Real-life spatial skills, handedness, and family history of handedness

According to , pronounced left hemisphere lateralization for language abilities in women, as in female absolute right-handers, limits their right hemisphere capacity and spatial abilities. This study examines the degree of handedness and the family history of non-right-handedness with respect to real-life spatial abilities in women. Twenty-four women had, first, to learn a new route and, second, to orient themselves within a labyrinth. In the former task, the number of errors and completion time were evaluated; in the latter task, degree of error for orienting was recorded. The results show that, contrary to Annett's prediction, right-handers with and without a family history of non-right-handedness did not differ on these measures. In addition, and unexpectedly, absolute right-handers were found to surpass non-absolute ones in the spatial orientation task. These findings do not support Annett's hypothesis and are discussed in relation to functional cerebral organization.     

Coding left and right

The present study compared the processing of direction for up and down arrows and for left and right arrows in visual displays. Experiment 1 demonstrated that it is more difficult to deal with left and right than with up and down when the two directions must be discriminated but not when they must simply be oriented to. Experiments 2 and 3 showed that telling left from right is harder regardless of whether the responses are manual or verbal. Experiment 4 showed that left-right discriminations take longer than up-down discriminations for judgments of position as well as direction. In Experiment 5 it was found that position information can intrude on direction judgments both within a dimension (e.g., a left arrow to the left of fixation is judged faster than a left arrow to the right of fixation) and across dimensions (e.g., judging vertically positioned left and right arrows is more difficult than judging horizontally positioned left and right arrows). There was indirect evidence in these experiments that although the spatial codes for up and down are symmetrical, the codes for left and right may be less so; this in turn could account for the greater difficulty of discriminating left from right.     

Accountability and ideology: When left looks right and right looks left

Managers face hard choices between process and outcome systems of accountability in evaluating employees, but little is known about how managers resolve them. Building on the premise that political ideologies serve as uncertainty-reducing heuristics, two studies of working managers show that: (1) conservatives prefer outcome accountability and liberals prefer process accountability in an unspecified policy domain; (2) this split becomes more pronounced in a controversial domain (public schools) in which the foreground value is educational efficiency but reverses direction in a controversial domain (affirmative action) in which the foreground value is demographic equality; (3) managers who discover employees have subverted their preferred system favor tinkering over switching to an alternative system; (4) but bipartisan consensus arises when managers have clear evidence about employee trustworthiness and the tightness of the causal links between employee effort and success. These findings shed light on ideological and contextual factors that shape preferences for accountability systems.     

The effects of right and left hemiparkinsonism on prosody

Recent studies show right hemisphere dominance in the mediation of emotional prosody and left hemisphere contribution to linguistic prosody in patients with cortical injury. The present study investigated emotional and linguistic functions of prosody as well as facial and musical processing in 21 patients with lateralized subcortical disease. Fourteen right hemiparkinsonians (RPD) and 7 left hemiparkinsonians (LPD) were compared to 17 normal controls (NC). Patients were impaired on receptive and expressive tests of emotional and linguistic prosody. Patients were also selectively impaired on emotional processing of facial stimuli and in the musical processing of pitch and tonal memory, though not timber. These findings suggest that monotone speech reported in PD is of multimodal origins and may involve dysfunction in neural centers involved in emotional and linguistic processing. There were no differences between RPD and LPD groups in the pattern of deficits, suggesting bilateral involvement in emotional processing at the subcortical level.     

The distribution of observing responses in a mixed FI-FR schedule,

In Exp I, three pigeons were trained on an observing response procedure where observing responses produced a stimulus correlated either with FI or with FR. Stimulus duration was 30 sec. During FR, the subjects completed the ratio before the stimulus terminated. During FI, the subjects usually observed the stimulus only once. Observing responses occurred immediately after food reinforcement. In Exp II, stimulus duration was shortened to 5 sec and the FR for food was increased. The results were similar to those of Exp 1. During most FIs and FRs, only one observing response occurred. The results of both experiments could be interpreted in a response competition framework. Immediately after food reinforcement, observing behavior is strong. When behavior on the food key begins it competes with further observing behavior.     

