5.3.2.1. Method

Participants. Sixteen undergraduate students participated (mean age of 23 years old, ranging from 19 to 28 years old).

Material. The materials used in Experiment 2 were identical to those in Experiment 1 with the exception of emotional stimuli used in Experiment 1.

Design. A 2 (Stroop congruency level) x 4 (ISI: 0, 50, 100, 150 ms) ANOVA factorial design was used. The main prediction was for a main effect of ISI indicating a tendency toward increasing interference with shorter ISIs.

Procedure. Participants were instructed to colour-name the colour patch as fast and as accurately as possible, ignoring the colour word stimulus. For each trial, a fixation point (+) was first displayed for 700 ms, then a colour word for 600 ms, and after four different ISI: 0, 50, 100, or 150 msec, a colour square was displayed until the participant pronounced the first syllable of the colour name. Four blocks were presented, each of which contained four sub-blocks. A sub-block consisted of eight trials with the same ISI. Half of the trials in a sub-block presented the congruent condition between word stimulus and colour stimulus and the other half represented the conflicting condition. Block and sub-block presentation order was different across participants (see Appendix 2), and all blocks were separated by a short break.