Abstract
Perceptual learning improves performance in perceptual tasks due to experience with perceptual representations. One key attribute of perceptual learning is specificity of learning to the specific stimulus attributes. The degree of task and stimulus specificity shows considerable variability depending upon the nature of the task. One important proposal concerning stimulus specificity (Ahissar & Hochstein, Nature, 1997) is that the specificity of learned improvements to a stimulus may depend upon the difficulty of the task: that learning difficult tasks requires learning at lower, more specific, levels of the visual processing hierarchy. This conclusion was based on higher transfer from one easy visual search task to another, and lower transfer from one difficult task to another. In their analysis, task difficulty was controlled by the orientation angle. Here, we examined transfer to an easy Gabor orientation discrimination task (± 12 degrees from base angle) following practice on either an easy or difficult (± degrees) task at a different base angle and location, and similarly for transfer to the hard task following practice on an easy or hard task. Testing was carried out in either no-external noise or high noise displays, and adaptive methods were used to track 2AFC performance. This orientation discrimination task exhibited partial transfer to either an easy or a hard test condition in both high and no external noise, but the extent of this transfer was identical regardless of the nature of the original training. Neither the initial level after transfer nor subsequent learning depended upon the difficulty of initial training. These results suggest a more complex view of the relation between task transfer and task difficulty.