Journal articles: 'Handedness'

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Cvetković, Milena, Perica Vasiljević, and Stevo Najman. "Handedness." Glasnik Antropoloskog drustva Srbije, no. 50 (2015): 115–24. http://dx.doi.org/10.5937/gads1550115c.

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Prichard, Eric C., Stephen D. Christman, and Jeanette Walters. "The Pen Is Not Always Mightier: Different Ways of Measuring Handedness With the Edinburgh Handedness Inventory Yield Different Handedness Conclusions." Perceptual and Motor Skills 127, no. 5 (June 2, 2020): 789–802. http://dx.doi.org/10.1177/0031512520927562.

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Although consistency of handedness (the strength of dominant hand preference) is increasingly recognized as an important individual difference, there are questions about how to best measure it. A recent meta-analysis showed that researchers have often failed to report details of responses and response formats to handedness test items. In addition to measuring handedness direction (i.e., left versus right handedness), there can be utility to dichotomizing the Edinburgh Handedness Inventory (EHI) into consistent and inconsistent dominant handedness, despite controversy over the best means of doing so. In this study, we performed a discriminant function analysis of EHI items to determine which items best predicted handedness consistency versus handedness direction. Although the same discriminant function accounted for most of the variance for both dependent measures, writing and drawing EHI items were the strongest predictors of handedness direction and combing and opening jars items were the strongest predictors of handedness consistency. As different items on the EHI predicted these different handedness dimensions, we discuss the implications of dichotomizing EHI items into both relevant dimensions for both biological and environmental theories of the basis of handedness and for future handedness research.

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Shimizu, Akinori, and Masaomi Endo. "Handedness Conversion in Children and Parental Handedness." Psychiatry and Clinical Neurosciences 39, no. 1 (March 1985): 19–24. http://dx.doi.org/10.1111/j.1440-1819.1985.tb01940.x.

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Marrion, Leslie V., and Lorne K. Rosenblood. "Handedness in the Kwakiutl Totem Poles: An Exception to 50 Centuries of Right-Handedness." Perceptual and Motor Skills 62, no. 3 (June 1986): 755–59. http://dx.doi.org/10.2466/pms.1986.62.3.755.

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A survey of handedness in Kwakiutl Indian totem and house poles found 56% bihandedness, 24% left-handedness, and 20% right-handedness. These findings are in marked contrast to other research findings on artforms, which show about 90% right-handedness. In the previous studies no systematic variation in the incidence of right-handedness was found across time eras, cultures, or geographic location. This apparent consistency was interpreted as supporting an hypothesis that right-handedness is universal and physiological. However, the present authors' findings with regard to Kwakiutl handedness clearly refutes the notion of universal right-handedness in artforms. In the current Kwakiutl population, there is a strong indication that sociocultural and environmental factors may also strongly influence the expression of handedness.

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Michel, George F. "Handedness Development: A Model for Investigating the Development of Hemispheric Specialization and Interhemispheric Coordination." Symmetry 13, no. 6 (June 2, 2021): 992. http://dx.doi.org/10.3390/sym13060992.

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The author presents his perspective on the character of science, development, and handedness and relates these to his investigations of the early development of handedness. After presenting some ideas on what hemispheric specialization of function might mean for neural processing and how handedness should be assessed, the neuroscience of control of the arms/hands and interhemispheric communication and coordination are examined for how developmental processes can affect these mechanisms. The author’s work on the development of early handedness is reviewed and placed within a context of cascading events in which different forms of handedness emerge from earlier forms but not in a deterministic manner. This approach supports a continuous rather than categorical distribution of handedness and accounts for the predominance of right-handedness while maintaining a minority of left-handedness. Finally, the relation of the development of handedness to the development of several language and cognitive skills is examined.

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Henry, Kevin. "Even-handedness." Senses and Society 1, no. 3 (November 2006): 399–403. http://dx.doi.org/10.2752/174589206778476306.

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Pohl, Fritz. "DNA Handedness." Science 264, no. 5165 (June 10, 1994): 1519. http://dx.doi.org/10.1126/science.264.5165.1519.c.

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Pohl, Fritz. "DNA Handedness." Science 264, no. 5165 (June 10, 1994): 1519. http://dx.doi.org/10.1126/science.264.5165.1519-c.

