Perceptual and Motor Skills

To determine stereopsis, a mathematical model and computer simulation specify that square wavelet coefficients be independently estimated for the images in each eye. Then, by comparing these independently determined coefficients, the model theorizes that the visual system both identifies those parts of the two images which lie across corresponding points and identifies those parts of the two images which lie across noncorresponding or disparate points. Given the latter occurrence, the retinal disparity is evaluated as being either stereopsis or binocular rivalry. If stereopsis is indicated, the wavelet coefficients provide a reference plane by which the depth of a disparate area is located either nearer than or more distant than the reference plane. In the model also it is proposed that the determination of depth with respect to the reference plane provides a signal for vergence of the eyes. If binocular rivalry is indicated, the model's computer simulation identifies the locus of the background fringes associated with binocular rivalry. In sum, it seems theoretically tenable that stereopsis or binocular rivalry occurs as a consequence of the comparison of one eye's wavelet coefficients with those of the other eye.

Incidence of right-hand preference in a sample of eating disordered patients, 18 probands and 18 controls, was investigated. They completed questions regarding eight functional hand tasks. Preferred right-hand use, mainly externally directed and complex, was less represented among these eating disordered patients (14%) than in the 18 controls (58%).

This study examined the predictive utility of self-efficacy and three types of outcome expectations (physical outcomes, social outcomes, and self-evaluative outcomes) on students' behavioral intentions and actual behaviors in a beginning weight training class. A total of 137 participants (62 men, 75 women; M_age = 21.4 yr., SD = 2.0) completed questionnaires assessing beliefs and intentions toward weight training. Attendance and workout log entries were used as a measure of actual behaviors. Regression analyses indicated that physical outcome expectations and self-efficacy emerged as significant predictors of students' behavioral intentions and actual behaviors. Findings of this study were interpreted from self-efficacy theory.

A Spring peak for 52,533 completed suicides in 1930–1938 was found in Hungary, stronger in rural regions than in urban regions.

Strategies for recovery of posture were studied after lateral mechanical perturbations. 11 participants standing in tandem stance were unexpectedly submitted to lateral support translations with the eyes open or closed at two translation amplitudes. The trajectories of the center of mass of the upper and lower body and muscle activities allowed identification of three strategies, involving either the ankle or the hip only, or both. Hip use increased with vision and with amplitude of perturbation. Short-to-medium latency electromyographic activities were observed in leg and trunk muscles, and long-latency responses in the back leg muscles. Vision increased the activity of both leg and trunk muscles but did not influence the onset of the muscular responses. These data suggest a hierarchy in the selection of these different strategies: the hip is mobilized when the perturbation is more destabilizing but this strategy has a cost and needs specific sensory information supplied by vision.

This study focused on statistical properties and interrelationships of graphometric variables of the signatures of outpatients, 100 men and 119 women, remitted from somatic and psychiatric clinics for possible psychotherapy or for tests of IQ, personality, or brain lesions. The patients' signature on test forms were used. The type of handwriting was classified into Common, Print and Block letters, quantified in breadth, length, and area and grades of slant of minuscules (“lower-case letters”) and majuscules (“upper-case”). Analysis indicated sex and age played roles in style of handwriting and size of letters; writing styles differed on most graphometric variables; and meaningful patterns of interrelationships among graphometric variables were specified by factor analysis.

The purpose of the study was to examine the influence of critical cues and task constraints on body-component levels and maximum ball velocity. 81 children (M age = 97.8 mo.) were systematically assigned to one of four strategies. Participants completed 15 throws during each of 4 practice sessions. Differences between groups were found for body-component developmental levels and ball velocity. The differences indicate prompts to throw the ball hard and fast impact ball velocity and body-components by developmental levels. Critical cues also appear to be a useful tool to improve the step component. Results suggest the use of forceful throwing tasks, cues, and velocity feedback can be useful tools to influence throwing performance.

