title: The development of contour processing: evidence from physiology and psychophysics.
abstract: Object perception and pattern vision depend fundamentally upon the extraction of contours from the visual environment. In adulthood, contour or edge-level processing is supported by the Gestalt heuristics of proximity, collinearity, and closure. Less is known, however, about the developmental trajectory of contour detection and contour integration. Within the physiology of the visual system, long-range horizontal connections in V1 and V2 are the likely candidates for implementing these heuristics. While post-mortem anatomical studies of human infants suggest that horizontal interconnections reach maturity by the second year of life, psychophysical research with infants and children suggests a considerably more protracted development. In the present review, data from infancy to adulthood will be discussed in order to track the development of contour detection and integration. The goal of this review is thus to integrate the development of contour detection and integration with research regarding the development of underlying neural circuitry. We conclude that the ontogeny of this system is best characterized as a developmentally extended period of associative acquisition whereby horizontal connectivity becomes functional over longer and longer distances, thus becoming able to effectively integrate over greater spans of visual space.
authors: Department of Psychology, Binghamton University, State University of New York Binghamton, NY, USA.
authors: Gemma
authors: G
authors: Taylor
authors: Department of Psychology, Binghamton University, State University of New York Binghamton, NY, USA.
authors: Daniel
authors: D
authors: Hipp
authors: Department of Psychology, Binghamton University, State University of New York Binghamton, NY, USA.
authors: Alecia
authors: A
authors: Moser
authors: US Army Research Laboratory, Department of the Army, RDRL-HRS-D, Aberdeen Proving Grounds MD, USA.
authors: Kelly
authors: K
authors: Dickerson
authors: Department of Psychology, Binghamton University, State University of New York Binghamton, NY, USA.
authors: Peter
authors: P
authors: Gerhardstein
keywords: closure; contour detection; development; horizontal connections; visual development