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Knight, Barry. "Script handedness." Nature 357, no. 6375 (May 1992): 202. http://dx.doi.org/10.1038/357202b0.

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Clarke, David. "On handedness." Physics World 27, no. 06 (June 2014): 24. http://dx.doi.org/10.1088/2058-7058/27/06/31.

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Mason, Stephen F. "Extraterrestrial handedness." Nature 389, no. 6653 (October 1997): 804. http://dx.doi.org/10.1038/39777.

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Pohl, F. "DNA Handedness." Science 264, no. 5165 (June 10, 1994): 1519. http://dx.doi.org/10.1126/science.264.5165.1519-b.

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Bada, Jeffrey L. "Extraterrestrial Handedness?" Science 275, no. 5302 (February 14, 1997): 942–43. http://dx.doi.org/10.1126/science.275.5302.942.

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14

Hancocks, Stephen. "Right handedness." British Dental Journal 218, no. 11 (June 12, 2015): 609. http://dx.doi.org/10.1038/sj.bdj.2015.477.

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15

Turner, B. S. "Left handedness." BMJ 307, no. 6919 (December 18, 1993): 1577–78. http://dx.doi.org/10.1136/bmj.307.6919.1577.

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Mason, Stephen F. "Biomolecular handedness." Biochemical Pharmacology 37, no. 1 (January 1988): 1–7. http://dx.doi.org/10.1016/0006-2952(88)90748-4.

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17

Skrabanek, Petr. "LEFT-HANDEDNESS." Lancet 341, no. 8836 (January 1993): 26–27. http://dx.doi.org/10.1016/0140-6736(93)92491-b.

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18

Hiscock, Merrill. "It's Not Only About Sex." Journal of the International Neuropsychological Society 7, no. 5 (July 2001): 650–51. http://dx.doi.org/10.1017/s1355617701245123.

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A few years ago, at the end of a lecture on handedness, a neuropsychology graduate student asked, “Why should I care about handedness? Left-handedness is not a disease.” She had missed the main point of the lecture, namely that left-handedness is an exciting experiment of nature. In the left-hander we find the opportunity to study a healthy brain that is organized differently from other healthy brains. Here is a chance to study the effects of neural diversity without the vagaries of pathology. The study of handedness differences is not just about handedness.

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19

Hoosain, Rumjahn. "Left Handedness and Handedness Switch Amongst the Chinese." Cortex 26, no. 3 (September 1990): 451–54. http://dx.doi.org/10.1016/s0010-9452(13)80094-9.

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20

Coren, Stanley. "Measurement of Handedness via Self-Report: The Relationship between Brief and Extended Inventories." Perceptual and Motor Skills 76, no. 3 (June 1993): 1035–42. http://dx.doi.org/10.2466/pms.1993.76.3.1035.

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Three self-report measures of handedness were explored. For simple dichotomous classification into right- versus left-handed groups, a brief (4-item) and an extended (12-item) inventory produced 98.8% classification concordance in a sample of 250 subjects. When handedness was treated as a continuous variable, indexes based upon the short and expanded scales correlated highly ( r = 0.95). A single-item handedness measure was also created which produced handedness classifications which were better than 97% concordant with the brief and extended handedness scales for dichotomous classification. The methodological implications of these findings for handedness measurement are discussed.

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Ransil, Bernard J., and Steven C. Schachter. "Inventory-Derived Task Handedness Preferences of Nine Professions and Their Associations with Self-Report Global Handedness Preferences." Perceptual and Motor Skills 86, no. 1 (February 1998): 303–20. http://dx.doi.org/10.2466/pms.1998.86.1.303.

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The handedness preference (laterality) of 1,196 professionals grouped in nine professions previously reported using self-reported global handedness and scores on a modified Edinburgh Handedness Inventory was further defined by evaluating the association between profession and the 10 manual tasks of the inventory. The previously reported ranking of professions in order of increasing righchandedness of laterality score arose from the handedness of specific inventory tasks. A similar association was found for self-reported global handedness. The evidence continues to support the hypothesis of an association between handedness preference and specific aptitudes or skills in this sample of professional persons.

