Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HANDEDNESS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources
PubMed2004

Evaluation of empirical methods and methodological foundations of human left-handedness.

The methodological and empirical foundations underlying the theories on human left-handedness are examined, including the definition and classification of left-handedness, its relation to pathology, and the results on family, adoption, and twin research. It is argued that major research findings on left-handedness are based on inadequate empirical methods, and the concrete definitions and assessment procedures do not meet validity and reliability criteria. This also casts doubt on the relationship between left-handedness and pathology reported in the literature. Furthermore, findings from family, adoption, and twin studies do not allow interpretation of possible direct genetic contributions to explaining left-handedness. It is concluded that the methodological limitations of a causal explanation should encourage an examination of the epistemological and methodological premises of theory formulation. The functional method and a theoretical framework based on early childhood experiences and the neural plasticity of the brain may be more appropriate for the selection of empirical methods in research of human left-handedness.

Brain↗
PubMed2004

Handedness and hobby preference.

The objective of this study was to investigate the relationship between handedness and hobby preference in healthy individuals. For this reason, the Annett handedness questionnaire and a standard questionnaire on preference for hobbies were administered to 879 healthy young men (age, M = 22.3, SD = 4.8 yr.). Analysis showed more cultured individuals were much less likely to be strongly right-handed. Especially, pure right-handedness highly overrepresented among those who mainly preferred doing sports, pure left-handedness among those who preferred reading books, collecting, or going to the cinema/theater, and mixed-handedness among those who preferred arts, like playing music, drawing, or handicraft. The findings support evidence that handedness is associated with hobby preference.

Adult↗
PubMed1990

Left-handedness: association with college major, familial sinistrality, allergies, and asthma.

366 juniors, seniors, and graduate students from seven departments at The Ohio State University were administered the 10-item Edinburgh Handedness Inventory and asked questions concerning familial handedness and personal incidence of allergies or asthma. The rate of left-handedness was 15.6% among the male students and 12.9% among the females. Maternal handedness was significantly related to female offspring handedness and to the incidence of allergies and asthma in both males and females. Departmental incidence of left-handedness ranged from a low of 7.5% (Microbiology) to a high of 21.7% (Law).

Achievement↗
PubMed1990

[Handedness in relation to reaching for an object--an analysis].

1. By using a decision tree an analysis is made about which types of handedness are possible in visually guided reaching. 2. The terms "ipsilateral handedness" and "contralateral handedness" are created. Considering the possible combinations 9 types of handedness can be described. 3. By analysis of information processing for using the right or the left hand in visually guided reaching the following facts can be described: a) The shortest time needed for decisions is found in the case of pure right- or left-handedness. b) If the object is in the symmetric plane and if the animal is not purely right- or left-handed a decision may be impossible. 4. In conclusion children should be urged decisively to use the right or left hand. However, urging should not be too early, as there is a spontaneous changing of the handedness up to the age of eight.

Child↗
PubMed1997

[Genetic problems of handedness].

The present review discusses the heredity of the most famous and important lateral sign, namely handedness. There are some problems in assessing the handedness and so it is not ever easy to describe the phenotype of handedness in relation to the genotype. Another important point is the biological foundation. It is possible to argue that genes are left-right agonistic. All available family studies on handedness are presented and altogether they show a clear intrafamiliar relationship. Data of adoption studies on handedness are rare but they indicate that the effects of shared biological heritage are more powerful determinants of handedness than sociocultural factors. Several genetic models are discussed shortly favoring the Annett- and the McManus-model because they calculate a directional and a fluctuating asymmetry. Finally the present review describes the factors favoring a genetic influence (presence of asymmetries in infants, structural and behavioral asymmetries) and those favoring sociocultural determination (twin data). The body of data offers substantial evidence for the influence of genes.

Adult↗
PubMed1999

The influence of handedness on the clinical presentation and neuropsychology of Alzheimer disease.

