offline processing are minimal or absent and do not contain sleep, as is the case in the broad literature on OSA and memory, the effects of OSA on memory are far less consistent.
Collapse
Affiliation(s)
- Shilpi Ahuja
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Rebecca K Chen
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Korey Kam
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Ward D Pettibone
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| | - Ricardo S Osorio
- Center for Brain Health, Department of Psychiatry, NYU School of Medicine, New York, NY, USA
| | - Andrew W Varga
- Mount Sinai Integrative Sleep Center, Division of Pulmonary, Critical Care, and Sleep Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, USA,
| |
Collapse
|
15
|
Noack H, Schick W, Mallot H, Born J. Sleep enhances knowledge of routes and regions in spatial environments. ACTA ACUST UNITED AC 2017; 24:140-144. [PMID: 28202719 PMCID: PMC5311385 DOI: 10.1101/lm.043984.116] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/21/2016] [Indexed: 11/24/2022]
Abstract
Sleep is thought to preferentially consolidate hippocampus-dependent memory, and as such, spatial navigation. Here, we investigated the effects of sleep on route knowledge and explicit and implicit semantic regions in a virtual environment. Sleep, compared with wakefulness, improved route knowledge and also enhanced awareness of the semantic regionalization within the environment, whereas signs of implicit regionalization remained unchanged. Results support the view that sleep specifically enhances explicit aspects of memory, also in the spatial domain. Enhanced region knowledge after sleep suggests that consolidation during sleep goes along with the formation of more abstract schema-like representations.
Collapse
Affiliation(s)
- Hannes Noack
- Institute for Medical Psychology and Behavioral Neurobiology, University Tübingen, 72076 Tübingen, Germany.,Department of Psychiatry and Psychotherapy, Medical School, University Tübingen, 72076 Tübingen, Germany
| | - Wiebke Schick
- Institute for Cognitive Neuroscience, University Tübingen, 72076 Tübingen, Germany
| | - Hanspeter Mallot
- Institute for Cognitive Neuroscience, University Tübingen, 72076 Tübingen, Germany
| | - Jan Born
- Institute for Medical Psychology and Behavioral Neurobiology, University Tübingen, 72076 Tübingen, Germany
| |
Collapse
|
16
|
Urbain C, De Tiège X, Op De Beeck M, Bourguignon M, Wens V, Verheulpen D, Van Bogaert P, Peigneux P. Sleep in children triggers rapid reorganization of memory-related brain processes. Neuroimage 2016; 134:213-222. [DOI: 10.1016/j.neuroimage.2016.03.055] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 03/21/2016] [Indexed: 10/22/2022] Open
|
17
|
Borragán G, Slama H, Destrebecqz A, Peigneux P. Cognitive Fatigue Facilitates Procedural Sequence Learning. Front Hum Neurosci 2016; 10:86. [PMID: 26973501 PMCID: PMC4776079 DOI: 10.3389/fnhum.2016.00086] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2015] [Accepted: 02/19/2016] [Indexed: 12/02/2022] Open
Abstract
Enhanced procedural learning has been evidenced in conditions where cognitive control is diminished, including hypnosis, disruption of prefrontal activity and non-optimal time of the day. Another condition depleting the availability of controlled resources is cognitive fatigue (CF). We tested the hypothesis that CF, eventually leading to diminished cognitive control, facilitates procedural sequence learning. In a two-day experiment, 23 young healthy adults were administered a serial reaction time task (SRTT) following the induction of high or low levels of CF, in a counterbalanced order. CF was induced using the Time load Dual-back (TloadDback) paradigm, a dual working memory task that allows tailoring cognitive load levels to the individual’s optimal performance capacity. In line with our hypothesis, reaction times (RT) in the SRTT were faster in the high- than in the low-level fatigue condition, and performance improvement was higher for the sequential than the motor components. Altogether, our results suggest a paradoxical, facilitating impact of CF on procedural motor sequence learning. We propose that facilitated learning in the high-level fatigue condition stems from a reduction in the cognitive resources devoted to cognitive control processes that normally oppose automatic procedural acquisition mechanisms.
Collapse
Affiliation(s)
- Guillermo Borragán
- Neuropsychology and Functional Neuroimaging Research Unit (UR2NF), Centre de Recherches en Cognition et Neurosciences (CRCN), ULB Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB) Brussels, Belgium
| | - Hichem Slama
- Neuropsychology and Functional Neuroimaging Research Unit (UR2NF), Centre de Recherches en Cognition et Neurosciences (CRCN), ULB Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB) Brussels, Belgium
| | - Arnaud Destrebecqz
- Consciousness Cognition & Computation Group (CO3), Centre de Recherches en Cognition et Neurosciences (CRCN), ULB Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB) Brussels, Belgium
| | - Philippe Peigneux
- Neuropsychology and Functional Neuroimaging Research Unit (UR2NF), Centre de Recherches en Cognition et Neurosciences (CRCN), ULB Neurosciences Institute (UNI), Université Libre de Bruxelles (ULB) Brussels, Belgium
| |
Collapse
|
18
|
Fogel SM, Ray LB, Binnie L, Owen AM. How to become an expert: A new perspective on the role of sleep in the mastery of procedural skills. Neurobiol Learn Mem 2015; 125:236-48. [PMID: 26477835 DOI: 10.1016/j.nlm.2015.10.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 10/01/2015] [Accepted: 10/07/2015] [Indexed: 12/29/2022]
Abstract
How do you get to Carnegie Hall? Practice, sleep, practice. With enough practice - and sleep - we adopt new strategies that eventually become automatic, and subsequently require only the refinement of the existing skill to become an "expert". It is not known whether sleep is involved in the mastery and refinement of new skills that lead to expertise, nor is it known whether this may be primarily dependent on rapid eye movement (REM), non-REM stage 2 (NREM2) or slow wave sleep (SWS). Here, we employed behavioural and scalp-recorded electroencephalography (EEG) techniques to investigate the post-learning changes in the architecture (e.g., REM, NREM2 and SWS duration) and the electrophysiological features (e.g., rapid eye movements, sleep spindles and slow wave activity) that characterize these sleep states as individuals progress from night to night, from "Novice" to "Experts" on a cognitive procedural task (e.g., the Tower of Hanoi task). Here, we demonstrate that speed of movements improves over the course of training irrespective of whether sleep or wake intervenes training sessions, whereas accuracy improves gradually, but only significantly over a night of sleep immediately prior to mastery of the task. On the night that subjects are first exposed to the task, the density of fast spindles increased significantly during both NREM2 and SWS accompanied by increased NREM2 sigma power and SWS delta power, whereas, on the night that subjects become experts on the task, they show increased REM sleep duration and spindles became larger in terms of amplitude and duration during SWS. Re-exposure to the task one-week after it had already been mastered resulted in increased NREM sleep duration, and again, increased spindle density of fast spindles during SWS and NREM2 and increased NREM2 sigma power and SWS delta power. Importantly, increased spindle density was correlated with overnight improvement in speed and accuracy. Taken together, these results help to elucidate how REM and NREM sleep are uniquely involved in memory consolidation over the course of the mastery of a new cognitively complex skill, and help to resolve controversies regarding sequential nature of memory processing during sleep in humans, for which consistent evidence is currently lacking.
