The Brain

Brain Rap

EEGelectrodes on the brain that record brain waves

Especially useful in sleep studies

CT Scan

shows structure of the brain

Especially useful in determining abnormalities such as tumors, decay, etc

PET Scan

use dye to show brain activity

Used most often in research and the study of cancer, epilepsy, Parkinson's, etc

MRIshows tissue responses to pulses of magnetic energy*used to diagnose abnormalities in brain tissue (tumors, decay, etc)

fMRIdistinguishes activity levels of individual brain cells during various mental processes

The 3 Layers of the Brain

• Brain Stem

• Limbic System

• Cerebral Cortex

3 Layers of the Brain

1. Brain Stem (R-Complex)

2. Limbic System

3. Cerebral Cortex

Carl Sagan video

Major Parts of the Brain Stem• Medulla- controls automatic functions• Pons- regulates sleep and dreams• Reticular Formation- core of BS; monitors

incoming sensory info and attention and serves as Emergency Warning System

• Thalamus- receives info and prioritizes and distributes it accordingly

• Cerebellum- handles coordination and balance

Anatomy of the Brain Stem

Mike the Headless Chicken

Major Elements of the Limbic SystemExists in all mammals- involved in memory, emotion and

caring for young• Hippocampus- establishes LTM• Amygdala- controls emotion; holds emotionally

charged LTM; center of fear and aggression (Waterboy got this wrong- don’t confuse with medulla!)

• Hypothalamus- body’s blood lab- monitors heart-rate, body temp, etc- important in _____ division of the PNS

Cerebral Cortex

• Primates ONLY: where all critical thought occurs

Lobes of the Cerebral Cortex1. Frontal- movement,

thinking1. Motor cortex

2. Parietal- touch, spatial relationships

1. Somatosensory cortex

3. Occipital- vision1. Visual cortex

4. Temporal- hearing, speech, some LTM1. Auditory cortex

Phineas Gage

Motor and Somatosensory Cortex• Homunculus:

represents the amount of space on the M and S cortexes dedicated for each location on the body.– Which part of the

human body has most representation on these cortexes? 2nd most? Least?

Association Cortex• Majority of cerebral cortex is used to associate

information from all cortical regions.– It will combine information from all over the brain,

interpret the sensations, plan, decide and prepare us to act.

21

LanguageAphasia is an impairment of language,

usually caused by left hemisphere damage either to Broca’s area (impaired speaking)

or to Wernicke’s area (impaired understanding).

Cerebral Dominance• Tendency of each hemisphere to control certain

functions

Left Brain Right Brain

• Regulates + emotion• Speech muscles• Movement sequence• Spontaneous

speaking/writing• Word and # memory• Understanding what you

hear or read

• Regulates – emotion• Response to simple

command• Shape and music

memory• Understanding spatial

relationships and visual images

• Recognition of faces

Hemispherical Communication• Corpus Callosum: bundle of nerve fibers that

transfers information between the hemispheres of the brain