Social context modulates basic properties of oculomotor control

Experiments performed in a lab are often considered generalizable over both people and social settings. The problems with generalizing over different groups of people are well known, but it is only recently that changes in behavior depending on the social setting have been examined. Large changes in behavior can be seen in trivial cognitive tasks, depending on whether the participant is alone or if other people are present. However, there are very few studies which have measured eye movements in social settings. In this paper, we used the antisaccade task to test whether basic parameters of oculomotor control are sensitive to the size of an experimental group. Seventy participants conducted 48 antisaccade trials in groups of one to seven people in a classroom equipped with multiple eye trackers. The results show that for horizontal saccades, but not for vertical saccades, participants make significantly more antisaccade errors when the group size become larger. The group size did however not significantly predict a change in antisaccade latency. These results are in line with a number of recent studies on social attention showing that the mere presence of other people in the room can modulate several aspects of performance, and show that behavior in a lab might not be easily generalizable to everyday life or social situations. Finally, from a methodological viewpoint, the results show that the group size should be considered when testing participants in a social setting.