Collapse
Affiliation(s)
- Stuart M Fogel
- The Brain & Mind Institute, Western University, London, Ontario, Canada; Department of Psychology, Western University, London, Ontario, Canada.
| | - Laura B Ray
- The Brain & Mind Institute, Western University, London, Ontario, Canada
| | - Lauren Binnie
- The Brain & Mind Institute, Western University, London, Ontario, Canada
| | - Adrian M Owen
- The Brain & Mind Institute, Western University, London, Ontario, Canada; Department of Psychology, Western University, London, Ontario, Canada
| |
Collapse
|
19
|
Not only … but also: REM sleep creates and NREM Stage 2 instantiates landmark junctions in cortical memory networks. Neurobiol Learn Mem 2015; 122:69-87. [PMID: 25921620 DOI: 10.1016/j.nlm.2015.04.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Revised: 04/16/2015] [Accepted: 04/16/2015] [Indexed: 12/13/2022]
Abstract
This article argues both rapid eye movement (REM) and non-rapid eye movement (NREM) sleep contribute to overnight episodic memory processes but their roles differ. Episodic memory may have evolved from memory for spatial navigation in animals and humans. Equally, mnemonic navigation in world and mental space may rely on fundamentally equivalent processes. Consequently, the basic spatial network characteristics of pathways which meet at omnidirectional nodes or junctions may be conserved in episodic brain networks. A pathway is formally identified with the unidirectional, sequential phases of an episodic memory. In contrast, the function of omnidirectional junctions is not well understood. In evolutionary terms, both animals and early humans undertook tours to a series of landmark junctions, to take advantage of resources (food, water and shelter), whilst trying to avoid predators. Such tours required memory for emotionally significant landmark resource-place-danger associations and the spatial relationships amongst these landmarks. In consequence, these tours may have driven the evolution of both spatial and episodic memory. The environment is dynamic. Resource-place associations are liable to shift and new resource-rich landmarks may be discovered, these changes may require re-wiring in neural networks. To realise these changes, REM may perform an associative, emotional encoding function between memory networks, engendering an omnidirectional landmark junction which is instantiated in the cortex during NREM Stage 2. In sum, REM may preplay associated elements of past episodes (rather than replay individual episodes), to engender an unconscious representation which can be used by the animal on approach to a landmark junction in wake.
Collapse
|
20
|
Schönauer M, Grätsch M, Gais S. Evidence for two distinct sleep-related long-term memory consolidation processes. Cortex 2015; 63:68-78. [DOI: 10.1016/j.cortex.2014.08.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 05/19/2014] [Accepted: 08/05/2014] [Indexed: 11/25/2022]
|
21
|
Memory Reactivation in Humans (Imaging Studies). SPRINGER SERIES IN COMPUTATIONAL NEUROSCIENCE 2015. [DOI: 10.1007/978-1-4939-1969-7_11] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
22
|
Havekes R, Meerlo P, Abel T. Animal studies on the role of sleep in memory: from behavioral performance to molecular mechanisms. Curr Top Behav Neurosci 2015; 25:183-206. [PMID: 25680961 DOI: 10.1007/7854_2015_369] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although the exact functions of sleep remain a topic of debate, several hypotheses propose that sleep benefits neuronal plasticity, which ultimately supports brain function and cognition . For over a century, researchers have applied a wide variety of behavioral, electrophysiological, biochemical, and molecular approaches to study how memory processes are promoted by sleep and perturbed by sleep loss. Interestingly, experimental studies indicate that cognitive impairments as a consequence of sleep deprivation appear to be most severe with learning and memory processes that require the hippocampus , which suggests that this brain region is particularly sensitive to the consequences of sleep loss. Moreover, recent studies in laboratory rodents indicate that sleep deprivation impairs hippocampal neuronal plasticity and memory processes by attenuating intracellular cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) signaling. Attenuated cAMP-PKA signaling can lead to a reduced activity of the transcription factor cAMP response element binding protein (CREB) and ultimately affect the expression of genes and proteins involved in neuronal plasticity and memory formation. Pharmacogenetic experiments in mice show that memory deficits following sleep deprivation can be prevented by specifically boosting cAMP signaling in excitatory neurons of the hippocampus. Given the high incidence of sleep disturbance and sleep restriction in our 24/7 society, understanding the consequences of sleep loss and unraveling the underlying molecular mechanisms is of great importance.
Collapse
Affiliation(s)
- Robbert Havekes
- Department of Biology, 10-170 Smilow Center for Translational Research, University of Pennsylvania, 3400 Civic Center Blvd Bldg 421, Philadelphia, PA, 19104-5158, USA,
| | | | | |
Collapse
|
23
|
Bernier A, Bélanger MÈ, Tarabulsy GM, Simard V, Carrier J. My mother is sensitive, but I am too tired to know: infant sleep as a moderator of prospective relations between maternal sensitivity and infant outcomes. Infant Behav Dev 2014; 37:682-94. [PMID: 25243613 DOI: 10.1016/j.infbeh.2014.08.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 06/16/2014] [Accepted: 08/26/2014] [Indexed: 10/24/2022]
Abstract
This study investigated the moderating role of infant sleep in the connections between maternal sensitivity and three indicators of infant functioning: attachment security, theory of mind, and executive functioning (EF). Maternal sensitivity was assessed when infants (27 girls and 36 boys) were 1 year of age. Infant sleep was assessed with actigraphy at age 2; attachment security, theory of mind, and EF were also assessed at age 2. Results indicated that maternal sensitivity was positively related to attachment security only among infants who got more sleep at night, and to conflict-EF and theory of mind only for infants who got greater proportions of their sleep during the night. These results suggest that sleep may enhance the benefits of maternal sensitivity for some aspects of infants' functioning, providing further support for the importance of sleep maturation as a salient developmental task of infancy.
