Effects of practice, stimuli complexity, and response biases in a target identification task

Abstract

How experience with similar stimuli affects performance in target identification tasks is still largely unknown. Thus, four experiments were conducted to evaluate perceptual learning effects in a target identification task by means of same-or-different judgments. Repeated practice with stimuli improved participants' ability to identify the target among 19 similar stimuli (Experiments 1-2), with participants being less accurate with more complex and similar stimuli (Experiment 2). Participants were more accurate when judging each stimulus as same rather than different from the target ( Experiments 3-4), and factors relevant for stimuli differentiation-such as stimuli similarity-only affected accuracy on different trials. These latter findings seemed unrelated to a response bias and not easily explained by associative theories for perceptual learning.