Work

Induced contrast asynchronies

Year: 2004

Type: article

Abstract: We document a new type of perceptual effect in which asynchronous contrast signals are presented simultaneously with synchronous luminance signals. The template for the basic effect consists of two physically identical disks (.75-deg diameter, 40 cd/m2), one surrounded by a dark annulus (1.5 deg, 20 cd/m2) and the other by a light annulus (1.5 deg, 60 cd/m2). The center disks are modulated in time, with a maximum luminance of 55 cd/m2 and a minimum luminance of 25 cd/m2. With this stimulus configuration, the luminance signals of the disks modulate in phase with each other while the contrast signals relative to the surrounds modulate in anti-phase. Observers can track the contrast and luminance signals when the luminance is modulated at 1 Hz but perceive primarily the contrast signal at 2-6 Hz. We show that the asynchrony can be perceived with a thin annular surround, that the appearance of the asynchrony is dependent on the modulation amplitude, and that a decrease in the relative strength of the asynchrony at 1 Hz corresponds to the band-pass shape of the temporal contrast sensitivity function in the presence of light and dark edges. We also introduce variations of the induced contrast asynchrony principle in which a single modulated disk is surrounded by a half-light and half-dark split annulus; we refer to these configurations as the window-shade and rocking-disk illusions.

Source: Journal of Vision

DOI: 10.1167/4.6.5

Authors: A. G. Shapiro, A. D. D'Antona, J. P. Charles, L. A. Belano, J. B. Smith, M. Shear-Heyman

Institution: Bucknell University

Language: English

Topic: Visual perception and processing mechanisms

Subfield: Cognitive Neuroscience

Field: Neuroscience

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $1,850

Funders: National Institutes of Health, National Eye Institute