A note on modulation of gait in man: Effects of constraining stride length and frequency

In this study, our aim was to investigate the effect of an imposed stride-length on walking speed and stride-frequency, and the effect of an imposed stride-frequency on walking speed and stride-length. These variations were determined in relation to the values obtained by analysing the subject's preferred pace. In the first case, the subject had to step on transversal stripes on the floor; in the second case, he had to synchronize his stride with a regular auditory signal. The results obtained with 8 subjects show that speed was the most variable factor. Variations in speed were correlated with variations in the imposed parameter: whenever the subject lengthened his stride or increased his stride-frequency, his walking speed increased proportionally. These results point to a relative independence between stride-length and stride-frequency, and a strong correlation between each of these parameters and speed.     

Simulation study of a decision-making model of squash competition, phase two: Testing the model through the use of computer simulation

This study aims at verifying the inner validity and logic of a squash competition decision-making model through the use of computer simulation. The model defines the cognitive-decisional strategy of the defending player (D) when selecting a motor reaction in response to his opponent's shot. Computer simulation of the model was carried out on a PDP-10 computer using a recent version of UCI-LISP. Protocol analysis data pertaining to the nature of the information D processes when awaiting the attacking player's shot were fed into the simulation program in order to examine the extent to which the model can reproduce decisions reached in various defensive contexts. Simulation results reveal that the proposed model can account for a substantial part of the variation in the speed and accuracy of D's motor reaction in real sport situations. Several factors like time pressure, expectancies, uncertainty, recency and familiarity of the relationship between signal and response appear to affect D's motor response via the cognitive-decisional strategy employed by the defending player. Particular discrepancies observed between simulation results and decisions reached by expert players in specific defensive situations nevertheless indicate that the decision rule utilized within the present model needs to be refined. In this regard, several issues are discussed and suggestions for further simulation studies are put forward in order to account more precisely for the various features characterizing the defensive player's motor reaction in real sporting context.     

AN IDIOGRAPHIC APPROACH TO THE STUDY OF WOMEN'S ACHIEVEMENT STRIVING

Biographical interviews with 80 women ranging in age from the late teens to the 80s (Mean Age = 46.8 years; SD = 7.8 years) elicited information concerning personality characteristics that predispose women toward achievement-striving behavior, taking into account the effects of family, friends, and role models. When asked if they had ever been in a situation where they were about to succeed and feared the success, the majority of women (91 %) replied "no". A large percentage of women (96%) did report that they wonder if their achievements are worth it and asked "success at what cost?" In addition, compared to older women, younger women were more concerned with interpersonal relationships and less concerned with competitive achievement. The reality status of the fear of success construct as well as methodological advances in its measurement are discussed.     

Language and the young stutterer: A new look at old theories and findings

The major theories and research approaches as to the etiology and development of stuttering are reviewed from a historical perspective. Findings are drawn from different sources indicating that language deficits are an initial contributing factor and a continuing component of this disorder. Those subsets of children which constitute high-risk groups are identified. It is suggested that researchers begin investigating the underlying organic bases of stuttering and its relationship to stages of language development. Finally, clinicians are encouraged to employ a therapy program that is concerned with all areas of language, rather than emphasizing treating only the symptoms of stuttering behavior.     

Intrinsic enjoyment and boredom coping scales: Validation with personality,evoked potential and attention measures

This paper reports the validation of brief, self-report measures of intrinsic enjoyment and boredom coping. Intrinsic enjoyment is characterized by intense involvement, interest and absorbed concentration; boredom coping is designed to reflect the disposition to restructure one's perceptions and participation in potentially boring activities so as to decrease boredom. Both traits are hypothesized to reflect the capacity for good attentional control across a variety of situations. Reliability was established by test-retest correlation and by an inter-item consistency measurement. Construct validity was established by comparison with previously-validated personality tests, real-life measures (such as Random Activities Experiential Sampling, which involves repeated self-report measures in daily life), as well as with laboratory measures of attention (including the averaged visual evoked potential (EP) and the Continuous Performance Test). Intrinsic enjoyment is significantly correlated with an independent measure of intrinsic involvement (low wish to be elsewhere in one's daily life), the affective experience of potency, self-reports of concentrating well with ease, high ego development, an internal locus of control, lack of boredom susceptibility and certain EP indices of attentional change and ‘cortical’ augmenting. Boredom coping is associated with a higher percent of time actually spent alone, high continuous performance task measures of attentional capacity, and low MMPI and Research Diagnostic Criteria indices of psychopathology.     

Frequency response characteristics for sinusoidal movement in the fovea and periphery

Threshold sensitivity was measured for sinusoidal movement of bright 1-deg lines against a dark background as a function of oscillation frequency and retinal location. Sensitivity was greatest in the fovea and at a frequency of 1–2 Hz. Peripheral sensitivity was more narrowly tuned than foveal sensitivity. The presence of a stationary reference line affected mainly the foveal sensitivity. The results are interpreted as evidence for both position- and velocity-sensitive mechanisms in the movement detection system.     

