Specificity of perceptual learning in a frequency discrimination task

On a variety of visual tasks, improvement in perceptual discrimination with practice (perceptual learning) has been found to be specific to features o f the training stimulus, including retinal location. This specificity has b een interpreted as evidence that the learning reflects changes in neuronal tuning at relatively early processing stages. The aim of the present study was to examine the frequency specificity of human auditory perceptual learn ing in a frequency discrimination task. Difference limens for frequency (DL Fs) were determined at 5 and 8 kHz, using a three-alternative forced choice method, for two groups of eight subjects before and after extensive traini ng at one or the other frequency. Both groups showed substantial improvemen t at the training frequency, and much of this improvement generalized to th e nontrained frequency. However, a small but statistically significant comp onent of the improvement was specific to the training frequency. Whether th is specificity reflects changes in neural frequency tuning or attentional c hanges remains unclear. (C) 2000 Acoustical Society of America. [S0001-4966 (00)04112-6].