Attentional Modulation of the Pupillary Light Response to Gaze Cueing of Covert Attention

Abstract

This paper explores whether a pupillary light response can be induced by gaze cueing. The conducted experiment was designed to draw the covert attention of participants towards a dark or bright stimulus, by means of exogenous and gaze cueing. Differences in pupil size between attending dark and attending bright indicate attentional modulation of the pupillary light response. The utilized eye-tracker and recorded responses allowed for pupillary and behavioural (accuracy, response times) analysis. In line with earlier findings it is hypothesized that the pupillary light response to gaze cueing shows attentional modulation. The results show no significant differences between attending bright or dark in the gaze cue condition. The pupillary light response in the exogenous cue condition was replicated, but no inhibition of return was visible in the behavioural or pupillary data. Because the known correlation between behaviour and pupil was not replicated, it is concluded the experimental design needs alterations. Ultimately, possible alterations are discussed.