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 325 records · Page 18Linked to original sources
PubMed2005

Handedness, dichotic-listening ear advantage, and gender effects on planum temporale asymmetry--a volumetric investigation using structural magnetic resonance imaging.

Previous research has often examined whether the asymmetrical structure of the planum temporale (PT) represents an anatomical correlate of lateralized language-processing functions, gathering diverging empirical evidence by comparing PT asymmetry in subjects with differing handedness, gender, or speech lateralization. Apart from other methodological problems, direct comparisons between studies are hampered by insufficient assessment and consideration of all three potential determinants of structural cerebral asymmetry. Based on volumetric assessment of structural Magnetic Resonance Imaging (MRI) scans of 104 healthy subjects, the present study replicated earlier observations of an overall leftward PT asymmetry, which was found to prevail irrespective of handedness, gender, or dichotic-listening ear advantage. However, the mean magnitude of this leftward asymmetry was not determined by either one of these factors in itself, but varied depending on their specific combination. A clear correspondence between structural and functional asymmetry was only observed among right-handed males. In this particular subgroup, more pronounced structural asymmetry was associated with an enlarged PT on the left side, while the enhanced leftward asymmetry of female sinistrals resulted from smaller adjusted volumes of their right PT. The existence of such complex interactions suggests that future research in this area can only be expected to overcome past inconsistencies by adequately considering handedness, gender, and speech lateralization.

Auditory Cortex↗
PubMed2005

Schizotypy and mixed-handedness revisited.

Although some previous studies assert that an association between schizotypy and loss of hand dominance is well established, the prevailing use of student populations, small effect sizes and arbitrariness of handedness classification suggest that this tentative association merits further investigation. The association of schizotypy and loss of hand dominance was examined using four samples. The first comprised 353 randomly selected individuals from the general community, the second comprised 131 screened volunteers participating as control subjects in a family study of schizophrenia, the third included 97 full siblings of schizophrenia patients, and the fourth consisted of 176 schizophrenia patients from the same study. The samples of screened volunteers and nonpsychotic siblings were used to replicate results from the community sample and to test the hypothesis that an increase in genetic liability is related to the association of schizotypal traits and mixed handedness. The results demonstrated that mixed handedness and schizotypy traits were unrelated in the representative sample from the community. This finding was replicated in the sample of screened volunteers, while siblings of schizophrenia patients showed a trend in the direction of the hypothesised relationship. In contrast, there was an expected significant but low in magnitude association between loss of hand dominance and the Schizotypal Personality Questionnaire factor of Cognitive Perceptual Dysfunction in schizophrenia patients.

Adolescent↗
PubMed2004

Is the intensity of Schneiderian symptoms related to handedness and speech disorder in subjects with psychosis?

OBJECTIVE: To explore the links between Schneiderian first-rank symptoms (FRS), handedness and speech disorder in subjects with psychosis. METHODS: A Schneiderian score was calculated by summing seven items of the Scale for the Assessment of Positive Symptoms (SAPS) exploring first-rank symptoms in 33 hospitalized patients presenting with psychotic symptoms. Speech disorder was rated using the Scale for the Assessment of Thought, Language and Communication Disorders (TLC). Handedness was assessed using the Edinburgh Handedness Inventory. RESULTS: Higher Schneiderian score was independently predicted by reduced right-hand preference and by lower TLC score. The associations between Schneiderian score and lateralisation or speech disorder were independent from level of psychotic and depressive symptoms, and from categorical diagnosis. CONCLUSION: The present study adds further support to the hypothesis that loss of normal cerebral asymmetry may be implicated in the emergence of FRS.

Adolescent↗
PubMed2006

Mixed handedness is associated with the Disorganization dimension of schizotypy in a young male population.

