Artículo de revista
Neural Mechanisms of Human Perceptual Learning: Electrophysiological Evidence for a Two-Stage Process
Fecha
2011-04-26Registro en:
PLOS ONE Volume: 6 Issue: 4 Article Number: e19221 Published: APR 26 2011
1932-6203
DOI: 10.1371/journal.pone.0019221
Autor
Hamamé, Carlos M.
Cosmelli, Diego
Henríquez, Rodrigo
Aboitiz Domínguez, Francisco Javier
Institución
Resumen
Background: Humans and other animals change the way they perceive the world due to experience. This process has been labeled as perceptual learning, and implies that adult nervous systems can adaptively modify the way in which they process sensory stimulation. However, the mechanisms by which the brain modifies this capacity have not been sufficiently analyzed.
Methodology/Principal Findings: We studied the neural mechanisms of human perceptual learning by combining electroencephalographic (EEG) recordings of brain activity and the assessment of psychophysical performance during training in a visual search task. All participants improved their perceptual performance as reflected by an increase in sensitivity (d') and a decrease in reaction time. The EEG signal was acquired throughout the entire experiment revealing amplitude increments, specific and unspecific to the trained stimulus, in event-related potential (ERP) components N2pc and P3 respectively. P3 unspecific modification can be related to context or task-based learning, while N2pc may be reflecting a more specific attentional-related boosting of target detection. Moreover, bell and U-shaped profiles of oscillatory brain activity in gamma (30-60 Hz) and alpha (8-14 Hz) frequency bands may suggest the existence of two phases for learning acquisition, which can be understood as distinctive optimization mechanisms in stimulus processing.