Neural evidence that perception is nonconceptual

Abstract

Abstract This chapter is about experiments that aim to isolate the neural basis of conscious perception, but in line with the methodology discussed in Chapter 1, I am putting the issues of consciousness to one side, focusing on the neural basis of perception itself as contrasted with the neural basis of perceptual judgment. The chapter discusses the “no-report” paradigm not from the point of view of homing in on the neural basis of consciousness independently of report but rather from the point of view of separating perception from the cognitive processes underlying report. The global workspace and higher order theories of consciousness are implicitly committed to conscious perception being conceptual, as I will show in Chapter 13. What this chapter is about is neural evidence that perception is nonconceptual. I distinguish between phenomenal consciousness of perception, what it is like to have a perceptual experience, and access-consciousness, cognitive access to the perceptual content. Cognitive access to perceptual content is indeed conceptual but the perceptual content itself, or rather the state that has the perceptual content, is not conceptual. The chapter explains this point by noting what is by now a well known problem in identifying the neural basis of perception: Experiments typically require responses such as pressing one button rather than another, and it is difficult to see how to separate the neural basis of the perception itself from the neural basis of the cognitive processes involved in deciding on a response (Block, 1995a; 1997b). Those cognitive processes include deciding how the task set by the experimenter fits with the perception, maintaining the representation of the task and the perceptual categories in working memory and deploying those working memory representations in deciding what the response should be. This problem is especially acute when it comes to isolating the nonconceptual ground of perception, since the subjects’ cognitive processing will inevitably involve perceptual judgments and the application of concepts required for judgments. In addressing this problem, this chapter distinguishes the “no-report” paradigm from the “no-cognition” paradigm in the context of the “bored monkey” problem and the controversy over binocular rivalry and consciousness. Recent evidence showing that the “bored monkey” problem is an important factor using a mind-wandering technique will be presented.