Go-getters and procrastinators: Investigating individual differences in visual cognition across university semesters.

University-based psychological research typically relies on the participation of undergraduate students for data collection. Using this particular sample brings with it several possible issues, including the self-scheduling done by the participants. Research on performance between students who sign up early versus late in the semester has been inconsistent. Some research report benefits for early participant semesters, while others find no differences between the two groups. Anecdotally, it seems that the former holds true, as many researchers worry about the data collected late in the semester, sometimes opting for more motivated earlier participants in the next semester. The purpose of our study was to examine for the effect of time of semester across a well-known set of visual cognition tasks. To do so, participants completed canonical versions of a rapid serial visual presentation task, a flanker task, an additional singleton paradigm task, a multiple object tracking task and a visual working memory task. These tasks were chosen as typical measures of executive control, temporal selectivity, visual working memory capacity, resistance to distraction, and attentional capacity. Crucially, we correlated task performance with time of semester students chose to participate. Our results demonstrate that there were no significant differences in any of the tasks across semester timing. Furthermore, our findings support the validity of cognitive research relying on the system of recruiting undergraduate students from volunteer pools where students can self-select the time of the semester they undertake the experiments.