Eye blinks are related to auditory information processing: evidence from a complex speech perception task

There is increasing evidence that spontaneous eye blinks are related to mental states and can predict performance in certain tasks because of their relation to dopaminergic activity. Moreover, it has been shown that eye blinks while performing visual tasks are preferably executed not before all available information and even the manual response has been processed and given. Thus, blinks provide a natural endpoint of visual information processing. In the present study, we investigate to what degree such functional assignment of eye blinks also applies when only auditory stimuli are processed. For that, we present blink analyses on data of an auditory stock price monitoring task to examine the timing and frequency of blinks relative to the temporal dynamics of the task and different kinds of available cues. Our results show that blinks are meaningfully rather than randomly paced, although no visual information has to be processed. Blinks are significantly accelerated if a no-go trial is indicated which made all the subsequent information irrelevant. Although the stimuli were exclusively auditory, blinks were mostly inhibited during stimulus presentation. Taken together, blinks depend on the information being presented and mark a distinct point in time at which this information is conclusively processed. These findings deliver further support for the usefulness of eyeblink analyses, independently of the modality of the information being processed.