Appendix E
Hemispheres of the Brain
Our brain is divided into two main hemispheres, the left and the right. Each hemisphere is dominant in certain functions. Click either the left or the right hemisphere of the brain below and fill in the hemisphere’s appropriate functions.
LEFT HEMISPHERE RIGHT HEMISPHERE
[pic]
Cerebral Lateralization and Functionality Researchers utilize a number of different methods to study lateralization of brain function. Four of these methods are: • Comparison of brain lesion effects in the left and right hemispheres,
• sodium amytal testing
• dichotic listening tests and
• functional brain imaging (Pinel, 2007, p. 444-445).
Studies in comparison of brain lesion effects arose from the discovery in the 1800’s that damage to Broca’s area in the left hemisphere caused one to have impaired speech abilities and impaired language comprehension as well (Pinel, 2007, p.444). This lead to the theory that the left hemisphere is dominant over the right, due to the further discovery of the wide variety of functions that may be impaired by damage to the left hemisphere (Pinel, 2007, p. 444). The sodium amytal test is designed to test the hemisphere’s language lateralization. The test is conducted by injecting sodium amytal into the carotid artery in the neck to one side at a time to anesthetize each hemisphere sequentially. The subject is then given a series of information to recite back as well as being asked to identify objects or pictures (Pinel, 2007, p. 445). The results of this test confirm the dominance of the left hemisphere in language and critical memory function (Pinel, 2007, p.445). Dichotic listening tests are a non invasive set of tests that are administered by presenting different sets of information simultaneously to each ear. This test also gives credence to the dominance theory since subjects can generally recall more information that was sent
References: Pinel, J.P. (2007). Basics of Biopsychology. Boston: Pearson Education.