Abstract
We blink more often than is required for eye lubrication, frequencies fluctuating greatly depending on task. Is there a benefit of increased blink rates? Some evidence suggests that blinks cause deactivation in dorsal attention areas (Nakano et al., 2013), possibly causing a "reset of attention". Contrariwise, retinal transients such as abrupt stimulus appearance, usually causing enhanced discrimination performance (e.g., Yantis & Jonidas, 1984), are known to be suppressed in cortical processing after eye blinks, particularly in parietal areas (Golan et al., 2016; Hari et al., 1994). We tested the effect of blinks and stimulus blanks on performance in a rapid serial visual presentation (RSVP) task. In experiment 1, participants identified a target digit embedded in a random stream of letter distractors, presented at 60 ms each. Participants were asked to blink once any time during the presentation. An eye tracker was used to identify blinks in real-time and present the target at varying delays after blink offset. In a separate condition, stimulus blanks using shutter glasses emulated the temporal properties of each observer's voluntary eye blinks. We found transient enhancements of performance (~15% increased accuracy) for targets appearing up to 180 ms after blink offset for both conditions. In experiment 2, participants judged numerosity of targets—a task supposedly dependent on parietal areas. Performance was poorer after natural blinks compared to artificial blanking up to 180 ms after blink offset. In both experiments we also observed a boost 800-1000 ms after blink offsets. Experiment 3 used natural scene distractors and animals as targets. Natural blinks again showed boosted performance up to 180 ms after blink offset. Based on the data collapsed across the 3 experiments, we suggest that the early boosts are due to transient effects, whereas the later boosts at 800-1000 ms are due to an attentional reset mechanism.
Meeting abstract presented at VSS 2018