- 1-1 Introduction
- 1-2 Decomposition and Reconstruction
- 1-3 Neurons and Synapses
- 1-4 Neural Networks
- 1-5 Systems Control Mechanisms in the CNS
- 1-6 Reflexes and Voluntary Movements
- 1-7 Integration of reflexes
- 1-8 Motor Actions
- 1-9 Cognitive Functions
- 1-10 Beyond Movements
- 1-11 Scope of This Monograph
- 1-12 Summary
1-9 Cognitive Functions
The prefrontal cortex is located rostral to the premotor cortex. It is implicated in working memory and acts as a key executive part of the CNS (Fuster, 1997). In the previous parlance on motor control systems, the prefrontal cortex receives instructions from the anterior cingulate gyrus and acts as an executive controller of a cognitive controlled object represented in the temporoparietal cortex. In Chapter 17, "Cognitive Functions," this executive-cognitive system is considered to control high-order brain functions involving language, thought, evaluation, and decision making in humans, these being core components of human intelligence.
During a thought process, the executive controller manipulates a cognitive concept encoded in the temporoparietal cortex, instead of a body part such as an arm or a leg. A crucial question is how to consider a cognitive concept as a controlled object. One may recall the term "mental model," which Craik (1943) and Johnson-Laird (1983) defined as a psychological substrate for a mental representation of real or imaginary situations. It is a small-scale model of reality that the mind constructs and uses to reason, to underlie explanations, and to anticipate a future event. More concretely, mental models are representations of images, concepts, and ideas. One may also recall the term "schema," which Jean Piaget (1896–1980) defined as being formed in a growing child learning to interpret and understand the world (Piaget, 1951). Piaget's schema included both a category of knowledge and the process of obtaining that knowledge. Currently, these concepts are not mechanistic, and they lack a computational basis. In the presently used control system model for cognitive function, these schemas correspond to cerebral cortical models. We assume that learning proceeds further by incorporating them into cerebellar internal models (Chapter 17).