Lateralization Of Function
Effects of Prenatal Testosterone on Lateralization Handedness and Language
Geschwind and Galaburda Prenatal testosterone in males
causes the right hemisphere to develop to the size of the left resulting in left-handedness
Witelson and Goldsmith
Exposure of prenatal testosterone to the Corpus Callosum instead of the hemisphere affected handedness
The Experiment
65 Children-31 girls, 34 boys
Testosterone levels were documented during their 16th-18th week prenatal state
At ages 5-7
Point System-1 For use of left
hand
0 For use of both hands at separate attempts
+1 For use of right hand
The Experiment
Tests every 10 mins: Drawing Tooth brushing Throwing (far) Hammering Stirring Erasing Opening a lid Cutting with scissors Grasping a glass of
lemonade Turning hands of a clock
Results!
Results showed that neither theories were correct but Witelson and Nowakowski did find that pT affected the mid-body of the corpus callosum when the boys of the same test groups were analyzed at age 11
This contributed to assymetry and the development of handedness