Figure 1
Experimental paradigm: vigilance task with task-irrelevant cue-words. A thought-probe method was used to collect self-reports about the subjects’ focus of attention during the task. Participants were asked to focus on the central fixation point and press the spacebar whenever a target (vertical bars) was detected. At 28 fixed points, the task was stopped by a thought-probe, which included the following questions: (i) “What were you thinking about just immediately prior to the probe?”; if participants reported a thought they were asked to (ii) give orally a short description of their mental content, (iii) indicate if the thought occurred spontaneously, if they deliberately decided to think about it or if they were not sure about the answer, and (iv) whether the thought had been triggered by the environment, by their own thoughts, by a word on the screen (if so, to specify the word) or if there was no trigger (see Method section).
Figure 2
Pupil traces aligned to the average pupil diameter during the presentation of the cue-word. Thick lines give the average across all trials, thin lines show the s.e. and circles show the average values entered the LMM analysis (average over the second half of each trial).
Figure 3
Pupil traces aligned to the average pupil diameter during the last trial before the thought-probe. Thick lines give the average across all trials, thin lines show the s.e. and circles show the average values entered the LMM analysis (average over the first half of each trial).
Figure 4
Pupil traces aligned to the average pupil diameter during the first 250 ms of each trial. Thick lines give the average across all trials, thin lines show the s.e. and circles show the average values entered the LMM analysis (average over the [.5:1]s interval). Left: trials with the horizontal bars that preceded a thought-probe at which MW or OT was reported. Right: trials with the frequent horizontal bars vs. the infrequent vertical bars that participants had to detect for their vigilance task.