Abstract
How do overt and covert attentional breadth extend over visual space at a given point time? Williams (1988, 1989) argued that for covert attention, "tunnel vision" requires a foveal load, while other attentional manipulations produce general interference (Crundall, Underwood, & Chapman, 2002). Nevertheless, several studies have shown that auditory loads cause tunneling of overt attention (e.g., Reimer et al, 2009; Greene et al., 2012). Previously, we reported two experiments where participants discriminated m-scaled, gaze-contingently presented Gabor patches at 0, 3, 6, or 9 degrees eccentricity. Attention was manipulated in dual-task conditions with either a foveal (rotated L/T discrimination) or auditory working memory (n-back) load (Ringer, et al., 2015). The foveal load produced tunnel vision whereas the auditory WM load produced general interference, demonstrating that a foveal bias is necessary to produce tunneling of covert attention. Here, we ask whether these load-dependent effects on covert attention translate into similar effects in overt attention, particularly when fixed visual limitations (i.e., cortical magnification) have been controlled for. To answer this question, we analyzed the length of saccades immediately following a Gabor presentation in dual versus single-task conditions of our previous auditory WM (N-back) and foveal (L/T discrimination) load experiments. Overall, the saccade lengths between auditory and foveal loads were quite similar, however the saccade lengths for auditory loads were slightly smaller than for the foveal load. This was surprising, since the foveal load produced greater covert attention decrements than the auditory WM load. However, when comparing the interaction between task and eccentricity (indicative of tunnel vision), there was a greater divergence between single versus dual-task saccade lengths for the foveal load. Thus, both our previously reported results for covert attention (Ringer, et al., 2015) and the currently reported results for overt attention are consistent in showing tunnel vision only with a foveal load.
Meeting abstract presented at VSS 2016