Abstract

In order to identify the neural correlates of consciousness it is necessary to distinguish these from the neural correlates associated with unconscious information processing. We describe the various techniques, such as masking, which can be used to generate conditions in which the same stimulus is presented either just above or just below a threshold for visibility. Directed attention can also be used to manipulate the extent to which a stimulus gains access to awareness, as can various methods for creating bi‐stable perception. A major problem for these studies is the possible confound of the need for participants to report their awareness and there is currently much interest in developing paradigms in which reporting awareness is not required. We also discuss studies exploring the neural correlates of imagination, illusions and hallucinations in which a perceptual experience occurs in the absence of a physical stimulus. Finally we consider techniques that go beyond correlation and attempt to identify the necessary and sufficient neural processes leading to conscious experience.