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22

Oyebode, Femi, and Kenneth Davison. "Handedness and Epileptic Schizophrenia." British Journal of Psychiatry 156, no. 2 (February 1990): 228–30. http://dx.doi.org/10.1192/bjp.156.2.228.

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Thirty-two epileptic patients with RDC diagnoses of schizophrenia were tested for handedness on the Annett Handedness Schedule, and handedness was assigned on the basis of Annett–Maudsley criteria. They were compared with three other groups of patients. Five (15.6%) of the epileptic schizophrenic patients were mixed or left handed. The prevalence of mixed and left handedness did not differ between the samples studied. However, there was a significant reduction of mixed and left handedness in male epileptics with schizophrenia. Mixed or left handedness in male epileptics appears to be protective against the development of psychiatric illness in general.

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23

Karpychev, Victor, Tatyana Bolgina, Svetlana Malyutina, Victoria Zinchenko, Vadim Ushakov, Grigory Ignatyev, and Olga Dragoy. "No Association Between Structural Properties of Corpus Callosum and Handedness: Evidence from the Constrained Spherical Deconvolution Approach." Russian Journal of Cognitive Science 7, no. 3 (September 30, 2020): 68–77. http://dx.doi.org/10.47010/20.3.4.

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Handedness is the most prominent trait of functional asymmetry in humans, associated with lateralized cognitive functions and considered in relation to mental disorders. However, the neuroanatomical correlates of handedness are still unclear. It has been hypothesized that the structural properties of sub-regions of the corpus callosum (CC) are linked to handedness. Nevertheless, tractography studies of the relation between directly measured structural properties of CC subregions and handedness are lacking. The Constrained Spherical Deconvolution (CSD) approach enables full reconstruction of the sub-regions of the CC. The current study aimed to investigate the relation between the structural properties of the CC, such as volume and the CSD metric, referred to as hindrance modulated orientational anisotropy (HMOA), and handedness. Handedness was considered in two dimensions: direction (right-handed, ambidextrous, left-handed) and degree (the absolute values of Handedness quotient). We found no association between 1) volume or HMOA as a proxy of microstructural properties, namely the axonal diameter and fiber dispersion, of each sub-region and 2) either the direction or the degree of handedness. These findings suggest the absence of a direct relation between sub-regions of the CC and handedness, demonstrating the necessity of future tractography studies.

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Karpychev, Victor, Tatyana Bolgina, Svetlana Malyutina, Victoria Zinchenko, Vadim Ushakov, Grigory Ignatyev, and Olga Dragoy. "No Association Between Structural Properties of Corpus Callosum and Handedness: Evidence from the Constrained Spherical Deconvolution Approach." Russian Journal of Cognitive Science 7, no. 3 (September 30, 2020): 68–77. http://dx.doi.org/10.47010/20.3.4.

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Handedness is the most prominent trait of functional asymmetry in humans, associated with lateralized cognitive functions and considered in relation to mental disorders. However, the neuroanatomical correlates of handedness are still unclear. It has been hypothesized that the structural properties of sub-regions of the corpus callosum (CC) are linked to handedness. Nevertheless, tractography studies of the relation between directly measured structural properties of CC subregions and handedness are lacking. The Constrained Spherical Deconvolution (CSD) approach enables full reconstruction of the sub-regions of the CC. The current study aimed to investigate the relation between the structural properties of the CC, such as volume and the CSD metric, referred to as hindrance modulated orientational anisotropy (HMOA), and handedness. Handedness was considered in two dimensions: direction (right-handed, ambidextrous, left-handed) and degree (the absolute values of Handedness quotient). We found no association between 1) volume or HMOA as a proxy of microstructural properties, namely the axonal diameter and fiber dispersion, of each sub-region and 2) either the direction or the degree of handedness. These findings suggest the absence of a direct relation between sub-regions of the CC and handedness, demonstrating the necessity of future tractography studies.

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25

Hirnstein, Marco, and Kenneth Hugdahl. "Excess of non-right-handedness in schizophrenia: meta-analysis of gender effects and potential biases in handedness assessment." British Journal of Psychiatry 205, no. 4 (October 2014): 260–67. http://dx.doi.org/10.1192/bjp.bp.113.137349.

