Visual and haptic priming of binocular rivalry

Abstract

Binocular rivalry describes the perceptual alternations that occur over time when dissimilar images are presented to the two eyes. Many factors affect dominance in rivalry, including low-level image attributes such as contrast or broadband spatiotemporal structure. Rivalry dominance can also be influenced by factors external to the stimuli, such as attention and spatial context. Recent work has found that unambiguous primes can facilitate or suppress a congruent rivalry image, depending on the prime strength, e.g. amount of luminance contrast (Pearson and Brascamp, 2008). We investigated the potential crossmodal aspects of rivalry priming. The present study asks whether similar facilitatory and suppressive effects can be seen for crossmodal primes. Each block of trials consisted of 120 3s Prime-Blank-Rivalry sequences. Rivalry stimuli were oriented Gabor patches (±45° from vertical), one to each eye. The prime stimulus matched one of the two rivalry patches. Primes were presented either visually (same image to both eyes), haptically (using a Phantom force feedback device), or in both visual and haptic domains simultaneously. Additionally, prime strength was manipulated by varying contrast (visual primes) or ridge height (haptic primes). The effect of the prime on onset dominance was modulated by prime strength (higher luminance / ridge height values). At low strengths, the prime stimulus facilitated the perception of the congruent rivalry stimulus. Conversely, at higher strengths, the prime supressed the congruent rivalry stimulus. In addition, the visual/haptic prime data showed evidence of a cross-modal additivity; both the visual and haptic components contributed to increase the effective strength of the prime. Meeting abstract presented at VSS 2013