Learning to sample: eye tracking and fMRI indices of changes in object perception.

We used an fMRI/eye-tracking approach to examine the mechanisms involved in learning to segment a novel, occluded object in a scene. Previous research has suggested a role for effective visual sampling and prior experience in the development of mature object perception. However, it remains unclear how the naive system integrates across variable sampled experiences to induce perceptual change. We generated a Target Scene in which a novel occluded Target Object could be perceived as either "disconnected" or "complete." We presented one group of participants with this scene in alternating sequence with variable visual experience: three Paired Scenes consisting of the same Target Object in variable rotations and states of occlusion. A second control group was presented with similar Paired Scenes that did not incorporate the Target Object. We found that, relative to the Control condition, participants in the Training condition were significantly more likely to change their percept from "disconnected" to "connected," as indexed by pretraining and posttraining test performance. In addition, gaze patterns during Target Scene inspection differed as a function of variable object exposure. We found increased looking to the Target Object in the Training compared with the Control condition. This pattern was not restricted to participants who changed their initial "disconnected" object percept. Neuroimaging data suggest an involvement of the hippocampus and BG, as well as visual cortical and fronto-parietal regions, in using ongoing regular experience to enable changes in amodal completion.