BACKGROUND: Research on the influence of handedness on the clinical presentation and neuropsychology of Alzheimer disease (AD) is scarce. OBJECTIVE: To compare clinical presentation and neuropsychological test performance of right- and left-handed patients with AD. DESIGN: We hypothesized that left-handedness would be associated with younger onset, more rapid progression, and possibly cognitive hemispheric asymmetry. After determining handedness with the Edinburgh Inventory for Handedness for 922 patients with AD, 18 left-handed patients were compared with 18 right-handed patients matched individually on Mini-Mental State Examination scores, education, and age. We compared clinical characteristics (eg, age of onset), estimated rate of initial cognitive decline, language and visuospatial test performances, and patterns of cognitive and motor asymmetries for the 2 groups. SETTING: Alzheimer's Disease Research Center at Baylor College of Medicine, Houston, Tex. MAIN OUTCOME MEASURES: Results of the Wechsler Adult Intelligence Scale-Revised verbal and performance IQ tests, the Western Aphasia Battery sequential commands subtest, the Boston Naming Test, the Halstead-Reitan Finger-Tapping Test, and the calculated Rate of Initial Progression. RESULTS: We found that left-handed patients had younger ages of onset but unexpectedly lower estimated rates of initial cognitive decline, and their results on language tests did not differ from those of right-handed patients. Regarding asymmetry, left-handed patients were more likely than right-handers to obtain lower verbal IQ than performance IQ scores and to exhibit faster finger-tapping speeds with their nondominant hand, but group differences did not attain statistical significance. There were disproportionately few left-handed patients with AD compared with population norms. CONCLUSIONS: Left-handed patients with AD do not differ from right-handed patients in the severity or pattern of neuropsychological deficits. Left-handedness or some factor associated with it may contribute to the early appearance of cognitive deficits during the development of Alzheimer disease, but may temper the subsequent rate of progression of deficits.

Aged↗
PubMed1996

Location of the handedness gene on the X and Y chromosomes.

Accumulated data from five handedness surveys show that concordance for sex is slightly but reliably higher among siblings of the same handedness than among those of opposite handedness. This is consistent with Crow's theory that the genetic locus for handedness is in an X-Y homologous region of the sex chromosomes. The small size of the effect is predicted from genetic models in which there is a substantial random component underlying phenotypic left handedness. The findings are relevant to the putative role of cerebral asymmetry in the aetiology of psychosis.

Chromosome Mapping↗
PubMed1996

Maternal effect of low temperature on handedness determination in C. elegans embryos.

C. elegans embryos, larvae, and adults exhibit several left-right asymmetries with an invariant dextral handedness, which first becomes evident in the embryo at the 6-cell stage. Reversed (sinistral) handedness was not observed among > 10,000 N2 adults reared at 16 degrees C or 20 degrees C under standard conditions. However, among the progeny of adults reproducing at 10 degrees C, the frequency of animals with sinistral handedness was increased to approximately 0.5%. Cold pulse experiments indicated that the critical period for this increase was in early oogenesis, several hours before the first appearance of left-right asymmetry in the embryo. Hermaphrodites reared at 10 degrees C and mated with males reared at 20 degrees C produced sinistral outcross as well as sinistral self-progeny, indicating that the low temperature effect on oocytes was sufficient to cause reversals. Increased frequency of reversal was also observed among animals developed from embryos lacking the egg shell. Possible mechanisms for the control of embryonic handedness are discussed in the context of these results, including the hypothesis that handedness could be dictated by the chirality of a gametic component.

Animals↗
PubMed1988

Cleft lip and handedness: a study of laterality.

Research on the malformation cleft lip with or without cleft of the palate is complex and may involve studies of etiology, pathogenesis, natural history, and other disease associations. One of the more intriguing areas of study is developmental lateralization. The 3 extant reports of the relationship between laterality of cleft lip and handedness are in conflict. The purpose of the present study is an attempt to resolve the confusion and to explore possible hypotheses that could explain the data. A random sample of 149 probands with unilateral cleft lip +/- palate was ascertained from 2 Los Angeles area hospitals. Laterality of clefting and handedness was determined for each, the former by inspection and the latter by the method of Oldfield [1971]. Information was also obtained on the nuclear family about the number of sibs, presence of clefting, and handedness of the probands' parents. The probability of non-right-handedness (NRH) was much greater for probands with left-sided cleft lip than those with right-sided cleft lips; this was independent of the proband's sex. The cleft lip laterality in probands was independent of parental handedness, suggesting that the significantly increased frequency of left-sided clefting and NRH is embryologic in origin and may have a common etiology and/or pathogenesis. Several explanations are proposed and discussed.

Biometry↗
PubMed2006

Agenesis of the corpus callosum and the establishment of handedness.

The goal of this study was to check whether an isolated agenesis of the corpus callosum, detected in utero with ultrasound recording, would impair the early development of unimanual and bimanual handedness. Twelve infants with isolated agenesis of the corpus callosum, either total (TACC) or partial (PACC) were tested for handedness at the end of their first year, and were compared to infants with typical development (TD), matched for age and sex. A majority of infants showed right-handedness at the unimanual grasping tasks, with no significant difference between the TD and ACC groups. When the object was presented to the left, the TACC infants were more likely to grasp the object with their right hand (with or without the left hand) than both the TD and the PACC infants who used mostly the ipsilateral left hand. The only significant difference between TD and ACC infants concerned bimanual coordination, as less ACC infants (especially TACC) succeeded at the bimanual task, compared with TD infants. In addition, the strategy of the former tended to be less right-handed than that of the latter. Our results confirm the role of the CC in bimanual coordination, indicating that the early emergence of bimanual coordination and, if confirmed, bimanual handedness, are likely to be delayed in the absence of corpus callosum, especially if agenesis is total. They do not support the idea that the CC is necessary for the early onset of handedness.

