Human patellar reflex and conditioned reflex compared electromyographically

Inspite of continued work on the stretch reflex and “voluntary” movement study of the conditioned stretch reflex declined early in this century. The present experiments surveyed seven classical conditioning regimens for the human rectus femoris EMG seen after a blow to the patellar tendon. It was possible to (1) rule out conditioning to a knee touch that occured together with the tap, (2) establish weak conditioned stimulus, Sc, control for a tape recorder click and subsequent fist clench that preceded the tap by variable elapsed times, and (3) establish strong Sc control for a tone that sounded an invariant 0.27 sec before the tap. There were large differences, however, in Sc power across subjects, as measured by amplitude, latency, and frequency of conditioned EMG activity that occured prior to tap or when the tap was omitted. Purely reflexive responses, especially later EMG segments, also varied in amplitude and frequency, to support a conclusion that numerous controlling stimuli added or competed from trial to trial. Further disclosure of Sc contributions, including those from movement-generated stimulation, is warranted, especially for behaviors whose rhythmic timings, as in locomotion, might favor Pavlovian conditioning.     

Noise stress and circadian arousal in self-paced computation

Previous work(Frankenhaeuser & Lundberg, 1977) has shown that unpaced mental arithmetic is performed at slower rates in noise, despite unchanged catecholamine indices of arousal; only male subjects were used, tested early in the day. Since the times of testing entail arousal effects that interact with noise stress, and the sex of subject further modifies these interactions, a new experiment was designed to include these variables. Men and women were tested on the Norinder mental arithmetic task, in quiet or in noise, either in the morning, when arousal was low, or during the early evening, when temperature curves indicate that arousal should be high. Analysis of the number of problems attempted shows a significant drop for men in noise in the morning, but an interaction due to reversal of the noise effect in the evening; there is no main effect of noise when women's scores are included. The results are compatible with interpretations combining motivation and cognition, and they demonstrate the importance of the experimental variables in explaining noise stress effects.The authors are indebted to the late David A. Shipp for his assistance in running subjects.     

Changes in Moods and Activation Levels During the Menstrual Cycle in Experimentally Naive Subjects

Two experiments providing additional validity data on the Profile of Mood States and the Thayer Activation-Deactivation Adjective Check List were per-formed. In the third and main experiment, seven normally menstruating women filled out both questionnaires at the same time every day for 90 days. They were not aware that they were participating in a study of menstruation. Analysis of the time series records of individual women revealed relatively few significant fluctuations in moods and activation levels. Analysis of the group data showed that Fatigue, Confusion, Deactivation/Sleep, and Depression/Dejection were significantly lower in the premenstrual phase than in the periovulatory phase of the cycle, while General Activation was higher. Anger/Hostility and Confusion were both lower in the menstrual phase than in the periovulatory phase. On a retrospective menstrual distress questionnaire, these same subjects say that they experience increases in anxiety, irritability, depression, and tension in the premenstrual phase of the cycle. The differences between individual and group data and the apparent discrepancy between daily self-reports and retrospective questionnaires are discussed.     

Analogical problem solving

The use of an analogy from a semantically distant domain to guide the problemsolving process was investigated. The representation of analogy in memory and processes involved in the use of analogies were discussed theoretically and explored in five experiments. In Experiment I oral protocols were used to examine the processes involved in solving a problem by analogy. In all experiments subjects who first read a story about a military problem and its solution tended to generate analogous solutions to a medical problem (Duncker's “radiation problem”), provided they were given a hint to use the story to help solve the problem. Transfer frequency was reduced when the problem presented in the military story was substantially disanalogous to the radiation problem, even though the solution illustrated in the story corresponded to an effective radiation solution (Experiment II). Subjects in Experiment III tended to generate analogous solutions to the radiation problem after providing their own solutions to the military problem. Subjects were able to retrieve the story from memory and use it to generate an analogous solution, even when the critical story had been memorized in the context of two distractor stories (Experiment IV). However, when no hint to consider the story was given, frequency of analogous solutions decreased markedly. This decrease in transfer occurred when the story analogy was presented in a recall task along with distractor stories (Experiment IV), when it was presented alone, and when it was presented in between two attempts to solve the problem (Experiment V). Component processes and strategic variations in analogical problem solving were discussed. Issues related to noticing analogies and accessing them in memory were also examined, as was the relationship of analogical reasoning to other cognitive tasks.     

