Perceptual averaging for auditory pro- and antisaccades


The visual antisaccade task requires the top-down and two-component processing of inhibiting a stimulus-driven prosaccade (i.e., response suppression) and the mirror-symmetrical inversion of a target's visual location (i.e., vector inversion). Notably, recent work by our group (Gillen and Heath 2014: Vis Res; Heath et al. 2015: J Vis) has shown that vector inversion is a perception-based process governed via a statistical summary representation (SSR). In particular, our work showed that antisaccade amplitudes were biased in the direction of the most frequently presented target in a stimulus-set. The present investigation was designed to examine whether a SSR influences auditory-based pro- and antisaccades. To that end, participants completed auditory (i.e., 50 ms burst, 70 dBA white noise) pro- and antisaccades to three target eccentricities (10.5°, 15.5° and 20.5°) in blocks wherein eccentricities were presented with equal frequency (i.e., control-weighting condition) and when the 10.5° (i.e., proximal-weighting condition) and 20.5° (i.e., distal-weighting condition) targets were presented five times as often as the other eccentricities. Results showed that pro- and antisaccade amplitudes were refractory to the different weighting conditions; however, the slope relating amplitude to target eccentricity was markedly shallower for the latter task (prosaccade: b=0.51; antisaccade: b=0.17;). Thus, preliminary results provide no evidence that weighting conditions differentially influenced the specification of pro- and antisaccade amplitudes. That said, the shallower amplitude/target eccentricity slope associated with antisaccades provides some evidence that an auditory vector inversion process is governed via a SSR that is similar to its visually based counterpart.

Acknowledgments: Supported by NSERC