Review of Medical Physiology - William F. Ganong 2002

Functions of the Nervous System
Higher nervous functions: conditioned reflexes, learning, and related phenomena
Methods

Understanding human Brain function has been made possible by the development and widespread use of PET, functional MRI (fMRI), and related techniques. These technologies make it possible to map The activity of various brain regions in both healthy individuals and those with various pathologies. They are employed to study not only simple reactions but also complex aspects of learning, memory, and perception. The Physiological Basis of these technologies is described in Chapter 32. An example of their application in studying Cerebral Cortex function is shown in Fig. 16-1; other Examples illustrating their use in normal physiology and disease Pathophysiology are provided in Chapters 7-15.

Other technologies that provide insight into cerebral cortex activity include direct stimulation of the cortex in conscious patients during neurosurgical Procedures. In some cases, investigations are conducted using temporarily implanted electrodes. Valuable information has also been gained through the observation of experimental primates. However, when interpreting these results, two important factors must be considered: first, the difficulty of communicating with such animals, and second, and most importantly, the fact that the brain of a rhesus macaque is only one-quarter the size of a chimpanzee's brain—our closest primate relative. Correspondingly, a chimpanzee's brain is four times smaller than a human brain.