Fig 1.
Different approaches to first dwell time of (A) previous studies [11, 12] and (B) the present study, with the 2AFC paradigm. Dots and solid lines represent participants’ eye movement, and the numbers represent the order of dwells. Dashed lines represent eye movements after the second look (not argued in this paper). In the previous studies, there was no discrimination between the first look (FL) and the second look (SL), because the effects of the order of dwells were not considered. In the present study, the FL and SL were clearly discriminated and the relationship between the order of dwells and gaze bias was considered.
Fig 2.
A schematic representation of selective encoding in the 2AFC paradigm suggested and examined in the present study.
At the time of the first look (FL) (i.e., initial encoding stage), participants cannot know whether an item is more appropriate than another item; thus, selective encoding does not occur. On the other hand, at the time of the second look (SL) (i.e., encoding and comparison stage), participants know all the items presented and they can judge which item meets their decision criteria better. Therefore, selective encoding occurs only in the SL, and not in the FL.
Fig 3.
Example of a trial in Experiment 1.
After a fixation point was presented in the center of the screen (2000 ms), a pair of photos was presented on the monitor. Once participants made a decision by pressing a key, the photos were replaced by the fixation point, before starting the next trial. This procedure was repeated for 30 trials in each task block (preference and roundness tasks).
Fig 4.
Averaged first dwell time in Experiment 1.
Error bars represent standard error of the mean.
Table 1.
Generalized linear mixed models fitting the first dwell time in Experiment 1.
Fig 5.
Averaged first dwell time in the wine block in Experiment 2.
Error bars represent the standard error of the mean.
Table 2.
Generalized linear mixed models fitting the first dwell time in the wine block in Experiment 2.
Fig 6.
Averaged first dwell time in the snack block in Experiment 2.
Error bars represent the standard error of the mean.
Table 3.
Generalized linear mixed models fitting the first dwell time in the snack block in Experiment 2.