The time course of learning a visual skill.
Several examples of experience-dependent perceptual improvement (perceptual learning) suggest that plasticity in specific neuronal loci could underlie the learning process. For a basic visual discrimination task (using an optimal stimulus for 'automatic' pre-attentive texture segregation), discrete retinal input-dependent changes within a very early stage in the stream of visual processing were indicated as the locus of a large and consistent learning effect. When do these changes occur? Here we report that except for a fast, rapidly saturating improvement early in the first practice session, performance was very stable within sessions. Indeed, observers showed little or no improvement until up to 8 hours after their last training session (latent phase). But large improvements occurred thereafter. Finally, there was almost no forgetting; what was gained was retained for at least 2-3 years. We conjecture that some types of perceptual experience trigger permanent neural changes in early processing stages of the adult visual system. These may take many hours to become functional.
Karni
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Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel.
Sagi
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D004192:Discrimination, Psychological; D006801:Humans; D007858:Learning / Q000502:physiology*; D010775:Photic Stimulation; D013997:Time Factors; D014796:Visual Perception / Q000502:physiology*