The Analysis of Autism Facilitates Neuroanatomical Investigations :: Biology Essays Research Papers

The Analysis of Autism Facilitates Neuroanatomical Investigations Studying the functions of the various structures of the brain is best carried out through analysis of brain defects. For example, individuals with autism exhibit particular behaviors that are not considered normal. Assuming that behavior originates from the brain, then it becomes clear that in order to discover the causes of the abnormal behavior a comparison must be made between and healthy brain and the brain of an autistic person. By finding structural differences such as size and composition, the role that the structures play in the behavior of the autistic can be inferred while also investigating the normal functions of brain structures. There are several differences between a healthy brain and the brain of an autistic person. Dr. Joseph Piven from the University of Iowa noticed a size difference . In the autistic brain, the cerebellum is larger and the corpus callosum is smaller. Another study showed that the amygdala and the hippocampus are different in an autistic brain. In an autistic these structures have densely packed neurons and the neurons are smaller than those in a healthy brain. Also, in the cerebellum there is a noticeable reduction in the number of Purkinje cells. Structure and function can not be separated from one another and changes in one indicate alterations in the other. Because an autistic person has brain defects, a reasonable assumption is made that changes in structure will alter the behavior. An autistic person is characterized by having impaired social interaction, difficulty with communication both verbal and nonverbal, trouble with imagination, and limited activities and interests. By analyzing the abnormal behaviors of the autistic person, the roles that the cerebellum, the corpus callosum, the amygdala, and the hippocampus play in the disease can be inferred. The cerebellum is usually associated with motor movements. Concerning this topic it is interesting to note the research of Dr. Eric Courchesne. He found that the VI and VII lobes of the cerebellum were smaller in autistics than those of a normal brain. This condition is called hypoplasia. The reverse condition, which is what Piven encountered, is called hyperplasia. Courchesne linked the cerebellum with attention shifting . He proposed that the autistic takes longer time to change the focus of his attention. He believed that this condition was caused by lack of development of the cerebellum in utero caused by perhaps oxygen deprivation, infection, toxic exposure, or genetically.