Neuronal responses to static texture patterns in area V1 of the alert macaque monkey

Abstract

1. We recorded responses from neurons in area V1 of the alert macaque monkey to textured patterns modeled after stimuli used in psychophysical experiments of pop-out. Neuronal responses to a single oriented line segment placed within a cell's classical receptive field (CRF) were compared with responses in which the center element was surrounded by rings of elements placed entirely outside the CRF. The orientations of the surround elements either matched the center element, were orthogonal to it, or were random. 2. The addition of the textured surround tended to suppress the response to the center element by an average of 34%. Overall, almost 80% of the 122 cells analyzed in detail were significantly suppressed by at least one of the texture surrounds. 3. Cells tended to respond more strongly to a stimulus in which there was a contrast in orientation between the center and surround than to a stimulus lacking such contrast. The average difference was 9% of the response to the optimally oriented center element alone. For the 32% of the cells showing a statistically significant orientation contrast effect, the average difference was 28%. 4. Both the general suppression and orientation contrast effects originated from surround regions at the ends of the center bar as well as regions along the sides of the center bar. 5. The amount of suppression induced by the texture surround decreased as the density of the texture elements decreased. 6. Both the general suppression and the orientation contrast effects appeared early in the population response to the stimuli. The general suppression effect took approximately 7 ms to develop, whereas the orientation contrast effect took 18-20 ms to develop. 7. These results are consistent with a possible functional role of V1 cells in the mediation of perceptual pop-out and in the segregation of texture borders. Possible anatomic substrates of the effects are discussed.

Suppression of contour perception by band-limited noise and its relation to nonclassical receptive field inhibition

“…The same authors called these latter neurons ''uniform cells.'' Similar data were obtained for alert monkeys (Knierim and van Essen 1992): 32% orientation contrast cells and 6% uniform cells. …”

“…For instance, response suppression by a bar texture surround outside the CRF was found in nearly 80% of all orientation-selective cells reported in Knierim and van Essen (1992) and Nothdurft et al (1999). Although only approximately one third of the cells showed dependence of the effect on the orientation of the texture surrounding the CRF, these authors suggested that this type of differential suppression might be the possible source of the pop-out effect in orientation contrast experiments (Fig.…”

“…Nearly 80% of all orientation-selective neurons in area V1 show some form of significant response modulation by texture surrounding their CRFs, with suppression being much more frequent than enhancement (Knierim and van Essen 1992;Nothdurft et al 1999). On average over the whole population of such cells the response to an optimal stimulus over the CRF is reduced by 42% when texture is added to the surround.…”

“…Various neurophysiological studies have shown that response modulation by stimuli beyond the CRF is a common phenomenon in area V1 (Knierim and van Essen 1992;Li and Li 1994;Kapadia et al 1995;Sillito et al 1995;Zipser et al 1996;Nothdurft et al 1999). For instance, response suppression by a bar texture surround outside the CRF was found in nearly 80% of all orientation-selective cells reported in Knierim and van Essen (1992) and Nothdurft et al (1999).…”

Attention and contrast differently affect contextual integration in an orientation discrimination task

“…Certain contextual configurations result in pop-out which enhance stimulus detection (Nothdurft 1993;Wang et al 1994;Braun and Julesz 1998), while others result in crowding and impair stimulus detection (Pelli et al 2004). Neural correlates of these perceptual phenomena have been found in sensory visual areas, where responses to a stimulus in the classical receptive field (CRF) are facilitated or suppressed by stimuli presented in the non-classical receptive field (nCRF) (Knierim and van Essen 1992;Polat et al 1998;Jones et al 2002;Schwabe et al 2006;Ichida et al 2007). Whether context facilitates or suppresses responses depends on a variety of factors, including luminance contrast of the target.…”