Collapse
Affiliation(s)
- Annie Bernier
- Department of Psychology, University of Montreal, PO Box 6128, Downtown Station, Montreal, QC, Canada H3C 3J7.
| | - Marie-Ève Bélanger
- Department of Psychology, University of Montreal, PO Box 6128, Downtown Station, Montreal, QC, Canada H3C 3J7
| | | | - Valérie Simard
- Université de Sherbrooke, Sherbrooke, QC, Canada J1K 2R1
| | - Julie Carrier
- Department of Psychology, University of Montreal, PO Box 6128, Downtown Station, Montreal, QC, Canada H3C 3J7
| |
Collapse
|
24
|
Caproni S, Muti M, Di Renzo A, Principi M, Caputo N, Calabresi P, Tambasco N. Subclinical visuospatial impairment in Parkinson's disease: the role of Basal Ganglia and limbic system. Front Neurol 2014; 5:152. [PMID: 25157239 PMCID: PMC4128219 DOI: 10.3389/fneur.2014.00152] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Accepted: 07/25/2014] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Visual perception deficits are a recurrent manifestation in Parkinson's disease (PD). Recently, structural abnormalities of fronto-parietal areas and subcortical regions, implicated in visual stimuli analysis, have been observed in PD patients with cognitive decline and visual hallucinations. The aim of the present study was to investigate the salient aspects of visual perception in cognitively unimpaired PD patients. METHODS Eleven right-handed non-demented right-sided onset PD patients without visuospatial impairment or hallucinations and 11 healthy controls were studied with functional magnetic resonance imaging while performing a specific visuoperceptual/visuospatial paradigm that allowed to highlight the specific process underlying visuospatial judgment. RESULTS Significant changes in both cortical areas and subcortical regions involved in visual stimuli processing were observed. In particular, PD patients showed a reduced activation for the right insula, left putamen, bilateral caudate, and right hippocampus, as well as an over-activation of the right dorso-lateral prefrontal and of the posterior parietal cortices, particularly in the right hemisphere. CONCLUSIONS We found that both loss of efficiency and compensatory mechanisms occur in PD patients, providing further insight into the pathophysiological role of the functional alterations of basal ganglia and limbic structures in the impairment of visuoperceptual and visuospatial functions observed in PD.
Collapse
Affiliation(s)
- Stefano Caproni
- Clinica Neurologica, Azienda Ospedaliera - Università di Perugia , Italy
| | - Marco Muti
- Servizio di Fisica Sanitaria, Azienda Ospedaliera di Terni , Italy
| | - Antonio Di Renzo
- Servizio di Fisica Sanitaria, Azienda Ospedaliera di Terni , Italy
| | - Massimo Principi
- Servizio di Neuroradiologia, Azienda Ospedaliera di Terni , Italy
| | - Nevia Caputo
- Servizio di Neuroradiologia, Azienda Ospedaliera di Terni , Italy
| | - Paolo Calabresi
- Clinica Neurologica, Azienda Ospedaliera - Università di Perugia , Italy ; I.R.C.C.S. - Fondazione S. Lucia - Roma , Italy
| | - Nicola Tambasco
- Clinica Neurologica, Azienda Ospedaliera - Università di Perugia , Italy
| |
Collapse
|
25
|
Moroni F, Nobili L, Iaria G, Sartori I, Marzano C, Tempesta D, Proserpio P, Lo Russo G, Gozzo F, Cipolli C, De Gennaro L, Ferrara M. Hippocampal slow EEG frequencies during NREM sleep are involved in spatial memory consolidation in humans. Hippocampus 2014; 24:1157-68. [PMID: 24796545 DOI: 10.1002/hipo.22299] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2014] [Indexed: 02/05/2023]
Affiliation(s)
- Fabio Moroni
- Department of Psychology; “Sapienza” University of Rome; Roma Italy
- Laboratory of Psychology; Department of Specialized; Diagnostics and Experimental Medicine, University of Bologna; Bologna Italy
| | - Lino Nobili
- Centre of Epilepsy Surgery “C. Munari”, Center of Sleep Medicine, Niguarda Hospital; Milan Italy
- Institute of Bioimaging and Molecular Physiology, Section of Genoa, National Research Council; Genova Italy
| | - Giuseppe Iaria
- Department of Psychology and Clinical Neurosciences; and Hotchkiss Brain Institute; University of Calgary; Calgary Alberta Canada
| | - Ivana Sartori
- Centre of Epilepsy Surgery “C. Munari”, Center of Sleep Medicine, Niguarda Hospital; Milan Italy
| | - Cristina Marzano
- Department of Psychology; “Sapienza” University of Rome; Roma Italy
| | - Daniela Tempesta
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| | - Paola Proserpio
- Centre of Epilepsy Surgery “C. Munari”, Center of Sleep Medicine, Niguarda Hospital; Milan Italy
| | - Giorgio Lo Russo
- Centre of Epilepsy Surgery “C. Munari”, Center of Sleep Medicine, Niguarda Hospital; Milan Italy
| | - Francesca Gozzo
- Centre of Epilepsy Surgery “C. Munari”, Center of Sleep Medicine, Niguarda Hospital; Milan Italy
| | - Carlo Cipolli
- Laboratory of Psychology; Department of Specialized; Diagnostics and Experimental Medicine, University of Bologna; Bologna Italy
| | - Luigi De Gennaro
- Department of Psychology; “Sapienza” University of Rome; Roma Italy
| | - Michele Ferrara
- Department of Life; Health and Environmental Sciences; University of L'Aquila; L'Aquila Italy
| |
Collapse
|
26
|
Abstract
Human brain dynamics are nowadays routinely explored at the macroscopic level using a wide variety of non-invasive neuroimaging techniques, including single photon emission computed tomography (SPECT) and positron emission tomography (PET), near infrared spectroscopy (NIRS) and functional magnetic resonance imaging (fMRI). In the past decades, the application of brain imaging methods to the study of sleep raised a renewed interest for the field, especially in the domain of neuroscience. Indeed, these studies enabled researchers to characterize the functional neuroanatomy of sleep stages and identify the neural correlates of phasic and tonic sleep mechanisms. Furthermore, they provided the scientific community with tools to address the crucial question of brain plasticity processes during human sleep, the role of sleep-related plasticity for memory consolidation, and how sleep and the lack of post-training sleep impacts brain functioning in the neural networks underlying memory-related cognitive processes. This chapter reviews the contributions of neuroimaging to our understanding of the functional neuroanatomy of sleep and sleep stages, and discusses how sleep contributes to the long-term consolidation of recently acquired memories in light of contemporary neural models for memory consolidation during sleep.
