Practice and Assimilation Effects in a Multilimb Aiming Task

When two limbs are required to move different distances simultaneously, assimilation effects are shown: The shorter distance limb tends to overshoot the target, whereas the longer distance limb undershoots. The effect of practice on assimilation effects was studied in two experiments, using a simultaneous four-limb aiming task. When subjects were required to move their left limbs a shorter distance than the right (5 cm vs. 9 cm), the right limbs moved a lesser distance and had greater variable and overall errors relative to a group required to move all limbs the same distance (9 cm). Practice reduced assimilation effects in the lower limbs, but spatial assimilations were present throughout 125 acquisition trials with KR and 50 no-KR transfer trials, spanning 24 hours. When the upper limbs were required to move a greater distance than the lower limbs (15 cm vs. 9 cm), the lower limbs showed longer distances and increased overall errors early in practice compared to the lower limbs of a group required to move all limbs 9 cm. With practice, the between-group differences decreased, with no assimilation effects shown on the transfer trials. The results suggest that neural crosstalk is greater between left and right sides than between upper and lower limbs. Results are discussed in light of the functional cerebral space model of simultaneous actions.     

Family Interaction as a Function of Experimental Task

To assess consistency family interaction across different experimental tasks, the present study evaluated family patterns of talking and interrupting, as elicited from discussions of a Plan Something Together Task, a set of TAT cards, and an Unrevealed Difference Questionnaire. With few exceptions, data analyses indicated that such family patterns are not altered significantly as a function of experimental tasks and, therefore, suggest considerable interactional stability across differing contexts. Characteristics of the present study (as well as related investigations of task effects) are discussed in terms of implications for future research efforts.     

Family interaction Patterns as a Function of Task Characteristics1

Data from two experiments were evaluated to test the widely held assumption that family process remains essentially constant regardless of the conditions under which it occurs. Significant differences and reversals in patterns of dominance between interacting husbands and wives were obtained under different task conditions. In general, stressful tasks and tasks with structured goals elicited paternal dominance, while maternal dominance of more equalitarian patterns resulted from tasks which involved discussion of feelings and opinions. These and other task dimensions were discussed. The findings of this study generate four conclusions: prior studies must be reviewed to evaluate task effects; future researchers must systematically investigate task characteristics; researchers must exercise care in the selection of tasks in future studies; and the relationship between role behaviors and task demands must be understood in order to help meet the increasing stress impinging upon the modern family system.     

Postural Precursors of Postboxing Motion Sickness in a Manual Aiming Task

We asked whether body sway during performance of a visual-manual task would differ between boxers who experienced post-match motion sickness and those who did not. Before and after boxing we measured standing body sway while participants performed a manual precision aiming task. After boxing, participants stated, yes/no, whether they were motion sick; they also reported motion sickness symptoms, and concussion-related symptoms. Seven of thirteen boxers reported motion sickness after boxing. We compared boxers who reported post-boxing motion sickness versus those who did not. Body sway before boxing differed between boxers who reported post-bout motion sickness and those who did not. Immediately after boxing, motion sickness symptoms and concussion-related symptoms were elevated among boxers who stated that they were motion sick. The results suggest that patterns of body sway may be related to individual differences in susceptibility to motion sickness and concussion-like symptoms in adult male boxers, such that objective measurements of body sway might be used to predict susceptibility in individuals.     

Limb Dominance and Its Effects on the Benefits of Intralimb Transfer of Learning: A Visuomotor Aiming Task

Research has attempted to address what characteristics benefit from transfer of learning; however, it is still unclear which characteristics are effector dependent or independent. Furthermore, it is not clear if intralimb transfer shows, similarly to interlimb transfer, an asymmetry of benefits between the upper limbs. The purpose of the current study is to examine if effector independence effects emerge, as observed in interlimb transfer studies, when transfer to new effector group within the same limb occurs, and whether the pattern of intralimb transfer benefits differ between the limbs. Our results suggest that a visuomotor task transfers within both limbs, even though the transfer benefits within the limbs seem to differ. This was supported by more transfer occurring in the dominant limb than the nondominant limb. Potential control mechanisms used for intralimb transfer are discussed.     

Flight Feedback and Learning a Projectile Task

Over KR acquisition trials of projecting an object a criterion distance, the hypotheses were tested that feedback from the flight of a projected object (flight feedback) would facilitate response recognition but not recall. Visual and auditory flight feedback variables each had two levels, flight feedback present or absent, forming a 2 × 2 × 61 trials design with 14 Ss per cell. Results supported the hypotheses, with flight flight feedback not facilitating response recall, though both flight feedback variables were strong determinants of response recognition. This latter finding was qualified by a discussion of the distinction between response recognition and recognition of response outcome.     