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BackgroundThe notion that schizophrenia is characterised by increased non-right-handedness is a cornerstone of the theory that schizophrenia arises from, and is genetically linked to, abnormal brain lateralisation. Reviews and meta-analyses have reported higher rates of non-right-handers in patients with schizophrenia. However, this was suggested to be the result of a gender artefact or a hidden bias in self-report handedness questionnaires.AimsTo investigate using a meta-analytical approach whether the excess of non-right-handedness is seen in both females and males, and also when handedness is assessed behaviourally.MethodElectronic databases were searched for studies that reported (a) the rate of female and male non-right-handers in schizophrenia compared with controls and (b) the rate of non-right-handers in schizophrenia (regardless of gender) based on behavioural handedness assessment.ResultsThe odds ratios (ORs) for females (OR = 1.63; based on 621 patients, 3747 controls) and males (OR = 1.50; based on 1213 patients, 3800 controls) differed significantly from 1.0, indicating both female and male patients were more often non-right-handed than controls. Moreover, there was an excess of non-right-handedness in patients with schizophrenia when handedness was assessed behaviourally: OR = 1.84 (1255 patients, 6260 controls). Even when both gender and behavioural handedness assessment were controlled for simultaneously, the excess of non-right-handedness persisted.ConclusionsThe findings clearly demonstrate that the excess of non-right-handedness in schizophrenia does not result from a gender artefact or from biased handedness questionnaires. It is a true empirical effect and may indeed reflect a genetic link between schizophrenia and brain lateralisation.

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Bryden, M. P. "Handedness, Cerebral Lateralization, and Measures of “Latent Left-Handedness”." International Journal of Neuroscience 44, no. 3-4 (January 1989): 227–33. http://dx.doi.org/10.3109/00207458908986203.

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27

Shamir, Lior. "ASYMMETRY BETWEEN GALAXIES WITH CLOCKWISE HANDEDNESS AND COUNTERCLOCKWISE HANDEDNESS." Astrophysical Journal 823, no. 1 (May 19, 2016): 32. http://dx.doi.org/10.3847/0004-637x/823/1/32.

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Dellatolas, G., S. Luciani, A. Castresana, C. Remy, P. Jallon, D. Laplane, and J. Bancaud. "Pathological left-handedness: Left-handedness correlatives in adult epileptics." Brain 116, no. 6 (December 1, 1993): 1565–74. http://dx.doi.org/10.1093/brain/116.6.1565.

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29

Schachter, Steven C., and Bernard J. Ransil. "Handedness Distributions in Nine Professional Groups." Perceptual and Motor Skills 82, no. 1 (February 1996): 51–63. http://dx.doi.org/10.2466/pms.1996.82.1.51.

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The relationships between profession and handedness were studied in approximately equal numbers of accountants, architects, dentists, lawyers, librarians, mathematicians, orthodontists, orthopedic surgeons, and psychiatrists ( ns = 133+36; N = 1196). Handedness was estimated using laterality scores derived from the Edinburgh Handedness Inventory and self-reported global handedness preference scores. Architects and lawyers had the most lefthanded average laterality scores. Orthopedic surgeons, mathematicians, and librarians had the most righthanded average laterality scores. Psychiatrists and lawyers had the most ambilateral laterality scores, mathematicians and librarians the least. These findings are discussed in relation to theories of handedness and cerebral localization of visuospatial and language function.

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Biehl, K., A. Frese, M. Marziniak, I.-W. Husstedt, and S. Evers. "Migraine and Left-Handedness are not Associated. A New Case—Control Study and Meta-Analysis." Cephalalgia 28, no. 5 (May 2008): 553–57. http://dx.doi.org/10.1111/j.1468-2982.2008.01553.x.

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To investigate the possible association between migraine and left-handedness, we enrolled 100 patients with a diagnosis of migraine according to the International Headache Society diagnostic criteria and 100 age- and sex-matched control subjects into a case—control study. Handedness was determined by the Edinburgh Handedness Inventory. There was no significant difference in the frequency or grade of left-handedness between the two groups. Additionally, we pooled our data with those from five similar studies, which did not alter the result. Thus, neither our study nor the meta-analysis support Geschwind and Behan's hypothesis of an association between migraine and left-handedness.