Collapse
Affiliation(s)
- Philippe Peigneux
- UR2NF-Neuropsychology and Functional Neuroimaging Research Unit, CRCN-Centre de Recherches Cognition et Neurosciences and UNI-ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), CP191, Av. F Roosevelt 50, 1050, Bruxelles, Belgium,
| |
Collapse
|
27
|
Urbain C, Schmitz R, Schmidt C, Cleeremans A, Van Bogaert P, Maquet P, Peigneux P. Sleep-dependent Neurophysiological Processes in Implicit Sequence Learning. J Cogn Neurosci 2013; 25:2003-14. [DOI: 10.1162/jocn_a_00439] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
Behavioral studies have cast doubts about the role that posttraining sleep may play in the consolidation of implicit sequence learning. Here, we used event-related fMRI to test the hypothesis that sleep-dependent functional reorganization would take place in the underlying neural circuits even in the possible absence of obvious behavioral changes. Twenty-four healthy human adults were scanned at Day 1 and then at Day 4 during an implicit probabilistic serial RT task. They either slept normally (RS) or were sleep-deprived (SD) on the first posttraining night. Unknown to them, the sequential structure of the material was based on a probabilistic finite-state grammar, with 15% chance on each trial of replacing the rules-based grammatical (G) stimulus with a nongrammatical (NG) one. Results indicated a gradual differentiation across sessions between RTs (faster RTs for G than NG), together with NG-related BOLD responses reflecting sequence learning. Similar behavioral patterns were observed in RS and SD participants at Day 4, indicating time- but not sleep-dependent consolidation of performance. Notwithstanding, we observed at Day 4 in the RS group a diminished differentiation between G- and NG-related neurophysiological responses in a set of cortical and subcortical areas previously identified as being part of the network involved in implicit sequence learning and its offline processing during sleep, indicating a sleep-dependent processing of both regular and deviant stimuli. Our results suggest the sleep-dependent development of distinct neurophysiological processes subtending consolidation of implicit motor sequence learning, even in the absence of overt behavioral differences.
Collapse
Affiliation(s)
- Charline Urbain
- 1Neuropsychology and Functional Neuroimaging Research Unit at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- 2Laboratoire de Cartographie Fonctionnelle du Cerveau, Hôpital Erasme, and UNI, ULB, Brussels, Belgium
| | - Rémy Schmitz
- 1Neuropsychology and Functional Neuroimaging Research Unit at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | | | - Axel Cleeremans
- 4Consciousness, Cognition & Computation Group, at CRCN and UNI, ULB, Brussels, Belgium
| | - Patrick Van Bogaert
- 2Laboratoire de Cartographie Fonctionnelle du Cerveau, Hôpital Erasme, and UNI, ULB, Brussels, Belgium
| | - Pierre Maquet
- 3Cyclotron Research Center, University of Liége, Liége, Belgium
| | - Philippe Peigneux
- 1Neuropsychology and Functional Neuroimaging Research Unit at CRCN - Center for Research in Cognition and Neurosciences and UNI - ULB Neurosciences Institute, Université Libre de Bruxelles (ULB), Brussels, Belgium
- 3Cyclotron Research Center, University of Liége, Liége, Belgium
| |
Collapse
|
28
|
Mary A, Schreiner S, Peigneux P. Accelerated long-term forgetting in aging and intra-sleep awakenings. Front Psychol 2013; 4:750. [PMID: 24137151 PMCID: PMC3797403 DOI: 10.3389/fpsyg.2013.00750] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 09/26/2013] [Indexed: 11/22/2022] Open
Abstract
The architecture of sleep and the functional neuroanatomical networks subtending memory consolidation processes are both modified with aging, possibly leading to accelerated forgetting in long-term memory. We investigated associative learning and declarative memory consolidation processes in 16 young (18–30 years) and 16 older (65–75 years) healthy adults. Performance was tested using a cued recall procedure at the end of learning (immediate recall), and 30 min and 7 days later. A delayed recognition test was also administered on day 7. Daily sleep diaries were completed during the entire experiment. Results revealed a similar percentage of correct responses at immediate and 30-min recall in young and older participants. However, recall was significantly decreased 7 days later, with an increased forgetting in older participants. Additionally, intra-sleep awakenings were more frequent in older participants than young adults during the seven nights, and were negatively correlated with delayed recall performance on day 7 in the older group. Altogether, our results suggest a decline in verbal declarative memory consolidation processes with aging, eventually leading to accelerated long-term forgetting indicating that increased sleep fragmentation due to more frequent intra-sleep awakenings in older participants contribute to the reported age-related decline in long-term memory retrieval. Our results highlight the sensitivity of long-term forgetting measures to evidence consolidation deficits in healthy aging.
