Windows of the soul - do you hear me?

A new study, recently published in the Journal of Experimental Psychology, has indicated that listeners are most likely to tune in when a speaker delivers the emotional peak of their story. The finding, based on patterns of pupil dilation, show that listener and narrator achieve synchronous pupil dilation at a peak of shared attention. The study also showed how empathy plays a role. Irrespective of whether the listener had high or low empathy they all tuned in for the climax of a story. As might be expected, listeners with higher empathy tuned in more. Highly expressive speakers were more likely to evoke pupillary synchrony.

It is well known that pupils dilate to adjust the amount of light that enters the eye and also in response to attraction. People are less aware that pupils dilate rapidly in response to information that is being processed moment by moment. Previous studies assessing attention and connection typically ask listeners what they remember about a speaker's story after the fact. This requires the listener to access consciousness or self-report what they think and feel, which is susceptible to bias and other memory issues. In contracts, the current study measures engagement in real-time by evaluating a physiological response or in this case, pupil dilations, which cannot be faked or controlled consciously.

Healthy young adults were videotaped telling their autobiographical narratives while their pupil dilations were tracked with an infrared eye-tracker. Subjects were recorded during four highly expressive and four low expressive video clips.  Independent observers listened to the audio only and were asked to evaluate how engaging each narrative was using a physical slider bar. Listeners watched speakers' video clips while their pupil dilations were tracked. As pupil dilations reflect conscious attention, the researchers looked for periods of shared attention by comparing speakers' and listeners' pupil dilation patterns for moments of synchrony.

Clearly, the eyes are truely the windows of the soul, as the often quoted biblical metaphone claims. Many scientific studies have demonstrated links between pupil dilation and eye gaze to mental states such as attention and intention. The present study underlines how the eyes not only reveal the inner workings of one mind, but reveal when two minds connect. The study adds to earlier findings that pupil dilation patterns reflect the contents of consciousness or what one pays attention to.