The BrainModule 8

Lower-Level Brain Structures

The Lower Brain

•Regulates basic functions such as breathing.

•Cerebral cortex covers the lower brain like bark. (Cortex means “bark”)

The Brainstem• The oldest part and central core of the brain,

beginning where the spinal cord swells as it enters the skull.

• The brainstem is responsible for automatic survival function.

• Medulla: the base of the brainstem; controls life-support functions like heartbeat, circulation, swallowing and breathing.

• Reticular Formation: a nerve network in the brainstem that plays an important role in controlling wakefulness and arousal.

Thalamus

•The brain’s sensory switchboard, located on top of the brainstem

•It directs messages to the sensory receiving areas in the cortex

The Cerebellum

•The “little brain” attached to the rear of the brainstem.

•It helps coordinate voluntary movements and balance

•Memories for knowing how to use your body for things like walking or playing the guitar.

The Limbic System•A ring of structures at of the border of the brain and the cerebral cortex.•It helps regulate important functions such as memory, fear, aggression, hunger, and thirst.

Hypothalamus•Part of the lower brain that regulates

basic needs and emotions.▫Needs:

Hunger & thirst “Fight of flight” reaction to stress Body temperature

▫Emotions: Pleasure Fear Rage Sexuality

•Amygdula: two almond-shaped neural clusters in the limbic system that are linked to emotion▫Fear▫Anger▫Aggression

•Hippocmpus: A neural center located in the limbic system; it helps process new memories for permanent storage.

The Cerebral CortexThe intricate fabric of interconnected neural cells that form the cerebral hemispheres; the body’s ultimate control and information-processing center.

Cerebral Cortex

•The outer most layer of the brain•Controls high level mental processes such

as thought•Size: Large bath towel•Trillions of computers do not equal our

brain power

Longitudinal Fissure

•The long crack running all the way from the front to the back of the cerebral cortex, separating the left and right hemispheres.

Hemispheres•One half of the cerebral cortex•Each half controls the opposite side of the

body•Fissure: a depression marking off an area

of the cerebral cortex•Corpus Callosum: a large bundle of nerve

fibers that transfer information from one half of the cerebral cortex to the other▫Several million nerve fibers

The Lobes•Major divisions of the cerebral cortex•Frontal Lobe: Contains the motor cortex,

prefrontal area, and frontal association area.▫Involved in making plans and judgments▫Motor Cortex: Controls all bodily movements.

(Motor functions)•Parietal Lobe: Contains the sensory

cortex and general association areas used for processing information.▫Somatosensory Cortex: Registers and provides

all sensation.

Frontal Lobe

•Functions▫“see” or be aware of ourselves when we

remember things we have done.▫Coming up with strategies or plans of

action▫Makes sense of our environment

Frontal Lobe•Prefrontal Area: part of the frontal lobe

that enables us to re-experience personal past events

•Frontal Association Area: part of the frontal lobe that engages in elaborate associations or mental connections.▫Plays an important part in integrating

personality and in forming complex thoughts.

The Lobes

•Occipital Lobe: Division of the cerebral cortex that interprets visual information. (back of the brain)

•Temporal Lobe: Division of the cerebral cortex responsible for hearing and some speech functions.

Hemispheric Differences

Hemispheres and Handiness

•Dominance: Control either the right or left hemisphere of the cerebral cortex is dominate in each individual; hence, one of them is preferred and controls the majority of actions performed▫Small fine motor movements

Hemispheres• Left Hemisphere

▫Speech ▫Language▫Logic▫Writing

• Right Hemisphere▫Spatial Reasoning▫Art▫Music▫Emotions▫Mathematical reasoning

Language

•Broca’s Area: a brain area of the frontal lobe, usually in the left hemisphere, that directs the muscle movements involved in speech.

•Wernicke’s Area: a brain area involved in language comprehension and expression; usually in the left temporal lobe.

PlasticityThe brain’s capacity for modification, as evident in brain reorganization following damage.

Puzzles

•NOON GOOD•HE’S HIMSELF•II II ooo ooo

Answers

•Good after noon•He’s beside himself•Circles under the eyes

Why are some people better than others at solving these kinds of puzzles?

1. Thicker and more efficient corpus callosum.

2. One hemisphere does not dominate over the other.