Overview
This lecture covers the main structures and functions of the brain, including methods for studying the brain, key brain regions, brain hemispheres, and concepts of consciousness.
Tools for Studying the Brain
- The brain enables the mind and defines a person’s identity.
- EEG (electroencephalogram) records brain’s electrical activity.
- CT scans show brain structure and reveal damage.
- PET scans show brain area’s glucose consumption (brain activity).
- MRI displays soft tissues and brain structure.
- fMRI detects blood flow to show brain function and structure.
Main Brain Structures & Functions
- The brainstem is the oldest part of the brain, including the medulla (controls breathing and heartbeat).
- Reticular formation: nerve network in brainstem controlling arousal (wakefulness).
- Cerebellum (at the back of the brain): coordinates movement and balance.
- Limbic system includes the amygdala (emotion, especially fear) and hypothalamus (fight, flight, food, fornication).
- The cerebral cortex: outer layer involved in muscle movement, sensory input, thinking, and planning.
Lobes and Cortex Areas
- Frontal lobe: planning, judgment, voluntary movement.
- Parietal lobe: processes touch and body position.
- Occipital lobe: processes visual information.
- Temporal lobe: processes auditory information.
- Motor cortex (back of frontal lobe): controls voluntary movement.
- Sensory cortex (front of parietal lobe): processes sensory input.
- Association areas: integrate information for learning, memory, and thinking.
Language and Brain Processing
- Reading aloud involves the visual area, angular gyrus, Wernicke’s area (language understanding), and Broca’s area (speech production).
- Brain divides mental tasks into subfunctions across specialized areas.
Brain Plasticity & Neurogenesis
- Plasticity: brain’s ability to reorganize after damage; unused areas repurposed.
- Neurogenesis: formation of new brain cells, possible in adults.
Hemispheric Specialization & Corpus Callosum
- Each brain hemisphere processes the opposite visual field.
- Corpus callosum connects hemispheres; severing it reduces epileptic seizures (split-brain).
- Right hemisphere: perceptual, creative tasks, interpreting meaning.
- Left hemisphere: language, calculation, literal interpretation.
Consciousness and Dual Processing
- Consciousness has physiological and psychological components.
- Cognitive neuroscience studies links between brain activity and cognition.
- Dual processing: the brain processes information on conscious and unconscious levels simultaneously.
Key Terms & Definitions
- EEG — records electrical activity in the brain.
- PET scan — imaging showing glucose consumption in the brain.
- MRI/fMRI — shows brain structure (MRI) and function (fMRI).
- Brainstem — oldest brain part, controls basic life functions.
- Medulla — controls heartbeat and breathing.
- Reticular formation — regulates arousal and wakefulness.
- Cerebellum — coordinates movement and balance.
- Limbic system — emotion and motivation center.
- Amygdala — processes emotions like fear.
- Hypothalamus — controls survival basics: fight, flight, food, fornication.
- Cerebral cortex — outer brain layer for higher-level functions.
- Corpus callosum — connects right and left brain hemispheres.
- Plasticity — brain’s ability to adapt or reorganize after injury.
- Neurogenesis — generation of new brain cells.
- Dual processing — simultaneous conscious and unconscious brain processing.
Action Items / Next Steps
- Review diagrams of brain structures and lobes.
- Read Unit 3B in Myers Psychology for AP for more detail and examples.