Color and material perception in the service of naturalistic tasks
Object color perception provides a model system for understanding how the brain transforms sensory signals into perceptual representations. In particular, the case of object color is interesting because the information explicitly available in the retinal image is ambiguous about object properties, in that both intrinsic object surface reflectance and extrinsic factors, such as the spectrum of the illumination, affect the spectrum of the light reflected from the object to the eye. Thus to provide a perceptual representation of object color that is stable across viewing conditions, the visual system must process the signals available from the retinal cone mosaic and separate out the influence of object reflectance from that of other factors. Interestingly, most studies of this so-called 'color constancy’ employ stimuli and tasks that are not representative of natural viewing nor of how we actually use color in everyday life. In this talk, I will introduce recent work in which we have developed what we call ‘selection-based’ methods to quantify color constancy, where subjects perform tasks that are more typical of everyday life. I will then present results obtained using these tasks that begin to characterize how color constancy depends on stimulus factors and how heavily subjects rely on color as opposed to other perceived object properties.
This event is open to the public.