title: Exploring the Use of Sensorial LTP/LTD-Like Stimulation to Modulate Human Performance for Complex Visual Stimuli.
abstract: Is it possible to passively induce visual learning/unlearning in humans for complex stimuli such as faces? We addressed this question in a series of behavioral studies using passive visual stimulation (flickering of faces at specific temporal frequencies) inspired by well-known synaptic mechanisms of learning: long-term potentiation (LTP) vs long-term depression (LTD). We administered a face identity change detection task before and after a passive stimulation protocol to test for potential changes in visual performance. First, with bilateral stimulation, subjects undergoing high-frequency LTP-like stimulation outperformed those submitted to low-frequency LTD-like stimulation despite equivalent baseline performance (exp. 1). Second, unilateral stimulation replicated the differential modulation of performance, but in a hemifield-specific way (exp. 2). Third, for both stimulation groups, a sudden temporary drop in performance on the stimulated side immediately after the stimulation, followed by progressive recovering, can suggest either 'visual fatigue' or 'face adaptation' effects due to the stimulation. Fourth, we tested the life-time of these modulatory effects, revealing they vanish after one hour delay (exp. 3). Fifth, a control study (exp. 4) using low-level visual stimuli also failed to show longer-term effects of sensory stimulation, despite reports of strong effects in the literature. Future studies should determine the necessary and sufficient conditions enabling robust long-term modulation of visual performance using this technique. This step is required to consider further use in fundamental research (e.g., to study neural circuits involved in selective visual processing) and potential educational or clinical applications (e.g., inhibiting socially-irrelevant aspects of face processing in autism).
authors.affiliation: Department of Brain and Cognition, KU Leuven, 3000 Leuven, Belgium.|Department of Neuroscience, Child & Adolescent Psychiatry, KU Leuven, 3000 Leuven, Belgium.
authors.forename: Felipe
authors.initials: F
authors.lastname: Pegado
authors.affiliation: Department of Brain and Cognition, KU Leuven, 3000 Leuven, Belgium.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Vankrunkelsven
authors.affiliation: Department of Neuroscience, Child & Adolescent Psychiatry, KU Leuven, 3000 Leuven, Belgium.|Research group Leuven Autism Research, KU Leuven, Leuven, Belgium.
authors.forename: Jean
authors.initials: J
authors.lastname: Steyaert
authors.affiliation: Department of Neuroscience, Child & Adolescent Psychiatry, KU Leuven, 3000 Leuven, Belgium.|Research group Leuven Autism Research, KU Leuven, Leuven, Belgium.
authors.forename: Bart
authors.initials: B
authors.lastname: Boets
authors.affiliation: Department of Brain and Cognition, KU Leuven, 3000 Leuven, Belgium.
authors.forename: Hans
authors.initials: H
authors.lastname: Op de Beeck
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000502:physiology; D005260:Female; D006801:Humans; D017774:Long-Term Potentiation; D036881:Long-Term Synaptic Depression; D008297:Male; D010775:Photic Stimulation; D011597:Psychomotor Performance; D011930:Reaction Time; D013997:Time Factors; D055815:Young Adult