The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
William D Hopkins - One of the best experts on this subject based on the ideXlab platform.
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A comparative assessment of Handedness and its potential neuroanatomical correlates in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus)
Behaviour, 2015Co-Authors: William D Hopkins, Adrien Meguerditchian, Jennifer Schaeffer, Jamie L. Russell, Stephanie L. Bogart, Olivier CoulonAbstract: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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Chimpanzees (Pan troglodytes) are predominantly Right-handed: replication in three populations of apes.
Behavioral Neuroscience, 2004Co-Authors: William D Hopkins, Michelle A Hook, Michael J. Wesley, M. Kay Izard, Steven J SchapiroAbstract:Population-level Right-Handedness has historically been considered a hallmark of human evolution. Even though recent studies in chimpanzees (Pan troglodytes) have demonstrated population-level Right-Handedness for certain behaviors, some have questioned the validity and consistency of these findings by arguing that reported laterality effects are specific to certain colonies of apes and to those chimpanzees reared by humans. The authors report evidence of population-level Right-Handedness in 3 separate colonies of chimpanzees. Moreover, Handedness in the 3 colonies was unrelated to the proportion of subjects that were raised by humans. This is the strongest evidence to date that population-level Handedness is evident in chimpanzees and is not an artifact of human rearing.
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Comparative assessment of Handedness for a coordinated bimanual task in chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus).
Journal of Comparative Psychology, 2003Co-Authors: William D Hopkins, Tara S. Stoinski, Kristen E. Lukas, Stephen R. Ross, Michael J. WesleyAbstract:Hand preferences for a coordinated bimanual task were assessed in a sample of 31 captive gorillas (Gorilla gorilla) and 19 captive orangutans (Pongo pygmaeus) and were compared with chimpanzee (Pan troglodytes) hand preferences in subjects that were matched on the basis of age, sex, and rearing history. The task required that the apes remove food from the inside edges of a symmetrical polyvinyl chloride pipe presented to them in their home cages. The results indicate significant species differences with chimpanzees showing population-level Right-Handedness and orangutans showing population-level left-Handedness. The gorillas showed a nonsignificant trend toward Right-Handedness. The results are discussed in terms of possible ecological or biomechanical factors that may influence hand preferences in different ape species.
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population level Right Handedness for a coordinated bimanual task in chimpanzees replication and extension in a second colony of apes
International Journal of Primatology, 2003Co-Authors: William D Hopkins, Michelle A Hook, Stephanie Braccini, Steven J SchapiroAbstract:The purpose of this study was to evaluate the reliability of previously published findings on hand preferences in chimpanzees by evaluating hand use in a second colony of captive chimpanzees. We assessed hand preferences for a coordinated bimanual task in 116 chimpanzees (Pan troglodytes) at the University of Texas M. D. Anderson Cancer Center and compared them to previously published findings in captive chimpanzees at the Yerkes National Primate Research Center. The new sample showed significant population-level Right Handedness, which is consistent with previously published findings in the Yerkes chimpanzees. Combined data on the 2 chimpanzee colonies, revealed a significant effect of rearing history on hand preference, with wild-caught chimpanzees showing less Right-Handedness than captive-born mother-reared chimpanzees. We discuss the results in terms of the role of early environment on the development of laterality.
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Genetic Influence on the Expression of Hand Preferences in Chimpanzees (Pan Troglodytes): Evidence in Support of the Right-Shift Theory and Developmental Instability
Psychological Science, 2001Co-Authors: William D Hopkins, Jeremy F. Dahl, Dawn L. PilcherAbstract:Genetic mechanisms have been proposed to explain the pervasive representation of Right-Handedness in humans, whereas random, nongenetic factors have been posited to explain the lack of population-level Right-Handedness in nonhuman primates. We report evidence that hand preferences in chimpanzees are heritable, even among related individuals raised in different environments. Furthermore, we report that the degree of heritability is modified by factors associated with developmental instability, notably, offspring parity. The data are interpreted to reconcile both genetic models for Handedness and hypotheses suggesting that developmental instability influences variation in Handedness.
Ketil Joachim Oedegaard - One of the best experts on this subject based on the ideXlab platform.
