title: Instructions to suppress semantic memory enhances or has no effect on P300 in a concealed information test (CIT).
abstract: The present study investigated the extent to which people can suppress semantic memory as indexed with the P300 ERP and the autobiographical implicit association test (aIAT). In EXP 1, participants (22) were run in a counterbalanced repeated measures study in both simply knowledgeable (SK) and knowledgeable with suppression (SP) conditions. A P300-based, concealed information test ("Complex Trial Protocol"; CTP) with a 50/50 Target/Nontarget (T/NT) ratio was given both with and without instructions to suppress semantic memories. The results showed increased P300s to probe name stimuli, reduced (but still high positive) aIAT d-scores, and increased simple reaction times to all stimuli used in ERP tests in the SP condition. EXP 2 was similar, but with SP and SK in two separate groups, and a 20/80 T/NT ratio. Again, ERP and aIAT results failed to show a suppression effect for semantic memory. The behavioral data suggest some task demand effects under suppression instructions, and that EXP 1 was more demanding than EXP 2.
authors.affiliation: Department of Psychology, Northwestern University, Evanston, IL 60201, USA. Electronic address: jp-rosenfeld@northwestern.edu.
authors.forename: J Peter
authors.initials: JP
authors.lastname: Rosenfeld
authors.affiliation: Department of Psychology, Northwestern University, Evanston, IL 60201, USA.
authors.forename: Anne
authors.initials: A
authors.lastname: Ward
authors.affiliation: Department of Psychology, Northwestern University, Evanston, IL 60201, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: Drapekin
authors.affiliation: Department of Psychology, Northwestern University, Evanston, IL 60201, USA.
authors.forename: Elena
authors.initials: E
authors.lastname: Labkovsky
authors.affiliation: Department of Psychology, Northwestern University, Evanston, IL 60201, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Tullman
mesh_terms: D000328:Adult; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D006801:Humans; D061212:Memory, Episodic; D011597:Psychomotor Performance / Q000502:physiology*; D012660:Semantics
keywords: Autobiographical implicit association test; Autobiographical memory; Complex trial protocol; Memory detection; Memory suppression; Neuroscience and law; P300