This study examined the effect of peer teaching at recess on improving disc-throwing skills for kindergartners to children in Grade 3. 167 boys and girls were instructed in basic disc-throwing skills, backhand and forehand throwing techniques, and peer teaching. The practice group (n = 73) was encouraged to practice with a disc using peer teaching for at least 10 min. during recess for 10 days. The control group (n = 94) took part in other activities without a disc. Two-way analysis of variance with repeated measures gave significant interaction of groups and tests for girls in Grade 3 as well as significant main effects between tests in kindergarten boys and Grade 2 boys and girls. This study suggests that peer teaching for disc-throwing skills is useful for girls in Grade 3 and may be more effective for girls than boys.

The aim of this study was to assess the effects of a 14-week swimming training program on the competence, problem behaviour, and body awareness in 13 children with cerebral palsy aged 5 to 10 years, compared with 10 subjects in a comparison group. Both of the groups continued a traditional rehabilitation program. The outcome measures were Child Behaviour Check List (CBCL) and Body Awareness. The parent forms were evaluated before and after training and also at 6 months followup. Teacher forms and body awareness were evaluated before and after training. The results showed that swimming training produced significant gain on body awareness in the Swimming Group, whereas no significant group differences were evident in competence and problem behaviours on parent or teacher forms of the CBCL.

The development of the perception of size is currently interpreted as the development of size constancy. Using data from prior studies, this paper reports a functional measurement analysis of the perceived size of rectangles located on a frontal plane. Analysis shows the development of the perception of size may depend on what can be called the development of size isomorphism. While size constancy may change during childhood with the ability to use cues of size and distance, it is proposed that the extent of size isomorphism may change with age given change with age in the neural representation of perceived length and in the working parameters of the neural mechanism which generates perceived length. Current interpretations of changes with age in the perception of size may confuse changes in perceived size given development of size constancy with changes in perceived size based on development of size isomorphism.

Landing errors account for most of the skydiving fatalities today in more experienced skydivers. The United States Parachute Association (USPA) states that this is due to a new generation of parachutes with higher wing loading. Using data on fatalities from 1992 to 2005 as reported by the USPA, hook turns were found to be a major cause of death but not significantly associated with higher wing loading. Fatalities caused by not having a functional parachute have decreased over the years, possibly due to introduction and widespread use of safety devices.

To test the effect of imagery in the training of skilled movements, an experiment was designed in which athletes learned a new motor action and trained themselves for a month either by overt action or by mental imagery of the action. The experiment was carried out with 30 male karateka (M age = 35 yr., SD = 8.7; M years of practice = 6, SD = 3) instructed to perform an action (Ura-Shuto-Uchi) that they had not previously learned. The athletes were divided into three groups: Untrained (10 subjects who did not perform any training), Action Trained (10 subjects who performed Ura-Shuto-Uchi training daily for 16 minutes), and Mental Imagery (10 subjects who performed mental imagery training of Ura-Shuto-Uchi daily for 16 minutes). The subjects were tested five times, once every 7 days. During each test, they performed a series of 60 motor action trials. In Tests 1, 3, and 5, they also performed a series of 60 mental imagery trials. During the trials, an electroencephalogram (EEG), electromyography (EMG), muscle strength and power, and other physiological parameters were recorded. The results differed by group. Untrained subjects did not show significant effects. In the Action Trained group, training had an effect on reactivity and movement speed, with a reduction of EMG activation and reaction times. Moreover, muscle strength, power, and work increased significantly. The Mental Imagery group showed the same effects on muscle strength, power, and work, but changes in reactivity were not observed. In the Mental Imagery group, the study of Movement Related Brain Macropotentials indicated a progressive modification of the profile of the waves from Test 1 to Test 5 during imagery, showing significant variations of the amplitude of the waves related to the premotor and motor execution periods. Results show that motor imagery can influence muscular abilities such as strength and power and can modify Movement Related Brain Macropotentials, the profile of which potentially could be used to verify the effectiveness of motor imagery training.

