This site has been permanently archived. This is a static copy provided by the University of Southampton.
<> "The repository administrator has not yet configured an RDF license."^^ .
<> .
.
"Testosterone and grasp-reflex differences in human neonates"^^ .
"According to the Geschwind-Behan-Galaburda (GBG) hypothesis, prenatal testosterone (T) causes a slowing in the development of the left brain with a consequent compensatory growth in the right brain, creating a reverse organisation of the cerebral lateralisation. That is, left- and right-handedness might be associated with high and low prenatal T levels, respectively. To test this\nhypothesis, the relations of T levels (umbilical cord blood) to grasp-reflex strengths were studied in human neonates. Handedness was assessed by measuring\nthe grasp-reflex strengths from the right and left hands in 10 trials from each hand alternatively. There were two handedness groups: right-handers (R-L significantly\ngreater than zero) and left-handers (significantly smaller than zero). Contrary to the GBG model, the mean free T concentration was found to be significantly higher in\nright-handers than left-handers for males and females. There was no significant difference in the total T levels between right- and left-handers. Free T concentrations positively correlated with R-L grasp-reflex strengths, i.e. right-handedness increased as T increased, and left-handedness increased as T decreased. Contrary to these positive correlations, T negatively correlated with\nthe grasp-reflex strengths from the right and left hands. These results partly supported the GBG hypothesis for this spinal-motor-asymmetry model. Total T did not significantly correlate with grasp-reflex strengths. The results suggest that prenatal T may at least play a role in prenatal determination of spinal motor lateralisation, with a possible consequent upward regulation of cerebral\nlateralisation.\n"^^ .
"2001" .
.
"6" .
"2" .
.
"Taylor & Francis"^^ .
.
.
" Laterality"^^ .
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
"Michael"^^ .
"Peters"^^ .
"Michael Peters"^^ .
.
"Meliha"^^ .
"Tan"^^ .
"Meliha Tan"^^ .
.
"Uner"^^ .
"Tan"^^ .
"Uner Tan"^^ .
.
"Chris"^^ .
"McManus"^^ .
"Chris McManus"^^ .
.
"Michael"^^ .
"Coraballis"^^ .
"Michael Coraballis"^^ .
.
.
.
.
.
"Testosterone and grasp-reflex differences in human neonates (PDF)"^^ .
.
.
.
.
.
"TANTANLAT.PDF"^^ .
.
"HTML Summary of #1439 \n\nTestosterone and grasp-reflex differences in human neonates\n\n" .
"text/html" .
.
.
"Neuroendocrinology" .
.
.
"Neuropsychology" .
.