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Dexheimer B, Sainburg R, Sharp S, Philip BA. Roles of Handedness and Hemispheric Lateralization: Implications for Rehabilitation of the Central and Peripheral Nervous Systems: A Rapid Review. Am J Occup Ther 2024; 78:7802180120. [PMID: 38305818 PMCID: PMC11017742 DOI: 10.5014/ajot.2024.050398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2024] Open
Abstract
IMPORTANCE Handedness and motor asymmetry are important features of occupational performance. With an increased understanding of the basic neural mechanisms surrounding handedness, clinicians will be better able to implement targeted, evidence-based neurorehabilitation interventions to promote functional independence. OBJECTIVE To review the basic neural mechanisms behind handedness and their implications for central and peripheral nervous system injury. DATA SOURCES Relevant published literature obtained via MEDLINE. FINDINGS Handedness, along with performance asymmetries observed between the dominant and nondominant hands, may be due to hemispheric specializations for motor control. These specializations contribute to predictable motor control deficits that are dependent on which hemisphere or limb has been affected. Clinical practice recommendations for occupational therapists and other rehabilitation specialists are presented. CONCLUSIONS AND RELEVANCE It is vital that occupational therapists and other rehabilitation specialists consider handedness and hemispheric lateralization during evaluation and treatment. With an increased understanding of the basic neural mechanisms surrounding handedness, clinicians will be better able to implement targeted, evidence-based neurorehabilitation interventions to promote functional independence. Plain-Language Summary: The goal of this narrative review is to increase clinicians' understanding of the basic neural mechanisms related to handedness (the tendency to select one hand over the other for specific tasks) and their implications for central and peripheral nervous system injury and rehabilitation. An enhanced understanding of these mechanisms may allow clinicians to better tailor neurorehabilitation interventions to address motor deficits and promote functional independence.
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Affiliation(s)
- Brooke Dexheimer
- Brooke Dexheimer, PhD, OTD, OTR/L, is Assistant Professor, Department of Occupational Therapy, Virginia Commonwealth University, Richmond;
| | - Robert Sainburg
- Robert Sainburg, PhD, OTR, is Professor and Huck Institutes Distinguished Chair, Department of Kinesiology, Pennsylvania State University, University Park, and Department of Neurology, Pennsylvania State College of Medicine, Hershey
| | - Sydney Sharp
- Sydney Sharp, is Occupational Therapy Doctoral Student, Department of Occupational Therapy, Virginia Commonwealth University, Richmond
| | - Benjamin A Philip
- Benjamin A. Philip, PhD, is Assistant Professor, Program in Occupational Therapy, Department of Neurology and Department of Surgery, Washington University School of Medicine, St. Louis, MO
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Caspar KR, Pallasdies F, Mader L, Sartorelli H, Begall S. The evolution and biological correlates of hand preferences in anthropoid primates. eLife 2022; 11:e77875. [PMID: 36454207 PMCID: PMC9714969 DOI: 10.7554/elife.77875] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 10/07/2022] [Indexed: 12/02/2022] Open
Abstract
The evolution of human right-handedness has been intensively debated for decades. Manual lateralization patterns in non-human primates have the potential to elucidate evolutionary determinants of human handedness, but restricted species samples and inconsistent methodologies have so far limited comparative phylogenetic studies. By combining original data with published literature reports, we assembled data on hand preferences for standardized object manipulation in 1786 individuals from 38 species of anthropoid primates, including monkeys, apes, and humans. Based on that, we employ quantitative phylogenetic methods to test prevalent hypotheses on the roles of ecology, brain size, and tool use in primate handedness evolution. We confirm that human right-handedness represents an unparalleled extreme among anthropoids and found taxa displaying population-level handedness to be rare. Species-level direction of manual lateralization was largely uniform among non-human primates and did not strongly correlate with any of the selected biological predictors, nor with phylogeny. In contrast, we recovered highly variable patterns of hand preference strength, which show signatures of both ecology and phylogeny. In particular, terrestrial primates tend to display weaker hand preferences than arboreal species. These results challenge popular ideas on primate handedness evolution, including the postural origins hypothesis. Furthermore, they point to a potential adaptive benefit of disparate lateralization strength in primates, a measure of hand preference that has often been overlooked in the past. Finally, our data show that human lateralization patterns do not align with trends found among other anthropoids, suggesting that unique selective pressures gave rise to the unusual hand preferences of our species.
