Brain Regions and Functions

Cerebral Cortex ·        Older brain networks sustain basic life, enable memory, emotions, and basic drives ·        Newer neural networks within the cerebrum, two large hemispheres, form special ‘work teams’ to enable our perceiving, thinking, and speaking. ·        Covering the two hemispheres is the cerebral cortex, a thin layer of connected neural cells. This is the ‘control center’

·        In the cerebral cortex alone, there are 20-23 billion nerve cells and 300 trillion synaptic connections. ·        Supporting all of these nerve cells are glial cells, (glue cells) ·        Glial cells provide nutrients and insulating myelin, guide connections, and clean up ions and neurotransmitters

Four Brain Lobes ·        The cortex as a whole is divided into 4 lobes, divided by prominent fissures/folds in the brain ·        Starting at the front: o       Frontal Lobe o       Parietal Lobes o       Occipital Lobes Temporal Lobes

Functions of the Cortex ·        Motor Functions o       Gustav Fritsch & Eduard Hitzig applied mild electrical stim to a dog’s cortex, and found that the dog would move when certain parts were stimulated o       The dog only moved when the stim was applied to an arch shaped structure in the back of the frontal lobe

o       They also discovered the left half of the cortex controlled the right side of the body, and vice versa o       These two men discovered the motor cortex o       Applications: a 25-year-old man had a neural prosthetic put in, was able to mentally control a TV, draw shapes on a computer, and play video games, thanks to a chip recording activity in his motor cortex

Sensory Functions o       Parallel and right next to the motor cortex, the sensory cortex is located in the front of the parietal lobe o       It handles the sensations our skin feels. The more sensitive the area of the body, the larger the area devoted to it in the sensory cortex Not all senses run through this area, some visual sensory info is routed to the occipital lobe, from here it is routed to other areas for more specific jobs

Association Areas o       These are areas of the cerebral cortex not involved with primary motor/sensory functions o       They instead are involved in higher functioning: learning, remembering, thinking, and speaking. o       Do we use only 10% of our brains? Not likely, the association areas cannot produce any observable result when electrically stimulated, but they still function in all 4 lobes

o       The assoc. areas in the frontal lobe enable judgment, planning, and processing of new memories. o       Damage to the frontal lobe can alter personality, removing one’s inhibitions: Phineas Gage o       Learning and association happen all over the brain, just in different ways.