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non Right Handedness is associated with migraine and soft bipolarity in patients with mood disorders
Journal of Affective Disorders, 2008Co-Authors: Kenneth Hugdahl, Ole Bernt Fasmer, Hagop S Akiskal, Ketil Joachim OedegaardAbstract:Abstract Background There is a substantial body of data showing differences in the functioning of the two hemispheres in unipolar depressive and bipolar disorders. Migraine is a frequent co-morbid disorder in these patients, and it has been proposed that migraine may be associated with left-Handedness. It would therefore be interesting to study migraine and Handedness in a population of patients with mood disorders. Methods A total of 201 patients with an index episode of either major depression or mania were interviewed with a semi-structured interview based partly on DSM-IV criteria and partly on TEMPS-I for affective temperaments. The criteria of the Headache Classification Committee of the International Headache Society were used to establish the diagnosis of migraine. Hand preference was assessed using the Edinburgh inventory, and the patients were classified as having Right-, left-, or mixed-Handedness. Results In the whole group 117 patients had migraine (58%) and 59 (29%) were classified as having non-Right hand preference. There was a significant increased prevalence of non-Right-Handedness in the migraine group (37% vs. 19%, p = 0.021, Chi-square test; OR 2.5; 95% CI 1.3 –4.8, p = 0.007). In patients with cyclothymic, hyperthymic or irritable temperaments the prevalence of non-Right-Handedness (42%) was significantly higher ( p = 0.013, Chi-square test; OR 2.2, 95% CI 1.2–4.3) compared to patients with a depressive or no affective temperament (24%). The prevalence of non-Right-Handedness was also significantly higher both in patients with co-morbid eating disorders (48% vs. 26%, p = 0.008 Chi-square test; OR 2.7, 95% CI 1.3–5.9, p = 0.01) and asthma (45% vs. 26%, p = 0.026 Chi-square test; OR 2.3, 95% CI 1.1–5.1, p = 0.029). Limitations Non-blind evaluation of affective diagnosis, migraine and Handedness. Conclusions Our main finding supports the hypothesis that non-Right-Handedness is associated with migraine and bipolar affective temperaments (“soft bipolarity”) in a sample of patients with major affective disorders.
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research report non Right Handedness is associated with migraine and soft bipolarity in patients with mood disorders
2008Co-Authors: Ole Bernt Fasmer, Kenneth Hugdahl, Hagop S Akiskal, Ketil Joachim OedegaardAbstract:Background: There is a substantial body of data showing differences in the functioning of the two hemispheres in unipolar depressive and bipolar disorders. Migraine is a frequent co-morbid disorder in these patients, and it has been proposed that migraine may be associated with left-Handedness. It would therefore be interesting to study migraine and Handedness in a population of patients with mood disorders. Methods: A total of 201 patients with an index episode of either major depression or mania were interviewed with a semi-structured interview based partly on DSM-IV criteria and partly on TEMPS-I for affective temperaments. The criteria of the Headache Classification Committee of the International Headache Society were used to establish the diagnosis of migraine. Hand preference was assessed using the Edinburgh inventory, and the patients were classified as having Right-, left-, or mixed-Handedness. Results: In the whole group 117 patients had migraine (58%) and 59 (29%) were classified as having non-Right hand preference. There was a significant increased prevalence of non-Right-Handedness in the migraine group (37% vs. 19%, p=0.021, Chi-square test; OR 2.5; 95% CI 1.3 –4.8, p=0.007). In patients with cyclothymic, hyperthymic or irritable temperaments the prevalence of non-Right-Handedness (42%) was significantly higher (p=0.013, Chi-square test; OR 2.2, 95% CI 1.2–4.3) compared to patients with a depressive or no affective temperament (24%). The prevalence of non-Right-Handedness was also significantly higher both in patients with co-morbid eating disorders (48% vs. 26%, p=0.008 Chi-square test; OR 2.7, 95% CI 1.3–5.9, p=0.01) and asthma (45% vs. 26%, p=0.026 Chi-square test; OR 2.3, 95% CI 1.1–5.1, p=0.029). Limitations: Non-blind evaluation of affective diagnosis, migraine and Handedness. Conclusions: Our main finding supports the hypothesis that non-Right-Handedness is associated with migraine and bipolar affective temperaments (“soft bipolarity”) in a sample of patients with major affective disorders. © 2007 Elsevier B.V. All Rights reserved.