This study followed the performance of 35 professional golfers who played from 1997 to 2004 on the Professional Golfers Association Tour (PGA Tour) and investigated whether any players were prone to “choke” when placed in high-pressure situations. Choking was defined as a player having significantly higher than expected final round scores and being less likely than other professional golfers to win when in contention to win tournaments. Analysis yielded no support for a choking under pressure hypothesis. None of the players when in contention to win were both more likely to have higher than expected scores in the final round and less likely to win than other professional golfers in the sample. Limitations of the study were mentioned.

The congruent facial response of a receiver may change a sender's facial display in subsequent facial communication. Senders were requested to smile and frown at a receiver of computer-synthesized animation and to rate how likeable the receiver was after the “interaction.” It was observed that a congruent facial response maintained the sender's facial expression longer than an incongruent response did. The results of the questionnaire revealed that senders reported a greater likeability for smiling receivers than for those who frowned. Likeability ratings did not depend on the congruency of the receiver's response but simply on whether the receiver was smiling or frowning.

The importance of accurate performance appraisals is central to many aspects of personnel activities in organizations. This study examined threats due to past performance to accuracy of evaluation of subsequent performance by raters differing in scores on field dependence. 162 college students were classified as Field-dependent (n = 81) or Field-independent (n = 81), using a median split on the Group Embedded Figures Test. Past performance (a lecture) was good or poor, presented directly via a videotape or indirectly via a written evaluation to the Field-independent or Field-dependent groups. Analysis indicated the hypothesized contrast effect (ratings in the opposite direction from that of prior ratings) in the Direct condition and an unexpected, albeit smaller, contrast effect in the Indirect condition. There were also differential effects of performance, presentation, and field dependency on rating of lecturer's style and ability.

It is well known that an auditory startle response can be modulated by several processes. In the present study shock sensitization and fear potentiation were examined in 17 hamsters to assess whether response enhancement is similar for another rodent. Immediately after presentation of electrical foot shocks, the auditory startle response increased significantly. This response was also enhanced after fear conditioning in the Experimental group using a light as a conditioned stimulus (CS) and the foot shock as the unconditioned stimulus (US). The auditory startle response remained unchanged in the Control group after nonpaired presentation of CS and US. Significant correlation between enhancement of the auditory startle response in sensitization and fear conditioning was found for the Experimental group. Shock sensitivity and effect of fear on modulation of the auditory startle response in hamsters are similar to those of other rodents. Further, neural mechanisms underlying enhancement of the auditory startle response seem not to be responsible for the deficit of prepulse inhibition in hamsters.

The present study was undertaken to provide preliminary data for norms on the Bender-Gestalt Test for 253 children ages 5 yr., 5 mo. to 11 yr., 10 mo. in Turkey. The Koppitz Developmental Scoring System gave mean error scores of 4.2 (SD = 3.3) for girls and 3.6 (SD = 3.0) for boys. The mean error scores obtained by all age groups are presented and compared with other cross-cultural data. These scores decreased across age groups, supporting Bender's maturational hypothesis of the test. The present sample performed at a higher developmental level than the Koppitz normative sample for the 5- and 6-year age groups, while means for other age groups were similar to the original U.S. norms. That this pattern is supported in other cross-cultural studies is discussed as well as the importance of developing local norms for visual spatial tests.

Manipulating the organization of practice conditions, through contextual interference, was identified as a method to promote motor skill acquisition by Brady in 1998. The generalizability of this learning effect is questionable and the amount of repetition versus the amount of change in task presentation requires investigation. The purpose of this study was to explore explanations for the performance of learners practicing the AAHPERD volleyball skills test when the change in task presentation varied. High school students were randomly assigned to blocked, random, and random-blocked practice groups. While all groups significantly improved all skills during acquisition, there was no support for the contextual interference effect. Potential explanations might be dependent upon the learners' skill and the complexity of the task to be learned. Further research is warranted examining contextual interference effect on practice organization at levels of difficulty appropriate to facilitate cognitive processing of task-related information.

