Adaptation as a Tool for Probing the Neural Correlates of Visual Awareness: Progress and Precautions

Adaptation within sensory systems broadens the dynamic range of those systems, making it possible for organisms to function efficiently over a wide variety of environmental conditions. To maximize efficiency sensory adaptation is characteristically 'selective' for different stimulus attributes, as it should be in order to promote adaptive changes in neural representations of environmental stimuli. This chapter considers several simple but potentially revealing questions about adaptation aftereffects, and interrelated questions that attempt to get at the neural bases of perceptual awareness: What happens when a visual adapting stimulus falls outside of conscious awareness for a substantial portion of the adaptation period, thereby dissociating phenomenal perception from physical stimulation? What transpires within the visual nervous system when a given stimulus takes on different appearances owing to visual adaptation?