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Pullman, Lesleigh E., Nabhan Refaie, Martin L. Lalumière, and DB Krupp. "Is Psychopathy a Mental Disorder or an Adaptation? Evidence From a Meta-Analysis of the Association Between Psychopathy and Handedness." Evolutionary Psychology 19, no. 4 (October 2021): 147470492110404. http://dx.doi.org/10.1177/14747049211040447.

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Psychopathy has historically been conceptualized as a mental disorder, but there is growing evidence that it may instead be an alternative, adaptive life history strategy designed by natural selection. Although the etiology of mental disorders is not fully understood, one likely contributor is perturbations affecting neurodevelopment. Nonright-handedness is a sign of such perturbations, and therefore can be used to test these competing models. If psychopathy is a mental disorder, psychopaths should show elevated rates of nonright-handedness. However, an adaptive strategy perspective expects psychopaths to be neurologically healthy and therefore predicts typical rates of nonright-handedness. We meta-analyzed 16 studies that investigated the association between psychopathy and handedness in various populations. There was no difference in the rates of nonright-handedness between community participants high and low in psychopathy. Furthermore, there was no difference between psychopathic and nonpsychopathic offenders in rates of nonright-handedness, though there was a tendency for offenders scoring higher on the Interpersonal/Affective dimension of psychopathy to have lower rates of nonright-handedness, and for offenders scoring higher on the Behavioral dimension of psychopathy to have higher rates of nonright-handedness. Lastly, there was no difference in rates of nonright-handedness between psychopathic and nonpsychopathic mental health patients. Thus, our results fail to support the mental disorder model and partly support the adaptive strategy model. We discuss limitations of the meta-analysis and implications for theories of the origins of psychopathy.

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Pullman, Lesleigh E., Nabhan Refaie, Martin L. Lalumière, and DB Krupp. "Is Psychopathy a Mental Disorder or an Adaptation? Evidence From a Meta-Analysis of the Association Between Psychopathy and Handedness." Evolutionary Psychology 19, no. 4 (October 2021): 147470492110404. http://dx.doi.org/10.1177/14747049211040447.

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Psychopathy has historically been conceptualized as a mental disorder, but there is growing evidence that it may instead be an alternative, adaptive life history strategy designed by natural selection. Although the etiology of mental disorders is not fully understood, one likely contributor is perturbations affecting neurodevelopment. Nonright-handedness is a sign of such perturbations, and therefore can be used to test these competing models. If psychopathy is a mental disorder, psychopaths should show elevated rates of nonright-handedness. However, an adaptive strategy perspective expects psychopaths to be neurologically healthy and therefore predicts typical rates of nonright-handedness. We meta-analyzed 16 studies that investigated the association between psychopathy and handedness in various populations. There was no difference in the rates of nonright-handedness between community participants high and low in psychopathy. Furthermore, there was no difference between psychopathic and nonpsychopathic offenders in rates of nonright-handedness, though there was a tendency for offenders scoring higher on the Interpersonal/Affective dimension of psychopathy to have lower rates of nonright-handedness, and for offenders scoring higher on the Behavioral dimension of psychopathy to have higher rates of nonright-handedness. Lastly, there was no difference in rates of nonright-handedness between psychopathic and nonpsychopathic mental health patients. Thus, our results fail to support the mental disorder model and partly support the adaptive strategy model. We discuss limitations of the meta-analysis and implications for theories of the origins of psychopathy.

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Ooki, Syuichi. "Genetic and Environmental Influences on the Handedness and Footedness in Japanese Twin Children." Twin Research and Human Genetics 8, no. 6 (December 1, 2005): 649–56. http://dx.doi.org/10.1375/twin.8.6.649.

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AbstractThe purpose of this study was to examine the genetic contribution to handedness and footedness in childhood using one of the largest available databases of Japanese twins. The participants were 1131 twin pairs, 1057 males and 1205 females, of 11 or 12 years of age (6th grade of secondary school in the Japanese education system). All data were gathered by questionnaire. The prevalence of left (nonright) handedness was 15% in males and 13% in females. The prevalence of left (nonright) footedness was 13% in males and 11% in females. The similarities between twin pairs, estimated by concordance rates and tetrachoric correlations, suggested a slight genetic effect on male handedness, no genetic effect on female handedness, and no genetic effect on footedness in either sex. Structural equation modeling showed small genetic factors (11%) in male handedness and no genetic factors in female handedness. As to footedness, no genetic factors were observed in either sex. The effects of nonshared environmental factors were large (85%) in males and moderate (44%) in females. Moreover, handedness and footedness tended to be concordant irrespective of sex, with polychoric correlations over r = .70. The results of bivariate genetic analyses were not necessarily satisfactory. For males, no model fit. For females, shared and nonshared environmental factors explained the concordance of handedness and footedness. It was concluded that the genetic effects on handedness and footedness are relatively small, as is their association; moreover, considerably large twin samples are needed to obtain stable and appropriate results.

