http://news.bbc.co.uk/2/hi/health/8008678.stm

Dr. Sperry used a tachistoscope to present visual information to one hemisphere or the other. The tachistoscope requires people to focus on a point in the center of their visual field. Because each half of the visual field projects to the opposite site of the brain (crossing in the optic chiasm), it is possible to project a picture to either the right hemisphere OR the left hemisphere.

http://raisingchildren.net.au/articles/physical_health_from_age_3_to_4_pbs.html

http://www.standards.dfes.gov.uk/eyfs/resources/downloads/card4_9.pdf

http://www.pbs.org/wholechild/abc/physical.html

http://www.zerotothree.org/site/PageServer?pagename=ter_key_brain_quiz

http://news.bbc.co.uk/2/hi/uk_news/magazine/7982327.stm