Kenneth Hugdahl - One of the best experts on this subject based on the ideXlab platform.
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excess of non Right Handedness in schizophrenia meta analysis of gender effects and potential biases in Handedness assessment
British Journal of Psychiatry, 2014Co-Authors: Marco Hirnstein, Kenneth HugdahlAbstract:Background The 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. Aims To 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. Method Electronic 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. Results The 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. Conclusions The 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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non Right Handedness is associated with migraine and soft bipolarity in patients with mood disorders
Journal of Affective Disorders, 2008Co-Authors: Kenneth Hugdahl, Ole Bernt Fasmer, Hagop S Akiskal, Ketil Joachim OedegaardAbstract:Abstract Background There is a substantial body of data showing differences in the functioning of the two hemispheres in unipolar depressive and bipolar disorders. Migraine is a frequent co-morbid disorder in these patients, and it has been proposed that migraine may be associated with left-Handedness. It would therefore be interesting to study migraine and Handedness in a population of patients with mood disorders. Methods A total of 201 patients with an index episode of either major depression or mania were interviewed with a semi-structured interview based partly on DSM-IV criteria and partly on TEMPS-I for affective temperaments. The criteria of the Headache Classification Committee of the International Headache Society were used to establish the diagnosis of migraine. Hand preference was assessed using the Edinburgh inventory, and the patients were classified as having Right-, left-, or mixed-Handedness. Results In the whole group 117 patients had migraine (58%) and 59 (29%) were classified as having non-Right hand preference. There was a significant increased prevalence of non-Right-Handedness in the migraine group (37% vs. 19%, p = 0.021, Chi-square test; OR 2.5; 95% CI 1.3 –4.8, p = 0.007). In patients with cyclothymic, hyperthymic or irritable temperaments the prevalence of non-Right-Handedness (42%) was significantly higher ( p = 0.013, Chi-square test; OR 2.2, 95% CI 1.2–4.3) compared to patients with a depressive or no affective temperament (24%). The prevalence of non-Right-Handedness was also significantly higher both in patients with co-morbid eating disorders (48% vs. 26%, p = 0.008 Chi-square test; OR 2.7, 95% CI 1.3–5.9, p = 0.01) and asthma (45% vs. 26%, p = 0.026 Chi-square test; OR 2.3, 95% CI 1.1–5.1, p = 0.029). Limitations Non-blind evaluation of affective diagnosis, migraine and Handedness. Conclusions Our main finding supports the hypothesis that non-Right-Handedness is associated with migraine and bipolar affective temperaments (“soft bipolarity”) in a sample of patients with major affective disorders.
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research report non Right Handedness is associated with migraine and soft bipolarity in patients with mood disorders
2008Co-Authors: Ole Bernt Fasmer, Kenneth Hugdahl, Hagop S Akiskal, Ketil Joachim OedegaardAbstract:Background: There is a substantial body of data showing differences in the functioning of the two hemispheres in unipolar depressive and bipolar disorders. Migraine is a frequent co-morbid disorder in these patients, and it has been proposed that migraine may be associated with left-Handedness. It would therefore be interesting to study migraine and Handedness in a population of patients with mood disorders. Methods: A total of 201 patients with an index episode of either major depression or mania were interviewed with a semi-structured interview based partly on DSM-IV criteria and partly on TEMPS-I for affective temperaments. The criteria of the Headache Classification Committee of the International Headache Society were used to establish the diagnosis of migraine. Hand preference was assessed using the Edinburgh inventory, and the patients were classified as having Right-, left-, or mixed-Handedness. Results: In the whole group 117 patients had migraine (58%) and 59 (29%) were classified as having non-Right hand preference. There was a significant increased prevalence of non-Right-Handedness in the migraine group (37% vs. 19%, p=0.021, Chi-square test; OR 2.5; 95% CI 1.3 –4.8, p=0.007). In patients with cyclothymic, hyperthymic or irritable temperaments the prevalence of non-Right-Handedness (42%) was significantly higher (p=0.013, Chi-square test; OR 2.2, 95% CI 1.2–4.3) compared to patients with a depressive or no affective temperament (24%). The prevalence of non-Right-Handedness was also significantly higher both in patients with co-morbid eating disorders (48% vs. 26%, p=0.008 Chi-square test; OR 2.7, 95% CI 1.3–5.9, p=0.01) and asthma (45% vs. 26%, p=0.026 Chi-square test; OR 2.3, 95% CI 1.1–5.1, p=0.029). Limitations: Non-blind evaluation of affective diagnosis, migraine and Handedness. Conclusions: Our main finding supports the hypothesis that non-Right-Handedness is associated with migraine and bipolar affective temperaments (“soft bipolarity”) in a sample of patients with major affective disorders. © 2007 Elsevier B.V. All Rights reserved.
