Decoupling location specificity from perceptual learning of orientation discrimination

Abstract

Perceptual learning of orientation discrimination is reported to be precisely specific to the trained retinal location. This specificity is often taken as evidence for localizing the site of orientation learning to retinotopic cortical areas V1/V2. However, the extant physiological evidence for training improved orientation turning in V1/V2 neurons is controversial and weak. Here we demonstrate substantial transfer of orientation learning across retinal locations, either from the fovea to the periphery or amongst peripheral locations. Most importantly, we found that a brief pretest at a peripheral location before foveal training enabled complete transfer of learning, so that additional practice at that peripheral location resulted in no further improvement. These results indicate that location specificity in orientation learning depends on the particular training procedures, and is not necessarily a genuine property of orientation learning. We suggest that non-retinotopic high brain areas may be responsible for orientation learning, consistent with the extant neurophysiological data.

Perceptual Learning at a Conceptual Level

“…Zhang et al, 2010;Zhang and Yang, 2014;Xiong et al, 2016). Therefore, we suspected that similar techniques could also be effective for the current learning tasks.…”

“…Zhang et al, 2010;Zhang and Yang, 2014;Xiong et al, 2016) and that the learning effect can even transfer to the opposite visual field represented by the untrained brain hemisphere (Wang et al, 2012). For example, Vernier learning can transfer to a new location or orientation completely if the observers receive additional exposure of the new location or orientation via performing an irrelevant task (Wang et al, 2012(Wang et al, , 2014J.Y.…”

Rule-Based Learning Explains Visual Perceptual Learning and Its Specificity and Transfer

“…1-3) and retinal locations (Xiao et al, 2008;Zhang et al, 2010) challenges the existing models of perceptual learning. First, the complete learning transfer contradicts V1-based models (Adini et al, 2002;Teich and Qian, 2003;Zhaoping et al, 2003) as well as reweighting models that place the decision unit in the visual cortex at a post-V1 stage (Poggio et al, 1992;Dosher and Lu, 1998).…”

“…We are also currently investigating how much exposure is needed for reactivation. In one study, we found that ϳ200 trials of pretest in the periphery enables complete transfer of foveal orientation learning to the periphery (Zhang et al, 2010), indicating that this process could be very fast for certain tasks. Without the pretest, there is no transfer (Schoups et al, 1995).…”

“…Based on our previous work (Xiao et al, 2008;Zhang et al, 2010), we hypothesized that learning takes place at a high-level decision stage beyond the retinotopic and orientation-selective visual areas. We reasoned that the orientation specificity might result because the high-level decision unit, which has learned at the trained orientation, cannot functionally connect to V1 inputs representing the untrained transfer orientation to transfer learning.…”