Copyright © 2007-2018 Russ Dewey
Neuropsychology is the study of brain/behavior relationships. The brain can be injured by strokes, injury, or anything cutting off the supply of oxygen to the brain.
Aphasias are usually caused by damage to the left hemisphere. They come in several distinct varieties, one impairing the expression of language, the other impairing its comprehension and organization.
Lobotomies were operations that involved disconnecting the frontal lobe from the rest of the brain. When lobotomies were performed on mentally normal people for pain relief, doctors discovered the operation produced serious impairments in creativity and ability to plan for the future.
The parietal syndrome (due to damage to the parietal lobe) involves spatial processing. People with this syndrome often get lost and show other symptoms of spatial disorganization.
People with prosopagnosia (facial blindness) have a specific problem recognizing faces. Neuropsychologist Oliver Sacks revealed toward the end of his life that he suffered from this disorder and could not recognize faces.
The modularity of the brain, revealed by brain injury and also by savant-level specialized intelligence, led Howard Gardner to write Frames of Mind. He outlined seven types of intelligence, each requiring specific brain areas. He later added an eighth type of intelligence: pattern recognition.
Neuropsychologists also study brain stimulation. Wilder Penfield stimulated the exposed brains of patients on the operating table.
Penfield elicited a wide range of psychological effects. Other researchers showed brain stimulation could produce aggression and rage. The so-called pleasure centeres produce variable effects when stimulated in humans.
Seizures themselves resemble natural brain stimulation experiments. Some epileptic individuals experience distinctive feelings before a seizure. These are called "auras" and many occur in non-epileptic people as well.
Auras include odors, feelings of dread, hallucinated sights or sounds, feelings that the environment is getting suddenly larger or smaller, and the déjà vu or déjà penseé sensations, in which everything seems familiar or feels as though it was predicted earlier.
Write to Dr. Dewey at firstname.lastname@example.org.