ABSTRACTIt has been argued that an important determinant of the cardiac response is the subject's intended transaction with his environment. The present study was designed to investigate whether cardiac deceleration would accompany the solution of a perceptual discrimination problem, whether the degree of cardiac deceleration would be related to the accuracy of the response, and the relationship between general intellectual ability and the cardiac response to the problem. Fifty‐one subjects, 44 months of age, were each given 20 trials of a matching figures task. This task required thatSmatch a figure (called standard) to one of four variations (one of which was identical to the standard). EKG was continuously recorded along with the latency and the accuracy of the response. If the first response was incorrect,Swas asked to choose again.The results indicated: (1) There was a significant cardiac deceleration from the timeSreceived the standard until he made his first choice. If the first response was correct, the cardiac rate, within 1–3 beats, returned to resting level; however, ifSwas told to guess again, the cardiac rate remained decelerated. (2) While accuracy of response was found to be related to the cardiac response, the effect was eliminated when response speed was controlled. (3) The degree of cardiac deceleration was correlated with general intellectual function as measured by a standard IQ test; however, it was significant only for gi