Classical conditioning of blood pressure in Macaca mulatta with cardiac rate controlled.
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Biomedical subjects
Publications and source records attributed to W N Schoenfeld.
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The functional relationship between heart rate, under atrial pacing, and the intensity of pacing pulses, was determined for intensities ranging from well below the complete heart rate capture threshold to suprathreshold intensities. A separate capture-intensity function was determined for each of the pacing frequencies 180, 240, 300 and 360 pulses per min, and then used to evaluate the effects of propranolol hydrochloride and atropine sulfate on atrial pacing. Propranolol resulted in an increase in the amount of current (mA) required to achieve a given degree of cardiac capture, whereas atropine resulted in a decrease. These shifts in the capture-intensity functions along the intensity axis were possibly caused by drug antagonism of beta-adrenergic and cholinergic receptors, respectively, although the effects might also have been due to modifications of the electrical responsivity of the cardiac muscle, independently of the neural blockade.
In its Pavlovian context, "reinforcement" was actually a descriptive term for the functional relation between an unconditional and a conditional stimulus. When it was adopted into operant conditioning, "reinforcement" became the central concept and the key operation, but with new qualifications, new referents, and new expectations. Some behavior theorists believed that "reinforcers" comprise a special and limited class of stimuli or events, and they speculated about what the essential "nature of reinforcement" might be. It is now known that any stimulus can serve a reinforcing function, with due recognition of such parameters as subject species characteristics, stimulus intensity, sensory modality, and schedule of application. This paper comments on these developments from the standpoint of reflex behavior theory.
The term "response" is a basic one in behavior theory, particularly reflex theory, but its definition is not clear. The origin of the term in the common vocabulary has affected its later extensions in the analysis of behavior. Some contemporary theorists accept the existence of two "types" of response, coordinating one with the Pavlovian conditioning procedure, the other with the operant conditioning procedure of the so-called "contingent" variety. Reservations are expressed here about such distinctions between response classes and conditioning paradigms, emphasizing the difficulties that arise from certain conventions and inadequacies in current definitions and conceptions of "response". The critical nature of the problem for behavior theory is illustrated once again by the recent laboratory finding that a familiar and accepted conditional reflex, that of the "conditioned cardiac CR," can be fractionated into "parts" and is therefore perhaps no longer to be treated as a single unitary "response".