title: Exploration of the mechanisms underlying the ISPC effect: evidence from behavioral and neuroimaging data.
abstract: The item-specific proportion congruent (ISPC) effect in a Stroop task - the observation of reduced interference for color words mostly presented in an incongruent color - has attracted growing interest since the original study by Jacoby, Lindsay, and Hessels [(2003) Psychonomic Bulletin & Review, 10(3), 638-644]. Two mechanisms have been proposed to explain the effect: associative learning of contingencies and item-specific control through word reading modulation. Both interpretations have received empirical support from behavioral data. Therefore, the aim of this study was to investigate the responsible mechanisms of the ISPC effect with the classic two-item sets design using fMRI. Results showed that the ISPC effect is associated with increased activity in the anterior cingulate (ACC), dorsolateral prefrontal (DLPFC), and inferior and superior parietal cortex. Importantly, behavioral and fMRI analyses specifically addressing the respective contribution of associative learning and item-specific control mechanisms brought support for the contingency learning account of the ISPC effect. Results are discussed in reference to task and procedure characteristics that may influence the extent to which item-specific control and/or contingency learning contribute to the ISPC effect.
authors.affiliation: Cyclotron Research Centre, University of Liège, Liège, Belgium.
authors.forename: Julien
authors.initials: J
authors.lastname: Grandjean
authors.forename: Kevin
authors.initials: K
authors.lastname: D'Ostilio
authors.forename: Wim
authors.initials: W
authors.lastname: Fias
authors.forename: Christophe
authors.initials: C
authors.lastname: Phillips
authors.forename: Evelyne
authors.initials: E
authors.lastname: Balteau
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.forename: André
authors.initials: A
authors.lastname: Luxen
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
authors.forename: Eric
authors.initials: E
authors.lastname: Salmon
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001245:Association Learning / Q000502:physiology; D001288:Attention; D002540:Cerebral Cortex / Q000098:blood supply / Q000502:physiology*; D003118:Color Perception / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D011930:Reaction Time / Q000502:physiology*; D057190:Stroop Test; D013998:Time Perception / Q000502:physiology*; D055815:Young Adult
chemical_list: D010100:Oxygen