Final answer:
The Wada test is used to determine language and memory functions in each hemisphere of the brain, but the effects of the anesthetic are temporary and do not result in permanent changes to the brain. The false statement is that the Wada test results in permanent changes.
Step-by-step explanation:
The Wada test is a medical procedure used to assess which hemisphere of the brain is responsible for language and memory functions, which is useful in planning surgery for epilepsy. Option (c) 'It results in permanent changes to the brain.' is FALSE about the Wada test. When performing a Wada test, a doctor injects a fast-acting anesthetic into one of the carotid arteries, which then temporarily numbs one hemisphere of the brain, allowing the functions of the other hemisphere to be assessed. The effects of the anesthetic are temporary and do not cause permanent changes to the brain. The purpose of the test is to understand the distinct functions of each hemisphere of the brain and to plan for surgeries that could affect language and memory, such as those for epilepsy.
Looking back at the history of brain mapping, before the advent of modern imaging techniques, scientists relied on post-mortem examinations to understand brain function. One of the limitations of this method is that it could only offer a snapshot after death, without providing information on how different brain regions interact during live, dynamic processes. Furthermore, these observations could not be generalized, as they were based on individual cases with specific brain injuries.
Regarding brain hemispheres control, it is noteworthy that while both cerebral hemispheres are essential for proper body function, each hemisphere controls the opposite side of the body due to the crossing of neural connections in the brainstem.