Relationship between creativity and right,left, and integrated thinking styles

ABSTRACT:

The purpose of the present study was to explore whether the so‐called “right thinking style” is related to creativity as measured by two types of creativity tests. The How Do You Think (HDYT) inventory evaluates personality and biographical information related to creativity, and the Sounds and Images is a type of divergent thinking test that assesses the originality of images elicited by abstract sounds. As a second purpose, this study permitted an analysis of the relationship between these two types of creativity measures. The two creativity measures and the Your Style of Learning and Thinking (SOLAT) test were administered to 109 undergraduates. Results indicated that the HDYT scores were positively correlated with right thinking scores on the SOLAT (r = .48) and negatively correlated with left thinking scores (r = ‐.70). Results from Sounds and Images were not as clear. Similar relationships were found when overlapping items were removed from the various measures.     

Some comments on Shettel-Neuber and O'Reilly's "handedness and career choice: another look at supposed left/right differences" (1983)

A property of attitudes, namely, the fact that attitudes select facts, is used to comment upon a paper on handedness and career choice.     

The distribution and development of handedness for manual gestures in captive chimpanzees (Pan troglodytes)

This article describes the distribution and development of handedness for manual gestures in captive chimpanzees. Data on handedness for unimanual gestures were collected in a sample of 227 captive chimpanzees. Handedness for these gestures was compared with handedness for three other measures of hand use: tool use, reaching, and coordinated bimanual actions. Chimpanzees were significantly more right-handed for gestures than for all other measures of hand use. Hand use for simple reaching at 3 to 4 years of age predicted hand use for gestures 10 years later. Use of the right hand for gestures was significantly higher when gestures were accompanied by a vocalization than when they were not. The collective results suggest that left-hemisphere specialization for language may have evolved initially from asymmetries in manual gestures in the common ancestor of chimpanzees and humans, rather than from hand use associated with other, non-communicative motor actions, including tool use and coordinated bimanual actions, as has been previously suggested in the literature.     

In hindsight, life flows from left to right

Three experiments investigated the mental representation of meaningful event sequences. Experiment 1 used extended (5 min long) naturalistic scenes excerpted from commercial movies. Experiments 2 and 3 presented everyday activities by means of sequences of six photographs. All experiments found both left–right and distance effects in an order decision task, suggesting that when contemplated in hindsight, experienced events unfold along a left-to-right analogical mental line. Present results are discussed in the context of the mental representation of other kinds of ordinal sequences, and other left–right effects reported in non-ordinal domains.     

Skill, strength, handedness, and fatigue

Thirty male subjects, 20 of whom were self-classified left-handers and 10 right-handers, were tested on a grip-strength task and a handwriting task with each hand, both under normal conditions and in a situation of induced experimental fatigue. On the basis of questionnaire scores, the left-handers were sub-divided into two groups comprising the 10 most left-handed and the 10 least left-handed subjects. The test of grip strength showed a small but significant deterioration in performance of both hands from fatigue. With the handwriting task, a similar significantly adverse effect of fatigue was recorded for all groups as well as a large significant difference in performance between the preferred and nonpreferred hands under normal conditions, which decreased under fatigue. An explanation of these differential effects is discussed in terms of the greater efficiency of the preferred hand in the highly developed skill of handwriting.     

Visuospatial competency, handedness, and cerebral dominance

The present study addressed the question of Levy's (1974, Psychobiological implications of bilateral assymetry. In S. Dimond &; J. G. Beaumont, Hemispheric function in the human brain, NY: Halstead. Pp. 121–183.) proposal that left handers would have lowered spatial skills relative to verbal skills. In the first part of the study, performance on the PMA (visuospatial subtest) and WAIS Block Design subtest were compared between right and left handed high school and college samples. No support could be found for deficient visuo-spatial performance in the left handers. In the second part of the experiment, no relative impairment of visuospatial skills was found when subjects were classified into predicted speech dominance groups on the basis of a dichotic listening task and/or a visual half-field task. An extreme groups comparison of the most left dominant and most right dominant groups again yielded no significant differences in visuo-spatial performance. Finally, the relationship between degree of speech lateralization and visuo-spatial skills was examined. Only partial support for differences in cerebral organization for speech in left handers was found in the college sample.     

