[Truncated abstract] Atypical handedness is found to be more prevalent in schizophrenia patients than in psychiatric and normal controls, suggesting atypical brain lateralisation, particularly of regions associated with language. This ‘behavioural aberration’ is commonly considered as a marker of disturbed neurodevelopment, which is usually indexed by minor physical abnormalities. A prevailing view in the literature is that the atypical lateralisation of hand preference provides an additional index for the neurodevelopmental hypothesis of schizophrenia. Consistent with this hypothesis, an atypical lateralisation of hand preferences can also be considered as a consequence of environmental agents that might have interfered with early embryonic development. Notwithstanding the above, an atypical lateralisation of hand preferences can occur as a result of genetic factors as well as an interaction between genetic and environmental factors. The overall objective of this thesis was to advance existing knowledge on atypical laterality in schizophrenia by addressing its various (though related) aspects, including measurement, classification and conceptualisation. Atypical lateralisation of hand preferences in schizophrenia patients was approached by five separate studies. ... Overall, this thesis argues that the causes of atypical lateralisation of hand preferences are due to combined genetic and environmental factors and that its use as a marker of vulnerability to schizophrenia is limited. A cautious interpretation of various associations between the laterality and other measures, particularly cognitive measures, is advised until a broad agreement on the true nature of handedness is reached.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - 2004|