Within the ASPIS (Athens Study of Psychosis Proneness and Incidence of Schizophrenia) we sought out to examine in accordance with previous reports if a deviation from dextrality is associated with an augmented endorsement of self rated schizotypal personality traits in a large population of 1129 young male army recruits. Schizotypal traits were assessed using the Schizotypal Personality Questionnaire and hand preference membership was determined by applying stringent criteria derived from the Annett Handedness Questionnaire and the Porac-Coren questionnaire of lateral preferences. By adopting three different definitions of hand preference membership, we confirmed an association between mixed handedness and increased schizotypal personality traits, and in particular with Disorganization schizotypy that encompasses aspects of self perceived difficulties in verbal communication. Non-verbal cognitive ability, as indexed by measurement of non-verbal IQ, sustained attention and working memory was not associated with hand preference. We argue that a deviation from normal cerebral lateralization, as indexed by mixed handedness, is associated with mild sub clinical language dysfunction, rather than non-verbal cognitive ability, and this might be relevant to the expression of psychosis phenotype.

Adolescent↗
PubMed2005

Interaction of fraternal birth order and handedness in the development of male homosexuality.

The present study investigated evidence for an interaction between two of the best established etiologic factors, or markers of etiologic factors, in the literature on male homosexuality: fraternal birth order and hand preference. By combining five samples, the authors produced study groups of 1774 right-handed heterosexuals, 287 non-right-handed heterosexuals, 928 right-handed homosexuals, and 157 non-right-handed homosexuals. The results showed a significant (P = 0.004) handedness by older brothers interaction, such that (a) the typical positive correlation between homosexuality and greater numbers of older brothers holds only for right-handed males, (b) among men with no older brothers, homosexuals are more likely to be non-right-handed than heterosexuals; among men with one or more older brothers, homosexuals are less likely to be non-right-handed than heterosexuals, and (c) the odds of homosexuality are higher for men who have a non-right hand preference or who have older brothers, relative to men with neither of these features, but the odds for men with both features are similar to the odds for men with neither. These findings have at least two possible explanations: (a) the etiologic factors associated with non-right-handedness and older brothers-hypothesized to be hyperandrogenization and anti-male antibodies, respectively-counteract each other, yielding the functional equivalent of typical masculinization, and (b) the number of non-right-handed homosexuals with older brothers is smaller than expected because the combination of the older brothers factor with the non-right-handedness factor is toxic enough to lower the probability that the affected fetus will survive.

Birth Order↗
PubMed1990

Left handedness and immune disorders.

The Geschwind-Behan hypothesis that immune disorder (IMD) is more common among left than among right handed persons was tested in a sample of 3080 college students. Subjects indicated, for each of a list of IMDs, whether they: (1) had no reason to believe they had the disorder; (2) thought they might have the disorder; (3) had the disorder diagnosed by a physician; or (4) had had a disorder diagnosed and treated by a physician. Females reported significantly more IMDs than did males. Among females, the distribution of responses across the four response categories was not different for left and right handers, but IMD was significantly higher among left handed females when only the extreme categories were considered. Among males, no handedness effect was seen across the four categories, nor when only the extreme categories were considered. Laterality quotients, from the Edinburgh Handedness Inventory, were unrelated to IMD reports in both sexes. Results provide no real support for the Geschwind-Behan hypothesis. Even in the case of the extreme categories of IMD reports of females, the association of left handedness (for writing) and IMD accounts for only three-tenths of one percent of the variance.

Female↗
PubMed1990

On the futility of using familial sinistrality to subclassify handedness groups.

Annett's right shift model was used to show that presence of left-handedness in parents or grandparents is an extremely weak indicator of whether or not a person's handedness is influenced by genetic factors. Furthermore, where a genetic influence is present, familial sinistrality is only weakly related to underlying genotype. The usual rationale given for subdividing handedness groups according to familial sinistrality is logically indefensible.

Functional Laterality↗
PubMed1993

Handedness in extremely low birth weight infants: aetiology and relationship to intellectual abilities, motor performance and behaviour at four and six years.

