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Does slow wave sleep strengthen the memory traces of both consciously and nonconsciously encoded episodes?

English title Does slow wave sleep strengthen the memory traces of both consciously and nonconsciously encoded episodes?
Applicant Henke Westerholt Katharina
Number 119953
Funding scheme Interdisciplinary projects
Research institution Klinische Psychologie und Psychotherapie Institut für Psychologie Universität Bern
Institution of higher education University of Berne - BE
Main discipline Psychology
Start/End 01.05.2008 - 30.04.2014
Approved amount 502'939.00
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All Disciplines (3)

Discipline
Psychology
Neurology, Psychiatry
Neurophysiology and Brain Research

Keywords (15)

Implicit memory; explicit memory; consciousness; memory consolidation; sleep; EEG; fMRI; learning; memory; consolidation; conscious; nonconscious; implicit; explicit; hippocampus

Lay Summary (English)

Lead
Lay summary
Established models of human long-term memory do not envision a role for the human hippocampus - a brain structure necessary for conscious learning - in nonconscious forms of learning and memory. These models posit a role for the human hippocampus in the conscious acquisition and retention of experienced episodes. In order to remember an episode, one has to encode the constituent parts of the episode (people, furniture, spoken words, etc.) and their conceptual, temporal and spatial relationships from moment to moment while experiencing the episode. Hence, the on-line encoding of a complete episode requires rapid learning of multiple conceptual, temporal, and spatial associations between the constituents of an episode. Therefore, rapid learning of new associations can be considered the precondition for episodic memory. Recent brain imaging experiments and patient studies have suggested that it is humanly possible to rapidly form and later retrieve new associations even outside consciousness and that the hippocampus is involved in this form of nonconscious learning. Consequently, the existence of a nonconscious form of episodic-like memory can be hypothesized. With this SNF project, we try to draw parallels between conscious and nonconscious forms of episodic learning and memory. We attempt to show that conscious and nonconsicous episodic memories invoke the same storage mechanisms in the brain and that these storage mechanisms are distinct from those storage mechanisms that support cognitively simpler forms of nonconscious learning. We hypothesize that the storage of both consciously and nonconsciously encoded episodic memories depends on the interaction between hippocampus and neocortex during slow wave sleep. To this end, we trigger a reactivation of the formed memories to induce the fixation of consciously and nonconsciously acquired memories by displaying cues over headphones to the sleeping subjects. We collect electroencephalographic and functional magnetic resonance imaging data to compare brain activity associated with conscious and nonconscious learning, memory reactivation during sleep, and retrieval. The results might potentially speak in favor of a new memory model that allots a role to the hippocampus in both conscious and nonconscious forms of episodic memory.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Publications

Publication
Formation of semantic associations between subliminally presented face-word pairs
Duss SB, Oggier S, Reber TP, Henke K (2011), Formation of semantic associations between subliminally presented face-word pairs, in CONSCIOUSNESS AND COGNITION, 20(3), 928-935.
Suppressed, but Not Forgotten
Meier B, Konig A, Parak S, Henke K (2011), Suppressed, but Not Forgotten, in SWISS JOURNAL OF PSYCHOLOGY, 70(1), 5-11.
MEMORY SYSTEMS - OPINION A model for memory systems based on processing modes rather than consciousness
Henke K (2010), MEMORY SYSTEMS - OPINION A model for memory systems based on processing modes rather than consciousness, in NATURE REVIEWS NEUROSCIENCE, 11(7), 523-532.
Sleep stage II contributes to the consolidation of declarative memories.
Ruch Simon, Markes Oliver, Duss Simone B, Oppliger Daniel, Reber Thomas P, Koenig Thomas, Mathis Johannes, Roth Corinne, Henke Katharina, Sleep stage II contributes to the consolidation of declarative memories., in Neuropsychologia.

Collaboration

Group / person Country
Types of collaboration
Stefan Schweinberger, University of Jena Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Exchange of personnel
Inselspital Bern, Dr. Kaspar Schindler Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
University of Wisconsin Milwaukee, D. Hannula United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Epilepsie Klinik Bonn, J. Fell und N. Axmacher Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
European Brain and Behaviour Society Meeting Talk given at a conference Episodic memories nondeclared 06.09.2013 Munich, Germany Henke Westerholt Katharina;
Advances in Memory Systems Talk given at a conference Hippocampus supports unconscious episodic memory 04.04.2013 New York, United States of America Henke Westerholt Katharina;
Benesco Meeting in Adelboden Talk given at a conference Memory systems in the brain 07.03.2013 Adelboden, Switzerland Henke Westerholt Katharina;
Winter Conference on Neural Plasticity, Annual Meeting, Feb. 9-16, 2013, Curaçao, Carribbean Talk given at a conference Impaired Unconscious Relational Encoding in Amnesia 09.02.2013 Curacao, Netherlands Antilles Henke Westerholt Katharina;
The 16th annual meeting of the ASSC Poster Unconscious detection of analogous relationships between current and past events: an fMRI study. 02.07.2012 Brighton, Great Britain and Northern Ireland Henke Westerholt Katharina;
Cognitive Neuroscience Society Meeting Poster Conscious intentions modulate the way subliminal words are processed. 31.03.2012 Chicago, United States of America Henke Westerholt Katharina; Duss Simone;
Cognitive Neuroscience Society Meeting Poster The contribution of sleep stage II to the consolidation of episodic memories. 31.03.2012 Chicago, United States of America Henke Westerholt Katharina; Duss Simone; Ruch Simon;
Cognitive Neuroscience Society meeting Talk given at a conference Unconscious relational inference recruits the hippocampus. 31.03.2012 Chicago, United States of America Henke Westerholt Katharina;
Winter Workshop on Memory Talk given at a conference Memory and the hippocampus 25.11.2011 Lübeck, Germany Henke Westerholt Katharina;
Annual Meeting of the Memory Disorders Research Society Talk given at a conference Unconscious episodic memories?”, 13.09.2011 Barcelona, Switzerland Henke Westerholt Katharina;
Clinical Neurosciences Bern Talk given at a conference Memory systems based on processing modes 09.11.2010 Bern, Switzerland Henke Westerholt Katharina;
Society for Neuroscience meeting Talk given at a conference Generalizations over temporally distinct ‘non-conscious episodes’ engage the hippocampus during learning and retrieval. 30.10.2009 Chicago, United States of America Henke Westerholt Katharina;


Self-organised

Title Date Place
Hans Sigrist Symposium “Unconscious information processing by the brain” 04.12.2009 Bern, Switzerland

Knowledge transfer events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Brain Week 11.03.2014 Bern, Switzerland
Brain Week Bern 11.03.2013 Bern, Switzerland
Brain Fair Bern 19.03.2010 Bern, Switzerland


Communication with the public

Communication Title Media Place Year
New media (web, blogs, podcasts, news feeds etc.) Center for Cognition, Learning and Memory Newsletter International 2013

Associated projects

Number Title Start Funding scheme
148941 Unconscious, sleep-assisted language learning 01.10.2013 Doc.CH
136249 Resting states of the brain and state dependent information processing in health and disease 01.01.2012 Sinergia
114012 Hippocampus mediates unconscious learning, consolidation and retrieval of episodes 01.11.2006 Project funding (Div. I-III)

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