The aim of this study was to examine whether outcome expectations can be generalized from one defined task to other tasks. A deception paradigm was employed in which outcome expectations were manipulated. High, low, or medium expectations toward performing five tasks, which gradually increased in complexity and shared a common skill, were manipulated. Ninety adult males were randomly assigned to manipulation groups. A within-subjects repeated measures ANOVA indicated that those manipulated by medium expectations showed elevated perceptions of outcome expectations. Their performance, however, was superior only in the two tasks most similar in complexity to the initial task. On the less similar tasks, the differences among the groups were insignificant. A generalization effect can therefore be demonstrated on outcome expectations and performance to a certain degree of task complexity. Implications of the superior performance of participants manipulated to produce medium outcome expectations are discussed.
Noam Eyal, Michael Bar-Eli, Gershon Tenenbaum and Joan S. Pie
Angela DiDomenico, Raymond W. McGorry and Jacob J. Banks
Time-to-contact (TtC) is an alternative measure of postural stability to center of pressure (CoP) velocity. TtC is based on both spatial and temporal aspects of CoP displacement, definition of the boundary shape, and quantity of minima analyzed. Three boundary shapes and three minima selection methods were used to compute TtC during bipedal quiet standing. The results suggest that there is a strong correlation between TtC values obtained using each of the calculation methods (r ≥.73) and mean CoP velocity (r ≥ −.70). TtC was significantly affected by boundary shape and minima selection method. This limits the ability to compare absolute values, but relative levels of stability computed using TtC can be compared due to strong correlations. Given the task parameters studied, mean CoP velocity may even be adequate to assess levels of stability. Future studies are needed to examine the generalizability of these findings for different groups and task parameters.
Karen L. Schmidt, Jessie M. Van Swearingen and Rachel M. Levenstein
The context of voluntary movement during facial assessment has significant effects on the activity of facial muscles. Using automated facial analysis, we found that healthy subjects instructed to blow produced lip movements that were longer in duration and larger in amplitude than when subjects were instructed to pucker. We also determined that lip movement for puckering expressions was more asymmetric than lip movement in blowing. Differences in characteristics of lip movement were noted using facial movement analysis and were associated with the context of the movement. The impact of the instructions given for voluntary movement on the characteristics of facial movement might have important implications for assessing the capabilities and deficits of movement control in individuals with facial movement disorders. If results generalize to the clinical context, assessment of generally focused voluntary facial expressions might inadequately demonstrate the full range of facial movement capability of an individual patient.
Zakkoyya H. Lewis, Kyriakos S. Markides, Kenneth J. Ottenbacher and Soham Al Snih
We investigated the relationship between physical activity and physical function on the risk of falls over time in a cohort of Mexican-American adults aged 75 and older from the Hispanic Established Population for the Epidemiologic Study of the Elderly (H-EPESE). Participants were divided into four groups according to their level of physical activity and physical function: low physical activity and low physical function (n = 453); low physical activity and high physical function (n = 54); high physical activity and low physical function (n = 307); and high physical activity and high physical function (n = 197). Using generalized linear equation estimation, we showed that participants with high physical activity and low physical function had a greater fall risk over time, followed by the high physical activity and high physical function group. Participants seldom took part in activities that improve physical function. To prevent falls, modifications to physical activity should be made for older Mexican Americans.
Walter E. Davis, William A. Sparrow and Terry Ward
A fractionation technique was employed to determine the locus of reaction time delay in Down syndrome (DS) and other adult subjects with mental retardation (MH). Twenty-three subjects (8 nondisabled, 8 MH, and 7 DS) responded to a light, sound, and combination light/sound signal. Dependent measures of premotor time, motor time, total reaction time, and movement time were obtained during a 20° elbow extension movement and were analyzed separately. As expected, both MH and DS subjects were slower and more variable in their responses than the subjects without disabilities. In turn, DS subjects were significantly slower but not more variable than the MH subjects. There were no significant differences between the DS and MH subjects on movement times. Evidence for both a specific (premotor) and a generalized (both premotor and motor) locus of delay was found. Some difference in signal effect was also found for the DS subjects.
