Eye Movement-Based Memory Assessment

Abstract

We introduce here a new indirect (implicit) measure of memory based on eye movement monitoring. Eye movement data collected while participants were viewing images of faces showed that viewers process repeated items differently than novel items. Participants viewed repeated items with fewer eye fixations to fewer regions and more randomness (i.e. less constraint) in their eye movement patterns. We term this effect the “eye movement-based memory effect”. Thus far, it appears that the effects of experience on eye movements generalize across different eyetrackers, types of visual stimuli, and types of prior exposure to the stimuli. Moreover, we show that the effects occur separately from explicit remembering by testing amnesic patients — i.e. patients with a profound impairment in learning and remembering of new declarative memory. Even in these patients who showed impairment learning the faces presented to them, there was evidence of prior processing in the eye movement data in the same direction as normal controls. With this in mind, we argue that certain of these eye movement measures can provide a useful index of procedural memory and that the use of eye movement measures as an indirect (implicit) measure of memory provides direct evidence that previous experience does indeed change the nature of perceptual processing.