Fixation-related potentials to faces in a free-viewing visual search task

LISANDRO N KAUNITZ; JUAN E KAMIENKOWSKI; MARIANO SIGMAN; RODRIGO QUIAN QUIROGA; MATIAS J ISON

Alghero

Congreso; European Conference on Visual Perception; 2012

The use of event related potentials (ERPs) has been almost exclusively limited to situations where eye movements are precluded. However, when subjects explore a scene or look for a target in the real world, they systematically produce discrete sequences of fixations, gathering and integrating information in each instance of the sequence. Despite the compelling contribution of ERPs and eye movements to cognitive neuroscience, to date only a handful of experiments have exploited both techniques simultaneously. In the present study we concurrently recorded EEG and eye movements in a free-viewing visual search paradigm. Subjects were asked to find a hidden target face in a crowded scene including distractor faces. We analyzed fixation-related potentials (fERPs) to target and distractor stimuli. Additionally, we compared the fERPs obtained in our free-viewing visual search task with the ERPs in an oddball control experiment performed without eye movements. Our findings show the emergence of fERP components associated with the perception of faces and the detection of targets, contributing towards a better understanding of brain activity during free viewing in real-world-like scenarios.