Affect and Performance on Cognitive Task as a Function of Crowding and Noise1

Sixty undergraduate males participated in an experiment with a 2 × 3 factorial design involving two levels of density and three levels of noise to demonstrate effects of the independent variables (density, noise) on cognitive task performance and affect. As predicted, it was found that crowding and noise lead to deterioration of subject's performance on cognitively complex tasks but not on simple (cognitive) task. Also, density and noise generated a negative feeling in the subjects. Significant two-way interaction for complex task, showed variation in performance of Ss of high and low density under low and high noise conditions. In addition, crowded-condition subjects reported more dissatisfaction about their performance and evaluated the presence of the experimenter as significantly less pleasant than their noncrowded-condition counterparts.     

Mechanical Efficiency and Metabolic Cost as Measures of Learning a Novel Gross Motor Task

“Efficiency,” or economy of movement with respect to energy expended in achieving the goal of the task, is implicit in many definitions of skilled performance. This study examined changes in mechanical efficiency and transport efficiency on a novel gross motor skill. The subjects were 5 physically fit adult males who were asked to perform 20 3-min trials walking on hands and feet (crawling) on a motor-driven treadmill at constant speed (0.76 mis). Transport efficiency, the metabolic cost of transporting the body mass a given distance at constant speed, improved significantly over practice trials. Mechanical efficiency, derived from the mechanical power output of individual body segments, showed an overall improvement of 13.7% by the last day of practice. Even though this improvement was not statistically significant it appears to be greater than that expected due to physiological training effects. The efficiency measures correlated significantly with changes in limb kinematics. It was concluded that with practice subjects tailored their movement pattern to produce energy efficient adaptations to task constraints. These findings provide empirical support for theoretical perspectives that have emphasized biological principles in the organization of motor coordination and control.     

Responding to a Challenging Perceptual-Motor Task as a Function of Level of Experiential Avoidance

The Psychological Record - Participants displaying high versus low levels of experiential avoidance as assessed by the Acceptance and Action Questionnaire (Hayes, Strosahl, et al., 2004) were...     

Changes in Sleep as a Function of Adolescent Development

Adolescence is marked by dramatic changes in sleep. Older adolescents go to bed later, have an increased preference for evening activities, and sleep less than younger adolescents. This behavior change is driven by external factors, notably increased pressures from academic, social, and extracurricular activities and by biological circadian factors. There are also substantial changes in sleep architecture across adolescence, with dramatic declines in slow wave sleep, and slow wave activity (delta, ~ 0.5–4.5 Hz). These changes are associated with underlying changes in brain structure and organization, with a decrease in synaptic density likely underlying the reduction in high amplitude slow waveforms. While changes in sleep across adolescence are a normal part of development, many adolescents are getting insufficient sleep and are consequently, less likely to perform well at school, more likely to develop mood-related disturbances, be obese, and are at greater risk for traffic accidents, alcohol and drug abuse.     

Changes in Negative Reciprocity as a Function of Age

Standard economic models assume people exclusively pursue material self‐interests in social interactions. However, people exhibit social preferences; that is, they base their choices partly on the outcomes others obtained in a social interaction. People care about fairness, and reciprocity affects behavior. This study examines the differences in negative reciprocity (costly punishment for unfair divisions) as a function of age. Sixty‐one kindergarteners (5‐year‐olds), 53 second graders (8‐year‐olds), and 57 sixth graders (12‐year‐olds) played a dictator game or a mini–ultimatum game either with a human proposer or with a random machine that determined the division between the two players. By keeping the divisions between the players constant and varying the source of the unfair proposal, we were able to differentiate between reciprocity‐based and inequality‐aversion preferences. We found that kindergarteners proposed and accepted unfair divisions regardless of the source of the offer, behaving according to the standard economic model. Children in the sixth grade tended to reject unfair offers from a human proposer but accept unfair divisions from a random device, indicating the emergence of negative reciprocity preferences by age eight (and contrary to inequality aversion). Children at this age also tended to give more fair offers in the ultimatum game than in the dictator game, indicating the emergence of strategic thinking. Copyright © 2012 John Wiley & Sons, Ltd.     

Efficiency of Learning as a Function of Practice Schedule and Initial Ability

2 groups of 50 Ss practiced a pursuit rotor skill under different schedules of practice. A massed practice (MP) group (40 sec. work, 20 sec. rest) performed just as well as a distributed practice (DP) group (20 sec. work, 20 sec. rest) on the first day of practice. However, after 24 hr. of interpolated rest MP Ss demonstrated significantly greater amounts of learning. A further analysis of the 15 high initial ability and 15 low initial ability Ss from each of the two main groups resulted in no statistical differences among these subgroups in Day 1 performance that could be attributed to the practice schedules; however, a significant Ability Level × Practice Schedule interaction was obtained for Day 2 performance. It was caused by the low ability Ss under MP learning relatively more than the high ability Ss under MP when compared to the two DP groups. Thus learning was seen as being a function not only of schedule of practice but also of initial ability level.     

