Final answer:
The evidence that cognition is primarily confined to the brain comes from observing the loss of cognitive functions following specific brain damage, establishing a map of the brain's functions. Monitoring neural activity allows assessment of cognitive states in comatose or brain-dead individuals, with scans typically showing cessation of activity.
Step-by-step explanation:
One of the strongest lines of evidence supporting the idea that cognition is primarily confined to the brain is loss of cognitive function following damage to specific brain regions. Unlike the loss of other body parts, such as a foot or kidney, which do not directly impair cognition, damage to particular areas of the brain can lead to specific cognitive deficits depending on the region affected. This is because the brain houses crucial cognitive functions such as memory, attention, language, and reasoning.
Through the cataloging of effects of brain damage, researchers have been able to develop a map of the brain's functions and their relationship to cognition. For example, damage to the temporal lobe can affect memory, as observed in patient HM who underwent a bilateral temporal lobectomy. Studies of individuals with strokes have also contributed significantly to understanding the regionalization of cognitive functions in the brain.The phenomenon of learning in isolated animal brains connected to circuitry challenges the notion of cognition being exclusively brain-based. It opens avenues for understanding how cognition might be supported by the brain but could also interact with other systemsFor individuals with brain death or in comas, professionals monitor brain waves and neural activity to assess the state of cognition. Typically, the brain scans of such individuals show a cessation of brain activity, distinguishing them clearly from active and healthy brains.