Hand preference was measured in a total group of 71 ELBW children to determine patterns of hand preference at 4 and 6 years, possible aetiological factors leading to handedness, and whether left or non right hand preference were markers for intellectual, motor, temperament or behavioural differences. At both 4 and 6 years the prevalence of left handedness was increased, though this prevalence changed over the period of the study. Results supported brain injury as one mechanism leading to increased left hand preference, though this process did not adequately explain this increase. Possible reasons for this and the apparent change in prevalence with time are examined. Mixed handedness at 4 years was associated with lower intellectual abilities though otherwise children were similar in motor skills, temperament and behaviour independent of hand preference category.

Brain Damage, Chronic↗
PubMed1994

Handedness as a function of twinning, age and sex.

Questions about twin birth, sex, age and handedness for writing were asked as part of a survey of hearing disability (Davis, 1989) in a large sample of the adult population. The findings show unequivocally that the prevalence of left handedness is higher in twins than in the singleborn, in males than in females and in younger than in older adults. There was a marked and regular decline in the percentage of left writers with increasing age, but the effects for twinning and sex were evident in all of 7 age bands from 18 years to 80+. The findings are consistent with the assumption of the right shift theory of handedness (Annett, 1972, 1985) that the rs+ gene is expressed more strongly in females than in males, and in the singleborn than in twins.

Adolescent↗
PubMed1977

Handedness and part-whole relationships: a replication.

Nebes' 1971 experiment reporting a deficit in the performance of left-handed subjects on a measure of part-whole relationships was replicated, controlling for family history of handedness and for experimenter knowledge of subject handedness. No differences were found for any comparisons. Results are examined in relation to similar failures to replicate, indicating that the arc-circle measure does not reliably discriminate any visual-spatial differences associated with handedness.

Cognition↗
PubMed1980

Multiple birth-risk factors and handedness in elementary school children.

The relationships between a set of birth-risk factors, i.e., sex, parity, and maternal age, and handedness were computed for 600 elementary school children. None of these birth-risk variables (or relevant combinations of them) were significantly related to handedness. These data further question the validity of the hypothesis that left-handedness results from stressful prenatal and birth conditions.

Adult↗
PubMed1980

Birth complications and the distribution of handedness.

In an attempt to clarify the relationship between self-reported birth complications and handedness, the handedness distributions of 181 college students who reported birth complications and 1320 students who reported no complications were compared. The results suggest a clear but modest shift in the birth complications group away from the dextral end of the continuum. However these data did not validate the hypothesis that left-handedness results from birth complications.

Adolescent↗
PubMed1981

Asymmetry of facial expression related to handedness, footedness, and eyedness: a quantitative study.

This study investigates the relationship between traditional measures of lateral dominance and facial asymmetry or facedness, i.e., the relative intensity of expression "and muscular involvement" on the two sides of the face. Subjects were 19 left-handed and 29 right-handed normal adults coached to produce eight facial expressions of emotion and one expression involving unilateral facial movement. Videotapes of each subject were reliably rated for facedness. A lateral dominance battery yielded preference scores for hand, foot, and eye, and performance scores for accuracy, speed, and strength. Facedness and lateral dominance scores were intercorrelated. For all subjects, facedness for the eight emotional expressions was positively related to eyedness, but unrelated to handedness or footedness. Facial asymmetry during emotional expression was more intense on the left side of the lower face and may be a right hemisphere function, regardless of handedness. The one expression requiring deliberate unilateral facial movement was significantly and inversely related to handedness and footedness.

Adult↗
PubMed1981

The relationship among handedness, sighting dominance, and acuity dominance in elementary school children.

The present study was an attempt to clarify the relationship between handedness, sighting dominance, and eye-acuity in children. Ninety-four males and ninety-seven females between the ages of five and eleven were assessed on standardized measures of handedness, sighting dominance, and visual acuity. Right-handers were more likely to show right-sighting dominance, whereas left-handers had an equal chance of being right-sighted or left-sighted. Acuity dominance was not consistently associated with handedness or sighting dominance. No effects for sex or age were found. It is suggested that further clarification of the function of various lateralized sensorimotor measures is needed before an understanding of how these measures may be related to cortical dominance is possible.

