The effects of muscle relaxation and stress on the blood pressure levels of normotensives

Shoemaker and Tasto (1975) found that progressive muscle relaxation lowers the blood pressure levels of essential hypertensives to within a normal range under laboratory conditions. As a sequel to this study the effects of muscle relaxation and stress on the blood pressure levels of normotensives were studied. One group was taught relaxation, one group was stressed, one group read, and one group did nothing. Blood pressure measurements taken immediately after the completion of these tasks indicated that muscle relaxation does not lower the blood pressure levels of normotensives but that stress significantly raises both the systolic and diastolic levels.Level of arousal can, at least in one sense, be viewed as occurring on a dimension defined by extreme anxiety at one end and extreme relaxation at the other. Research on the physiological correlates and/or defining properties of arousal has produced inconsistent and equivocal results. Little work has been done relating blood pressure levels to arousal, however. Shoemaker and Tasto (1975) found a consistent and predictable drop in the blood pressure levels of essential hypertensives as a result of progressive muscle relaxation. In their study those subjects with the highest blood pressure levels showed the greatest drop while those with moderately high levels showed moderate drops and those with the lowest levels (yet still above normal) showed the least amount of change. The amount by which blood pressure dropped as a result of progressive relaxation was positively correlated with the pretreatment level of blood pressure. The result of progressive relaxation was to lower blood pressure levels to within a normal range, with all subjects appearing to approach a lower asymptotic level. Because of the consistent picture which began to emerge, the question arose as to whether blood pressure might be a reliable physiological correlate of the relaxation-anxiety dimension.The more specific questions emanating from this issue were: what effect does progressive relaxation have on the blood pressure levels of normotensives; what effect does stress have on the blood pressure levels of normotensives; and, what effect does stress have on the blood pressure levels of essential hypertensives? Since we could not immediately foresee the benefits that would outweigh the potential harm that might arise by placing hypertensives under stress, this study was limited to addressing the first two questions.Since the blood pressure levels of normotensives are probably at an optimal level for the physiological functioning of the organism, lower levels would be physiologically nonadaptive. and thus progressive relaxation should not lower the blood pressure levels of normotensives as it does those of essential hypertensives. On the other hand, if the elevated blood pressure levels of essential hypertensives are at least in part the result of a stress reaction, it would be expected that the blood pressure levels of normotensives might rise under stress conditions.     

Developmental trends in the use of perceptual and conceptual attributes in grouping,clustering, and retrieval

In Experiment I, two tasks were administered to children aged 4, 5, and 9 in order to investigate preference for perceptual versus conceptual attributes in grouping of common objects, and in various aspects of memory. The grouping task revealed a clear chronological progression: color and form determined the youngest children's grouping about equally; form dominated in the 5-year-olds; and most of the oldest children grouped primarily by conceptual attributes. In the memory task, three lists—one organized by color, one by form, one by superordinate category—were presented for free, followed by cued recall. Clustering showed the developmental shift from color to form to concept, while cued recall showed conceptual superiority at all ages. Experiment II replicated the memory task, yielding the same results. The results were discussed in terms of the relative abstractness and predictability of conceptual versus perceptual attributes and the difficulty of abstraction in encoding and the function of predictability in retrieval.     

Remembering information related to one's self

How does memory for an incident vary depending on whether, and how, the person relates the information to himself? Trait adjectives are better remembered if they were judged in reference to oneself rather than judged for meaning or sound. Our first experiment found a similar mnemonic advantage of referring a described episode or object to some event from one's life. Pleasant events were remembered better than unpleasant ones. A second experiment found incidental memory for trait adjectives was equally enhanced by judging each directly in reference to one's self-concept or indirectly by retrieving an episode either from one's life or from one's mother's life. Contrariwise, memory was poorer when traits were judged in reference to a less familiar person. Thus, good memory depends on relating the inputs to a well-differentiated memory structure.     

The gestures of a gorilla: language acquisition in another pongid

A female lowland gorilla, Koko, has been engaged in an ongoing language program since July 1972 when she was 1 year old. During the first 30 months of training she acquired a vocabulary of 100 words in American Sign Language which she spontaneously combined into meaningful and often novel statements of up to 11 signs in length. The gorilla is using a rapidly expanding vocabulary of signs to express semantic and possibly grammatical relations similar to those expressed by human children in the early stages of language acquisition. Patterns of generalization, gradual increase in mean length of utterance, and innovative use of gestural language are discussed in relation to data available on children and chimpanzees.     

Methodological issues in the study of sex-related differences

Ten ubiquitous methodological problems are described in relation to group differences research and particularly sex-related research. Substantive issues in sex-related research are used as illustrations of the methodological problems.     

An attempt to understand students' understanding of basic algebra

This paper reports the results obtained with a group of 24 14-year-old students when presented with a set of algebra tasks by the Leeds Modelling System, LMS. These same students were given a comparable paper-and-pencil test and detailed interviews some four months later. The latter studies uncovered several kinds of student misunderstandings that LMS had not detected. Some students had profound misunderstandings of algebraic notation: Others used strategies such as substituting numbers for variables until the equation balanced. Additionally, it appears that the student errors fall into several distinct classes: namely, manipulative, parsing, clerical, and “random.” LMS and its rule database have been enhanced as the result of this experiment, and LMS is now able to diagnose the majority of the errors encountered in this experiment. Finally, the paper gives a process-oriented explanation for student errors, and re-examines related work in cognitive modelling in the light of the types of student errors reported in this experiment. Misgeneralization is a mechanism suggested to explain some of the mal-rules noted in this study.