Cortical mechanisms of normal and abnormal processes in the visual system, Part 2. Cortical regions involved in perceiving object shape: a review.

摘要

Within a few hundred milliseconds of casting the eyes on a novel object, one has extracted a representation of its shape. To do this, the visual system must use a variety of different cues present in the image that provide information about the structure of the object. For example, line drawings portray object structure using contours, whereas grayscale photographs provide surface cues such as shading information. Monocular or binocular depth cues can also convey information about object shape. Each of these kinds of cues implicates very different image features that carry the critical shape information and very different computations likely to be involved in extracting that information. Functional magnetic resonance imaging (fMRI) asks whether common mechanisms are involved in the extraction and representation of object shape, independent of the image cues defining that shape.