Hand Preference in India

The degree of asymmetric handedness was measured by a 22-item hand preference questionnaire in a sample of 442 Indian subjects. Factor analysis of the data for right-handers yielded four item-clusters: Gross activities, skilled activities (general), skilled activities (specific), and activities subject to social pressure. Identical analysis for left-handers yielded three item-clusters: Activities that are executed with difficulty, with ease, and with greater frequency. The degree of asymmetric handedness in right-handers was positively (high) correlated with an index of social pressure against left-hand use, especially for the items, writing and eating. The correlation was negative (moderate) in left-handers, however, who had preferred the right hand for eating purposes.     

Skill Level,Vision, and Proprioception in Simple One-Hand Catching

Two experiments examined the interaction of vision and articular proprioception in simple one-hand catching. In Experiment 1 (N = 18) skilled baseball and Softball players used the left and right hands to catch slowly moving tennis balls, while Experiment 2(N = 16) used novice catchers as subjects. In half the trials, sight of the catching hand was prevented by placing a screen alongside the subjects’ face. Results of Experiment 1 revealed that the screen caused minimal disruption of the positioning phase of the catch, with moderate disruption of the grasping phase. However, for the unskilled subjects of Experiment 2, the screen caused considerable disruption of positioning. The data provide only minimal support for Smyth and Marriott’s (1982) contention that limb position is inadequately specified by articular proprioception. It is argued that skill level serves as a mediator in the ability to use proprioception for limb positioning, but vision appears necessary to control the precise temporal organization of the grasp phase of one-hand catching.     

Skill in map reading and memory for maps

Studies of expertise have typically shown that experts have better memory for materials from their fields than do novices. However, previous research on memory for maps has not shown the expected effect of expertise. The present study differed from previous studies by using contour maps as well as planimetric maps. In Experiment 1 the expected superiority in memory performance was found for skilled map readers when contour maps were used, but not when planimetric maps were used.

In Experiment 2, the main results of Experiment 1 were replicated, and, in addition, process tracing data were obtained during both study and test phases of contour map learning. Objective measures of attentional and retrieval focussing revealed almost no differences between the skilled and unskilled subjects. However, analyses of verbal protocols showed that the skilled subjects made more use of specialist schemata, whereas the unskilled subjects spent more time in reading place names. During recall, the skilled subjects made more use of both specialist and “lay” schemata, whereas the unskilled retrieved more place-name information.

The results are interpreted in terms of a schema-based approach to expertise.     

Lateral preference profiles and right shift attempt histories of consistent and inconsistent left-handers

Differences in abilities and preferences exist between left-handers who both write and throw with their left hands (consistent left-handers) and those who write with their left hand but prefer to throw with their right (inconsistent left-handers). It is also known that many left-handers are pressured to switch to right-hand writing, and that these pressures can lead to a right shift attempt. The present study is the first to explore the joint effects of the consistent/inconsistent left-handedness dichotomy, right shift attempt history, and lateral preference profiles. Testing 379 Canadian adults between the ages of 18 and 94 indicated that, while both types of left-handers were equally likely to experience a right shift attempt, the inconsistent left-handers were more likely to successfully switch to right-hand writing. Further analyses revealed that throwing hand was more associated than writing hand with the direction of sidedness for a lateral preference index based upon eye, foot, and ear preferences. More specifically, right-hand throwers were much more likely to have a rightward lateral preference score than were left-hand throwers, regardless of current preferred writing hand. Overall, the results support an hypothesis that the left-handers who are least likely to submit to rightward switch pressures are those with the strongest, most consistent left-sided lateral preference profile.     

Cultural and environmental pressure against left-hand preference in urban and semi-urban Malawi

The study assessed views of teachers, pupils and their guardians on left-hand preference. Seventy-five percent of the responders indicated that the left hand should not be preferred for habitual activities and 87.6% of them indicated that left-handers should be forced to change the hand. Gender had significant effect on the view on left hand preference (df = 1, OR (odds ratio) = 0.465, p = 0.027). Giving a handshake when greeting a person, drawing and writing were the three top target activities against left-hand preference. An assumption that the left hand is less skilled and less powerful than the right one was the most common reason for negative view on left-hand use. Most of volunteers reported that parents and close relatives were the primary group of people who usually discourage left-hand use. Eighty point one percent of the responders indicated that people should stop preferring the left hand as soon as somebody noticed their left-handedness. The results indicated that cultural and environmental pressures might significantly affect visibility of left-handedness in urban Malawian populations.     

