Quantitative assessment of infant reaching movements

We have identified a fundamental property of human motor behavior as a tight coupling of the curvature-speed relationship in the reaching movements of 5- to 9-month-old infants. This relationship termed a movement unit, occurs regardless of the distance of duration of the reach and in spite of the developmental change that occurs in grasping during this period. Movement unit durations are tightly clustered around 200 ms regardless of overall duration or distance or the position of the unit in the reach. The curvature-speed coupling has been identified by others in adult reaching and handwriting. Models of biological motor control must account for this invariant relationship.     

Fusing Apples and Oranges: A Rejoinder to Carver & Scheier and to Fenigstein

ABSTRACT A simple parable is introduced that serves as an analogy to the private/public self-focus distinction The analogy elucidates that the reliability of the effects observed by the private/public research direction is not the focus of the Wicklund and Gollwitzer critique Rather, the critique questions the validity of the explanations offered More importantly, the analogy implies the conclusion that construing social dependency as an issue of self-focus does injustice to both the social dependency and self-focus concepts     

Task-dependent compensatory responses to perturbations applied during rhythmic movements in humans

Modulation of the responses to perturbation applied during different phases of three rhythmic movements in humans-running, cycling, and hopping-was studied. The perturbation was an electrical stimulus. The results showed gating and modulation of the responses in both ipsi- and contralateral limb muscles. The responses during running and cycling were only excitatory in nature, while during hopping an inhibitory response was observed. These responses were not correlated with the normal activity during the movement. The latency of the response in general was not altered for different stimulation phases. The alterations in the step cycle demonstrated overt behavioral changes due to the responses. There were differences between the responses observed during these movements and walking. In running, the major adaptation to perturbations appears to be in the contralateral side as seen in the changes in the step cycle. During cycling (except for one phase) and hopping, the same set of muscles was activated in response to perturbation. This represents a simplifying strategy in response organization. The dependency of the response on the task characteristics, postural stability requirement, and external constraints imposed on the subject is discussed. These studies provide insights into task-dependent strategies adopted by the nervous system to meet unexpected perturbation during rhythmic movements in humans.     

Study of neuromotor reaction times under the influence of thyrotropin-releasing hormone

Neuromotor reaction times (simple, choice, and decision) were measured when Thyrotropin-releasing hormone (TRH) was administered intravenously to nine healthy men in a double-blind study. Measurements were made of simple reaction time, choice reaction time, and decision time for each subject at various intervals over a 54-hr. period. Given the observed inherent interaction of the drug with the long time used (54 hr.), most analyses were conducted across separate time epochs. Injected subjects showed inhibition in the normal improvement of simple reaction time (which occurs with practice), and they reduced the time required to make a decision. Choice reaction time, however, remained unchanged across the drug-nondrug experimental conditions.     

Selected parameters of response organization in mildly mentally retarded children

The purpose of this study was to investigate the effect of response organization on reaction time (RT) and movement time (MT) of mildly mentally retarded children. Two groups of 30 subjects each were formed: a retarded group 9 yr. of age and a normal group matched for chronological age. Subjects were randomly assigned to one of three precued conditions in which they were told that the forthcoming response would be performed with the right or left hand (precue hand), be to the right or left side (precue direction), or cross or not cross the body midline (precue midline). The retarded group performed significantly more slowly than the normal group on both RT and MT. Both groups, however, were able to utilize precued hand information as opposed to other precued variables, indicating that knowing which hand to use is important when organizing responses.     

Interhemispheric integration of compound nouns: effects of stimulus arrangement and mode of presentation

Normal subjects had to name German compound nouns which were presented tachistoscopically. The compound nouns were displayed either unilaterally to the left or right visual field or bilaterally with one element to each visual field. In the bilateral condition a distinction was made as to whether familiar or unfamiliar arrangement of the elements was used. Representation in print was compared with pictorial representation of the compound nouns. A right visual-field superiority was observed with printed representation, but no laterality effects with pictorial representation. Bilateral processing was superior to unilateral processing. Within the bilateral conditions, the familiar arrangement of the elements yielded a significantly better performance than unfamiliar arrangement. This difference can be explained by reading habits and/or by different styles of interhemispheric integration.     

The varieties of fear

Conclusion I shall conclude with a methodological moral. I have tried to show that there are several fundamentally different kinds of fear. One is a pure propositional attitude, one is partially a bodily state, and one is a relation between a person and a nonpropositional object. Other emotions come in similar varieties, such as hope and happiness, but with significant differences. The state of happiness, for example, does not entail any particular bodily state or feeling. So one lesson is this: it is hard to generalize about the emotions. Further detailed, analytical studies of particular emotions are needed before a general theory of the emotions can be fruitfully attempted.     

SELF-ASSESSED TRAINING NEEDS: THE EFFECTS OF ATTITUDES TOWARD TRAINING, MANAGERIAL LEVEL, AND FUNCTION

Self-assessment research has concentrated on validity and psychometric issues in selection and appraisal contexts. Little is known about factors that affect self-assessment of training needs. The present study examines the influence of managerial position (level, function) and managerial attitudes toward training utility on self-reported training needs. A training-needs survey consisting of items related to basic managerial, interpersonal, administrative, and quality control skills was completed by 506 lower and middle level managers across four functional areas. Correlational and regression analyses indicated that managerial level and function had some effect on reported administrative training needs, while function and attitudes towards training utility had some impact on self-reported training needs for quality control. Level, function, and attitude were not related to reported basic managerial and interpersonal training needs. The implications and limitations of the results are discussed, and future research directions are presented.     

ALTERNATIVE WORK SCHEDULES: TWO FIELD QUASI-EXPERIMENTS

In the first ( N = 140) of two quasi-experimental field studies, trial group employees were changed from a 5/40 to a 4/40 work schedule for four months then returned to a 5/40 schedule. In a second study ( N = 102), trial group employees were changed from 5/40 to flextime. Reactions were evaluated using a model for understanding the impact of work schedules. The effects of schedule changes matched those anticipated by pre-intervention surveys of employees. Factors related to organizational effectiveness were enhanced where specific organizational needs were met. Interference with personal activities was reduced where employees had experienced specific difficulties. The most powerful effect, however, was on worker attitudes toward specific work schedules. In addition, a mild positive (perhaps Hawthorne) effect was evident for a wide range of general worker reactions.