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