Shape encoding consistency across colors in primate V4.

Brittany N . Bushnell and Anitha Pasupathy V 4 Shape encoding consistency across colors in primate

Contour Curvature As an Invariant Code for Objects in Visual Area V4.

UNLABELLED Size-invariant object recognition-the ability to recognize objects across transformations of scale-is a fundamental feature of biological and artificial vision. To investigate its basis in the primate cerebral cortex, we measured single neuron responses to stimuli of varying size in visual area V4, a cornerstone of the object-processing pathway, in rhesus monkeys (Macaca mulatta). Le...

Role of primate visual area V4 in the processing of 3-D shape characteristics defined by disparity.

We studied the responses of V4 neurons in awake, fixating monkeys to a diverse set of stereoscopic stimuli, including zero-order disparity (frontoparallel) stimuli, surfaces oriented in depth, and convex and concave shapes presented at various mean disparities. The responses of many V4 cells were significantly modulated across each of these stimulus subsets. In general, V4 cells were broadly tu...

Partial occlusion modulates contour-based shape encoding in primate area V4.

Past studies of shape coding in visual cortical area V4 have demonstrated that neurons can accurately represent isolated shapes in terms of their component contour features. However, rich natural scenes contain many partially occluded objects, which have "accidental" contours at the junction between the occluded and occluding objects. These contours do not represent the true shape of the occlud...

The role of visual area V4 in the discrimination of partially occluded shapes.

The primate brain successfully recognizes objects, even when they are partially occluded. To begin to elucidate the neural substrates of this perceptual capacity, we measured the responses of shape-selective neurons in visual area V4 while monkeys discriminated pairs of shapes under varying degrees of occlusion. We found that neuronal shape selectivity always decreased with increasing occlusion...