5.3.3.1. Method

Participants. Sixty undergraduate students participated in the experiment (48 females and 12 males). The mean age was 24 years old (range = 19 to 48 years old). The other conditions were the same as in Experiment 1.

Materials and Apparatus. Identical to those in Experiment 1.

Design. A 2 (ISI: 90 ms, 0 ms) x 2 (congruency level) x 3 (emotional valence: negative, neutral and positive) x 3 (block) ANOVA factorial design was used. ISI was a between-subjects factor and the others were within-subjects factors. We predicted that there would be an ISI x emotional valence interaction, such that participants in the ISI level of 90 ms condition would respond more rapidly when colour-naming with a negative face than participants in the ISI level of 0 ms condition. In fact, emotional valence consisted of four levels: negative, neutral, positive face, and absence of face, as in Experiment 1, but the condition of “absence of face” was included only to calculate bias scores and was not included in the ANOVA. The other conditions were the same as in Experiment 1.

Procedure. A schematic face was presented for 30 ms immediately after the offset of the colour word for 30 participants (ISI level of 90 ms) and just before the onset of the colour patch for the other 30 participants (ISI level of 0 ms). The ISI between colour word and colour patch was 120msec in all two conditions. There were three blocks; a block consisted of 32 trials randomized in a list after counterbalancing face valence and Stroop congruency level. The other conditions were the same as in Experiment 1.