---
abstract: |
  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
  hypothesis, the relations of T levels (umbilical cord blood) to grasp-reflex strengths were studied in human neonates. Handedness was assessed by measuring
  the 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
  greater 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
  right-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
  the 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
  lateralisation.
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creators_name:
  - family: Tan
    given: Uner
    honourific: ''
    lineage: ''
  - family: Tan
    given: Meliha
    honourific: ''
    lineage: ''
date: 2001
date_type: published
datestamp: 2001-04-08
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editors_name:
  - family: Coraballis
    given: Michael
    honourific: ''
    lineage: ''
  - family: McManus
    given: Chris
    honourific: ''
    lineage: ''
  - family: Peters
    given: Michael
    honourific: ''
    lineage: ''
eprint_status: archive
eprintid: 1439
fileinfo: /style/images/fileicons/application_pdf.png;/1439/2/TANTANLAT.PDF
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keywords: |-
  testosterone, cerebral laterality, reflex, handedness,
  spinal cord, neonate
lastmod: 2011-03-11 08:54:37
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note: ~
number: 2
pagerange: 181-192
pubdom: FALSE
publication: ' Laterality'
publisher: Taylor & Francis
refereed: FALSE
referencetext: |
  Bryden, M.P., McManus, I.C., & Bulman-Fleming, M.B. (1994). Evaluating the empirical support
  for the Geschwind-Behan-Galaburda model of cerebral lateralization. Brain and Cognition, 26,
  103-167.
  Buonomano, D.V., & Merzenich, M.M. (1998). Cortical plasticity: From synapses to maps. Annual
  Reviews of Neuroscience, 21, 149-186.
  Clark, M.M., Crews, D.,& Galef, B.G. (1991). Concentrations of sex steroid hormones in pregnant
  and fetal Mongolian gerbils. Physiology and Behavior, 49, 239-243.
  Clark, M.M., Santamaria, B.T., Robertson, R.K., & Galef, B.G. (1998). Effects of gonadectomy in
  infancy and adulthood on handedness in male and female Mongolian gerbils. Behavioral
  Neurosience, 112, 1026-1029.
  Clark, M.M., Von Saal, F.S., & Galef, B.G. (1992). Intrauterine positions and testosterone levels of
  adult male gerbils are correlated. Physiology and Behavior, 51, 957-960..Corballis, M.C., & Morgan, M.J. (1978). On the biological basis of human laterality: I. Evidence for
  a maturational left-right gradient. The Behavioral and Brain Sciences, 1, 261-269.
  DoÈrner, G. (1976). Hormones and brain differentiation. Amsterdam: Elsevier.
  Elkadi, S., Nicholls, M.E.R., & Clode, D. (1999). Handedness in opposite and the same-sex dizygotic
  twins: Testing the testosterone hypothesis. NeuroReport 10, 333-336.
  Filipkowski, R.K., Rydz, M., Berdel, B., Morys, J., & Kaczmarek, L. (2000). Tactile experience
  induces c-fos expression in rat barrell cortex. Learning and Memory, 7, 116-122.
  Finegan, J.J., Bartleman, B., & Wong, P.Y. (1989). A window for the study of prenatal sex hormone
  influences on postnatal development. Journal of Genetic Psychology, 150, 191-112.
  Geschwind, N., & Behan, P. (1982). Left-handedness: Association with immune disease, migraine,
  and developmental learning disorder. Proceedings of the National Academy of Sciences USA, 79,
  5097-5100.
  Geschwind, N., & Galaburda, A.M. (1985). Cerebral lateralization, biological mechanisms,
  associations, and pathology: I. A hypothesis and a program for research. Archives of Neurology,
  42, 428-459.
  Greenspan, F.S. (1991). Basic and clinical endocrinology . London: Appleton & Lange.
  Grimshaw, G.M., Bryden, M.P., & Finegan, J.K. (1993). Relations between prenatal testosterone
  and cerebral lateralization at age 10. Journal of Clinical and Experimental Neuropsychology ,
  15, 39-40.
  Grimshaw, G.M., Bryden, M.P., & Finegan, J.K. (1995). Relations between prenatal testosterone and
  cerebral lateralization in children. Neuropsychology, 9, 68-79.
  Halpern, D.F. (1994). Evaluating support for the Geschwind-Behan-Galaburda Model: With a rubber
  ruler and a thumb on the scale. Brain and Cognition, 26, 185-190.
  Hepper, P.G., McCartney, G.R., & Shannon, E.A. (1998). Lateralized behaviour in first trimester
  human foetuses. Neuropsychologia, 36, 531-534.
  Keefer, D.A., Stumpf, W.E., & Sar, M. (1973). Topographical localization of estrogen-concentrating
  cells in the rat spinal cord following H-stradiol administration. Proceedings of the Society for
  Experimental Biology and Medicine, 143, 414-417.