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Affiliation(s)
- Kai R Caspar
- Department of General Zoology, University of Duisburg-EssenEssenGermany
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life SciencesPrahaCzech Republic
| | - Fabian Pallasdies
- Institute for Theoretical Biology, Department of Biology, Humboldt-Universität zu BerlinBerlinGermany
| | - Larissa Mader
- Department of General Zoology, University of Duisburg-EssenEssenGermany
| | | | - Sabine Begall
- Department of General Zoology, University of Duisburg-EssenEssenGermany
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Limb Preference in Animals: New Insights into the Evolution of Manual Laterality in Hominids. Symmetry (Basel) 2022. [DOI: 10.3390/sym14010096] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Until the 1990s, the notion of brain lateralization—the division of labor between the two hemispheres—and its more visible behavioral manifestation, handedness, remained fiercely defined as a human specific trait. Since then, many studies have evidenced lateralized functions in a wide range of species, including both vertebrates and invertebrates. In this review, we highlight the great contribution of comparative research to the understanding of human handedness’ evolutionary and developmental pathways, by distinguishing animal forelimb asymmetries for functionally different actions—i.e., potentially depending on different hemispheric specializations. Firstly, lateralization for the manipulation of inanimate objects has been associated with genetic and ontogenetic factors, with specific brain regions’ activity, and with morphological limb specializations. These could have emerged under selective pressures notably related to the animal locomotion and social styles. Secondly, lateralization for actions directed to living targets (to self or conspecifics) seems to be in relationship with the brain lateralization for emotion processing. Thirdly, findings on primates’ hand preferences for communicative gestures accounts for a link between gestural laterality and a left-hemispheric specialization for intentional communication and language. Throughout this review, we highlight the value of functional neuroimaging and developmental approaches to shed light on the mechanisms underlying human handedness.
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Prieur J, Le Du G, Stomp M, Barbu S, Blois-Heulin C. Human laterality for manipulation and gestural communication: A study of beach-volleyball players during the Olympic Games. Laterality 2020; 25:229-254. [PMID: 31366285 DOI: 10.1080/1357650x.2019.1648485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Comparative studies can help understand better brain functional lateralization for manipulation and language. This study investigated and compared, for the first time, human adults' laterality for manipulation and gestures in a non-experimental social context. We analysed the manual laterality of 48 beach volleyball athletes for four frequently expressed behaviours: a complex throwing action (jump serve) and three gestures (CLAP HAND, PUMP FIST and SLAP HAND-TO-HAND). We evaluated population-level laterality bias for each of the four behaviours separately, compared manual laterality between behaviours and investigated factors influencing gestural laterality. We furthered our between-gestures comparison by taking into account three categories of factors simultaneously: gesture characteristics (sensory modality), interactional context components (positions of interactants and emotional valence), and individual demographic characteristics (age, sex and country). Our study showed that (1) each behaviour considered presented a population-level right-hand bias, (2) differences of laterality between behaviours were probably related to gesture sensory modality and (3) signaller's laterality was modulated differently in relation to positions of interactants, emotional valence, age and sex. Our results support the literature suggesting that left-hemisphere specialization for manipulation and language (speech and gestures) may have evolved from complex manual activities such as throwing and from gestural communication.
