داوطلبی غیر ارادی: سرکوب اندیشه و تنظیم تجربه اراده

Participants were asked to carry out a series of simple tasks while following mental control instructions. In advance of each task, they either suppressed thoughts of their intention to perform the task, concentrated on such thoughts, or monitored their thoughts without trying to change them. Suppression resulted in reduced reports of intentionality as compared to monitoring, and as compared to concentration. There was a weak trend for suppression to enhance reported intentionality for a repetition of the action carried out after suppression instructions had been discontinued.

Initial analyses showed that participants took their instructions seriously. Participants indicated trying fairly hard to concentrate on the thought in concentration trials (M=6.14 on the 9-point scale), and also trying fairly hard to suppress the thought in suppression trials (M=6.63). They reported thinking primarily about the action rather than other things on the monitoring trials (M=6.26). These thought manipulations did not influence action per se, however, as all participants carried out all tasks. Participants’ initial level of intentionality on the practice task was near the scale midpoint of 5 (M=5.67) and the means for all the tasks across conditions were near this value. Initial analyses also indicated, however, that one of the experimental tasks (anagrams) elicited high intentionality ratings overall, so further analyses were conducted with this task excluded. Mean intentionality pooled across tasks was examined in a 3 (order of tasks) × 3 (instruction: concentration, monitoring, or suppression) × 2 (action: target action vs. later action) analysis of variance (ANOVA) with repeated measures on the latter two variables. Although there were significant main effects of action and instruction, and also significant interactions of order with each of these variables, these are best interpreted in light of the significant interaction of instruction and action, F(2,42)=8.46,p<.001,η2=.29. Task order did not qualify this effect, so the influence of order will not be examined further. The means are shown in Fig. 1.