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Hopkins, William D., Jennifer Schaeffer, Jamie L. Russell, Stephanie L. Bogart, Adrien Meguerditchian, and Olivier Coulon. "A comparative assessment of handedness and its potential neuroanatomical correlates in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus)." Behaviour 152, no. 3-4 (2015): 461–92. http://dx.doi.org/10.1163/1568539x-00003204.

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The evolutionary origins of human right-handedness remain poorly understood. Some have hypothesized that tool use served as an important preadaptation for the eventual evolution of population-level right-handedness. In contrast, others have suggested that complex gestural and vocal communication served as prerequisite for the evolution of human right-handedness. In this study, we tested these competing hypotheses by comparing the handedness of bonobos and chimpanzees, two closely related species of Pan, on three different measures of hand use including simple reaching, manual gestures and coordinated bimanual actions. Chimpanzees are well known for their tool using abilities whereas bonobos rarely use tools in the wild. In contrast, many have suggested that bonobos have a more flexible gestural and vocal communication system than chimpanzees. The overall results showed that chimpanzees were significantly more right-handed than bonobos for all three measures suggesting that adaptations for tool use rather than communication may have led to the emergence of human right-handedness. We further show that species differences in handedness may be linked to variation in the size and asymmetry of the motor-hand area of the precentral gyrus. The results are discussed within the context of evolutionary theories of handedness, as well as some limitations in the approach to handedness measurement in nonhuman primates.

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Bernard, Jessica A., Stephan F. Taylor, and Rachael D. Seidler. "Handedness, Dexterity, and Motor Cortical Representations." Journal of Neurophysiology 105, no. 1 (January 2011): 88–99. http://dx.doi.org/10.1152/jn.00512.2010.

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Motor system organization varies with handedness. However, previous work has focused almost exclusively on direction of handedness (right or left) as opposed to degree of handedness (strength). In the present study, we determined whether measures of interhemispheric interactions and degree of handedness are related to contra- and ipsilateral motor cortical representations. Participants completed a battery of handedness assessments including both handedness preference measures and behavioral measures of intermanual differences in dexterity, a computerized version of the Poffenberger paradigm (PP) to estimate interhemispheric transfer time (IHTT), and they underwent transcranial magnetic stimulation (TMS) mapping of both motor cortices while we recorded muscle activity from the first dorsal interosseous muscle bilaterally. A greater number of ipsilateral motor evoked potentials (iMEPs) were elicited in less lateralized individuals with the number of iMEPs correlated with IHTT. There were no relationships between handedness or lateralization of dexterity and symmetry of contralateral motor representations, although this symmetry was related to IHTT. Finally, IHTT was positively correlated with multiple measures of laterality and handedness. These findings demonstrate that degree of laterality of dexterity is related to the propensity for exhibiting iMEPs and the speed of interhemispheric interactions. However, it is not clear whether iMEPs are directly mediated via ipsilateral corticospinal projections or are transcallosally transmitted.

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Sandars, P. G. H. "Chirality in the RNA world and beyond." International Journal of Astrobiology 4, no. 1 (January 2005): 49–61. http://dx.doi.org/10.1017/s1473550405002442.

