The Influence of color on visual performance

BEATRIZ M. O´DONELL , ELISA M. COLOMBO, JOSÉ F. BARRAZA.

Regensburg, Alemania

Congreso; 31th Annual European Conference on Visual Perception - ECVP 2009; 2009

Universidad de Regensburg - Perception

We measured the reaction time (RT) as a function of luminance contrast (C) -up to ±40- for a set of colors belonging to RG or YB axes with different purity excitations (RMSi). A range of size (0.129-1.045°) and two values of luminance (5 and 40cd/m2) were considered. Results show that for low values of luminance contrast, the presence of color information in the stimulus improves the visual performance. This effect is stronger for colors modulated on the RG mechanism and weaker for colors on the YB mechanism. For higher contrasts, results from chromatic and achromatic stimulus become indistinguishable. We proposed an empirical model based on a modification of Pieron’s Law: RT=RTo+{k / [b Cn +(1-b)RMSin]}. The parameter n is around 2 and is independent on stimulus’ parameters, k represents a shared gain mechanism, and is higher for stimuli modulated on the RG than on the YB axes, and it also reflects the effect of size and luminance on the RT. Interestingly, the parameter b only depends on color and results show two very well differentiated groups, corresponding to colors modulated on the RG and on the YB axes, which suggests that b would be measuring the relative weight of color and luminance in the RT. ANPCyT PICT 2006 – N°1920 / CIUNT 26 / E410