Personal semantics: Is it distinct from episodic and semantic memory? An electrophysiological study of memory for autobiographical facts and repeated events in honor of Shlomo Bentin.
Declarative memory is thought to consist of two independent systems: episodic and semantic. Episodic memory represents personal and contextually unique events, while semantic memory represents culturally-shared, acontextual factual knowledge. Personal semantics refers to aspects of declarative memory that appear to fall somewhere in between the extremes of episodic and semantic. Examples include autobiographical knowledge and memories of repeated personal events. These two aspects of personal semantics have been studied little and rarely compared to both semantic and episodic memory. We recorded the event-related potentials (ERPs) of 27 healthy participants while they verified the veracity of sentences probing four types of questions: general (i.e., semantic) facts, autobiographical facts, repeated events, and unique (i.e., episodic) events. Behavioral results showed equivalent reaction times in all 4 conditions. True sentences were verified faster than false sentences, except for unique events for which no significant difference was observed. Electrophysiological results showed that the N400 (which is classically associated with retrieval from semantic memory) was maximal for general facts and the LPC (which is classically associated with retrieval from episodic memory) was maximal for unique events. For both ERP components, the two personal semantic conditions (i.e., autobiographical facts and repeated events) systematically differed from semantic memory. In addition, N400 amplitudes also differentiated autobiographical facts from unique events. Autobiographical facts and repeated events did not differ significantly from each other but their corresponding scalp distributions differed from those associated with general facts. Our results suggest that the neural correlates of personal semantics can be distinguished from those of semantic and episodic memory, and may provide clues as to how unique events are transformed to semantic memory.
School of Psychology, University of East Anglia, Norfolk, UK. Electronic address: L.Renoult@uea.ac.uk.
Louis
L
Renoult
School of Psychology, University of Ottawa, Ontario, Canada.
Annick
A
Tanguay
School of Psychology, University of Ottawa, Ontario, Canada.
Myriam
M
Beaudry
School of Psychology, University of Ottawa, Ontario, Canada.
Paniz
P
Tavakoli
School of Psychology, University of Ottawa, Ontario, Canada.
Sheida
S
Rabipour
School of Psychology, University of Ottawa, Ontario, Canada.
Kenneth
K
Campbell
Rotman Research Institute, Baycrest, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Ontario, Canada.
Morris
M
Moscovitch
Rotman Research Institute, Baycrest, Toronto, Ontario, Canada; Department of Psychology, University of Toronto, Ontario, Canada; Department of Medicine (Neurology), University of Toronto, Ontario, Canada.
Brian
B
Levine
School of Psychology, University of Ottawa, Ontario, Canada.
Patrick S R
PSR
Davidson
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D004569:Electroencephalography; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005145:Face; D005260:Female; D006801:Humans; D008297:Male; D061212:Memory, Episodic; D011939:Mental Recall / Q000502:physiology*; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010775:Photic Stimulation; D011930:Reaction Time / Q000502:physiology; D012660:Semantics; D013997:Time Factors; D055815:Young Adult
Autobiographical Memory; Autobiographical facts; ERPs; Episodic memory; LPC; N400; Personal semantic memory; Repeated events; Semantic memory