Perceptual learning specificity to the trained context of stimulus display durations in difficult visual discriminations

Compelling evidence stemming from past research suggests that a wide variety of visual search tasks can undergo perceptual learning. Such learning is typically characterized by a marked improvement in the speed and accuracy of target detection or identification by observers, as a result of repeated practice with the visual search task at hand. For difficult visual discriminations, the improvement in visual search performance associated with perceptual learning has been shown to be specific to the training context. Such contexts include, but are not limited to, the trained target stimuli and their trained retinal positions within the visual field. The current compilation of psychophysical experiments aimed to investigate an aspect of perceptual learning specificity in difficult visual discriminations previously unreported in the relevant literature. These experiments assessed whether perceptual learning for difficult visual discriminations is specific to the trained context of stimulus display durations in which such discriminations are embedded. With training, a significant improvement in performance for trials with a 50-millisecond stimulus display duration (difficult discriminations) resulted when such trials were embedded within sessions containing a variety of longer stimulus display durations (easier discriminations). However, this improvement was lost when difficult trials were no longer embedded within the context of easier trials. These findings may supplement our current knowledge regarding the perceptual plasticity of the visual system