In contrast to the abundant literature investigating how orientation coding depends on edges
defined by various image features, relatively little is known about how coding of orientation …

Prior studies using brief stimulus sequences revealed “opponent shape aftereffects”,
indicative of direct opponent coding of global shape attributes such as aspect ratio, skew …

Humans can perceive illusory or subjective contours in the absence of any real physical
boundaries. We used an adaptation protocol to look for orientation-selective neural …

We investigated the first-order inputs to contour-shape mechanisms using the shape-
frequency after-effect (SFAE), in which adaptation to a sinusoidally modulated contour …

The tilt aftereffect (TAE) was used to study interactions between real and subjective
contours. Subjects adapted to either real or illusory lines and were then shown test stimuli …

Previous research has shown that the mechanisms that process curved contours are
selective for low-level attributes such as luminance contrast polarity and luminance spatial …

We investigated whether contour-shape processing mechanisms are selective for color
direction using the shape-frequency and shape-amplitude after-effects, or SFAE and SAAE …

Selective visual attention modulates neuronal activation in various cortical areas. This type
of neuronal modulation could happen even in the early stages of visual processing where …

Mechanisms selective for complex shape are vulnerable to adaptation techniques
historically used to probe those underlying performance in lower-level visual tasks. We …

Normal visual perception readily overcomes suboptimal or degraded viewing conditions
through perceptual filling-in processes, enhancing object recognition and discrimination …