Abstract
Functional brain imagining research and studies of brain-damaged patients suggest that colour perception and colour imagery have some overlap and independence in their neural mechanisms. Previous research into colour imagery has focused on compound images of both colour and form e.g. whole objects. Little is known regarding the characteristics of pure colour imagery, colour without form structure. The binocular rivalry method has been proved successful for measuring mental imagery objectively, quantitatively and reliably. Here we utilised the binocular rivalry technique to assess pure colour imagery. Experiment 1 consisted of three conditions, participants were asked to 1) imagine pure colours according to a letter cue. 2) imagine pure colours in the presence of background luminance. 3) passively view weak colour patches on the screen, prior to a binocular rivalry display of pure Gaussian colour patches, where one of the rivalry stimuli was always the colour that imagined or viewed. Results showed that dominance of binocular rivalry was significantly biased by colour imagery and perception; however, imagery trials in the presence of background luminance did not show the priming effect. In Experiment 2, we tested whether colour imagery was location-specific, i.e. whether it primed subsequent dominance in a binocular rivalry display presented at a different retinotopic location to the colour imagery. Colour imagery only primed subsequent rivalry when the imagery and rivalry occurred at the same retinotopic location. Our current study demonstrated that imagery of pure colour without form structure can have similar priming effects on subsequent rivalry displays as colour perception. In addition, the strength of this imagery bias effect was attenuated by concurrent uniform perception and was location specific. These results are consistent with previous studies of mental imagery using compound visual stimuli, demonstrating the potential to investigate mental imagery of different visual features.
Meeting abstract presented at VSS 2013