Abstract
Perceptual learning (PL), defined as experience-dependent performance improvement on a visual feature often shows specificity to the trained feature. Recently it was reported that when one type of task is trained, followed by a similar but different type of task, PL on the first task is disrupted with specificity to some trained features. Systematic investigation of the relationship between PL specificity and interference may lead to a better understanding of the PL mechanism. In the present study, we examined whether feature specificity is related to interference in the texture discrimination task (TDT), which shows learning specificity to the orientation of background elements but not to that of target elements. We conducted a series of experiments where the orientation of target elements or background elements was manipulated under two types of training paradigms, blocked or roving, with 36 participants. First, we found that TDT learning was interfered with when orientations of background elements were changed in the blocked paradigm but not in the roving. Second, the changes in orientation of target elements resulted in a reverse effect: TDT learning occurred in the blocked paradigm but not with roving. Given that TDT learning is specific to background element orientation but not to target element orientation, these results indicate that interference in TDT learning (blocked) is feature specific while that is not the case for roving. These results provide important implications regarding the mechanism for TDT learning and interference. First, learning of background element orientation in TDT and disruption may mainly involve a low-level stage of visual processing. Second, it may be either that learning of target element orientation is not requisite for TDT learning or that learning of target element orientation mainly involves a higher stage of visual information processing, given that roving is suggested to impede more central stages.
Supported by NIH-NEI R21 EY018925, NIH-NEI R01 EY015980-04A2 and NIH-NEI R01 EY019466 to TW. YY is supported by Japan Society for the Promotion of Science. YS was support by ERATO Shimojo Implicit brain function project, Japan Science Technology.