Agenesis of Corpus Callosum↗
PubMed2006

Is mixed-handedness a marker of treatment response in posttraumatic stress disorder?: a pilot study.

Recent studies suggest that mixed-handedness is a risk factor for posttraumatic stress disorder (PTSD). This study examined whether mixed-handed veterans with combat-related PTSD respond more poorly to psychosocial treatment. Consistency of hand preference was assessed in 150 Vietnam combat veterans with PTSD using the Edinburgh Handedness Inventory (R. C. Oldfield, 1971). Growth modeling analyses using Mplus (L. K. Muthén & B. Muthén, 2002) identified that PTSD veterans with mixed-handedness reported significantly less treatment improvement on the PTSD Checklist (F. W. Weathers, B. T. Litz, D. S. Herman, J. A. Huska, & T. M. Keane, 1993) than did veterans with consistent handedness. These data suggest that mixed-handedness is associated with poorer PTSD treatment response. Several possible explanations for this finding are discussed.

Combat Disorders↗
PubMed2005

Opposite effects of androgen receptor CAG repeat length on increased risk of left-handedness in males and females.

Prenatal exposure to testosterone has been hypothesised to effect lateralization by influencing cell death in the foetal brain. Testosterone binds to the X chromosome linked androgen receptor, which contains a polymorphic polyglutamine CAG repeat, the length of which is positively correlated with testosterone levels in males, and negatively correlated in females. To determine whether the length of the androgen receptor mediates the effects of testosterone on laterality, we examined the association between the number of CAG repeats in the androgen receptor gene and handedness for writing. Association was tested by adding regression terms for the length of the androgen receptor alleles to a multi-factorial-threshold model of liability to left-handedness. In females we found the risk of left-handedness was greater in those with a greater number of repeats (p=0.04), this finding was replicated in a second independent sample of female twins (p=0.014). The length of the androgen receptor explained 6% of the total variance and 24% of the genetic variance in females. In males the risk of left-handedness was greater in those with fewer repeats (p=0.02), with variation in receptor length explaining 10% of the total variance and 24% of the genetic variance. Thus, consistent with Witelson's theory of testosterone action, in all three samples the likelihood of left handedness increased in those individuals with variants of the androgen receptor associated with lower testosterone levels.

Adult↗
PubMed2005

A school-based twin study of handedness among adolescents in Taiwan.

This study aimed to evaluate whether twinning might influence handedness and the relative contribution of genetic and environmental factors to handedness in a total of 321 pairs of twins, 36 same-sex sib-pairs, and 1020 singletons, aged 12-16 and systematically recruited from the junior high schools in Taipei. Twins' zygosity was determined by a combination of DNA typing and physical similarity. The direction and consistency of handedness in twins did not differ from that seen in singletons. Compared with the full model containing additive genes (A), shared (C), and non-shared (E) environment, both AE and CE models had equivalently acceptable fit. The contribution from additive genes in the AE model was estimated to be 16% (directional) to 13% (consistent) for the continuous handedness and 34-10% for the categorical one, whereas the corresponding contribution from shared environment in the CE model was 14-14% and 32-11%, respectively. Handedness in adolescents appears to be not influenced by twinning and not substantially heritable, whereas environmental factors, especially those not shared between siblings, are the most important ones for explaining individual variations.

Adolescent↗
PubMed1991

Left-handedness in male schizophrenic patients is associated with increased impairment on the Luria-Nebraska Neuropsychological Battery.

Several studies suggest increased mixed and left-handedness in schizophrenia. This is of interest as early cerebral injury can result in increased left-handedness and some investigations have suggested a role for early developmental insult (e.g., birth complications) in schizophrenia. We administered the Luria-Nebraska Neuropsychological Battery (LNNB) to 24 left-handed male schizophrenic patients and a separate group of 24 right-handed schizophrenic patients who were age and education matched to the left-handed patients. The test protocol also was administered to 15 left-handed non-psychiatric control subjects and 15 right-handed controls. Direct comparisons (t-test) of the left- to right-handed schizophrenics revealed that the left-handed patients showed significantly greater impairment on several LNNB measures sensitive to cognitive deficits in schizophrenia. There were no differences between left- and right-handed control subjects. A further 2 X 2 ANOVA pooling all subjects noted several significant interactions between handedness and diagnostic group. The findings suggest a unique interaction between left-handedness and neuropsychological impairment in schizophrenia and could support a relationship between left-handedness, early cerebral insult, and cognitive deficits.

