Jamie G.E Cochrane¹ (), Natasha Lacku¹, Allison B. Sekuler^1,2,3, Patrick J. Bennett¹; ¹Department of Psychology, Neuroscience & Behaviour, McMaster University, ²Rotman Research Institute, Baycrest, ³Department of Psychology, University of Toronto

Visual perceptual learning (PL) is characterized by long-lasting, stimulus-specific improvements in simple visual tasks. One explanation for stimulus specificity is that PL causes changes in early cortical areas; an alternative explanation is that PL is due to a higher-level process, reflecting what is learned rather than where it occurs in the visual pathway. One method to evaluate this hypothesis is to test if PL occurs in a task using complex stimuli encoded later in the visual pathway. We measured response accuracy with a 1-of-5 identification task using complex stimulus types (textures and faces) encoded by mechanisms in the inferotemporal cortex. In the training phase, participants saw one of the two stimulus types above or below a central fixation point. In the test phase, Group 1 identified the same stimuli in the same position; Group 2 identified the same stimuli in a new position; Group 3 identified new stimuli of the same type at the same position; and Group 4 identified new stimuli of the same type in a new position. For both stimulus types, we found evidence of both generalized and stimulus-specific learning: changing the stimuli and/or stimulus position significantly reduced accuracy but not to the level shown at the start of training. In addition, for textures (but not faces), accuracy was significantly lower in Group 4 than in Groups 2 and 3. Therefore, stimulus- and position-specific PL occurs in an identification task using complex stimuli.

Acknowledgements: NSERC