Galer, S. 1, 2 , Schmitz, R. 2 , De Tiège, X. 1 , Van Bogaert, P. 1 & Peigneux, P. 2, 3
1 LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
2 UR2NF - Neuropsychology and Functional Neuroimaging Research Unit, Université Libre de Bruxelles, Brussels, Belgium
3 CRC - Cyclotron Research Center, University of Liège, Liège, Belgium
In the Stroop task, an interference effect between reading a word naming a color and its printed color is a robust phenomenon. Here we tested whether within-task variations in the interstimulus interval (ISI) may impact on this interference. Twelve healthy young adults performed a modified version of the Stroop task, where they responded by pressing buttons to the color of a color-word stimuli when the two sources of information were congruent (e.g., “red” printed in red) or incongruent (e.g., “red” printed in blue). Control stimuli, i.e. neutral words matched with each color were interspersed to annihiliate undesirable effects. Within the task, ISI was pseudo-randomly manipulated so that stimuli within each category were displayed after 1000, 1500 or 3000 msec. A repeated measures ANOVA with interval and condition as within-subject factors was computed on mean reaction times for correct responses . Results disclosed higher RTs for incongruent than congruent stimuli (p < 0.01), and than control items (p < 0.01). The main effect of the interval (p > 0.05) and the interaction between interval and category (p > 0.05) were non-significant. These results indicate that interference effects in the Stroop task are not influenced by ISI variations within this time range.