Perceptual learning in clear displays optimizes perceptual expertise: Learning the limiting process
Barbara Anne Dosher , and Zhong-Lin Lu
Memory, Attention, and Perception (MAP) Laboratory, Department of Cognitive Sciences and Institute of Mathematical Behavioral Sciences, University of California, Irvine, CA 92697-5100; and Laboratory of Brain Processes (LOBES), Departments of Psychology and Biomedical Engineering and Neuroscience Graduate Program, University of Southern California, Los Angeles, CA 90089-1061
Communicated by Richard M. Shiffrin, Indiana University, Bloomington, IN, February 24, 2005 (received for review August 25, 2004)

Abstract


Human operators develop expertise in perceptual tasks by practice or perceptual learning. For noisy displays, practice improves performance by learned external-noise filtering. For clear displays, practice improves performance by improved amplification or enhancement of the stimulus. Can these two mechanisms of perceptual improvement be trained separately? In an orientation task, we found that training with clear displays generalized to performance in noisy displays, but we did not find the reverse to be true. In noisy displays, the noise in the stimulus limits performance. In clear displays, performance is limited by noisiness of internal representations and processes. Our results suggest that training in one display condition optimizes the limiting factor(s) in performance in that condition and that noise filtering is also improved by exposure to the stimulus in clear displays. The asymmetric pattern of transfer implies the existence of two independent mechanisms of perceptual learning, which may reflect channel reweighting in adult visual system. These results also suggest that training operators with clear stimuli may suffice to improve performance in a range of clear and noisy environments by simultaneous learning by two mechanisms