Brain pt 2

hemisphere

one of the two separated lateral (right or left) halves of your brain. The two hemispheres are mirror images of one another on the outside, but each hemisphere does somewhat different jobs.

corpus callosum

the band of many millions of nerve fibers that exist deep in your brain and connect the two hemispheres. In split-brain patients, the corpus callosum has been surgically severed.

decussation

"cross-over" wiring, the fact that, for both sensory and motor systems, the right half of your brain is connected to the left half of your body, and vice versa.

lateralization

the fact that the different hemispheres of most people's brains are responsible for somewhat different functions (e.g., language in the left hemisphere, facial recognition in the right).

chimeric faces

faces that are a blend of each of two different right and left half-faces. Example: a face whose left half is smiling but whose right half is frowning. They are used to study brain lateralization.

dominant eye

whichever of your two eyes you visually favor, in much the same way that you probably favor one hand over the other. The "finger-scope" test can allow you to see which eye is dominant.

split-brain patients

those whose corpus callosa (plural of corpus callosum) has been surgically severed - so that the two hemispheres of the brain cannot communicate. Such people are studied intensively by experts on brain lateralization.

"eye-bee-rose" experiment

a study that used chimeric (right and left blended) objects to show that the right and left hemispheres perform different jobs (e.g., naming an object vs. recognizing it)

hindbrain

the deep, central, evolutionarily ancient division of your brain that blends into the top of your spinal cord. It includes the cerebellum. It helps you regulate breathing, sleep, and rapid movements.

cerebellum

the "little brain" (part of the hindbrain) that is below the occipital lobe. It helps you carry out complex motor movement while also playing a role in language, emotions, and memory.

midbrain

the major division of the brain that sits between the ancient hindbrain and the more recently evolved forebrain. Its functions include movement, arousal, and attention to abrupt changes.

forebrain

the largest and most complex of the three divisions of the human brain. It sits above and to the front of the hindbrain and the midbrain, and it is the large majority of the brain. It includes both the cerebral cortex ("outer brain") and the deeper subcortical structures

hypothalamus

a forebrain structure deep in the brain that is the brain's "thermostat" in that it helps regulate feeding, fighting, fleeing, and sexual activity.

pituitary gland

a pea-sized portion of the forebrain that acts as the "master gland". Together with the hypothalamus, it controls many of the hormone-producing systems in your body. It regulates growth during childhood, for example.

hippocampus

a deep forebrain structure that is crucial to the formation and maintenance of memories.

cerebral cortex

the outermost part of the forebrain. This large, complex, wrinkly structure allows you to engage in complex perception and thinking, including language use.

lobes

the four large, functionally separate divisions of the cerebral cortex. The four lobes include the parietal ("top central"), temporal (lower central"), occipital (rear), and frontal ("front") lobes. (Remember PTOF)

parietal lobes

the part of your cerebral cortex (one per hemisphere) that is responsible mainly for your sense of touch. They include but are not limited to the somatosensory cortex ("body-sensing cortex").

somatosensory homunculus

a cartoonish character drawn or sculpted so that body parts are exaggerated in size precisely to the degree that they are richly represented by the cells of the somatosensory cortex.

temporal lobes

the lobes that sit roughly at the bottom center of each of the two hemispheres (near the ears). They are heavily devoted to understanding sound (including speech), but they also help us process visual information .

occipital lobes

the posterior (back) lobe of your brain. These lobes are very heavily devoted to vision.

frontal lobes

the aptly named lobes that occupy much of the front portion of the cerebral cortex. The frontal lobes allow for planning, self-regulation, and decision-making, especially emotional decision-making.