How do Motor Systems Deal with the Problems of Controlling Three-Dimensional Rotations?

Rotations are fundamental to motor control, not only for orienting to stimuli but also in the joint articulations that underlie translational movements. Studying three-dimensional (3-D) rotations of the simplest joint system, the eye, has provided general insights into the neural control of movement. First, in selecting one 3-D eye orientation for each two-dimensional (2-D) gaze direction, the oculomotor system generates a behavior called Listing's law that constrains eye position to a 2-D plane, Listing's plane. This selection is made internally by an inverse kinematic transformation called the Listing's law operator. Second, the oculomotor system incorporates the inherent multiplicative relationship between rotational velocity and position to generate the 3-D movement and position commands required by Listing's law. Finally, the coordinate systems for these commands appear to align with Listing's plane rather than with anatomic structures. Recent investigations have revealed similar behavioral constraints in the orientations of the head and arm, suggesting that the neural mechanisms for Listing's law may have analogues in many motor systems.     

Evidence of Incomplete Motor Programming in Parkinson's Disease

One of the essential questions regarding movement deficits in Parkinson's disease (PD) is whether they stem from impaired selecting and switching among movements, impaired use of predictive information to prepare movement, or impaired execution of movement. PD subjects (n = 9) and age-matched control subjects (n = 8) performed a cued, sequential-response RT task. The cue provided either no information, accurate information, or inaccurate information about the upcoming response. PD subjects used predictive information to prepare and to switch among movement sequences normally, but second and third key press latencies were prolonged in comparison with the first key press latency. In Experiments 2 and 3, the effects of choice set and sequence length on key press latencies were examined. These results provide evidence that PD subjects initiate movement before the entire response sequence is prepared. PD does not impair motor programming or execution processes themselves but impairs the smooth coordination of those processes.     

Handedness and Hemispheric Asymmetry in the Control Of Movements

This study investigated the influence of hemispheric specialization of function on the motor performance of the hands. Right-handed (n=17), ambidextral (n=21), and ambisinistral (n=12) subjects performed Fitts' (1954) reciprocal tapping task under two conditions with each hand. Conditions had the same index of difficulty but differed in movement precision. The left hand of righthanders was superior in the condition requiring the greatest amount of preprogramming. Conversely, the right hand was not superior in the condition having the greatest demand for feedback control. For ambidextrals, left-hand superiority in the relatively preprogrammed condition was also revealed. Ambisinistrals showed no significant difference between conditions with either hand. The results partially support the hypothesis that the motor performance of the hands mirrors the dominant processing mode of their contralateral hemisphere. Failure to find supportive evidence in ambisinistrals is consistent with the contention that they lack hemispheric specialization of function.     

Bilateral Transfer as a Function of Mental Imagery

Three experiments are reported which investigate the role of mental imagery in the bilateral transfer from right to left hand of rotary pursuit skill. In Experiment 1 both mental imagery and physical rehearsal showed significant positive transfer relative to a control condition. However, work decrement may have accumulated and transferred in the physical rehearsal group thereby depressing this group’s left-hand performance. Experiment 2 was conducted under conditions designed to allow work decrement to dissipate prior to transfer to the contralateral limb. The data still showed no difference between physical re-hearsal and mental imagery. One interpretation of these data is that work decrement was present under both the physical rehearsal and mental imagery manipulations in Experiment 1. The data from Experiment 3 confirmed this interpretation as well as replicated the positive transfer effects found for mental imagery in Experiments 1 and 2. The data are discussed in terms of central versus peripheral explanatory mechanisms.     

Context-Dependent Learning in People With Parkinson's Disease

Context-dependent learning is a phenomenon in which people demonstrate superior performance in the context in which they originally learned a skill but perform less well in a novel context. This study investigated context-dependent learning in people with Parkinson's disease (PD) and age-matched nondisabled adults. All participants practiced 3 finger sequences, each embedded within a unique context (colors and locations on a computer screen). One day after practice, the participants were tested either under the sequence-context associations remained the same as during practice, or the sequence-context associations were changed (SWITCH). Compared with nondisabled adults, people with PD demonstrated significantly greater decrement in performance (especially movement time) under the SWITCH condition, suggesting that individuals with PD are more context dependent than nondisabled adults.     