A minimal limit-cycle model to profile movement patterns of individuals during agility drill performance: Effects of skill level

Identification of control strategies during agility performance is significant in understanding movement behavior. This study aimed at providing a fundamental mathematical model for describing the motion of participants during an agility drill and to determine whether skill level constrained model components. Motion patterns of two groups of skilled and unskilled participants (n = 8 in each) during performance of a forward/backward agility drill modeled as limit-cycles. Participant movements were recorded by motion capture of a reflective marker attached to the sacrum of each individual. Graphical and regression analyses of movement kinematics in Hooke’s plane, phase plane and velocity profile were performed to determine components of the models. Results showed that the models of both skilled and unskilled groups had terms from Duffing stiffness as well as Van der Pol damping oscillators. Data also indicated that the proposed models captured on average 97% of the variance for both skilled and unskilled groups. Findings from this study revealed the movement patterning associated with skilled and unskilled performance in a typical forward/backward agility drill which might be helpful for trainers and physiotherapists in enhancing agility.     

Stroop范式中不同语言条件下的双语优势效应

目的:采用Stroop范式探讨不同语言条件下的双语优势效应。方法:两个实验均为2(被试类型)x 3(色词一致性)的混合实验设计,被试为熟练双语者和非熟练双语者。结果:(1)L1条件下熟练双语者的Stroop效应量小于非熟练双语者,L2条件下无显著差异。(2)熟练双语者在两个实验条件下的平均反应时均小于非熟练双语者,L2条件下的易化效应量显著大于非熟练双语者。结论:(1)熟练双语者在L1条件下的抑制控制能力好于非熟练双语者,体现了"双语优势效应";(2)熟练双语者在Stroop干扰任务中可能比非熟练双语者具有更好的信息监控能力。     

The influence of perceptual and motor factors on bimanual coordination in a polyrhythmic tapping task

Summary In this study the role of perceptual and motor factors on the motor organization (integrated versus parallel) adopted by musically skilled and unskilled subjects in a polyrhythmic tapping task was investigated. Subjects tapped a 3:2 polyrhythm to match the timing of two isochronous tone trains, one tone train for each hand. Perceptual factors were examined by the manipulation of the frequency difference between the tone trains to produce either an integrated or a streamed percept. Motor factors were examined by comparison of performance on two versions of the 3:2 polyrhythm. In one (simultaneous) version, each cycle of the polyrhythm began with a simultaneous left- and right-hand tap. In the other (shifted) version a 100-ms interval was introduced between the initial left and right taps in each cycle. Examination of the pattern of variances and covariances among intertap intervals suggested that most of the subjects in this study adopted an integrated motor organization that involved interleaving the timing of the two hands. Further analysis revealed that a serial chained model described the pattern of covariances best for the simultaneous pattern, whereas a hierarchical organization described the pattern of covariances for the shifted pattern best. The finding that performance was more accurate with integrated tones than with streamed tones provides some support for a perceptual-motor facilitation hypothesis.     

Memory for meaning in skilled and unskilled readers

Skilled and unskilled readers from grades 3, 5, and 7 (9, 11, and 13 years of age, respectively) performed one of three memory tasks on a randomized list of primary word associates. One group rated each word as “good” or “bad” (incidental semantic task), another group produced a rhyming word for each list word (incidental rhyming task), and a third group attempted to memorize the list (intentional learning task). The recall results indicated equivalent recall for skilled and unskilled readers at all grades on the rhyming and intentional tasks; whereas, skilled readers were superior to unskilled readers on the semantic task. A clustering analysis produced a similar effect as skilled readers, who performed the semantic task, tended to cluster semantically-associated words together during recall more readily than unskilled readers. The results were construed as evidence for reading-skill differences in the semantic encoding of individual words.     

An Empirical Validation of Bipolar Risk Perception Scaling Methods1

Bipolar rating scales (e. g., semantic differentials) are a common tool for gathering perceptions about attributes of persons, events, or activities. Researchers have questioned, however, whether individual responses are methodologically constrained when bipolar scales are used. Comparing both bipolar and unipolar scales, the present study investigates previous research findings on perceptions of risk by Fischhoff, Slovic, Lichtenstein, Read, and Combs (1978). The subjects in the current study (N= 94) rated the same 30 technologies, substances, and activities as in the Fischhoff et al. (1978) study but used unipolar scales. Correlational analysis indicated that some presumed antagonistic adjective pairs were indeed opposites, while others were not. On the other hand, factor analyses indicated that the same factors described by Fischhoff et al. (1978) were uncovered in the present study. However, the use of a unipolar methodology allowed us to refine the interpretations of both factors.     