The role of domain-specific practice, handedness, and starting age in chess

The respective roles of the environment and innate talent have been a recurrent question for research into expertise. The authors investigated markers of talent, environment, and critical period for the acquisition of expert performance in chess. Argentinian chess players (N = 104), ranging from weak amateurs to grandmasters, completed a questionnaire measuring variables including individual and group practice, starting age, and handedness. The study reaffirms the importance of practice for reaching high levels of performance, but it also indicates a large variability: The slower player needed 8 times as much practice to reach master level than the faster player. Additional results show a correlation between skill and starting age and indicate that players are more likely to be mixed-handed than individuals in the general population; however, there was no correlation between handedness and skill within the sample of chess players. Together, these results suggest that practice is a necessary but not sufficient condition for the acquisition of expertise, that some additional factors may differentiate chessplayers and nonchessplayers, and that starting age of practice is important.     

The influence of gender, handedness, and performance level on specialized cognitive functioning

Individual differences in performance on neuropsychological tests were analyzed across age (prepubertal to adult), gender, and handedness groups and examined for performance level as a moderating variable. No differences were observed for the factor structure of these tests across ages and between genders, suggesting similar cognitive structures among these groups. Significant differences in performance were observed between males and females and, to a lesser extent, between right and left handers. Of interest, were significant Gender x Handedness and Gender x Handedness x Level (of performance) interactions seen especially in the older (postpubertal and adult) subjects. High performing, right handed males and left handed females performed better on visuospatial tasks while left handed males and right handed females performed better on verbosequential tasks.     

Symmetric distribution in latencies of cortical somatosensory potentials evoked by right and left posterior tibial nerve stimulation in right-, left-, and mixed-handed men and women

The latencies of the P1, N1, P2, and N2 components of the somatosensory potentials evoked by stimulation of the right and left posterior tibial nerves in the right-, left-, and mixed-handed men and women were subjected to a statistical analysis. The mean latencies of the primary and secondary cortical responses are symmetrically distributed between the right and left sides for all the subjects. The mean latencies obtained of women were significantly shorter than those of men. This difference was accounted for by the fact that the mean body height of women was significantly less than that of men, since there was a significant positive correlation between body height and latency. It was concluded that the conduction times for the cortical input as well as the early cortical information processing, despite synaptic interventions, cannot play a role in the cerebral lateralization concerning the perceptual and manipulospatial tasks.     

The estimation of the parameters of a negative binomial distribution with special reference to psychological data

As an analytical tool the negative binomial distribution may have wide applications in the psychological field. The estimation of its parameters is demonstrated to be often inefficient when fitting by the method of moments. This causes possibly true hypotheses to be rejected. Formulas for the efficiency of the moment method and solution of the likelihood equations are derived. Efficiency graphs and detailed tables for the function reduce the maximum-likelihood method to a minimum of computational labour. Practical applications of the ease and power of the M.L. procedure are given.The author wishes to express his gratitude to the South African Council for Scientific and Industrial Research for permission to publish this paper; to Mr. A. G. Arbous for supplying the data on absenteeism; to Mr. R. V. Sutton for the data on Two-hand Co-ordination errors; and last, but not least, to the staff of the Statistical Section who computed various tables under the expert guidance of Mr. J. S. Maritz.     

Bilateral tachistoscopic perception, handedness, and laterality.

Right-handed, familial left-handed, and nonfamilial left-handed males and females reported high- or low-imagery words which were located to the left and right of fixation in bilateral tachistoscopic displays. On each trial, an arrowhead appeared in the center of the display. The arrowhead pointed to either the left or the right half-field, indicating the order of report. Right-handers reported more accurately from the right half-field, and familial left-handers reported more accurately from the left half-field. The order of report results showed that right-handers were similar to nonfamilial left-handers; for left half-field presentation, both groups were more accurate when the arrowhead pointed to the left than when it pointed to the right (i.e., first report was more accurate than second report). There was a main effect of word imagery, but this factor did not interact with visual half-field. Thus, there was no evidence that representations of high-imagery words are lateralized differently than representations of low-imagery words. The results are discussed with respect to lateralization of memory for verbal material.     

Sex, handedness, mathematical ability, and biological causation

An important part of Benbow's (1988) assertion that sex differences in mathematical ability are primarily due to biological factors is the link between a trait that is assumed to reflect differences in brain organization (left-handedness) and mathematical giftedness. It is shown that the link between mathematical giftedness and an increased prevalence of left-handedness is not convincing. However, Benbow's (1986) data do show a convincing link between strong right-handedness and the lack of mathematical giftedness, in agreement with Annett and Manning's (1990a, 1990b) recent work.