title: Time- but not sleep-dependent consolidation promotes the emergence of cross-modal conceptual representations.
abstract: Conceptual knowledge about objects comprises a diverse set of multi-modal and generalisable information, which allows us to bring meaning to the stimuli in our environment. The formation of conceptual representations requires two key computational challenges: integrating information from different sensory modalities and abstracting statistical regularities across exemplars. Although these processes are thought to be facilitated by offline memory consolidation, investigations into how cross-modal concepts evolve offline, over time, rather than with continuous category exposure are still missing. Here, we aimed to mimic the formation of new conceptual representations by reducing this process to its two key computational challenges and exploring its evolution over an offline retention period. Participants learned to distinguish between members of two abstract categories based on a simple one-dimensional visual rule. Underlying the task was a more complex hidden indicator of category structure, which required the integration of information across two sensory modalities. In two experiments we investigated the impact of time- and sleep-dependent consolidation on category learning. Our results show that offline memory consolidation facilitated cross-modal category learning. Surprisingly, consolidation across wake, but not across sleep showed this beneficial effect. By demonstrating the importance of offline consolidation the current study provided further insights into the processes that underlie the formation of conceptual representations.
authors.affiliation: Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Zochonis Building, Brunswick Street, Manchester M13 9PL, UK. Electronic address: nora.hennies@postgrad.manchester.ac.uk.
authors.forename: Nora
authors.initials: N
authors.lastname: Hennies
authors.affiliation: Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Zochonis Building, Brunswick Street, Manchester M13 9PL, UK.
authors.forename: Penelope A
authors.initials: PA
authors.lastname: Lewis
authors.affiliation: Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Zochonis Building, Brunswick Street, Manchester M13 9PL, UK; School of Psychology, University of Lincoln, Lincoln LN6 0BG, UK.
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Durrant
authors.affiliation: Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Zochonis Building, Brunswick Street, Manchester M13 9PL, UK.
authors.forename: James N
authors.initials: JN
authors.lastname: Cousins
authors.affiliation: Neuroscience and Aphasia Research Unit, School of Psychological Sciences, University of Manchester, Zochonis Building, Brunswick Street, Manchester M13 9PL, UK.
authors.forename: Matthew A Lambon
authors.initials: MA
authors.lastname: Ralph
mesh_terms: D000293:Adolescent; D000328:Adult; D001307:Auditory Perception; D003210:Concept Formation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008568:Memory; D012890:Sleep; D013997:Time Factors; D014796:Visual Perception; D055815:Young Adult
keywords: Abstraction; Category learning; Cross-modal object representations; Memory consolidation; Sleep