Analysis of Variance↗
PubMed1989

Origins and implications of handedness and relative birth weight for IQ in monozygotic twin pairs.

The implications of left-handedness for intellectual functioning in monozygotic (MZ) twinships remain unresolved. Two proposed explanations of hand-discordance in MZ twin pairs, elevated birth stress and delayed zygotic splitting, were used to generate hypotheses and predictions concerning IQ, both within and between twin pairs. A comparison of Full Scale IQ, Verbal IQ and Performance IQ scores for MZ twin children, from 67 twin pairs, organized according to concordance or discordance for handedness and relative birth weight, is presented. The results support the hypothesis that left-handedness in lower birth weight MZ co-twins may be associated with pre-natal pathological events, while left-handedness in higher birth weight left-handed MZ co-twins may be associated with delayed zygotic splitting and disrupted asymmetry determination. Birth weight status within MZ twin pairs may predict a lower IQ for the lower birth weight twin only when lower birth weight co-occurs with left-handedness. Pre-natal insult similarly reduced Verbal IQ, but not Performance IQ, within these particular twinships.

Birth Order↗
PubMed1990

Handedness, immune disorders and information bias.

In order to investigate the relations between handedness and migraine or immune disorders, we performed a case control study comparing the handedness of patients suffering from systemic lupus erythematosus (SLE), type I diabetes, Graves' disease, or migraine to that of a random sample of controls from the general population. A handedness index was measured from a 10-item questionnaire. No significant difference was observed. But when the controls who denied having ever suffered from migraine or any allergic disease were set apart from those who gave at least one positive answer to the same questions, the former were found more right-handed, i.e. with a lower handedness index than the latter (P less than 0.05) and than the SLE patients (P less than 0.05). More generally, the mean observed handedness index of controls giving a positive answer to any question about their health was found repeatedly higher than that of controls giving a negative answer: this was observed for 27 of the 32 questions. These results are highly suggestive of an information bias, the subjects saying they use the right hand for each of the 10 activities considered in the questionnaire being more likely to deny having suffered from a given disease or used, more or less recently, some drug or medical service. Our conviction is that previous observations dealing with the same topic are also more easily explained by the presence of an information bias than by Geschwind's theory. The implications for the design of further epidemiologic studies are discussed.

Adult↗
PubMed1992

Spatial ability as a predictor of math achievement: the importance of sex and handedness patterns.

In accordance with major theories of handedness and brain organization, differential predictors for math achievement were found as a function of sex and handedness subgroups among eighth graders. Although there was no difference in absolute levels of performance as a function of either sex or handedness, predictive structures did differ. Regression analyses showed that spatial ability predicts math achievement for: (1) girls with anomalous dominance (non-right-handers and right-handers with non-right-handed relatives), and (2) all boys (independent of handedness group). In contrast, for the standard dominance girls who are right-handed with all right-handed relatives (considered strongly left-hemisphere dominant for language), spatial ability did not predict for math achievement. These findings occurred, even when scholastic aptitude and verbal achievement factors were controlled. It was concluded that further studies of sex differences in math achievement should consider subgroup differences within the sexes, based on handedness patterns.

Achievement↗
PubMed2004

The handedness of Leonardo da Vinci: a tale of the complexities of lateralisation.

The handedness of Leonardo da Vinci is controversial. Although there is little doubt that many of his well-attributed drawings were drawn with the left hand, the hatch marks of the shading going downwards from left to right, it is not clear that he was a natural left-hander, there being some suggestion that he may have become left-handed as the result of an injury to his right hand in early adulthood. Leonardo's lateralisation may be illuminated by an obscure passage in his notebooks in which he describes crouching down to look into a dark cave, putting his left hand on his knee, and shading his eyes with his right hand. We carried out a questionnaire survey, using 33 written and photographic items, to find whether this behaviour was typical of right handers or left handers. In fact the 'Leonardo task' showed almost no direct association with handedness, meaning that it contributes little to the immediate problem of elucidating Leonardo's handedness. However, the lateralisation of the task did relate to other aspects of behavioural laterality in surprisingly complex ways. This suggests that individual differences in handedness, and behavioural laterality in general, have a structural complexity which is not fully encompassed by simple measures of direction or degree of handedness.

Adult↗