Abstract
Goal When preparing a saccade, visual sensitivity at the saccade target is enhanced before saccade onset. This effect, presaccadic attention, might play a role similar to covert attention by prioritizing the target of interest and improving performance. Recently, we used psychophysical reverse correlation and found that presaccadic attention modulates feature representations by sharpening orientation tuning and shifting spatial frequency (SF) tuning toward higher SFs (Li, Barbot, Carrasco, Current Biology 2016). Here, we investigate whether this shift of SF tuning occurs even when it might be detrimental to the task at hand. Methods In an orientation discrimination task, the target (1 cpd grating oriented +/- 45° from vertical) was superimposed with masks of different SFs (0.67/1/1.5 cpd). The stimulus was presented 10° left or right from fixation. In the saccade condition, a precue instructed observers to saccade to the cued location. Shortly after the precue (12-224 ms), the stimulus flashed (35 ms) at the cued location, being presented presaccadically in most trials. In the neutral condition, the precue pointed to both locations and observers maintained fixation throughout the trial. We hypothesize that if presaccadic attention shifts SF tuning automatically, presaccadic attention will either improve or impair performance depending on the SF of the mask. Results Compared to the neutral condition, presaccadic attention improved performance (d') when the mask SF was the same or lower than the target, but impaired performance when the mask SF was higher than the target. In a control experiment with the same timing, covert attention did not affect performance. Conclusion Presaccadic attention shifts SF tuning toward higher SFs, even when it impairs performance for the task at hand. Besides prioritizing the saccade target, presaccadic attention reshapes its representation by enhancing resolution, possibly to mimic the post-saccadic representation of the saccade target.
Meeting abstract presented at VSS 2018