Response feedback triggers long-term consolidation of perceptual learning independently of performance gains

Visual perceptual learning (VPL) is defined as a long-term performance enhancement on a visual task, and is typically thought of as a manifestation of plasticity in visual processing. It is thought that neural representations relevant to a recently learned task are consolidated over the course of hours or days and made robust against the effects of deterioration and interference. However, recent work has shown that when these representations are reactivated by further task exposure, they become plastic again and are vulnerable to deterioration effects. Here we used a perceptual learning paradigm in combination with performance feedback (knowledge of task accuracy provided to the observer in real-time) to investigate behavioral factors that influence consolidation. Subjects were trained to detect two coherent motion directions embedded in noise over several days. It was found that without feedback, performance improvements accrued during training rapidly deteriorated upon exposure to novel, neighboring motion directions. However, when one of the two directions was consistently paired with feedback during training, the paired direction was resilient against the effects of deterioration. This benefit coincides with a gradual inhibition of learning for the unpaired stimuli. Furthermore, this stabilizing effect operates independently of the magnitude of performance gains during training and suggests a useful behavioral marker for the study of consolidation processes.