The Effect of Attention or Mental Activity on the Patellar Tendon Reflex.

Abstract

In studying the knee-jerk Lombard (I) found in one subject that whatever increased or decreased the activity of the central nervous system as a whole increased or diminished the activity of this reflex. Howell (2) states that this general fact is supported, especially as regards mental activity-such, for instance, as the condition of the nervous center controlling the bladder.In view of the paucity of quantitative data on this subject it was decided to measure the knee-jerk under active and passive conditions of highly socialized forms of peripheral stimulation. We did not feel free to hazard a definition of what psychologists have generally agreed to include under the term 'attention' or 'mental activity' but preferred to assign to the subject a problem which we felt reasonably sure would release the type of response which most psychologists would agree required 'attention' or was performed under 'attentive attitudes.' The terms passive and active which we have chosen in place of non-attentive and attentive are not meant to carry theoretical implications as to their psychological character beyond those which the reader himself wishes to interpret from the nature of the problems that were assigned to the subjects. Data were collected from seven normal sl,lbjects in good health, four of whom were well trained in knee-jerk experi-M ~I

A photographic study of tremor during postural contraction.

“…We believe that in explaining the increase of nerve impulse discharge during voluntary tension we may arrive at an adqeuate explanation of why tension occurs during mental activity. That mental work has a muscular effect similar to that of voluntary tension has been shown by our results, and by the studies of Tuttle (46), Jacobson (25) (26), Freeman (16) and others.…”

Factors influencing the latent time of the patellar reflex.

“…It is for this reason that such a great number of the studies on extent have dealt with various phases of this problem. Tuttle (28,29,30,31), in the most complete series of studies on kneejerk extent that has been made in recent years, has shown (30) that mental activity increases the extent of the kick. These and other studies by Miles (22), Dodge (3), Emery (4,5) and others seem essentially to be elaborations and verifications of the generalization made by Lombard (21, p. 70) in 1888:…”

“…Loeb's contention that the nervous system is merely an efficient 'protoplasmic bridge' between receptor and effector is most basic as physiological support for the revolt issuing out of the experimental results obtained by Franz (10,11) and Lashley (18), in one field and by Tuttle (28,29,30), Emery (5) and Freeman (12,13) in another. The basic protest underlying these and many other studies has achieved at least one major systematic presentation in Gestalt psychology.…”

Consciousness and Self-Regulation

“…The question mark in Column 3 indicates that no other bodily measures were concomitantly made with arm activity. Tuttle (1924) tapped subjects' patellar tendons with a constant force at constant intervals and obtained measures of muscle tonus during conditions of rest, problem solving, and conversation. Muscle tonus was measured as the distance of leg deflection during the knee jerk.…”

“…Problem Solving Golla (1921): Increases in forearm tonicity were positively related to the difficulty of the problem to be solved. Tuttle (1924): Muscle tonus (patellar reflex) increased from relaxation to conversation to problem solving. Freeman (1930): Leg tension increased during the first part of mental tasks directly as a function of task difficulty.…”