Abstract
The current research investigated whether eyeblinks interfere with cognitive processing. In Experiment 1 subjects performed a partial report iconic memory task in which a letter array was presented for 100 ms, followed 50, 150, or 750 ms later by a tone that cued recall of one row of the array. On some trials subjects were told to blink their eyes as soon as the array was presented, while on other trials they did not; blink latency was approximately 225 ms. At an ISI of 50 ms between array offset and cue onset (i.e., 75 ms before blink onset) letter report accuracy was lower under blink than under no blink conditions and subjects made more mislocation errors. This result suggests that blink programming interferes with the binding of object identity and object position during readout from iconic memory. At longer ISIs there were no differences in accuracy or errors between the blink and no blink conditions, suggesting that blinking did not affect short-term memory. Experiment 2 demonstrated that blinks' disruptive effects on iconic memory are not a result of general motoric dual-task interference; button presses that matched the timing of blinks in Experiment 1 did not affect performance. Experiment 3 showed that performance on the iconic memory task was not hindered by prolonged eye closures that had the same latency as the blinks in Experiment 1 but were of longer duration, suggesting that blinks are unique in their disruption of iconic memory. More broadly, these experiments provide evidence for a new phenomenon, cognitive blink suppression, in which performing an eyeblink inhibits cognitive processing. This phenomenon may be the result of neural interference; blinks rely on posterior parietal cortex and influence activation in area V1, and this may interfere with the representation and spatial processing of information in iconic memory.
This research was supported by NSF grant BCS 01-32272.