Overview

One of the most striking features of contemporary cognitive science, as compared with cognitive science in the 1970s for example, is the fundamental role that neuroscience and the study of the brain now plays in cognitive science. This chapter reviews some landmarks in cognitive science's turn to the brain.

For both theoretical and practical reasons neuroscience was fairly peripheral to cognitive science until the 1980s. We begin in section 3.1 by looking at the theoretical reasons. The key idea here is the widely held view that cognitive systems are functional systems. Functional systems have to be analyzed in terms of their function. Many cognitive scientists held (and some continue to hold) that this type of functional analysis should be carried out completely independently of the details of the physical machinery that actually performs that function.

This conception of cognitive systems goes hand in hand with a top-down approach to thinking about cognition. Marr's study of the visual system is a very clear example of this. For Marr, the key to understanding the early visual system is identifying the algorithms by which the visual system solves the basic information-processing task that it confronts – the task of specifying the distribution and basic characteristics of objects in the immediate environment. As we saw, these algorithms are specifiable in abstract information-processing terms that have nothing to do with the brain. The brain enters the picture only at the implementational level.