Top-Down Reorganization of Activity in the Visual Pathway after Learning a Shape Identification Task

• Published in: Neuron (Cambridge, Mass.) Mass.), 2005-06, Vol.46 (5), p.823-835
• Main Authors: Sigman, Mariano, Pan, Hong, Yang, Yihong, Stern, Emily, Silbersweig, David, Gilbert, Charles D.
• Format: Article
• Language: English
• Subjects: Adult; Brain; Brain - physiology; Female; Humans; Learning - physiology; Magnetic Resonance Imaging - methods; Male; Pattern Recognition, Visual - physiology; Photic Stimulation - methods; Psychomotor Performance - physiology; Visual Pathways - physiology; Visual task performance
• ISSN: 0896-6273; 1097-4199
• DOI: 10.1016/j.neuron.2005.05.014

Learning in shape identification led to global changes in activation across the entire visual pathway, as revealed with whole-brain fMRI. Following extensive training in a shape identification task, brain activity associated with trained shapes relative to the untrained shapes showed: (1) an increased level of activity in retinotopic cortex (RC), (2) a decrease in activation of the lateral occipital cortex (LO), and (3) a decrease in the dorsal attentional network. In addition, RC activations became more correlated (and LO activation, less correlated) with performance. When comparing target-present and target-absent trials within the trained condition, we observed a similar decrease in the dorsal attentional network but not in the visual cortices. These findings indicate a large-scale reorganization of activity in the visual pathway as a result of learning, with the RC becoming more involved (and the LO, less involved) and that these changes are triggered in a top-down manner depending on the perceptual task performed.