Cerebral Lateralization
The human brain is divided into two major divisions- the left and right hemispheres- that are believed to be identical in structure but with several lateral differences. These two major parts of the brain have always appealed to the attention of many scholars who have incessantly tried to unravel their various functions. In this light, a number of assorted methods have been proved to be utilitarian in the study of the different functionalities of the left and right hemispheres.
The Sodium Amytal Test as described by Wada (1946) is one of such tests that have remarkably aided in cerebral lateralization (as cited in Pinel, 2009). The Sodium Amytal Test, which entails an unilateral intracarotid injection of sodium amytal, is useful in the determination of part of the brain that is responsible for speech and memory (Albright, Adelson, & Pollack, 2008). Ideally, sodium amytal serves to suppress the function of the “ipsilateral hemisphere” (Albright, Adelson, & Pollack, 2008). Additionally, Pinel (2009) affirms that cerebral lateralization can also be achieved with the help of dichotic listening test; a test that basically involves the mapping of the channels through which auditory signals presented to the ears are transmitted to the brain. In most cases, the test reveals a right ear advantage in hearing though with slight discrepancies in certain people.
Functional Brain Imaging techniques and split brain method can also be used in studying the asymmetry of the brain hemispheres. While Functional Brain Imaging employs methods such Positron emission tomography (PET) and fMRI (functional magnetic resonance imaging) techniques in studying the functionalities of the hemispheres of the brain while performing various activities like reading, the split brain method involves a complete transaction through the corpus callosum to see the effect of lack of communication between the right and left hemispheres (Glassman, Glassman& Hadad, 2009; Pinel, 2009).
Associate Level Material
Appendix E
Functions of the Hemispheres of the Brain
LEFT HEMISPHERE RIGHT HEMISPHERE
References
Albright, A. L., Adelson, P. D.,& Pollack, I. F. (2008). Principles and Practice of Pediatric Neurosurgery, 2nd Ed. New York, NY: Thieme Medical Publishers.
Glassman, W., Glassman, W. E., Hadad, Marilyn. (2009). Approaches To Psychology, 5th Ed. Berkshire: Open University Press.
Pinel, J. P.J. (2009). Biopsychology, 7th Ed. Boston: Allyn & Bacon.
Seaward, B. L. (2012). Managing Stress: Principles and Strategies for Health and Well-Being, 7th ed. Burlington, MA: Jones and Bartlett Learning.
