Descriptionary

neglect a bizarre brain condition in which one hemi­sphere of the brain is damaged, causing the sufferer to perceive only one side of his environment.

neocortex the latest part of the brain to evolve, which includes the frontal, temporal, parietal, and occipital lobes, the heavily wrinkled outer layer of gray matter surrounding the cerebrum; it is known to be involved with conscious thought, language, and sensory perception.

neuron one of millions of specialized nerve cells that carry electrochemical impulses in the brain.

nucleus accumbens a grouping of neurons in the forebrain, involved in laughter, pleasure, and the pla­cebo effect.

occipital lobe a lobe of the cerebrum, at the back of the head, the center of visual processing and reading skills.

operculum in the inferior frontal gyrus, a portion of the brain involved in the coordination of other brain areas.

orbitofrontal cortex part of the frontal lobe that has been implicated in regulating personality, social functioning, sense of responsibility, and mood.

paragraphia confused or distorted handwriting, caused by a brain condition.

parietal lobe the topmost lobe of the cerebrum, the center of sensory processing involving touch, pres­sure, pain, and temperature. Parts of the parietal lobe are also involved in attention and language.

Parkinson's disease a disease characterized by a shuffling gait, muscular rigidity, and uncontrollable tremors, thought to be due to a chemical imbalance in the brain.

pituitary attached to the hypothalamus, the gland that controls most of the hormones in the body.

pons a bundle of nerve fibers forming a bridge con­necting the cerebellum and the medulla oblongata with the frontal lobe and other brain areas.

posterior parietal cortex the back portion of the parietal lobe, involved with face recognition and com­municating socially.

prefrontal cortex at the very front of the frontal lobes, the portion of the brain involved in planning and decision making.

primary auditory cortex in a gyrus of the upper part of the temporal lobe, the part of the brain that processes sound.

primary motor cortex in the posterior of the fron­tal lobe, part of the brain involved in movement.

primary visual striate cortex in the occipital lobe, a processing area for visual images.

prosopagnosia the inability to recognize faces, including those of close family members, due to a brain condition. The sufferer may recognize the faces, however, as soon as he hears them speak.

reticular formation the part of the brain stem that regulates wakefulness and attention; it is the part of the brain that is shut off by anesthesia.

right parietal lobe part of the parietal lobe involved in processing numbers.

sinistrality the right-brain dominance over the left brain that produces left-handedness.

somatosensory neocortex in the parietal lobe, the area involved in processing touch sensations, includ­ing pressure, pain, positioning, and movement.

stereoanesthesia the inability to identify objects by touch, due to a brain condition.

sulcus any cleft or groove in the cerebrum.

superior temporal gyrus in the temporal lobe, a gyrus containing the primary auditory cortex.

supplementary motor area in the frontal lobe, a processing area for the control of movement.

suprachiasmatic nucleus part of the hypothalamus that regulates the body's circadian rhythm or biologi­cal clock.

synesthesia the confusion of senses (seeing sounds, hearing sights, etc.), a mysterious brain condition.

temporal lobe a lobe of the cerebrum, above the hindbrain, an area involved in hearing and the pro­cessing of memory and the naming of things.

thalamus at the top of the brain stem, the structure known as the "great relay station" because it conveys signals between the brain stem and the rest of the brain. It is also the origination of the sensations of heat, cold, pain, and pressure.

water on the brain hydrocephalus.

Wernicke's area auditory processing area involved in processing language.

wet brain a disease of chronic alcoholism, charac­terized by fluid buildup and mental deterioration.

white matter brain tissue composed largely of axons insulated with myelin. Women have more white mat­ter in their neocortexes than men do, while men have more gray matter than women do. See gray matter.

Nerves

Names Function and Location

abducens supplies eye muscles

accessory supplies neck muscles, voice box,

shoulders

acoustic supplies the inner ear, deafness

results when damaged. Also known as the auditory nerve