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Affiliation(s)
- Jacques Prieur
- CNRS, EthoS (Ethologie animale et humaine), Univ Rennes, Normandie Univ, Paimpont, France
| | - Gwendoline Le Du
- CNRS, EthoS (Ethologie animale et humaine), Univ Rennes, Normandie Univ, Paimpont, France
| | - Mathilde Stomp
- CNRS, EthoS (Ethologie animale et humaine), Univ Rennes, Normandie Univ, Paimpont, France
| | - Stéphanie Barbu
- CNRS, EthoS (Ethologie animale et humaine), Univ Rennes, Normandie Univ, Paimpont, France
| | - Catherine Blois-Heulin
- CNRS, EthoS (Ethologie animale et humaine), Univ Rennes, Normandie Univ, Paimpont, France
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Tzourio-Mazoyer N, Zago L, Cochet H, Crivello F. Development of handedness, anatomical and functional brain lateralization. HANDBOOK OF CLINICAL NEUROLOGY 2020; 173:99-105. [PMID: 32958198 DOI: 10.1016/b978-0-444-64150-2.00011-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The present chapter offers a report on the recent literature on the neural bases of hemispheric specialization (HS), anatomical and functional developmental timecourse of HS, and on the available knowledge of their relationships with the development of handedness. Strong anatomical asymmetries can be seen located along the end of the sylvian fissure and the superior temporal sulcus (STS) as soon as the 23rd gestational week. They correspond to a leftward sulcal depth asymmetry of the Sylvian fissure coupled with a rightward asymmetry of STS. These neonatal asymmetries targeting speech processing areas do not further change with development. Different from these anatomical asymmetries, the functional asymmetries of language areas develop during childhood. Such a development is characterized at birth by a predominant interhemispheric intrinsic connectivity between homotopic areas that will evolve toward left hemisphere intrahemispheric intrinsic connectivity between anterior and posterior language poles. The development of such a typical architecture of language networks in the left hemisphere dominant for language in more than 90% of humans translates into a continuous increase in the leftward asymmetries of activation during language production throughout childhood. With regard to the rightward cerebral lateralization for visuospatial functions, neuroimaging studies tend to indicate an increase in rightward lateralization of frontal-parietal network with age during visuospatial memory and visuospatial search tasks. In addition, the spatial-attentional behavioral asymmetries emerge early (in preschool children) and, then, can be modulated by factors linked to motor asymmetry and handedness. Finally, the study of manual lateralization in relation to language development has shown the importance of considering several characteristics of manual activities. In particular, the dissociation between manipulative activities and communicative gestures in young children may open further perspectives for future research on HS.
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Affiliation(s)
| | - Laure Zago
- Institut des Maladies Neurodegeneratives, University of Bordeaux, Bordeaux, France
| | - Hélène Cochet
- Laboratoire Cognition, Langues, Langage, et Ergonomie, Toulouse University, CNRS, UT2J, Toulouse, France
| | - Fabrice Crivello
- Institut des Maladies Neurodegeneratives, University of Bordeaux, Bordeaux, France
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Language or music? Environmental influences on infants' handedness from 5 to 12 months. Brain Cogn 2018; 129:1-8. [PMID: 30545579 DOI: 10.1016/j.bandc.2018.12.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 10/19/2018] [Accepted: 12/05/2018] [Indexed: 11/21/2022]
Abstract
The main purpose of this study was to test the influence of music environment on hand-use preference in infants from 5 to 12 months, compared to speech environment. According to hemispheric specialization, our hypothesis was that infants would reach for objects more with their right hand in a speech context (left hemisphere), and more with their left hand in a music context (right hemisphere). 61 full-term infants aged from 5 to 12 months participated in this study. A prehension task was proposed successively in two sound environments (music and speech) in a counterbalanced order. Left-, right-movement and/or bimanual movements were scored. Results show that whatever the sound context, from 8 months a lateral right bias occurs and increases strongly. However, 5- to 7-months-old infants used more their left hand when they listen to a piece of classical music that an adult speech. Bimanual movements were more frequent at 6 and 7 months than unimanual movements in the speech condition. Results are discussed in terms of manual specialization.
