Eye-Blink Patterns Reflect Attention to Continuous Speech

Eye blinks not only serve to maintain the tear film of the eye but also seem to have a functional role in information processing. People tend to inhibit an eye blink when they expect relevant information to occur in their visual environment and blink more often when the information has been processed. Recent studies have shown that this relation also holds for auditory information processing. However, only artificial auditory stimuli like tones or controlled lists of words were used in studies so far. In the current study, we tested whether there would be a temporal association between the pauses in a continuous speech stream and the listener's eye blinks. To this end, we analyzed the eye blinks of 35 participants who were instructed to attend to one of two simultaneously presented audiobooks. We found that the blink patterns of 13 participants were coupled with the speech pauses in the attended speech stream. These participants blinked more often during the pauses in the attended speech stream. Contrary to our prediction, participants did not inhibit their blinking preceding a pause in the attended speech stream. As expected, there was no evidence that the listeners' blink pattern was coupled to the pauses in the ignored speech stream. Thus, the listeners' blink patterns can reflect attention to continuous speech.