Performance Accomplishment Information as Predictors of Self-Efficacy as a Function of Skill Level in Amateur Golf

The predictive capabilities of different types of performance accomplishment information (PAI) towards self-efficacy for amateur golfers were compared as a function of skill level. Male golfers (N = 197; skilled n = 84, lesser skilled n = 113) recorded self-efficacy levels before and after competitive golf performance. Multiple regression analyses revealed that handicap was the most significant predictor of PAI towards pre-round self-efficacy for skilled golfers while practice satisfaction was the most significant predictor for lesser skilled. Handicap achievement was a significant predictor of post-round self-efficacy for both skilled and lesser skilled golfers. The findings imply athletes of varying skill level utilize different information when developing efficacy beliefs. Further study of the relationship between PAI and self-efficacy is therefore warranted in the sports domain.     

The distribution of hand preference is discrete: A taxometric examination

The dominant genetic models of human handedness ( Annett, 1985 ; McManus, 1985a ) have contrasting views on its nature. Whereas Annett's model proposes that handedness is distributed continuously (following the distribution of performance asymmetries of the hands), McManus's model proposes that handedness is distributed dichotomously. The aim of this study was to investigate the nature of the underlying distribution. The taxonomy of hand preference was analysed by two independent taxometric procedures, ‘mean‐above–mean‐below‐a‐cut’ and ‘maximum‐eigenvalue’, separately in two geographically, demographically, and culturally distinct samples; one of Australian adults (N=787), and the other of Serbian high school students (N=1,224). The analyses revealed a latent categorical structure in both samples, with estimated mean base‐rates of a right‐handed taxon of 0.80 and 0.94 from the two analyses of the adult sample and of 0.79 and 0.93 from the two analyses of the high school sample. Subsequent analyses showed that the initial right‐handed class could be subdivided into consistent and inconsistent right‐handed subclasses in both samples. A supplementary analysis, including a measure of hand proficiency in a subset of the sample of Australian adults (N=596), also revealed a latent categorical structure, showing evidence for a categorical latent structure from a continuous measure of hand performance. We conclude that the distribution of hand preferences in humans is discrete and not continuous.     

Constraints in the performance of bimanual tasks and their expression in unskilled and skilled subjects

Unskilled and skilled subjects were asked to perform a variety of bimanual tapping tasks. Three major effects were seen. First, right-handers performed dual tasks better when the preferred hand took the “figure” and when the nonpreferred hand took the “ground” of the dual movement. This effect was not seen in left-handers. Second, subjects performed a simple slow/fast dual task better when they commenced the task with the fast rather than with the slow hand. This effect was seen in right- and lefthanders. Third, both unskilled and skilled subjects showed marked interdependence of movements such that performance of one hand was a function of movements in the other hand. The results are in agreement with a model that postulates the presence of a superordinate control mechanism that initiates action in subordinate control mechanisms, which in turn set the movement trajectories in the two hands. The results also show that attention is an important factor in the interaction between these two levels of control.     

Note on hand use in the manipulation of joysticks by rhesus monkeys (Macaca mulatta) and chimpanzees (Pan troglodytes)

In a recent article MacNeilage, Studdert-Kennedy, and Lindblom (1987) proposed that nonhuman primate handedness may be contingent on the specific task requirements with visual-spatial tasks yielding left-hand preferences and fine motor tasks producing right-hand preferences. This study reports hand preferences in the manipulation of joysticks by 2 rhesus monkeys (Macaca mulatta) and 3 chimpanzees (Pan troglodytes). Reach data were also collected on these same subjects and served as a basis for comparison with preference data for manipulation of the joystick. The data indicated that all 5 subjects demonstrated significant right-hand preferences in manipulating the joystick. In contrast, no significant hand preferences were found for the reach data. Reaction time data also indicated that the right hand could perform a perceptual-motor task better than the left hand in all 5 subjects. Overall, the data indicate that reach tasks may not be sensitive enough measures to produce reliable hand preferences, whereas tasks that assess fine motor control produce significant hand preferences.     