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Prieur J, Lemasson A, Barbu S, Blois‐Heulin C. History, development and current advances concerning the evolutionary roots of human right‐handedness and language: Brain lateralisation and manual laterality in non‐human primates. Ethology 2018. [DOI: 10.1111/eth.12827] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Jacques Prieur
- CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 Universite de Rennes, Normandie Universite Paimpont France
| | - Alban Lemasson
- CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 Universite de Rennes, Normandie Universite Paimpont France
| | - Stéphanie Barbu
- CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 Universite de Rennes, Normandie Universite Paimpont France
| | - Catherine Blois‐Heulin
- CNRS, EthoS (Ethologie animale et humaine) – UMR 6552 Universite de Rennes, Normandie Universite Paimpont France
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Do Mechanical Effectiveness and Recipient Species Influence Intentional Signal Laterality in Captive Chimpanzees (Pan troglodytes)? INT J PRIMATOL 2018. [DOI: 10.1007/s10764-018-0054-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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9
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Challenges Facing the Study of the Evolutionary Origins of Human Right-Handedness and Language. INT J PRIMATOL 2018. [DOI: 10.1007/s10764-018-0038-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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10
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Robira B, Pouydebat E, San-Galli A, Meulman EJM, Aubaile F, Breuer T, Masi S. Handedness in gestural and manipulative actions in male hunter-gatherer Aka pygmies from Central African Republic. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 166:481-491. [PMID: 29427288 DOI: 10.1002/ajpa.23435] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 01/22/2018] [Accepted: 01/25/2018] [Indexed: 02/04/2023]
Abstract
OBJECTIVES All human populations display a right-biased handedness. Nonetheless, if studies on western populations are plenty, investigations of traditional populations living at subsistence levels are rare. Yet, understanding the geographical variation of phenotypes of handedness is crucial for testing evolutionary hypotheses. We aimed to provide a preliminary investigation of factors affecting handedness in 25 Aka pygmies from Central African Republic when spontaneously gesturing or manipulating food/tools (Nactions = 593). MATERIALS AND METHODS We recorded spontaneous behaviors and characterized individuals' hand preference using GLMM with descriptive variables as target position, task complexity (unimanual/bimanual), task nature (food/tool manipulation, gesture), and task physical/cognitive constraints (precision or power for manipulative actions and informative content for gestures). RESULTS Individuals were lateralized to the right (93%, N = 15) when manipulating food/tools but not when gesturing. Hand preference was affected by target position but not by task complexity. While nonexplicitly informative gestures were more biased to the right compared to explicitly informative ones, no differences were found within food/tool manipulation (power or precision vs. none). DISCUSSION Although we do not intend to assume generalizable results due to our reduced sample, our observations provide additional information on handedness in a contemporary traditional society. Especially, the study mainly evidenced considerable cultural effects in gestures while also supporting theories considering active tool manipulation as one of the overriding factor in human handedness evolution.