This study was conducted to test the effect of task level and item consistency when two conditions, with and without the assistance of a scoring guide, were used to score essays. The use of generalization theory was proposed as a framework for examining the effect of task variability and use of the scoring guide on achievement measures. Participants were 21 students in Grade 9 enrolled in regular Turkish language and literature classes. Of these students 11 were men and 10 were women. Ten teachers from the city were raters. In the past, raters of essays have given varied judgements of writing quality. Utilizing decision and generalizability theories, variation in scores was evaluated using a three-way (person × rater × task) analysis of variance design. The scoring guide was beneficial in reducing variability of evaluating grammar and reading comprehension but not as helpful when assessing knowledge of concepts.

Normative data are presented for Bender test performance, following the system of Koppitz, of 695 Mexican students between 5.0 and 12.1 yr. old (M = 8.7, SD = 2.01) and belonging to different socioeconomic status. The data are compared with the normative group of U.S. students used by Koppitz and with a representative sample of children from Barcelona, Spain. The results indicate that the total number of Bender errors decreased with increasing age of the children and that significant differences existed with respect to socioeconomic status. The comparison of these data with U.S. and Spanish children shows significant differences in all age groups, with the Mexican children scoring lowest. Differences in quality of schooling and in other aspects of education could explain the variability in Bender test performance.

The number of resamplings necessary to accurately estimate a probability value is an open question. One million resamplings is shown to be sufficient to ensure precision to three places under most conditions.

In two studies of American and Kuwait students, scores on a measure of having a Taoist orientation were associated with less psychopathology on measures of anxiety, death anxiety, existential anxiety, optimism-pessimism, suicidality, and obsessive-compulsiveness.

This study examined the relationship between inhibition of older adults and difficulties using automatic teller machines. 22 older adults performed three transactions on an ATM simulator, and errors were recorded. Participants also performed the Stroop interference task to assess inhibition. Both interference effect in response latencies and rate of intrusion errors in the Stroop task were moderately correlated with number of errors on the task. Older adults with low Stroop performance made more errors in the categories of Forgetting an operation, Screen mix-up, and Overlooking an input error than those with high performance. These results suggest that low inhibition may be associated with difficulties in automatic teller machine use, and the importance of designing a user interface which lessens the likelihood of errors for older adults or others.

This study employed Nicholls' social-cognitive approach to achievement motivation along with beliefs about the causes of success. The aims of the study were (a) to test the factor structure of the Greek adaptation of the Perception of Success Questionnaire and the Beliefs about the Causes of Sport Success Questionnaire in a sample of Greek track and field athletes, (b) to explore goal orientation and beliefs about the causes of success in the same sample of track and field athletes, and (c) to interpret both factor structures together, according to the respective theoretical frameworks of achievement motivation. The results verified the task and ego goal orientation dimensions for the Perception of Success Questionnaire. The proposed dimensions for the Beliefs about the Causes of Sport Success Questionnaire were also supported. Two dimensions were found when the two sets of factors were conjointly described, named “winning by all means” and “working hard,” which might act as an alternative framework when dealing with achievement issues in sports.

Observers (N = 3, all males, M age = 30.7 yr.) were presented pairs of visual targets and instructed to fixate one as quickly as possible. The resulting saccades were of two types; bistable saccades accurately acquired one of the targets whereas averaging saccades landed at intermediate locations. The hypothesis was that averaging saccades result from a pooling of afferent activity prior to selection of saccadic direction and amplitude (i.e., coactive parallel processing) and that bistable saccades would show evidence of response competition between incompatible motor programs within a parallel architecture. Analysis of the distributions of saccadic reaction times showed that in all cases saccadic responses to double targets were too slow to be consistent with either the channel summation or any form of race model. Results indicate that inhibitory interactions operate during the selection of a target for a saccadic eye movement.

