seem to be that the child would continue to be dependent at later ages on the motor-touch association system in order to react to external stimuli. At an early age such a system would be viewed as normal, but at a later stage in the child's life, it would be viewed as abnormally superactive. The older child with fluent visual and verbal associations need not invoke his motortouch system as much. Again, as suggested by Gellner, the role of tactual stimulation is invoked as an explanation of superactivity.
Bindra ( 1961) has recently attempted a formulation which is concerned with the kinds of acts which comprise general activity rather than the amount of general activity of the organism. These spontaneous acts are so pervasive and frequent that their occurrences and nonoccurrences must be considered when trying to formulate laws about the less frequent consummatory acts with which the psychologist is mostly concerned. As well as studying the relationship between stimulus conditions and the relevant responses in a situation, Bindra thinks that various factors, such as drugs, brain damage, and past learning, should be studied which affect the irrelevant responses which are competing with those that are relevant. Typically, the relevant response is already in the repertory of the organism, and learning consists in the elimination of the irrelevant responses. Bindra's term "novelty reactions," which he uses to describe the exploratory and nonexploratory behaviors which would be irrelevant in a simple maze- learning situation, reminds one of the fidgety, irrelevant kinds of behavior observed while a human subject is being measured in a ballistograph.
The formulation suggested by Bindra emphasizes that relevant versus irrelevant activity should be a major construct in analyzing the total activity matrix. Perhaps this is supported by the sometimes low correlations between different operational measures of general activity. Perhaps the correlation between activity wheel and straight alley activity is low because irrelevant and relevant activity show a different prominence in each measure. The lack of correlation between ballistographic and open-floor activity might merit a similar explanation. The relevant-irrelevant activity distinction also brings to mind the Straussian notion of impairment in ability to consider the perceived stimulus in relation to the goals of the organism. If one assumes such a condition could occur, it would seem that the probability of irrelevant behavior would be increased by neurological impairment.
The study of activity level, although diversely explored, has never been a central organized focal point of attention in science. Perhaps the major reasons why it has been studied are associated with (1) the practical problems of managing superactive children, (2) its obvious role as a behavior correlate in the attempts made to understand brain function, (3) its role in the psychology of motivation and learning, (4) the recent attention to the importance of irrelevant activity, and (5) its obvious convenience in studying drug effects. The methodologies developed to measure activity