Victoria Jones¹ (), McKenzie Sheets³, Micalee Segers², Shannon Ross-Sheehy⁴; ¹University of Tennessee

When visually attending to a stimulus, viewers typically direct their eyes towards the item of their attention (overt attention). However, covert attention shifts even before the eyes move, likely facilitating accurate eye movements to the attended location (Posner, 1989). Spatial cueing tasks use a small spatial precue to elicit covert attention shifts, facilitating faster reaction times when targets appear in the cued location. Although adults inhibit eye movements during spatial cueing tasks, infant tasks necessarily rely on eye movements to assess spatial attention (Ross-Sheehy et al, 2015), making it difficult to assess covert attention. Fortunately, recent adult work used pupillometry to assess covert attention prior to a saccade (Salvaggio et al, 2022). Additionally, individual differences of pupil asymmetry may be linked to spatial attention control (Meyyapan et al, 2023). If pupil change (PC) and pupil asymmetry (PA) reveal covert attention, then they may be useful for assessing infant attentional development. To explore this, infants were tested in a cued-attention task and eye-tracking was used to monitor pupil prior to eye movements. If PC reflects covert attention, then we expect strong attention-related pupil changes, particularly for the eye contralateral to the cue and/or target. Infants were tested in a spatial cueing task (N=234 5, 8, and 11-mo-olds). Gaze and pupil were tracked binocularly (300Hz). LME models were used to assess PC and PA. Preliminary model results reveal several significant effects, including significant pre-movement PC ( β=0.0004, p<0.001) and PA, with ipsilateral targets producing the greatest dilation ( β=0.023, p<0.001). Moreover, PA was greatest for valid and baseline cue conditions (β=0.026, p<0.001 ), suggesting PA may be a useful assessment both of attention orienting and cue effects. Poster analyses will fully explore pupil change and pupil asymmetry as a function of age and cue condition.