Collapse
Affiliation(s)
- Alison Mary
- UR2NF - Neuropsychology and Functional Neuroimaging Research Unit at CRCN - Center for Research in Cognition and Neurosciences, Université Libre de Bruxelles Brussels, Belgium ; UNI - ULB Neurosciences Institute, Université Libre de Bruxelles Brussels, Belgium
| | | | | |
Collapse
|
29
|
Urbain C, Galer S, Van Bogaert P, Peigneux P. Pathophysiology of sleep-dependent memory consolidation processes in children. Int J Psychophysiol 2013; 89:273-83. [DOI: 10.1016/j.ijpsycho.2013.06.022] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 06/13/2013] [Accepted: 06/17/2013] [Indexed: 11/30/2022]
|
30
|
Nguyen ND, Tucker MA, Stickgold R, Wamsley EJ. Overnight Sleep Enhances Hippocampus-Dependent Aspects of Spatial Memory. Sleep 2013; 36:1051-1057. [PMID: 23814342 PMCID: PMC3669068 DOI: 10.5665/sleep.2808] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
STUDY OBJECTIVES Several studies have now demonstrated that spatial information is processed during sleep, and that posttraining sleep is beneficial for human navigation. However, it remains unclear whether the effects of sleep are primarily due to consolidation of cognitive maps, or alternatively, whether sleep might also affect nonhippocampal aspects of navigation (e.g., speed of motion) involved in moving through a virtual environment. DESIGN Participants were trained on a virtual maze navigation task (VMT) and then given a memory test following either a day of wakefulness or a night of sleep. Subjects reported to the laboratory for training at either 10:00am or 10:00pm, depending on randomly assigned condition, and were tested 11 h later. Overnight subjects slept in the laboratory with polysomnography. SETTING A hospital-based academic sleep laboratory. PATIENTS OR PARTICIPANTS Thirty healthy college student volunteers. INTERVENTIONS N/A. MEASUREMENTS AND RESULTS Point-by-point position data were collected from the VMT. Analysis of the movement data revealed a sleep-dependent improvement in maze completion time (P < 0.001) due to improved spatial understanding of the maze layout, which led to a shortening of path from start to finish (P = 0.01) rather than faster exploration speed through the maze (P = 0.7). CONCLUSIONS We found that overnight sleep benefitted performance, not because subjects moved faster through the maze, but because they were more accurate in navigating to the goal. These findings suggest that sleep enhances participants' knowledge of the spatial layout of the maze, contributing to the consolidation of hippocampus-dependent spatial information. CITATION Nguyen ND; Tucker MA; Stickgold R; Wamsley EJ. Overnight sleep enhances hippocampus-dependent aspects of spatial memory. SLEEP 2013;36(7):1051-1057.
Collapse
Affiliation(s)
- Nam D. Nguyen
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA
| | - Matthew A. Tucker
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA
- Department of Psychiatry, Harvard Medical School, Boston, MA
| | - Robert Stickgold
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA
- Department of Psychiatry, Harvard Medical School, Boston, MA
| | - Erin J. Wamsley
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Boston, MA
- Department of Psychiatry, Harvard Medical School, Boston, MA
| |
Collapse
|
31
|
Rahman A, Languille S, Lamberty Y, Babiloni C, Perret M, Bordet R, Blin OJ, Jacob T, Auffret A, Schenker E, Richardson J, Pifferi F, Aujard F. Sleep deprivation impairs spatial retrieval but not spatial learning in the non-human primate grey mouse lemur. PLoS One 2013; 8:e64493. [PMID: 23717620 PMCID: PMC3661499 DOI: 10.1371/journal.pone.0064493] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 04/15/2013] [Indexed: 12/04/2022] Open
Abstract
A bulk of studies in rodents and humans suggest that sleep facilitates different phases of learning and memory process, while sleep deprivation (SD) impairs these processes. Here we tested the hypothesis that SD could alter spatial learning and memory processing in a non-human primate, the grey mouse lemur (Microcebus murinus), which is an interesting model of aging and Alzheimer's disease (AD). Two sets of experiments were performed. In a first set of experiments, we investigated the effects of SD on spatial learning and memory retrieval after one day of training in a circular platform task. Eleven male mouse lemurs aged between 2 to 3 years were tested in three different conditions: without SD as a baseline reference, 8 h of SD before the training and 8 h of SD before the testing. The SD was confirmed by electroencephalographic recordings. Results showed no effect of SD on learning when SD was applied before the training. When the SD was applied before the testing, it induced an increase of the amount of errors and of the latency prior to reach the target. In a second set of experiments, we tested the effect of 8 h of SD on spatial memory retrieval after 3 days of training. Twenty male mouse lemurs aged between 2 to 3 years were tested in this set of experiments. In this condition, the SD did not affect memory retrieval. This is the first study that documents the disruptive effects of the SD on spatial memory retrieval in this primate which may serve as a new validated challenge to investigate the effects of new compounds along physiological and pathological aging.
Collapse
Affiliation(s)
- Anisur Rahman
- Mécanismes Adaptatifs et Evolution, UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Solène Languille
- Mécanismes Adaptatifs et Evolution, UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Yves Lamberty
- UCB Pharma s.a., Neuroscience Therapeutic Area, Braine l'Alleud, Belgium
| | - Claudio Babiloni
- Department of Clinical and Experimental Medicine, University of Foggia, Foggia, Italy, and IRCCS San Raffalele Pisana, Rome, Italy
| | - Martine Perret
- Mécanismes Adaptatifs et Evolution, UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Regis Bordet
- Département de Pharmacologie Médicale, EA 1046, Université Lille Nord de France, UDSL, Faculté de Médecine, CHU, Lille, France
| | - Olivier J. Blin
- CPCET-CIC, AP-HM Timone, INT, UMR 7289, CNRS - Aix Marseille Université, Marseille, France
| | - Tom Jacob
- Johnson and Johnson Pharmaceutical Research and Development, A Division of Janssen Pharmaceutica, Beerse, Belgium
| | - Alexandra Auffret
- CPCET-CIC, AP-HM Timone, INT, UMR 7289, CNRS - Aix Marseille Université, Marseille, France
| | | | - Jill Richardson
- GlaxoSmithKline, R&D China U.K. Group, Stevenage, Hertfordshire, United Kingdom
| | - Fabien Pifferi
- Mécanismes Adaptatifs et Evolution, UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| | - Fabienne Aujard
- Mécanismes Adaptatifs et Evolution, UMR 7179 Centre National de la Recherche Scientifique, Muséum National d'Histoire Naturelle, Brunoy, France
| |
Collapse
|
32
|
Lustenberger C, Maric A, Dürr R, Achermann P, Huber R. Triangular relationship between sleep spindle activity, general cognitive ability and the efficiency of declarative learning. PLoS One 2012. [PMID: 23185361 PMCID: PMC3504114 DOI: 10.1371/journal.pone.0049561] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
EEG sleep spindle activity (SpA) during non-rapid eye movement (NREM) sleep has been reported to be associated with measures of intelligence and overnight performance improvements. The reticular nucleus of the thalamus is generating sleep spindles in interaction with thalamocortical connections. The same system enables efficient encoding and processing during wakefulness. Thus, we examined if the triangular relationship between SpA, measures of intelligence and declarative learning reflect the efficiency of the thalamocortical system. As expected, SpA was associated with general cognitive ability, e.g. information processing speed. SpA was also associated with learning efficiency, however, not with overnight performance improvement in a declarative memory task. SpA might therefore reflect the efficiency of the thalamocortical network and can be seen as a marker for learning during encoding in wakefulness, i.e. learning efficiency.