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Homochirality is an essential feature of biology, but how it developed in early life remains unclear. Our aim in this paper is to add to the discussion by taking a somewhat arbitrary but definite sequence of events and examining carefully the chirality at each stage. Our scenario for the development of life starts with the prebiotic, continues through a pre-RNA stage to the RNA world. This leads to the development of proteins and then to the incorporation of DNA in RNA–DNA–protein biochemistry.We argue that homochirality probably did not develop prebiotically. We see the likely chiral bifurcation point to be during the development of RNA from an achiral pre-RNA. Surprisingly, we find the driving force for this to be enantiomeric cross-inhibition in which the addition of a ‘wrong-handed’ enantiomer to a growing polymer brings the polymerization to a halt. This, it is often argued, is a serious impediment to the development of chiral purity. We suggest that the sign of handedness at this stage was probably determined by chance. We then point out that homochiral RNA was unlikely by itself to lead to homochiral proteins. We identify the additional nonlinear feature required for bifurcation to be the rapid increase in enzymic power available when the amino acids in proteins approach single handedness and structural features such as α-helices and β-sheets become viable. If this is correct, then the handedness of the protein sector is indeed linked to that of RNA. However, the relative sign of the two handednesses will have depended on the precise stereo-sensitive interaction between the RNA and protein systems. We suggest that the most plausible scenario is via the recently discovered RNA binding sites for amino acids, which are both stereo-selective and have contact with the developing genetic code. The detailed steps that determine the handedness are not yet clear and may be specific to the precise development path.It follows that if biochemistry similar to that on Earth developed extraterrestrially, we would surely have homochirality but at this stage we cannot be sure about the handedness of either the nucleic acid or the protein components.

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Lewin, J., D. Kohen, and G. Mathew. "Handedness in Mental Handicap: Investigation into Populations of Down's Syndrome, Epilepsy and Autism." British Journal of Psychiatry 163, no. 5 (November 1993): 674–76. http://dx.doi.org/10.1192/bjp.163.5.674.

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The handedness in three randomly sampled groups of people with learning disabilities consisting of patients with Down's syndrome, epilepsy, and autism were studied using a validated instrument. All subjects were controlled for neurological and other medical disorders. A statistically significant increase in left-handedness and ambiguous handedness compared with the general population was found in all groups. There was no significant difference in the rate of left-handedness between the three groups.

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Verdino, Michele, and Sherry Dingman. "Two Measures of Laterality in Handedness: The Edinburgh Handedness Inventory and the Purdue Pegboard Test of Manual Dexterity." Perceptual and Motor Skills 86, no. 2 (April 1998): 476–78. http://dx.doi.org/10.2466/pms.1998.86.2.476.

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This study investigated the relationship between a paper-and-pencil measure of laterality in handedness, the Edinburgh Handedness Inventory, and a test of manual dexterity, the Purdue Pegboard test. Individuals of extreme handedness based on the Edinburgh Handedness Inventory (Laterality Quotients of +90 to +100 and −100 and +54; 50 each) were recruited to complete the Purdue Pegboard test of manual dexterity. Subjects in the sinistral group had significantly smaller mean discrepancy scores in performance between their hands [ t80 = 5.12, p=.0001] and much greater variance in performance than dextral subjects ( F1,98 = 2.85, p=.0001). These findings suggest that paper-and-pencil measures of lateral preference for handedness may not identify proficiency of subgroups within a sinistral group.

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Messinger, Harley B., Margaret I. Messinger, and John R. Graham. "Migraine and Left-Handedness: Is There a Connection?" Cephalalgia 8, no. 4 (December 1988): 237–44. http://dx.doi.org/10.1046/j.1468-2982.1988.0804237.x.

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In 1982, Geschwind and Behan reported an association between migraine headache and left-handedness. The present study was an attempt to test this hypothesis by comparing the frequency of left-handedness in migraine and tension headache patients at a headache center. Cluster headache cases were also included because Geschwind and Behan suspected that the association might be even stronger in this disorder. A special scoring method for handedness was devised by Geschwind and Behan to help identify a possible higher risk in mixed-handedness subjects. No significant associations emerged in any of these tests. A modest association of cluster headache and left-handedness disappeared when adjustment was made for the strong predilection of cluster headache for the male sex.

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Messinger, HB, MI Messinger, L. Kudrow, and LV Kudrow. "Handedness and Headache." Cephalalgia 14, no. 1 (February 1994): 64–67. http://dx.doi.org/10.1046/j.1468-2982.1994.1401064.x.

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A California handedness study involved 199 male and 74 female cluster headache sufferers as well as 477 migraineurs. Earlier reported data indicated that cluster headache patients had a left-handedness prevalence of over 15%. With the current data the prevalence in males was 11.0% and in females, 8.2%. The corresponding migraine figures were 11.8% and 8.1%. The cluster and migraine headache groups did not differ significantly from each other or from the expected 10% frequency of left-handedness in either sex.