The Efficiency of the Group Rorschach Test in the Psychiatric Screening of Marine Corps Recruits

In a study to extend the theory of cognitive dissonance into the area of person perception, 108 male freshmen dormitory students were led to believe that they either would or would not be sharing a room in the future with a negative other. They were also informed that they were either low, moderate, or high in similarity to this negative other. The major response measure was the extent to which the negative first impression changed in a more positive direction. A 2 × 3 ANOVA showed that both the proximity and similarity manipulations had the predicted effect. However, the trend in similarity was not linear, as hypothesized. Similarity was also found to be a more salient source of dissonance than proximity.     

The Home-Based Occupational Therapy Intervention in the Alzheimer's Disease Multiple Intervention Trial (ADMIT)

There is no way to prevent functional declines related to Alzheimer's Disease (AD). The use of occupational therapy (OT) has been shown to be successful in managing some aspects of AD. We added home-based OT to evidence-based best practice for AD with the aim of delaying functional decline in people with AD. OT was delivered in the home to a caregiver dyad including the person with AD and her/his caregiver. This article describes the OT intervention for the AD Multiple Intervention Trial, a parallel randomized controlled trial. We include baseline data on the 180 caregiver dyads.     

A study of the greater male variability hypothesis in creative thinking in Mainland China: Male superiority exists

This study tested the greater male variability hypothesis in creative thinking with a Chinese student sample in Mainland China. The Test for Creative Thinking-Drawing Production (TCT-DP) was administered to 627 Chinese adolescent boys (n = 332) and girls (n = 295). Results using the boy/girl variance ratio (VR) generally supported the hypothesis that boys have greater variability than girls in creativity test performance. However, results using the boy/girl ratios from different regions of the creativity score distribution revealed a pattern of male superiority. While boys significantly outnumbered girls in the higher extremes, girls tended to outnumber boys in the central region and the lower extremes. Results from an analysis of the means lent further support to the findings of male superiority. Plausible explanations for greater male variability and male superiority in Mainland China are proposed. The theoretical and practical implications of the findings are discussed.     

In conversation with J. Philippe Rushton

The interview covers Rushton’s background in England, South Africa, and Canada, his education at the University of London (B.Sc., 1970; Ph.D., 1973), and his early research (1970–1980) on the social learning of generosity in 7- to 11-year olds. In his first book, Altruism, socialization, and society (1980), Rushton solved two “anomalies” for his social learning perspective—altruism in animals and traits in people—causing a “paradigm shift” for him toward sociobiology. He spent January to June 1981 at the University of California, Berkeley, to study the longitudinal stability of personality traits like altruism. There, he was influenced by Jensen’s work on g and race differences in rate of maturation and two-egg twinning. Subsequently, Rushton found that across 60 variables, Europeans fall between East Asians and Africans, closer to East Asians. He extrapolated Wilson’s (fast–slow) r-K life history theory to explain the pattern. Also covered is Rushton’s research on the heritability of altruism, and Genetic Similarity Theory explaining assortative mating and ethnic nepotism. Spouses and best friends are as similar as half-siblings and people randomly chosen from the same ethnic group are as related as first cousins. Altruism follows lines of similarity to replicate genes effectively. Rushton’s research on creativity is described.     

Creencias de los profesores y estrés docente en función de la experiencia profesional

Resumen

Se investigó la relación entre las creencias de los profesores, el burnout y las diferencias de edad. Participaron 165 profesores de educación secundaria. Se evaluó: actitud hacia la profesión, fuentes de estrés; burnout; eficacia docente, competencia personal, y afrontamiento. Los resultados indicaron que en el grupo de maestros entre 46 y 60 años difirieron del resto en su actitud hacia la profesión, estrategia de afrontamiento y valor de las fuentes de estrés. El burnout fue relacionado con la creencia en la eficacia de la docencia, con una percepción pobre de la propia competencia personal y con ver las condiciones laborales como una fuente importante de estrés. La conclusión fue que el burnout docente depende de una alta expectativa y motivación para enseñar, combinada con una baja percepción de la competencia personal para resolver problemas en general.