Memory and pupil-linked arousal

How can the eyes of a person reveal how their brain works? Here I am not talking about blue-eyed people being funnier than others, but about pupil dilation reflecting a change in your central brain arousal state.

While I was working as a research assistant in Tobias Donner’s lab, he gave me the opportunity to do a study with Josefine Hebisch on how phasic changes in arousal, measured through pupil dilation, affect the memory encoding and retrieval of information.

We used loud white noise (as a task-irrelevant stimulus) to manipulate the arousal state, and we wanted to see if 1) the arousal state would be reflected in the pupil dilation, and 2) if it had an impact on how well people remembered certain stimuli.