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Affiliation(s)
- Benjamin Robira
- Institut de biologie de l'Ecole normale supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France.,Département Hommes, Natures, and Sociétés, Muséum National d'Histoire Naturelle, Musée de l'Homme, UMR 7206-CNRS/MNHN, Paris, France
| | - Emmanuelle Pouydebat
- Department of Ecology and Management of Biodiversity, Muséum National d'Histoire Naturelle, UMR 7179-CNRS/MNHN, MECADEV, Paris, France
| | - Aurore San-Galli
- Département Hommes, Natures, and Sociétés, Muséum National d'Histoire Naturelle, Musée de l'Homme, UMR 7206-CNRS/MNHN, Paris, France
| | - Ellen J M Meulman
- Département Hommes, Natures, and Sociétés, Muséum National d'Histoire Naturelle, Musée de l'Homme, UMR 7206-CNRS/MNHN, Paris, France
| | - Françoise Aubaile
- Département Hommes, Natures, and Sociétés, Muséum National d'Histoire Naturelle, Musée de l'Homme, UMR 7206-CNRS/MNHN, Paris, France
| | - Thomas Breuer
- Global Conservation Program, Wildlife Conservation Society, 2300 Southern Boulevard, Bronx, New York
| | - Shelly Masi
- Département Hommes, Natures, and Sociétés, Muséum National d'Histoire Naturelle, Musée de l'Homme, UMR 7206-CNRS/MNHN, Paris, France
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Prieur J, Barbu S, Blois-Heulin C. Human laterality for manipulation and gestural communication related to 60 everyday activities: Impact of multiple individual-related factors. Cortex 2018; 99:118-134. [DOI: 10.1016/j.cortex.2017.10.023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Revised: 10/23/2017] [Accepted: 10/30/2017] [Indexed: 12/13/2022]
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Prieur J, Barbu S, Blois-Heulin C, Pika S. Captive gorillas' manual laterality: The impact of gestures, manipulators and interaction specificity. BRAIN AND LANGUAGE 2017; 175:130-145. [PMID: 29145029 DOI: 10.1016/j.bandl.2017.10.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/23/2017] [Accepted: 10/08/2017] [Indexed: 06/07/2023]
Abstract
Relationships between humans' manual laterality in non-communicative and communicative functions are still poorly understood. Recently, studies showed that chimpanzees' manual laterality is influenced by functional, interactional and individual factors and their mutual intertwinement. However, what about manual laterality in species living in stable social groups? We tackled this question by studying three groups of captive gorillas (N=35) and analysed their most frequent manual signals: three manipulators and 16 gesture types. Our multifactorial investigation showed that conspecific-directed gestures were overall more right-lateralized than conspecific-directed manipulators. Furthermore, it revealed a difference between conspecific- and human-directed gestural laterality for signallers living in one of the study groups. Our results support the hypothesis that gestural laterality is a relevant marker of language left-brain specialisation. We suggest that components of communication and of manipulation (not only of an object but also of a conspecific) do not share the same lateralised cerebral system in some primate species.
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Affiliation(s)
- Jacques Prieur
- Ethos "Ethologie Animale et Humaine", Université de Rennes 1 - CNRS UMR 6552, Station biologique de Paimpont, France.
| | - Stéphanie Barbu
- Ethos "Ethologie Animale et Humaine", Université de Rennes 1 - CNRS UMR 6552, Station biologique de Paimpont, France
| | - Catherine Blois-Heulin
- Ethos "Ethologie Animale et Humaine", Université de Rennes 1 - CNRS UMR 6552, Station biologique de Paimpont, France
| | - Simone Pika
- Max Planck Institute for Evolutionary Anthropology, Department of Primatology, Deutscher Platz 6, 04103 Leipzig, Germany.
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Cochet H. Manual asymmetries and hemispheric specialization: Insight from developmental studies. Neuropsychologia 2016; 93:335-341. [DOI: 10.1016/j.neuropsychologia.2015.12.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 12/17/2015] [Accepted: 12/18/2015] [Indexed: 10/22/2022]
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Cochet H, Centelles L, Jover M, Plachta S, Vauclair J. Hand preferences in preschool children: Reaching, pointing and symbolic gestures. Laterality 2015; 20:501-16. [DOI: 10.1080/1357650x.2015.1007057] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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16
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Cochet H, Vauclair J. Deictic gestures and symbolic gestures produced by adults in an experimental context: hand shapes and hand preferences. Laterality 2013; 19:278-301. [PMID: 23758417 DOI: 10.1080/1357650x.2013.804079] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The objective of this study was to gain new insights into the processes underlying gestural communication in adults by examining hand shapes and hand preference patterns associated with different types of gestures. Several communicative situations eliciting pointing gestures and symbolic gestures were presented to 81 participants in an experimental context. Results have highlighted some differences in hand shapes depending on the function of pointing: contrary to results reported in children, the proportion of index-finger gestures was higher in imperative situations than in declarative situations. The distance between the gesturer and the referent was also found to influence hand shapes, proximal pointing being more frequently associated with index-finger gestures than distal pointing. The comparison of hand preferences revealed a greater right-sided asymmetry for declarative pointing than for non-communicative activities, whereas there was no difference between imperative pointing and non-communicative activities, or between symbolic gestures and non-communicative activities. The present study thus sheds some light on the features and the roles of communicative gestures in adults. Results are discussed in relation to the ontogenetic and phylogenetic origins of communication.
