title: Fixation-related potentials in visual search: a combined EEG and eye tracking study.
abstract: We report a study of concurrent eye movements and electroencephalographic (EEG) recordings while subjects freely explored a search array looking for hidden targets. We describe a sequence of fixation-event related potentials (fERPs) that unfolds during ∼ 400 ms following each fixation. This sequence highly resembles the event-related responses in a replay experiment, in which subjects kept fixation while a sequence of images occurred around the fovea simulating the spatial and temporal patterns during the free viewing experiment. Similar responses were also observed in a second control experiment where the appearance of stimuli was controlled by the experimenters and presented at the center of the screen. We also observed a relatively early component (∼150 ms) that distinguished between targets and distractors only in the freeviewing condition. We present a novel approach to match the critical properties of two conditions (targets/distractors), which can be readily adapted to other paradigms to investigate EEG components during free eye-movements.
authors: Laboratorio de Neurociencia Integrativa, Departamento de Física, FCEyN UBA and Pabellón 1, Ciudad Universitaria, Ciudad Atutonóma de Buenos Aires, Argentina. juank@df.uba.ar
authors: Juan E
authors: JE
authors: Kamienkowski
authors: Matias J
authors: MJ
authors: Ison
authors: Rodrigo Quian
authors: RQ
authors: Quiroga
authors: Mariano
authors: M
authors: Sigman
mesh_terms: D000328:Adult; D001288:Attention / Q000502:physiology; D004569:Electroencephalography / Q000379:methods*; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D005556:Form Perception / Q000502:physiology*; D005584:Fovea Centralis / Q000502:physiology; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011930:Reaction Time / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D055815:Young Adult