We present work demonstrating that the nature of an object for our visual system depends on the actions we are programming and on the presence of action relations between stimuli. For example, patients who show visual extinction are more likely to become aware of two objects if the objects fall in appropriate visual locations for a common action. This effect of the action relations between objects is modulated both by the familiarity of the positioning of the objects for action, and (...) by the mere possibility of action (the ‘affordance’) between the objects. In addition, the programming of an action to a part of an object alters the representation of that object, making the ‘part’ into the object selected by the visual system. These results point to object coding being a rather flexible process, affected not only by the perceptual properties of stimuli but also by the relations between these properties and action. We discuss the implications for theories of perception as well as considering why action information, in particular, may be important for perception. (shrink)
We discuss the difficulty of measuring the perceptual experience of colour, supporting Palmer's assertion that neuropsychological disorders of colour processing can be informative in this respect. We point out that some disorders seem to affect the perceptual experience of colour over and above the perceptual processing of colour, providing direct insights into the neural mechanisms supporting perceptual experience.