The role of top-down task context in learning to perceive objects.

In high-level perceptual regions of the ventral visual pathway in humans, experience shapes the functional properties of the cortex: the fusiform face area responds most strongly to faces of familiar rather than unfamiliar races, and the visual word form area (VWFA) is tuned only to familiar orthographies. But are these regions affected only by the bottom-up stimulus information they receive during learning, or does the effect of perceptual experience depend on the way that stimulus information is used during learning? Here, we test the hypothesis that top-down influences (i.e., task context) modulate the effect of perceptual experience on functional selectivities of the high-level visual cortex. Specifically, we test whether experience with novel visual stimuli produces a greater effect on the VWFA when those stimuli are associated with meanings (via association learning) but produces a greater effect on shape-processing regions when trained in a discrimination task without associated meanings. Our result supports this hypothesis and further shows that learning is transferred to novel objects that share parts with the trained objects. Thus, the effects of experience on selectivities of the high-level visual cortex depend on the task context in which that experience occurs and the perceptual processing strategy by which objects are encoded during learning.