Child↗
PubMed1987

Handedness distributions among adults who stutter.

Handedness testing carried out in the course of clinical treatment and research with stutterers has provided no support for an association between left-handedness and stuttering. Stutterers had neither a greater incidence of left-handedness than is usually reported for the general population, nor demonstrated less consistency than fluent speakers in hand preference.

Female↗
PubMed1996

Left-handedness in twins: genes or environment?

Twin family data can cast light on the longstanding problem about the influences of genes and environment on the etiology of left-handedness. Therefore, hand preference was assessed in 1700 adolescent twin pairs and their parents. Left-handedness (LH) appeared not significantly enhanced among twins compared to the general population. In addition the following observations were made: (1) Significant more LH in first born twins than in second born twins. (2) Significant higher left-handedness association in MZmm pairs compared to DZmm pairs and not or may be marginally so in MZff versus DZff pairs. These results, combined with the observations that (a) left-handed fathers increase the probability of LH in sons but not in daughters; (b) LH in mothers increases LH prevalence in both sons and daughters to the same degree; and (c) very low birth weight, corrected for the effect of gestational age, increases LH prevalence in first born twins only, make an environmental explanation more likely. The possibility that exposure to prenatal male hormones - to which low birth weight and high birth stress children are more vulnerable - might be a crucial condition for the etiology of LH, is discussed.

Adolescent↗
PubMed2004

Androgenic influences on neural asymmetry: Handedness and language lateralization in individuals with congenital adrenal hyperplasia.

This study tested the hypothesis that prenatal androgen levels influence hand preferences and language lateralization, two manifestations of neural asymmetry. Participants were individuals with congenital adrenal hyperplasia (CAH, a genetic disorder that results in excess adrenal androgen production beginning prenatally) (40 females; 29 males) and their unaffected relatives (29 females; 30 males) who ranged in age from 12-45 years. The Edinburgh-Crovitz Inventory and the performance of five simple tasks (the Handedness Activities Test) were the measures of hand preferences, and a dichotic listening task composed of consonant-vowel nonsense syllables was the measure of language lateralization. No sex differences were observed among relative controls in hand preferences or language lateralization. Male participants with CAH were less consistently right-handed for writing than unaffected male relatives, when those who had been forced to switch writing hands from left to right were considered with left-handers as being not consistently right-handed. There were no other significant differences between individuals with CAH and unaffected relatives. These results do not support the hypothesis that prenatal androgens influence language lateralization, nor do they support the Geschwind-Behan-Galaburda model that posits a key role for testosterone in the development of cognitive problems in males, secondary to changes in hemispheric development and cognitive lateralization. Hormonal influences on handedness, although not always consistent, may be more likely. However, given that sex differences in both language lateralization and handedness are small, it is possible that limited sample size precludes the detection of consistent group differences.

Adolescent↗
PubMed1998

Handedness identification from intertubercular sulcus of the humerus by discriminant function analysis.

The accurate determination of skeletal handedness is a critical requirement in physical anthropology and forensic science. To differentiate handedness, discriminant function analysis is applied using the parameters of right and left intertubercular sulci. A total of 200 matched unpaired adult humeri (100 right and 100 left), collected from the Department of Anatomy, were used to measure four parameters of the intertubercular sulcus namely, width (X1), depth (X2), angle of medial wall (X3) and angle of lateral wall (X4) and to note the presence of supratubercular ridge of Meyer (X5). The discriminant function obtained with the significant variables, angle of medial wall (X3), angle of lateral wall (X4) and presence of the supratubercular Meyer (X5) is: Y = 0.093X3 + 0.056X4 + 0.775X5 - 13.46. The accuracy of correct classification using the discriminant function is 89% which is the best starting point for handedness determination approach. The methodology of using discriminant function can be crucial for medicolegal jurisprudence.

Adult↗