Dynamic Properties of Dopamine Asymmetry: A Basis for Functional Lateralization

Persistent Link:
http://hdl.handle.net/10150/299105
Title:
Dynamic Properties of Dopamine Asymmetry: A Basis for Functional Lateralization
Author:
Hancock, Roeland
Issue Date:
2013
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Functional asymmetries, most commonly associated in humans with population-level hand preference and lateralization in language processing, are complex, heterogeneous traits with poorly understood biological and genetic bases. Notably, functional asymmetries are also associated with familial non-right handedness suggesting that common genetic factors influence both handedness and functional lateralization. This dissertation has two aims. The first is the development of a specific biological hypothesis that may partially account for the consistent co-lateralization of hand preference and prefrontal language function. I argue that asymmetries in local neural properties that affect the excitability and signal-to-noise ratio of neural assemblies can produce a bias in the direction and, to some extent, the degree of functional lateralization for complex functions. At a high level of representation, this hypothesis is similar to long-standing theories of hemispheric differences, but differs from these by providing a single biological difference between hemispheres that influences both motor and prefrontal asymmetries. Specifically, I propose that a hemispheric asymmetry in the ratio of activity at D1 and D2 dopamine receptors can account for both forms of asymmetry. The second aim is to identify novel electrophysiological and behavioral correlates of genetic effects linked to handedness. By applying a standard genetic model to familial handedness data, I obtain an estimate of these genetic effects for individual research participants that may improve sensitivity over previous studies that have primarily used categorical classifications to study familial handedness effects. Two EEG studies of executive function provide evidence for computational changes associated with familial handedness. The first, an auditory oddball paradigm, suggests that cortical noise is increased in conjunction with estimated genetic effects associated with left handedness. In the second study, a go-nogo task, a dissociation between response inhibition and response conflict processing was found with respect to estimated genetic effects associated with left handedness. In addition to bearing on current theories of conflict processing, these results may provide indirect evidence for dopaminergic contributions to neurological and behavioral differences associated with familial sinistrality. Additional studies of resting EEG and behavioral responses to Necker cube viewing provide additional evidence for broad effects of familial sinistrality.
Type:
text; Electronic Dissertation
Keywords:
EEG; Handedness; Lateralization; Psychology; Dopamine
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Psychology
Degree Grantor:
University of Arizona
Advisor:
Bever, Thomas G.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleDynamic Properties of Dopamine Asymmetry: A Basis for Functional Lateralizationen_US
dc.creatorHancock, Roelanden_US
dc.contributor.authorHancock, Roelanden_US
dc.date.issued2013-
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractFunctional asymmetries, most commonly associated in humans with population-level hand preference and lateralization in language processing, are complex, heterogeneous traits with poorly understood biological and genetic bases. Notably, functional asymmetries are also associated with familial non-right handedness suggesting that common genetic factors influence both handedness and functional lateralization. This dissertation has two aims. The first is the development of a specific biological hypothesis that may partially account for the consistent co-lateralization of hand preference and prefrontal language function. I argue that asymmetries in local neural properties that affect the excitability and signal-to-noise ratio of neural assemblies can produce a bias in the direction and, to some extent, the degree of functional lateralization for complex functions. At a high level of representation, this hypothesis is similar to long-standing theories of hemispheric differences, but differs from these by providing a single biological difference between hemispheres that influences both motor and prefrontal asymmetries. Specifically, I propose that a hemispheric asymmetry in the ratio of activity at D1 and D2 dopamine receptors can account for both forms of asymmetry. The second aim is to identify novel electrophysiological and behavioral correlates of genetic effects linked to handedness. By applying a standard genetic model to familial handedness data, I obtain an estimate of these genetic effects for individual research participants that may improve sensitivity over previous studies that have primarily used categorical classifications to study familial handedness effects. Two EEG studies of executive function provide evidence for computational changes associated with familial handedness. The first, an auditory oddball paradigm, suggests that cortical noise is increased in conjunction with estimated genetic effects associated with left handedness. In the second study, a go-nogo task, a dissociation between response inhibition and response conflict processing was found with respect to estimated genetic effects associated with left handedness. In addition to bearing on current theories of conflict processing, these results may provide indirect evidence for dopaminergic contributions to neurological and behavioral differences associated with familial sinistrality. Additional studies of resting EEG and behavioral responses to Necker cube viewing provide additional evidence for broad effects of familial sinistrality.en_US
dc.typetexten_US
dc.typeElectronic Dissertationen_US
dc.subjectEEGen_US
dc.subjectHandednessen_US
dc.subjectLateralizationen_US
dc.subjectPsychologyen_US
dc.subjectDopamineen_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplinePsychologyen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorBever, Thomas G.en_US
dc.contributor.committeememberFellous, Jean-Marcen_US
dc.contributor.committeememberLin, Kevin K.en_US
dc.contributor.committeememberPiattelli-Palmarini, Massimoen_US
dc.contributor.committeememberBever, Thomas G.en_US
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