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Affiliation(s)
- Hélène Cochet
- a School of Psychology & Neuroscience , University of St Andrews , Fife , UK
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Evolutionary origins of human handedness: evaluating contrasting hypotheses. Anim Cogn 2013; 16:531-42. [PMID: 23546932 PMCID: PMC3684717 DOI: 10.1007/s10071-013-0626-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 01/22/2013] [Accepted: 03/16/2013] [Indexed: 12/12/2022]
Abstract
Variation in methods and measures, resulting in past dispute over the existence of population handedness in nonhuman great apes, has impeded progress into the origins of human right-handedness and how it relates to the human hallmark of language. Pooling evidence from behavioral studies, neuroimaging and neuroanatomy, we evaluate data on manual and cerebral laterality in humans and other apes engaged in a range of manipulative tasks and in gestural communication. A simplistic human/animal partition is no longer tenable, and we review four (nonexclusive) possible drivers for the origin of population-level right-handedness: skilled manipulative activity, as in tool use; communicative gestures; organizational complexity of action, in particular hierarchical structure; and the role of intentionality in goal-directed action. Fully testing these hypotheses will require developmental and evolutionary evidence as well as modern neuroimaging data.
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Carey DP, Hutchinson CV. Looking at eye dominance from a different angle: is sighting strength related to hand preference? Cortex 2012; 49:2542-52. [PMID: 23357202 DOI: 10.1016/j.cortex.2012.11.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2011] [Revised: 08/24/2012] [Accepted: 11/04/2012] [Indexed: 10/27/2022]
Abstract
Sighting dominance (the behavioural preference for one eye over the other under monocular viewing conditions) has traditionally been thought of as a robust individual trait. However, Khan and Crawford (2001) have shown that, under certain viewing conditions, eye preference reverses as a function of horizontal gaze angle. Remarkably, the reversal of sighting from one eye to the other depends on which hand is used to reach out and grasp the target. Their procedure provides an ideal way to measure the strength of monocular preference for sighting, which may be related to other indicators of hemispheric specialisation for speech, language and motor function. Therefore, we hypothesised that individuals with consistent side preferences (e.g., right hand, right eye) should have more robust sighting dominance than those with crossed lateral preferences. To test this idea, we compared strength of eye dominance in individuals who are consistently right or left sided for hand and foot preference with those who are not. We also modified their procedure in order to minimise a potential image size confound, suggested by Banks et al. (2004) as an explanation of Khan and Crawford's results. We found that the sighting dominance switch occurred at similar eccentricities when we controlled for effects of hand occlusion and target size differences. We also found that sighting dominance thresholds change predictably with the hand used. However, we found no evidence for relationships between strength of hand preference as assessed by questionnaire or by pegboard performance and strength of sighting dominance. Similarly, participants with consistent hand and foot preferences did not show stronger eye preference as assessed using the Khan and Crawford procedure. These data are discussed in terms of indirect relationships between sighting dominance, hand preference and cerebral specialisation for language and motor control.
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Affiliation(s)
- David P Carey
- School of Psychology, Bangor University, Gwynedd LL57 2AS, UK.
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