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Malesu, R. R., M. Cannon, P. B. Jones, K. McKenzie, K. Gilvarry, L. Rifkin, B. K. Toone, and R. M. Murray. "Mixed-Handedness in Patients with Functional Psychosis." British Journal of Psychiatry 168, no. 2 (February 1996): 234–36. http://dx.doi.org/10.1192/bjp.168.2.234.

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BackgroundAn excess of non-right-handedness has been shown among patients with schizophrenia. However it is not clear whether this finding can be accounted for by an increase in left-handedness, mixed-handedness or both. It is not known whether atypical patterns of hand preferences occur in other functional psychotic illnesses.MethodThe Annett hand preference questionnaire was administered to patients with schizophrenia (n=120); affective psychosis (n=55); schizoaffective psychosis (n=41), and control subjects (n=86). Handedness was classified into three categories: right, mixed and left-handedness.ResultsThe hand preference patterns of patients with functional psychotic illnesses were not significantly different from controls. Patients with schizophrenia showed a non-significant excess of mixed-handedness compared with controls. Patients with schizophrenia and affective psychosis showed a non-significant decrease in left-handedness compared with controls.ConclusionsAlthough our results showed a trend in the hypothesised direction, we failed to demonstrate that patients with psychotic illness differed from controls on self-reported hand preference patterns.

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Naugle, Richard I., Erin D. Bigler, C. Munro Cullum, and Paul J. Massman. "Handedness and Dementia." Perceptual and Motor Skills 65, no. 1 (August 1987): 207–10. http://dx.doi.org/10.2466/pms.1987.65.1.207.

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Some researchers have speculated that left-hand dominance is more prevalent among patients suffering from dementia of the Alzheimer's type which began prior to age 65 yr. and that, in those patients, the disease runs a more rapid course. In the present study, seven left-handed dementia patients were matched with seven right-handed dementia patients on the basis of age and years of education and were compared with regard to neuropsychological compromise. While the left-handed group was somewhat more impaired than the right-handed subjects, the difference between the two groups was not statistically significant.

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Kalodner, Melissa F., Regina A. Rodin, and David Lester. "Handedness and Personality." Perceptual and Motor Skills 78, no. 3_suppl (June 1994): 1066. http://dx.doi.org/10.2466/pms.1994.78.3c.1066.

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James, William H. "Handedness and Size." Perceptual and Motor Skills 80, no. 3_suppl (June 1995): 1250. http://dx.doi.org/10.2466/pms.1995.80.3c.1250.

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Since baseball pitchers are selected for height and left-handedness, nothing can validly be inferred about the general population from the fact that left-handed Major League pitchers are shorter than right-handed pitchers.

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Hicks, Robert A., Jose Bautista, and Gregory J. Hicks. "Boundaries and Handedness." Perceptual and Motor Skills 88, no. 3_suppl (June 1999): 1313–14. http://dx.doi.org/10.2466/pms.1999.88.3c.1313.

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Callaghan, William L. "Emily's right-handedness." Brontë Society Transactions 25, no. 1 (April 2000): 86. http://dx.doi.org/10.1179/030977600794195373.

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Firth, Alison Y. "Handedness in strabismics." Acta Ophthalmologica Scandinavica 73, no. 6 (May 27, 2009): 486–90. http://dx.doi.org/10.1111/j.1600-0420.1995.tb00321.x.

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Lester, David. "Handedness and Personality." Perceptual and Motor Skills 80, no. 3_suppl (June 1995): 1290. http://dx.doi.org/10.1177/003151259508003c01.

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Rodenhauser, Paul, H. J. Khamis, and Alice Faryna. "Alexithymia and Handedness." Psychotherapy and Psychosomatics 45, no. 4 (1986): 169–73. http://dx.doi.org/10.1159/000287945.

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KING, R. BRUCE. "Chirality and Handedness." Annals of the New York Academy of Sciences 988, no. 1 (May 2003): 158–70. http://dx.doi.org/10.1111/j.1749-6632.2003.tb06095.x.

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Journal articles on the topic 'Handedness'

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