Conservation of Weight with the Mentally Retarded

Institutionalized retardates (N = 54), Public School retardates (N = 65), and a group of normal subjects (N = 112) were compared at several mental age levels on three conservation of weight tasks. The functioning of normal subjects was higher at each mental age level. An analysis of covariance was performed on the number of correct responses on the three tasks, covarying mental age, and not including any normal subjects above 13 years 11 months in mental age (N = 82). Normal subjects conserved significantly more often than either retardate group in the covariance analysis also.     

Development of Japanese version of the long‐term mating orientation scale (LTMO‐J)

The purpose of this study was to validate the 7‐item long‐term mating orientation scale (LTMO) as translated into Japanese. Two samples of Japanese adults (N = 2000; 50.0% male; Mage = 40.9 for the first survey; N = 300; 54.7% male; Mage = 42.4 for the second survey) completed a web‐based questionnaire, including the Japanese translation of the LTMO. The results showed that the psychometric properties of the Japanese LTMO scale were comparable to those of the original English version. The scale had adequate reliability based on Cronbach's α and McDonald's ω. Convergent validity was demonstrated by the correlation between the LTMO scores and related variables: human life history strategies, short‐term sociosexual orientation, attitude to infidelity, romantic attachment style, and so on. The translated scale provides a valid and reliable instrument in Japanese that measures human mating strategy.     

A developmental analysis of the relationship between hand preference and performance: I. Preferential reaching into hemispace

The present study describes a developmental performance measure of hand preference that considers task complexity and position in hemispace. Eighty right-handed children and adults (ages 3-4, 6-7, 9-10, 18-24) were observed for hand selection responses to 2 unimanual tasks (simple vs complex) across positions in hemispace. Results revealed an age-related trend in the tendency to use the preferred hand in right and left hemispace. While the adult's and 3- to 4-year-old's preferred hand use decreased as they moved into left hemispace, children between the ages of 6 and 10 years tended to use their preferred hands consistently throughout both regions of hemispace. The relationship between hand preference and skilled, cost-efficient performance throughout development are discussed.     

Interests and Leadership among Adolescents

The purpose of this study was to ascertain whether there is a differential relationship in the socialization of children with respect to gender identification when responses of children were examined with respect to race and sex (N = 596 fifth and sixth grade boys and girls). Strong father preference was found to have no effect on the choice a boy will make when choosing between male and female peers, during preadolescence, while a strong mother preference by a girl is related to the sex of the peers she chooses. Preadolescent girls who identify with their mothers chose girls with whom to interact in a variety of activities more frequently than they chose boys. A greater proportion of girls preferred to engage in activities with their mothers than boys preferred to engage in activities with their fathers. No differences were observed between racial groups in terms of girls' choices involving peers. Black boys, however, preferred to engage in activities with opposite-sex rather than same-sex peers to a greater extent than white boys.     

Sex differences and bilateral electrodermal activity

The present study was aimed at replicating the results of a previous work on sex differences and electrodermal asymmetry from our laboratory (Román,et al. 1987). Skin conductance was bilaterally recorded in a sample of 44 dextral volunteers (22 males and 22 females) during a stimulus-free period, and the performance of two tasks (verbal and spatial). Subjects were grouped into two groups of right-hand and left-hand dominance in their electrodermal responses (EDRs) in accordance with their laterality coefficient scores at rest. During the tasks subjects appeareed clearly differentiated by their lateralization in the magnitude and frequency of EDRs independently of gender: right-hand responders showed higher electrodermal activity on their right hand, while left-hand responders showed higher electrodermal activity on their left hand. Sex differences were not observed within each responsiveness pattern. The orientation of phasic electrodermal changes remained constant throughout the different conditions.     

Reliability and Validity of a Paper-and-Pencil Test Measuring Hemisphere Preference

The present studies examined the reliability and validity of the Preference Test (PT), a widely used self-report index of preferred hemisphere thinking styles. The PT consists of items that intend to tap left-hemisphere and right-hemisphere cognitions. In the first study (N=47), PT scores were found to have reasonable test–retest stability. In the second study (N=334), a factor analysis of PT scores showed that the PT has a two-factor solution that can best be interpreted in terms of putative left- and right-hemisphere items. In the third study (N=29), background EEG activity (F3, F4, P3 and P4) of subjects was recorded. PT scores were found to be related to EEG asymmetry patterns for frontal, but not for parietal, recording sites. More specifically, subjects with a left-hemisphere preference displayed relatively stronger left frontal activity than subjects with a right-hemisphere preference. By and large, the present findings provide strong support for the reliability and some suggestive evidence for the validity of the PT.