Training-induced brain network reorganization predicts location specificity and transfer in perceptual learning

Visual perceptual learning is often highly specific to the trained retinal location, a hallmark observation that is traditionally interpreted as evidence that training-induced plasticity occurs in retinotopic early visual cortex. However, under properly designed training conditions, such as double training, adaptation prevention, and attention modulation, learning can transfer fully to untrained locations, challenging this classical view and raising the question of what determines whether learning remains specific or generalizes. Here, we analyzed EEG data from a Vernier learning task in which some participants showed strong location specificity while others exhibited robust interhemifield transfer. Time-frequency analyses revealed post-training beta-band suppression in location-specific learners, but not in transfer learners. Graph-theoretic analyses further showed that location specificity was associated with increased clustering and longer shortest path lengths, indicating stronger local segregation and reduced global integration. In contrast, learners who transferred maintained a comparatively stable network organization. These findings provide a systems-level account of learning specificity and transfer, with implications extending beyond visual perception to other domains of skill acquisition.