Motivational and emotional controls of cognition.

The central nervous System is a serial information processor that must serve an organism endowed with multiple needs, and living in an environment that presents unpredictable threats and opportunities. These requirements aie met by 2 mechanisms: (a) goal-terminating mechanisms, permitting goals to be processed serially without any 1 monopolizing the processor, (b) interruption mechanism, having the properties usually ascribed to emotion, allowing the processor to respond to urgent needs in real time. Mechanisms of these kinds, to control the direction of attention and activity, have been incorporated in some information-processing theories of human cognition, and their further elaboration will permit these theories to explain wider ranges of behavior.