  Kimura, D. (1996). Sex, sexual orientation and sex hormones influence human cognitive function.
  Current Opinion in Neurobiology, 6, 259-263.
  Kolb, B., & Whishaw, I.Q. (1998). Brain plasticity and behavior. Annual Review of Psychology, 49,
  43-64.
  Levitt, P., Barbe, M.F., Eagleson, K.L. (1997). Patterning and specification of the cerebral cortex.
  Annual Review of Neuroscience, 20, 1-24.
  Lorenz, K. (1937). Die Bildung des Instinktbegriffes. Naturwissenschaften, 25, 289-300.
  McCartney, G., & Hepper, P. (1999). Development of lateralized behaviour in the human fetus from
  12 to 27 weeks? gestation. Developmental Medicine of Child Neurology, 41, 83-86.
  Moffat, S.D., & Hampson, E. (1996). Salivary testosterone levels in left- and right-handed adults.
  Neuropsychologia, 34, 225-233.
  Morgan, M.J. (1977). Embryology and inheritance of asymmetry. In S. Harnad, R.W. Doty, L.
  Goldstein, J. Jaynes, & G. Krauthamer (Eds.), Lateralization in the nervous system. New York:
  Academic Press.
  Polack, S. (1960). The grasp response of the neonate: Its characteristics and interaction with tonic
  neck reflex. Archives of Neurology, 3, 574-581.
  Rosen, G.D., Sherman, G.F., & Galaburda, A.M. (1991). Ontogenesis of neocortical asymmetry: A
  [3H] thymidine study. Neuroscience, 41, 779-790.
  Sar, M., & Stumpf, W.E. (1977). Androgen concentration in motor neurons of cranial nerves and
  spinal cord. Science, 197, 77-79.
  Sanes, J.N., & Donoghue, J.P. (2000). Plasticity and primary motor cortex. Annual Reviews of
  Neuroscience, 23, 393-415.
  Simerly, R.B., Chang, C., Muramatsu, M., & Swanson, L.W. (1990). Distribution of androgen and
  TESTOSTERONE AND GRASP REFLEX 191.estrogen receptor mRNA-containing cells in the rat brain: An in situ hybridization study. Journal
  of Comparative Neurology, 294, 76-95.
  Stefan, K., Kunesch, E., Cohen, L.G., Benecke, R., & Classen, J. (2000). Induction of plasticity in the
  human motor cortex by paired associative stimulation. Brain, 123, 572-584.
  Stirnimann, F. (1941). Greifversuche mit der Hand Neugeborener. Annual Paediatrie, 157, 17-27.
  Tan, U. (1984). Lateral asymmetry of H-reflex recovery curves in cat: Evidence for a spinal motor
  asymmetry. International Journal of Neuroscience, 24, 45-52.
  Tan, U. (1985). Left-right differences in the Hoffmann reflex recovery curve associated with
  handedness in normal subjects. International Journal of Psychophysiology , 3, 75-78.
  Tan, U. (1990). Relation of testosterone and hand preference in right-handed young adults to sex and
  familial sinistrality. International Journal of Neuroscience, 53, 157-165.
  Tan, U. (1991). Serum testosterone levels in male and female subjects with standard and anomalous
  dominance. International Journal of Neuroscience, 58, 211-214.
  Tan, U. (1994). The grasp reflex from the right and left hand of human neonates indicates that the
  development of both cerebral hemispheres in males, but only the right hemisphere in females, is
  favoured by testosterone. International Journal of Psychophysiology , 16, 39-47.
  Tan, U., Ors, R., Kurkcuoglu, M., Kutlu, N., & Cankaya, A. (1992). Lateralization of the grasp reflex
  in male and female newborns. International Journal of Neuroscience , 62, 155-163.
  Tan, U., & Tan, M. (1999). Incidences of asymmetries for the palmar grasp reflex in neonates and
  hand preference in adults. NeuroReport, 10, 3253-3256.
  Tan, U., & Zor, N. (1994). Relation of free-testosterone level to grasp-reflex strength in human
  neonates with right-ear and left-ear facing out in-utero position. International Journal of
  Neuroscience, 75, 9-18.
  Wisniewski, A.B. (1998). Sexually-dimorphic patterns of cortical asymmetries, and the role for sex
  steroid hormones in determining cortical patterns of lateralization. Psychoneuroendocrinology,
  23, 519-547.
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rev_number: 10
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status_changed: 2007-09-12 16:37:47
subjects:
  - neuro-endocrin
  - neuro-psy
succeeds: ~
suggestions: ~
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title: Testosterone and grasp-reflex differences in human neonates
type: journalp
userid: 491
volume: 6