This review attempts to organize a range of neuropsychological and psychophysiological data on attention. Three separate, but interacting, neural systems are distinguished: One controls arousal, which is defined in terms of phasic physiological responses to input. The arousal control circuits center on the amygdala. A second system controls activation, which is defined in terms of tonic physiological readiness to respond. The readiness circuits center on the basal ganglia of the forcbrain. A third system is discerned which coordinates arousal and activation. This coordinating activity is defined as demanding effort.Its circuitry centers on the hippocampus. When arousal, activation, and effort are involved in problem solving, at least two further distinctions can be made. During categorising, arousal precedes activation; during reasoning, activation precedes arousal. Finally, the review addresses the question of whether effort in problem solving is to be attributed solely to peripheral muscular factors or whether, in fact, direct monitoring of changes in brain organization (changes in set, attitude, etc.) can be productive of measurable indicators of effort.In the mid 1960s, R. J. Douglas and K. H. Pribram presented a series of experiments detailing the effects of hippocampal lesions on problem-solving behavior. The results of these experiments were accounted for by recourse to the concept of experiencing a change in awareness which was interpreted as indicating the involvement of "attention." A continuing interest in problems of attention has been reflected not only in the work reported from our laboratory (a dozen and a half papers) but also in that of many others (see reviews by Mostofsky, 1970;Horn and Hinde, 1970;and Kahneman, 1973). Research has largely been directed to two general paradigms defined by the following operations: (a) recording the occurrence of physiological or behavioral responses against a background of monotonous repetition of We wish to express our gratitude to Muriel Bagshaw for additional data analysis and for allowing us to present her unpublished work in this manuscript, and to Linda Heider and Barbara Honegger for their patient help. sensory events (orienting, vigilance, and habituation) and (b) the invariant (categorizing), or the variable but computable (reasoning), pairing of the outcome of response (reinforcement) to sensory events. An assessment of the data derived from the?e paradigms (in approximately 200 experiments) has led us to identify three basic attentional control processes: One regulates arousal resulting from input; a second controls the preparatory activation of response mechanisms; and a third operates to coordinate arousal and activation, an operation that demands effort. The first two sections of this review will delineate these attentional control systems; the last section will deal primarily with higher order cortical attentional controls that operate during categorizing and reasoning.
REFLEX ATTENTION, REPRESENTATION, AND THE CONTROL OF AROUSALArousal is said t...