NÉCESSITÉ ET SIGNIFICATION DES RECHERCHES COMPARATIVES EN PSYCHOLOGIE GÉNÉTIQUE

Need and meaning of comparative studies in genetic psychology. — The comparative studies in the field of genetic psychology are indispensable for Psychology in general and also for Sociology, because only such studies allow us to separate the effects of biological or mental factors from those of social and cultural influences on the formation and the socialization of individuals. Relevant to this discussion is the well-known issue between culturalistic psychoanalysts like Fromm, Horney, etc., and classical freudian psychoanalysts who reduce the whole individual development to an endogenous evolution of « instinct ». In the field of cognitive functions to which this paper is devoted, at least four kinds of various factors must be distinguished, the respective influences of which can be separated through comparative studies : I. Biological factors depending on the “epigenetic” system (maturation of nervous system, etc.). These factors probably explain the sequential aspects (constant and necessary order) of the stages in the development of operative intelligence. However, if only these factors were acting, the stages would not only appear in a sequence, but at the same ages, whereas in fact, the ages where a stage appears differ from one environment to another. 2. Equilibration or autoregulation factors, determining behavior and thought in their various specific activities. They correspond to the sequential forms in general coordination of the actions of individuals as interacting with their physical environment; such intervening regulations are probably at the origin of the mental operations themselves, especially logical - mathematical operations. 3. General socialization factors, which are identical for all societies : cooperations - discussions - oppositions - exchanges, etc., between children or between adults or between adults and children. These factors 3 are closely related with the factors 2, because the general coordination of actions concerns inter-individual as so as intra-individual actions. 4. Factors related to educational and cultural transmission, which differ from one society to another; they are those we usually have in mind when we say briefly “social factors”. To discuss the influence of these four factors, Mohseni's study on Teheran school children and illiterate rural children is given as an example. Three results were obtained : (1) For “conservation” tasks, the same stages of intellectual development are observed for urban and rural children, in Iran as well as in Europe. (2) For these same tasks, a systematic delay of two to three years is observed among rural children with respect to Teheran children. (3) For performance tests (i.e. Porteus, Goodenough, etc.) there is a delay of four and primarily five years. These data seem to show that there is some sequential order of the stages which depends partially on the factors I. But, the ages for each stage are not constant, showing the factors 2 and 3 are intervening in a probably inseparable way. On the other hand, the difference between the actual operative results and the performance tests seems to indicate that a distinction might be made between the factors of general coordination (factors 2 and 3) and the educational transmissions (factors 4). About these last factors, the three and four year delays observed by Canadian psychologists working in Martinique with school children (French curriculum) in operative tasks (like conservations) seem to indicate that the general operations depend less on school than on the activities themselves of children or in general on the adult stimulations in the environment. We must pay special attention to the problems raised by language. In some precise and systematic experiments in Geneva, Sinclair shows children on the “preoperative” level (i.e. with no conservation…) do not spontaneously use the same language as operative children : the former use chiefly “scale” words (“much” or “many”, “little” or “few”, “large”, “small”) and the latter use chiefly “vector” words (“more”, “less”). If the younger subjects are submitted to a verbal training, they do learn to use the older children's language, but it only results in very little operative improvement (about one case out of 10 subjects on the average). Therefore, replicating the same experiments in countries speaking different languages would be very interesting. For instance, in the Turkish language, there is only one “vector” word, i.e. “again”; so that the Turk says “again much, again many” to say “more”. Then, the question is to know whether a change will be observed for the stages of logical-mathematical operations or whether these operations will be found everywhere with their identical common background; it seems that this last conclusion has already been observed in Aden (Hyde), Hong Kong (Goodnow), South Africa (Price-Williams). In conclusion, the kind of psychology we develop in our social environments, remains conjectural as long as comparative extensive and systematical research is not available; a great effort is still to be made in this direction.     

Disruption of proofreading by irrelevant speech: Effects of attention,arousal or memory?

A series of five experiments examined the effects of irrelevant speech on proofreading and memory. Four of the experiments used a proofreading task and showed that the deleterious effects of irrelevant speech: (1) depend on the speech being meaningful, (2) are only present when the burden on short-term memory is low and (3) are manifested in a lower detection rate for non-contextual as opposed to contextual errors. Neither the spatial location of the speech (either in terms of spatial dispersion of sources or spatial movement of a single source) nor the intensity of the speech (in a range bounded by 50 dB(A) and 70 dB(A)) had any effect on proofreading. Late selection models of attention are favoured by the results in preference to models having arousal, short-term memory or early selection in attention as their basis. A final experiment showed serial recall for visual lists to be impaired by the presence of any speech-like sound (including reversed speech and speech in an unfamiliar language) which suggests a set of phenomena qualitatively different from those associated with proofreading. Throughout the article the practical consequences of the findings are emphasized.     

Negative priming insame-different matching: Further evidence for a central locus of inhibition

Responses to recently ignored information may be slower or less accurate than responses to information not recently encountered. Such negative priming effects imply that the mechanism of selective attention operates on unattended, as well as attended, information. In the present experiment, subjects judged the second and fourth letters of five-letter strings (e.g., BABAB) as “same” or “different.” Responses were slower when a target letter was identical to the distractors presented in the immediately preceding trial. This effect did not depend on which response was required on the current or preceding trial. The results suggest that ignored information is functionally disconnected from the response system as a whole, rather than from a specific response.