Collapse
Affiliation(s)
- Caroline Lustenberger
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, Zurich, Switzerland
| | - Angelina Maric
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland
| | - Roland Dürr
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
| | - Peter Achermann
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP) University of Zurich, Zurich, Switzerland
| | - Reto Huber
- Child Development Center, University Children's Hospital Zurich, Zurich, Switzerland
- Neuroscience Center Zurich (ZNZ), University and ETH Zurich, Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP) University of Zurich, Zurich, Switzerland
- * E-mail:
| |
Collapse
|
33
|
Collet G, Schmitz R, Urbain C, Leybaert J, Colin C, Peigneux P. Sleep may not benefit learning new phonological categories. Front Neurol 2012; 3:97. [PMID: 22723789 PMCID: PMC3379727 DOI: 10.3389/fneur.2012.00097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Accepted: 05/30/2012] [Indexed: 11/13/2022] Open
Abstract
It is known that sleep participates in memory consolidation processes. However, results obtained in the auditory domain are inconsistent. Here we aimed at investigating the role of post-training sleep in auditory training and learning new phonological categories, a fundamental process in speech processing. Adult French-speakers were trained to identify two synthetic speech variants of the syllable /d∂/ during two 1-h training sessions. The 12-h interval between the two sessions either did (8 p.m. to 8 a.m. ± 1 h) or did not (8 a.m. to 8 p.m. ± 1 h) included a sleep period. In both groups, identification performance dramatically improved over the first training session, to slightly decrease over the 12-h offline interval, although remaining above chance levels. Still, reaction times (RT) were slowed down after sleep suggesting higher attention devoted to the learned, novel phonological contrast. Notwithstanding, our results essentially suggest that post-training sleep does not benefit more than wakefulness to the consolidation or stabilization of new phonological categories.
Collapse
Affiliation(s)
- Gregory Collet
- Fonds National de la Recherche ScientifiqueBruxelles, Belgium
- Unité de Recherche en Neurosciences Cognitives, Université Libre de BruxellesBruxelles, Belgium
- Laboratoire Cognition Langage Développement, Université Libre de BruxellesBruxelles, Belgium
| | - Rémy Schmitz
- Unité de Recherche en Neuropsychologie et Neuroimagerie Fonctionnelle, Université Libre de BruxellesBruxelles, Belgium
| | - Charline Urbain
- Unité de Recherche en Neuropsychologie et Neuroimagerie Fonctionnelle, Université Libre de BruxellesBruxelles, Belgium
| | - Jacqueline Leybaert
- Laboratoire Cognition Langage Développement, Université Libre de BruxellesBruxelles, Belgium
| | - Cécile Colin
- Unité de Recherche en Neurosciences Cognitives, Université Libre de BruxellesBruxelles, Belgium
| | - Philippe Peigneux
- Unité de Recherche en Neuropsychologie et Neuroimagerie Fonctionnelle, Université Libre de BruxellesBruxelles, Belgium
| |
Collapse
|
34
|
Holzschneider K, Wolbers T, Röder B, Hötting K. Cardiovascular fitness modulates brain activation associated with spatial learning. Neuroimage 2012; 59:3003-14. [DOI: 10.1016/j.neuroimage.2011.10.021] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Revised: 10/04/2011] [Accepted: 10/08/2011] [Indexed: 11/15/2022] Open
|
35
|
Impact of focal interictal epileptiform discharges on behaviour and cognition in children. Neurophysiol Clin 2011; 42:53-8. [PMID: 22200342 DOI: 10.1016/j.neucli.2011.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 09/29/2011] [Accepted: 11/01/2011] [Indexed: 11/23/2022] Open
Abstract
It is hypothesised that focal interictal epileptiform discharges (IED) may exert a deleterious effect on behaviour and cognition in children. This hypothesis is supported by the abnormally high prevalence of IED in several developmental disorders, like specific language impairment, and of cognitive and behavioural deficits in epileptic children after excluding confounding factors such as underlying structural brain lesions, drug effects, or the occurrence of frequent or prolonged epileptic seizures. Neurophysiological and functional neuroimaging evidence suggests that IED may impact cognition through either transient effects on brain processing mechanisms, or through more long-lasting effects leading to prolonged inhibition of brain areas distant from but connected with the epileptic focus (i.e. remote inhibition effect). Sustained IED may also impair sleep-related learning consolidation processes. Nowadays, the benefits of anti-epileptic treatment aimed at reducing IED are not established except in specific situations like epileptic encephalopathies with continuous spike and waves during slow-wave sleep. Well-designed pharmacological studies are still necessary to address this issue.
Collapse
|
36
|
Abstract
While a role for sleep in declarative memory processing is established, the qualitative nature of this consolidation benefit, and the physiological mechanisms mediating it, remain debated. Here, we investigate the impact of sleep physiology on characteristics of episodic memory using an item- (memory elements) and context- (contextual details associated with those elements) learning paradigm; the latter being especially dependent on the hippocampus. Following back-to-back encoding of two word lists, each associated with a different context, participants were assigned to either a Nap-group, who obtained a 120-min nap, or a No Nap-group. Six hours post-encoding, participants performed a recognition test involving item-memory and context-memory judgments. In contrast to item-memory, which demonstrated no between-group differences, a significant benefit in context-memory developed in the Nap-group, the extent of which correlated both with the amount of stage-2 NREM sleep and frontal fast sleep-spindles. Furthermore, a difference was observed on the basis of word-list order, with the sleep benefit and associated physiological correlations being selective for the second word-list, learned last (most proximal to sleep). These findings suggest that sleep may preferentially benefit contextual (hippocampal-dependent) aspects of memory, supported by sleep-spindle oscillations, and that the temporal order of initial learning differentially determines subsequent offline consolidation.
