Purchase this article with an account.
Ema Shamasdin Bidiwala, Miranda Scolari; Exploring Pupil Diameter as a Cognitive Spatial Filter. Journal of Vision 2020;20(11):1677. doi: https://doi.org/10.1167/jov.20.11.1677.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Previous studies have successfully used changes in pupil diameter to index general top-down cognitive and attentional control. However, few studies have explored its ability to track the spatial extent of selective attention. To investigate this, subjects performed a modified flanker compatibility task with eye tracking, where performance is best facilitated by restricting spatial selection to the target item. To manipulate attentional spread, targets and distractors were presented in a common object (two rings connected by a line) or separately in (independent rings). Distractors were either compatible, incompatible, or absent. Pupil data was analyzed separately during a cueing period (rings alone) and after target onset, prior to response. Behaviorally the flanker effect (higher accuracy on compatible compare to incompatible distractor trials) was equally significant across both grouping conditions. Furthermore, a simple linear regression across subjects revealed differences response time difference could be predicted by in pupil size during the cueing period between grouping conditions. A similar relationship was observed for distractor conditions after target onset, with larger pupil diameters on compatible conditions predicting faster responses than incompatible. Results on this task implicate pupil size as a general exertion of cognitive effort or effort related to spatial filtering. To elucidate these patterns, a second experiment was conducted manipulating spatial spreading of attention while holding cognitive effort constant. Subjects completed the aforementioned task, interleaved with a spatial inducer task eliciting a diffused or focused spread of attention. The inducer task allowed observation of spatial filtering ability when it was detrimental (diffused) or advantageous (focused). Preliminary results show presence of a flanker effect in focused conditions and absence in diffused. Consistent with results from the first experiment, spatial filtering seems to be related to exertion of cognitive effort. Both experimental results provide explanations for pupil behavior during exertion of cognitive effort in spatial tasks.
This PDF is available to Subscribers Only