Steven J Schapiro - One of the best experts on this subject based on the ideXlab platform.
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Chimpanzees (Pan troglodytes) are predominantly Right-handed: replication in three populations of apes.
Behavioral Neuroscience, 2004Co-Authors: William D Hopkins, Michelle A Hook, Michael J. Wesley, M. Kay Izard, Steven J SchapiroAbstract:Population-level Right-Handedness has historically been considered a hallmark of human evolution. Even though recent studies in chimpanzees (Pan troglodytes) have demonstrated population-level Right-Handedness for certain behaviors, some have questioned the validity and consistency of these findings by arguing that reported laterality effects are specific to certain colonies of apes and to those chimpanzees reared by humans. The authors report evidence of population-level Right-Handedness in 3 separate colonies of chimpanzees. Moreover, Handedness in the 3 colonies was unrelated to the proportion of subjects that were raised by humans. This is the strongest evidence to date that population-level Handedness is evident in chimpanzees and is not an artifact of human rearing.
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population level Right Handedness for a coordinated bimanual task in chimpanzees replication and extension in a second colony of apes
International Journal of Primatology, 2003Co-Authors: William D Hopkins, Michelle A Hook, Stephanie Braccini, Steven J SchapiroAbstract:The purpose of this study was to evaluate the reliability of previously published findings on hand preferences in chimpanzees by evaluating hand use in a second colony of captive chimpanzees. We assessed hand preferences for a coordinated bimanual task in 116 chimpanzees (Pan troglodytes) at the University of Texas M. D. Anderson Cancer Center and compared them to previously published findings in captive chimpanzees at the Yerkes National Primate Research Center. The new sample showed significant population-level Right Handedness, which is consistent with previously published findings in the Yerkes chimpanzees. Combined data on the 2 chimpanzee colonies, revealed a significant effect of rearing history on hand preference, with wild-caught chimpanzees showing less Right-Handedness than captive-born mother-reared chimpanzees. We discuss the results in terms of the role of early environment on the development of laterality.
Arve Vorland Pedersen - One of the best experts on this subject based on the ideXlab platform.
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There Are Indeed More Left-Handers Within the Autism Spectrum Disorder Compared with in the General Population, but the Many Mixed-Handers Is the More Interesting Finding.
Journal of Autism and Developmental Disorders, 2018Co-Authors: Anne Langseth Rysstad, Arve Vorland PedersenAbstract:Letter to the editor in response to Howard Kushner’s claims that our data on non-Right-Handedness within the autism spectrum disorder were organized, by sleight of hand, so they would give a significant result that would support our desired conclusion. Here, we have re-categorized our data, and present evidence that there are indeed more left-handers within the ASD. Furthermore, we refute claims that we have misinterpreted our results in order to conclude about a causal link between left-Handedness and ASD, and highlight our original suggestion that mixed-Handedness, more specifically unclear Handedness, is the bigger problem, and that our findings of a total 60% non-Right-Handedness was the more interesting finding.
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brief report non Right Handedness within the autism spectrum disorder
Journal of Autism and Developmental Disorders, 2016Co-Authors: Anne Langseth Rysstad, Arve Vorland PedersenAbstract:A larger distribution of left-Handedness in the population of Autism Spectrum Disorder has been repeatedly reported. Despite of this, the sample sizes in the individual study’s are too small for any generalization to be made. Using both description-based and citation-based searches, the present review combines the individual results in order to examine whether non-Right-Handedness is a general trait of the autism spectrum disorder. With a relatively large combined sample size (N = 497), it can be concluded that the distribution of non-Right-Handedness is significantly greater within the autism spectrum disorder population, compared with the population in general.