Collapse
|
37
|
Abstract
We investigated human hippocampal functional connectivity in wakefulness and throughout non-rapid eye movement sleep. Young healthy subjects underwent simultaneous EEG and functional magnetic resonance imaging (fMRI) measurements at 1.5 T under resting conditions in the descent to deep sleep. Continuous 5 min epochs representing a unique sleep stage (i.e., wakefulness, sleep stages 1 and 2, or slow-wave sleep) were extracted. fMRI time series of subregions of the hippocampal formation (HF) (cornu ammonis, dentate gyrus, and subiculum) were extracted based on cytoarchitectonical probability maps. We observed sleep stage-dependent changes in HF functional coupling. The HF was integrated to variable strength in the default mode network (DMN) in wakefulness and light sleep stages but not in slow-wave sleep. The strongest functional connectivity between the HF and neocortex was observed in sleep stage 2 (compared with both slow-wave sleep and wakefulness). We observed a strong interaction of sleep spindle occurrence and HF functional connectivity in sleep stage 2, with increased HF/neocortical connectivity during spindles. Moreover, the cornu ammonis exhibited strongest functional connectivity with the DMN during wakefulness, while the subiculum dominated hippocampal functional connectivity to frontal brain regions during sleep stage 2. Increased connectivity between HF and neocortical regions in sleep stage 2 suggests an increased capacity for possible global information transfer, while connectivity in slow-wave sleep is reflecting a functional system optimal for segregated information reprocessing. Our data may be relevant to differentiating sleep stage-specific contributions to neural plasticity as proposed in sleep-dependent memory consolidation.
Collapse
|
38
|
Landsness EC, Ferrarelli F, Sarasso S, Goldstein MR, Riedner BA, Cirelli C, Perfetti B, Moisello C, Ghilardi MF, Tononi G. Electrophysiological traces of visuomotor learning and their renormalization after sleep. Clin Neurophysiol 2011; 122:2418-25. [PMID: 21652261 DOI: 10.1016/j.clinph.2011.05.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 04/16/2011] [Accepted: 05/04/2011] [Indexed: 01/18/2023]
Abstract
OBJECTIVE Adapting movements to a visual rotation involves the activation of right posterior parietal areas. Further performance improvement requires an increase of slow wave activity in subsequent sleep in the same areas. Here we ascertained whether a post-learning trace is present in wake EEG and whether such a trace is influenced by sleep slow waves. METHODS In two separate sessions, we recorded high-density EEG in 17 healthy subjects before and after a visuomotor rotation task, which was performed both before and after sleep. High-density EEG was recorded also during sleep. One session aimed to suppress sleep slow waves, while the other session served as a control. RESULTS After learning, we found a trace in the eyes-open wake EEG as a local, parietal decrease in alpha power. After the control night, this trace returned to baseline levels, but it failed to do so after slow wave deprivation. The overnight change of the trace correlated with the dissipation of low frequency (<8 Hz) NREM sleep activity only in the control session. CONCLUSIONS Visuomotor learning leaves a trace in the wake EEG alpha power that appears to be renormalized by sleep slow waves. SIGNIFICANCE These findings link visuomotor learning to regional changes in wake EEG and sleep homeostasis.
Collapse
Affiliation(s)
- E C Landsness
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Abstract
The brain encodes huge amounts of information, but only a small fraction is stored for a longer time. There is now compelling evidence that the long-term storage of memories preferentially occurs during sleep. However, the factors mediating the selectivity of sleep-associated memory consolidation are poorly understood. Here, we show that the mere expectancy that a memory will be used in a future test determines whether or not sleep significantly benefits consolidation of this memory. Human subjects learned declarative memories (word paired associates) before retention periods of sleep or wakefulness. Postlearning sleep compared with wakefulness produced a strong improvement at delayed retrieval only if the subjects had been informed about the retrieval test after the learning period. If they had not been informed, retrieval after retention sleep did not differ from that after the wake retention interval. Retention during the wake intervals was not affected by retrieval expectancy. Retrieval expectancy also enhanced sleep-associated consolidation of visuospatial (two-dimensional object location task) and procedural motor memories (finger sequence tapping). Subjects expecting the retrieval displayed a robust increase in slow oscillation activity and sleep spindle count during postlearning slow-wave sleep (SWS). Sleep-associated consolidation of declarative memory was strongly correlated to slow oscillation activity and spindle count, but only if the subjects expected the retrieval test. In conclusion, our work shows that sleep preferentially benefits consolidation of memories that are relevant for future behavior, presumably through a SWS-dependent reprocessing of these memories.
Collapse
|
40
|
Tramoni E, Felician O, Barbeau EJ, Guedj E, Guye M, Bartolomei F, Ceccaldi M. Long-term consolidation of declarative memory: insight from temporal lobe epilepsy. Brain 2011; 134:816-31. [DOI: 10.1093/brain/awr002] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
41
|
Shi HS, Luo YX, Xue YX, Wu P, Zhu WL, Ding ZB, Lu L. Effects of sleep deprivation on retrieval and reconsolidation of morphine reward memory in rats. Pharmacol Biochem Behav 2011; 98:299-303. [PMID: 21255602 DOI: 10.1016/j.pbb.2011.01.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 12/21/2010] [Accepted: 01/07/2011] [Indexed: 11/18/2022]
Abstract
Relapse induced by exposure to cues associated with drugs of abuse is a major challenge to the treatment of drug addiction. Drug seeking can be inhibited by manipulation of the reconsolidation of drug-related memory. Sleep has been proposed to be involved in various memory processes. However, the role of sleep in drug reward memory is not clear. The present study used conditioned place preference to examine the effects of total sleep deprivation on retrieval and reconsolidation of morphine reward memory in rats. Six-hour total sleep deprivation had no effect on the retrieval of morphine reward memory. However, sleep deprivation from 0-6 h, but not 6-12 h, after re-exposure disrupted the reconsolidation of morphine reward memory. This impairment was not attributable to the formation of an aversive associative memory between the drug-paired context and sleep deprivation. Our findings suggest that sleep plays a critical role in morphine reward memory reconsolidation, and sleep deprivation may be a potential non-pharmacotherapy for the management of relapse associated with drug-related memory.
