title: Chromatic collinear facilitation, further evidence for chromatic form perception.
abstract: Collinear facilitation of contrast detection of achromatic stimuli has been studied over the past decade by different groups. We measured collinear facilitation of chromatic contrast detection under equal-luminance (photometric quantity) and under isoluminance (minimum motion technique) conditions, as two different controls. The facilitation was tested for chromatic contrast detection of a foveal Gabor signal flanked by two high chromatic-contrast Gabor signals. The results indicated a significant facilitation in the presence of spatial adjacent collinear chromatic contrast signals, when the flankers were located at a short distance, across all observers for three chromatic channels. The facilitation was compared to a non-collinear flanker configuration. The results indicated no facilitation effect at the opposing phase configuration, at a short flanker distance, whereas a small facilitation was observed with a configuration at a longer flanker distance. The findings suggest that the performance and specificity of chromatic collinear facilitation is not impaired with regard to achromatic mechanisms.
authors.affiliation: Department of Biomedical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv, Israel.
authors.forename: Tal
authors.initials: T
authors.lastname: Ellenbogen
authors.forename: Uri
authors.initials: U
authors.lastname: Polat
authors.forename: Hedva
authors.initials: H
authors.lastname: Spitzer
mesh_terms: D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology*; D006801:Humans; D010775:Photic Stimulation; D014793:Visual Cortex / Q000502:physiology