Karen Davranche, Danny Paleresompoulle, Rémy Pernaud, Julie Labarelle and Thierry Hasbroucq
The present study investigated the effects of acute paddling on performance in a typical decision-making task. It was aimed at assessing whether the effects of moderate exercise can be replicated using the feet as response effectors when physical exercise essentially solicits upper-body muscles. Twelve national-level paddling athletes performed a Simon task while paddling at a moderate (75% of maximal heart rate, HRmax) and at very light (40% of HRmax) intensities. The results showed that the effects of moderate exercise can be generalized to exercises involving different response effectors and upper-body muscle groups. They suggest (1) that the activation-suppression hypothesis (Ridderinkhof, 2002) holds when the task is performed with the feet, and (2) that moderate exercise speeds up reaction time and impairs the suppression of direct response activation.
Roy J. Shephard
A quantitative hypothetico-deductive approach has continued to contribute greatly to advances in biological and medical science. Quantitative methods are adopted over other approaches primarily because they contribute the most new knowledge about biological processes. Nevertheless, investigators make many assumptions when testing a biological hypothesis quantitatively. These assumptions may become invalid unless experiments are designed with great care. Problems arise in relation to formulating appropriate hypotheses, using volunteer samples, controlling the experimental intervention and potentially interfering behaviors, reaching an acceptable level of proof, excluding alternative hypotheses, and generalizing findings beyond the immediate experimental sample. When biologists are aware of these issues, they can take appropriate countermeasures and reach valid conclusions. However, the issues become more critical and resolution is less clear-cut when the same methods are extended from biology to psychology and the social sciences, and from general to special populations. In such situations, case studies and single-subject designs may have continuing relevance.
Luke E. Kelly, James H. Rimmer and Richard A. Ness
The purpose of this investigation was to determine the percent body fat of 553 institutionalized mentally retarded adults, ages 18 to 40 yrs, from the Denton State School in Texas. The subjects included 343 males and 210 females. Their percent body fat was estimated with generalized regression equations. Body density for males was measured by the sum of three skinfolds, two girths, and age. Body density for females was measured by the sum of three skinfolds and age. The results from this study revealed that 45.2% of the males and 50.5% of the females were obese. The percent body fat of the female subjects was significantly greater than that of the male subjects. A post hoc analysis revealed that profoundly mentally retarded subjects had significantly lower percent body fat than those subjects functioning at the severe and mild levels. These findings indicate a serious need for more investigation of the caloric intake and expenditure of this population in an institutional environment.
Ron E. McBride
Six physical education specialists—two elementary, two junior high, and two high school (three males and three females)—were studied in an attempt to discern possible sex-role stereotyping in their classes. Data were triangulated from teacher observations, a sex-role inventory, and junior and senior high school student perceptions of teacher treatment in physical education classes. Results revealed that the female teachers used more managerial cues in their classes and called boys by name more frequently than did male teachers. Two male teachers were classified as being gender typed, but results from students of both sexes revealed no perceived differential treatment in class. From this teacher sample, the results suggest that perhaps the gymnasium is not quite the bastion of gender typing as is often assumed. Due to the small sample size, results were not generalized to a larger population and thus additional research is recommended.
Leona Holland, Jeff McCubbin, Ewen Nelson and Robert Steadward
The purpose of this study was to determine the reliability of eccentric and concentric strength of adults with cerebral palsy (CP) as measured on the Kin-Corn. Fourteen subjects performed four eccentric and concentric contractions of shoulder adduction and abduction, and knee flexion and extension at a speed of 60°/s during three testing sessions. Peak and average torque were calculated for each type of contraction for each of the four movements. Generalizability coefficients were high for all scores (r = .79 to .96) except average eccentric extension of the knee (r = .26). The variance components revealed that differences between test sessions were large (8.5%–65.8%) compared to the differences between trials (0.0%–5.8%). These data indicate that the Kin-Corn is a reliable mode for testing average and maximal concentric muscular strength, and maximal eccentric contractions on adults with CP, following an initial orientation session.