Collapse
Affiliation(s)
- Hai-Shui Shi
- National Institute on Drug Dependence, Peking University, Beijing 100191, China
| | | | | | | | | | | | | |
Collapse
|
42
|
Hagewoud R, Havekes R, Tiba PA, Novati A, Hogenelst K, Weinreder P, Van der Zee EA, Meerlo P. Coping with sleep deprivation: shifts in regional brain activity and learning strategy. Sleep 2011; 33:1465-73. [PMID: 21102988 DOI: 10.1093/sleep/33.11.1465] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
STUDY OBJECTIVES dissociable cognitive strategies are used for place navigation. Spatial strategies rely on the hippocampus, an area important for flexible integration of novel information. Response strategies are more rigid and involve the dorsal striatum. These memory systems can compensate for each other in case of temporal or permanent damage. Sleep deprivation has adverse effects on hippocampal function. However, whether the striatal memory system can compensate for sleep-deprivation-induced hippocampal impairments is unknown. DESIGN with a symmetrical maze paradigm for mice, we examined the effect of sleep deprivation on learning the location of a food reward (training) and on learning that a previously nonrewarded arm was now rewarded (reversal training). MEASUREMENTS AND RESULTS five hours of sleep deprivation after each daily training session did not affect performance during training. However, in contrast with controls, sleep-deprived mice avoided a hippocampus-dependent spatial strategy and preferentially used a striatum-dependent response strategy. In line with this, the training-induced increase in phosphorylation of the transcription factor cAMP response-element binding protein (CREB) shifted from hippocampus to dorsal striatum. Importantly, although sleep-deprived mice performed well during training, performance during reversal training was attenuated, most likely due to rigidity of the striatal system they used. CONCLUSIONS together, these findings suggest that the brain compensates for negative effects of sleep deprivation on the hippocampal memory system by promoting the use of a striatal memory system. However, effects of sleep deprivation can still appear later on because the alternative learning mechanisms and brain regions involved may result in reduced flexibility under conditions requiring adaptation of previously formed memories.
Collapse
Affiliation(s)
- Roelina Hagewoud
- Department of Molecular Neurobiology, University of Groningen, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
43
|
Dang-Vu TT, Schabus M, Desseilles M, Sterpenich V, Bonjean M, Maquet P. Functional neuroimaging insights into the physiology of human sleep. Sleep 2010; 33:1589-603. [PMID: 21120121 PMCID: PMC2982729 DOI: 10.1093/sleep/33.12.1589] [Citation(s) in RCA: 135] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Functional brain imaging has been used in humans to noninvasively investigate the neural mechanisms underlying the generation of sleep stages. On the one hand, REM sleep has been associated with the activation of the pons, thalamus, limbic areas, and temporo-occipital cortices, and the deactivation of prefrontal areas, in line with theories of REM sleep generation and dreaming properties. On the other hand, during non-REM (NREM) sleep, decreases in brain activity have been consistently found in the brainstem, thalamus, and in several cortical areas including the medial prefrontal cortex (MPFC), in agreement with a homeostatic need for brain energy recovery. Benefiting from a better temporal resolution, more recent studies have characterized the brain activations related to phasic events within specific sleep stages. In particular, they have demonstrated that NREM sleep oscillations (spindles and slow waves) are indeed associated with increases in brain activity in specific subcortical and cortical areas involved in the generation or modulation of these waves. These data highlight that, even during NREM sleep, brain activity is increased, yet regionally specific and transient. Besides refining the understanding of sleep mechanisms, functional brain imaging has also advanced the description of the functional properties of sleep. For instance, it has been shown that the sleeping brain is still able to process external information and even detect the pertinence of its content. The relationship between sleep and memory has also been refined using neuroimaging, demonstrating post-learning reactivation during sleep, as well as the reorganization of memory representation on the systems level, sometimes with long-lasting effects on subsequent memory performance. Further imaging studies should focus on clarifying the role of specific sleep patterns for the processing of external stimuli, as well as the consolidation of freshly encoded information during sleep.
Collapse
Affiliation(s)
- Thien Thanh Dang-Vu
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Department of Neurology, Liege University Hospital, Liege, Belgium
| | - Manuel Schabus
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Laboratory for Sleep and Consciousness Research, Department of Psychology, University of Salzburg, Salzburg, Austria
| | - Martin Desseilles
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Department of Neuroscience, University of Geneva, Geneva, Switzerland
| | | | - Maxime Bonjean
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Howard Hughes Medical Institute, The Salk Institute & School of Medicine, University of California, San Diego, CA
| | - Pierre Maquet
- Cyclotron Research Center, University of Liege, Liege, Belgium
- Department of Neurology, Liege University Hospital, Liege, Belgium
| |
Collapse
|
44
|
Wang B, Fu XL. Gender difference in the effect of daytime sleep on declarative memory for pictures. J Zhejiang Univ Sci B 2009; 10:536-46. [PMID: 19585672 PMCID: PMC2704972 DOI: 10.1631/jzus.b0820384] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2008] [Accepted: 04/24/2009] [Indexed: 11/11/2022]
Abstract
OBJECTIVE To investigate gender difference in the effects of daytime sleep on item and source memories, which are dissociable elements of declarative memory, and the effects of sleep on recollection and familiarity, which are two processes underlying recognition. METHODS Participants saw a series of pictures with either blue or red background, and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition, participants remained awake until the posttest; in the sleep condition, participants slept for 1 h until awakened and asked to remain awake until the posttest. RESULTS Daytime sleep contributed to retention of source memory rather than item memory in females, whereas males undergoing daytime sleep had a trend towards increased familiarity. For females, however, neither recollection nor familiarity appeared to be influenced by daytime sleep. CONCLUSION The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies, as well as with different electrophysiological changes during daytime sleep.
Collapse
Affiliation(s)
- Bo Wang
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
- Graduate University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiao-lan Fu
- State Key Laboratory of Brain and Cognitive Science, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China
| |
Collapse
|