The effects of episodic and semantic memory on the identification of sentences masked by white noise

Two studies examine how episodic and semantic memory affect subjects’ abilities to repeat sentences masked by white noise. Subjects first hear a list of 70 sentences that are not masked. Subjects in the framework conditions are told prior to hearing the list that all sentences refer to a contextual framework concerning a deserted island. Subjects in the no-framework groups are not given this information. Subjects in the framework-after condition are given this information only after hearing the list of sentences. Subjects then perform a white-noise identification task. The results indicate that framework subjects are able to identify both old and new framework-related information better than other subjects. Subjects in the no-framework and framework-after conditions identify old information better than control subjects who do not participate in an acquisition phase. Emphasis is placed on the interdependence of episodic and semantic memory, including conditions leading to such interdependence.     

Locus of control and the perception of freedom in an agent of reinforcement

Internals and externals observed a staged videotape presentation that portrayed a “teacher” and a “learner” engaging in a 20-item anagrams task. For externals, any variability (10, 50, and 90% schedule) in the reinforcing behavior of the “teacher” (agent of reinforcement) resulted in significantly greater perceived freedom than when no variability (0 and 100% schedule) occurred in behavior. For internals, perceived freedom was a negative linear function of the amount of reinforcement administered. Internals indicated that they could influence the behavior of the “teacher” in all reinforcement conditions, whereas externals indicated that they could influence only the “teachers” in the variable reinforcement conditions. It was concluded that greater freedom is attributed to a person whose behavior is perceived as congruent with the person's inner disposition.     

Sex differences in the professional orientation of first-year medical students

This article, presenting the findings from a 1975 survey of first-year medical students in the state of North Carolina, explores the relationship between students' sex and professional orientations considered relevant to current health care problems. The professional orientations concern four problem areas: (1) physicians' relationships with patients, (2) political and economic change in the medical profession, (3) the treatment of women physicians and women patients, and (4) geographic and specialty mal-distribution of physicians. Substantial sex differences are found for some professional orientations. As hypothesized, women orient more highly than men to humanizing physician-patient relationships, political and economic change in medicine, the problems facing women physicians and patients, and expecting an inner-city practice. Implications of the findings for health care and medical education are discussed.This report is based on the author's doctoral dissertation, Boys and Girls in White: Professional Orientation of the Student Physician Department of Sociology, Duke University, 1976. The author would like to express appreciation to Jim House for his continued guidance and encouragement as dissertation advisor.     

Vicarious extinction of phobic behavior in early childhood

Fifteen children who had previously demonstrated phobic behavior under dental treatment were randomly assigned to one of three experimental conditions. Each condition involved six sessions which were conducted over a three week interval. Results supported the efficacy of modeling as a means of ameliorating phobic behavior in the dental treatment situation. Although viewing the operatory and professional staff alone appeared therapeutic, modeling was considered a superior mode of treatment.     

Response set effects in recognition memory

In three experiments, Ss responded to individual digits or letters according to whether or not each was in some prememorized list. There were either two possible responses (yes-no condition) or a single response (yes-only and no-only conditions). With memory sets of one, two, or four digits, RT was a linear function of memory set size. The slope of the function was least under the yes-only condition and greatest under the yes-no condition. Nonspecific practice had little effect on any of the slopes. With memory sets of 4, 8, or 12 letters, the slopes under the yes-only and yes-no conditions did not seem to differ, and practice with specific sets flattened the function considerably in both cases. Overall, the errors under the yes-no condition were mostly false alarms, those under the no-only condition mostly misses, and those under the yes-no condition were divided about equally. The results are interpreted partially in terms of a multiple-observations model of decision time.     

Pavlovian theory of dreaming

Pavlovian theory provides a conceptual scheme for the examination of recent empirical data on dreaming. Consistencies are examined between these data and Pavlovian theory of the general properties of the nervous system. An equation is made between Pavlov’s excitation-inhibition continuum, the REM-NREM cycle, and the basic rest-activity cycle. Speculations, based on this equation, are made about the inter-relation between waking and sleeping behaviors. Testable hypotheses are suggested throughout the paper.