Developmental Changes in Pointing as a Function of Attentional Focus

Three experiments investigate the effect of a parent's attentional focus on the pointing of children from 1 to 2 years of age. Children were presented with an interesting sight on one or the other side of a laboratory room while the parent was either looking toward that side or not. The results show that 1-year-olds are more likely to point when the parent is looking at them, whether or not the parent has already seen the interesting sight. In contrast, 2-year-olds tend to point more both when the partner has not seen and when she is no longer looking at the sight than when she is looking at it. These findings are consistent with the idea that when they first start to point, infants use the gesture to enhance the interaction rather than to redirect the attention of the partner. By 2 years of age, children point to redirect attention to an interesting sight and to share attention with a communicative partner.     

Peer Nominations for Leadership and Likability in Problem-Solving Groups as a Function of Gender and Task

Abstract

The relation of situational variables and gender to leadership selection and likability ratings was examined. Six mixed-gender groups of American students were given either an impersonal or personal task. There were measurements of frequency of speaking, leadership nominations, and likability ratings by group members. No significant differences in task performance associated with gender were found, but, consistent with traditional sex roles, in impersonal groups male students spoke more and were selected as leaders and most important contributors more frequently than were female students. The reverse was found for personal groups, in which women spoke more, were chosen as leaders more often, and received higher contribution rankings. Likability ratings were not as strongly determined by context: Female students were selected more frequently as most likable in both groups.     

Gender Differences in Spatial Task Performance as a Function of Speed or Accuracy Orientation

Performance differences in spatial abilities as a function of gender may be modified by practice and relevant background experiences, as well as by directions given in laboratory situations. We examined whether a focus on speed or accuracy influenced performance in various spatial domains, using several different scoring techniques. Men and women from a small, predominantly White private college completed tasks of spatial perception, spatial visualization, and mental rotation under one of three conditions: speed-emphasis, accuracy-emphasis, or control. Participants also provided information concerning experiences pertinent to spatial ability. Results revealed relative parity between men and women on tasks of spatial visualization and spatial perception; speed/accuracy orientation did not alter these findings. Men outperformed women on mental rotation, but only when scored in a strict manner and when explicitly told to focus on accuracy, but not when directional emphasis was absent or geared toward speed. Self-reported background in math, sports, and the arts was unrelated to performance. The results are discussed in terms of women's efficacy beliefs about performing tasks explicitly designated as spatial in nature.     

Effect of Learning Goal Orientation on Performance: Role of Task Variety as a Moderator

Journal of Business and Psychology - Building on trait activation and attention capacity theories, we hypothesized and tested the moderating effect of task variety on the relationship between...     

Motor Learning as a Function of KR Schedule and Characteristics of Task-Intrinsic Feedback

Forty participants (age range = 18–35 years) practiced 1 of 2 versions of an aiming task (with or without spring resistance). Knowledge of results (KR) was provided to them either immediately or after a delay of 2 trials. Immediate KR led to significantly more accurate performance during the 80 trials in acquisition but significantly less accurate performance on a 40-trial retention test given 24 hr after practice. In addition, the spring version of the task was performed significantly less accurately than the no-spring version on the 24-hr retention test. Most important, a significant interaction on the 24-hr retention test revealed that performance of the no-spring version of the task, when KR had been given after a 2-trial delay, was significantly more accurate than performance of the other 3 combinations of task version and KR schedule. The results suggest that KR dependency in motor skill learning is related to familiarity with task-intrinsic feedback in addition to the schedule on which KR is presented.     

Age-Related Changes in Auditory Abilities and in a Competing Task

This study explores the relationship between age and performance on auditory tasks. The primary auditory factors which define broad auditory functions (Ga) show a clear decline with age. This finding supports a claim that Ga is an independent function, separate from crystallized intelligence (Gc). This study also explores the assumption, derived from several theories about the causes of intellectual decline, that competing (dual) tasks would show greater decline in performance than single tests. Present data do not provide evidence to support this assumption.     

Muscular Fatigue and the Learning and Performance of a Motor Control Task

Four groups of 12 female college students performed a pursuit-rotor task during learning under one of four conditions of exercising the muscles of the limb used in the task: (a) no muscular exercise, (b) low-fatiguing, (c) medium-fatiguing, and (d) high-fatiguing muscular exercise. All four groups were tested 48 hr later on the same pursuit-rotor task with no exercise interpolated between the ten 20-sec trials. Differences in the performances among the four groups were not statistically significant on either the first or the second day alone or when the data of the two days were combined. The data appear to support the hypothesis of an inverted-U or inverted-J model relating performance (and learning) to muscular fatigue in motor-control tasks.