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Abstract:
Abstract: Although hand preference is used to categorize
individuals as left or right handed, our understanding of the
neural systems that mediate hand preference remains limited. This
is due in part to disagreement over whether distinct groups with
differing structural or functional asymmetry exist. Similarly,
groups with distinct performance asymmetries on unimanual tasks
have not been identified. In the present research, multivariate
analyses were used to identify groups with differing manual
asymmetry patterns. Hand preference for sixteen tasks was surveyed
in sixty-two adults. Individuals were assigned to left and right
hand preference groups, based upon survey responses. Performance
asymmetries in grooved pegboard and finger-tapping tasks were then
examined. Laterality quotients (LQs) did not indicate distinct
groups for either motor task. However, when LQs for both tasks were
examined simultaneously, via multivariate analyses, distinct
performance-based groups emerged. In over 90% of the cases, the
performance-based groups corresponded to preference-based groups.
This suggests that there are distinct groups of individuals that
differ in terms of both hand preference and performance on
unimanual tasks. This method can serve as a model for identifying
differing patterns of neural asymmetry between left and right
handers. For example, although asymmetry in one neural area may
seem similar for both hand preference groups, it is possible that
when multiple cortical areas are examined simultaneously, using
multivariate analyses, between-group differences in neural
asymmetry will emerge.
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