This study examined models of Fitts' law and effective target widths of three pointing devices in vibration environments. From a research institute 10 employees, ages 26 to 31 years were recruited as paid subjects. Pointing tasks consisted of four square target sizes, four movement distances, and four target angles and were performed on a motion platform using a touch screen, a mouse, and a track ball. The platform simulated two levels of sea wave vibration environments besides a static one. Analysis showed effective target widths increased with vibration, indicating increased variability of the pointing task under vibration. The increase in the track ball was smaller, indicating resistance to motion disturbance. The study also suggests an enlarged target (button) size for the touch screen under the vibration environment. The findings have implications in motor control and human-computer interfacing.

This study evaluated a competition-based employer-sponsored physical activity program using pedometers. City employees (N∼2,600) formed teams in groups of 10 persons (N = 640). The groups competed against each other over a 12-wk. period with the goal of attaining 10,000 steps per day, per person. Only teams with complete data were included in the formal evaluation. A repeated-measures analysis of variance indicated significant differences in team steps by week of the program, with post hoc comparisons indicating significant differences from baseline step counts evident during Weeks 6–8 but not at the end of the program. These data confirm that competition-based physical activity programs using pedometers may not be an effective means of increasing the long-term physical activity of employees.

One of the classic research topics in adaptive behavior is the collective displacement of groups of organisms such as flocks of birds, schools of fish, herds of mammals, and crowds of people. However, most agent-based simulations of group behavior do not provide a quantitative index for determining the point at which the flock emerges. An index was developed of the aggregation of moving individuals in a flock and an example was provided of how it can be used to quantify the degree to which a group of moving individuals actually forms a flock.

The regimen selected for use in speechreading training is an important consideration for audiological rehabilitation purposes and may play a role in its success. Short-term improvement on a commercially available speechreading training program was compared for two training regimens (daily and weekly). Two groups of university student volunteers (ages 20 to 31 years) (12 students per group) were trained daily or weekly on a vowel speechreading task. Percent correct was recorded for each training session. Both groups showed improved performance across training sessions, but there was no significant difference in improvement by type of training regimen.

The present article addresses issues in reliability assessment that are often neglected in psychological research such as acceptable levels of internal consistency for research purposes, factors affecting the magnitude of coefficient alpha (α), and considerations for interpreting α within the research context. A new reliability matrix anchored in classical test theory is introduced to help researchers judge adequacy of internal consistency coefficients with research measures. Guidelines and cautions in applying the matrix are provided.

Part-set cuing has frequently been found to inhibit the recall of previously learned information; see Nickerson's 1984 work. This study investigated whether negative part-set cuing effects extend to the disruption of reminiscence, the production of new items, on a delayed second recall trial. 64 psychology students from local Further Education colleges volunteered to participate. Following random assignment to conditions participants were presented 20 unrelated words at 2-sec. intervals. After a 30-sec. interference task participants free recalled. After a delay of 5 or 30 min., part icipants recalled a second time either with or without cues. Part-set cuing inhibited the production of new words (reminiscences). Time delay, however, had no effect on reminiscence.

In 1944, Levinson and Sanford created a scale to measure anti-Semitism. Their data showed that the scale had sound psychometric qualities, with a reliability of .96 to .98. Shaw and Wright later stated that the scale was too long for use in some research studies. In the current study, a shorter version (32 items; 38.5% reduction) was created and examined. A high level of internal consistency reliability (r_u = .98) was maintained. A test-retest reliability coefficient of .91 was obtained over four weeks. A minimum residual factor analysis with Tandem Criteria rotation found two factors. This shortened Levinson and Sanford Anti-Semitism Scale could be used in research situations with less administration and scoring time. The shorter version still requires further research in terms of validity and social desirability.