1. The Brain: Our Control Center
Unit II

2. The Three Brains
Hindbrain – Found at the rear base of the brain & involved in the basic processes of life.
Responsible for automatic and survival functions
Three Parts
Medulla
Pons
Cerebellum

3. The Three Brains
Midbrain – Located just above the hindbrain and relays sensory information (vision & hearing) upward.
Contains the Reticular Activating System
Forebrain – Located at the front of the brain and controls complex emotions, thoughts, and movements.
Most highly developed portion of the brain
4 Parts
Thalamus, Hypothalamus, Cerebrum, & Limbic System

4. Three Brains

5. Hindbrain
Medulla – controls breathing, heart rate, swallowing, digestion – vital life functions
Pons – Involved in regulating body movement, attention, sleep, alertness, and facial expressions.
Cerebellum – Involved in balance and coordination.
Effected by alcohol (DUI test)

8. Midbrain
Reticular Activating System (RAS) – Stretches from the hindbrain through the midbrain into the lower part of the forebrain.
The “ignition” system of the brain
Coordinates basic sensory information involving attention, sleep, & arousal (heart rate/blood pressure)
Damage to the RAS can result in a permanent coma.
“Adapts” to sounds (ex. Sounds in the city)
Alcohol reduces activity

9. Midbrain

10. Forebrain Thalamus – Relay station for sensory stimulation
Sorts & sends messages from the sense organs to the cerebral cortex for interpretation.
Hypothalamus – regulates vital functions – body temperature (homeostasis), storage of nutrients, motivation, and emotion
Hunger, thirst, sexual behavior, caring for offspring and aggression are regulated.
Controls the release of hormones from the pituitary gland.

11. Forebrain Cerebrum – 70% of the brain’s weight
Receives sensory information
Transmits voluntary (conscious) motor information
Cerebral Cortex – the thinking center of the brain
Wrinkled surface of the brain
Involved in memory, language, emotions, complex motor functions, perception, etc.
Corpus Callosum – Connects the two brain hemispheres of the cerebral cortex

12. Forebrain
Limbic System – Located in the core of the forebrain on the inner edge of the cerebrum
Involved in learning & memory, emotion, hunger, sex & aggression
Two Structures:
Amygdala
Memory during emotional events
Fear & Aggression
Hippocampus
Memory Formation

14. Brain Lobes Occipital Lobe (Back Of The Brain)
Main center for visual processing
Enables experiencing shapes, color, and motion.
Damage can cause blindness
Parietal Lobes (Top & Rear)
Involved in touch sensation (integrates sensory systems)
Touch, Temperature, & Pressure
Damage can destroy sense of touch

15. Brain Lobes Temporal Lobe (Side, Behind Ears) Hearing/Auditory Area
Wernicke’s Area
Involves the understanding of written & spoken language
Damage results in difficulty understanding written/spoken language
Can speak quickly & easily but speech often makes no sense
Broca’s Area
Involves the production of speech
Damage involves difficulty speaking
Damage to areas causes “aphasia”
Trouble understanding/Producing Language

17. Brain Lobes Frontal Lobe (behind forehead)
Executive Center – Higher Mental Processes
Planning, Social Skills, Emotional Control, Problem Solving & Abstract Thinking
Motor Skills - Involved in the coordination of movement
Define “Abstract Thinking”

19. Cerebral Hemispheres
Corpus Callosum – Collection of nerve bundles that carries messages between the two hemispheres
Each hemisphere controls the opposite side of the body.
Ex. Left hemisphere controls right side of the body

20. Cerebral Hemispheres
Lateralization – Specialization of a hemisphere in a particular function
Left Hemisphere – Generally handles verbal processing, language, speech, reading & writing
Right Hemisphere – Generally handles nonverbal processing, spatial relations, music, and visuals
People often thought of as “right or left-brained”
Misconception
Primary sensory & motor areas are symmetrical.
Broca’s & Wernick’s area for language in the left hemisphere. Why left hemisphere is language dominant.

22. “Left-Brained” Or “Right-Brained”

23. Split Brain Patients
Patients who suffer from severe epileptic seizures have their corpus callosum severed
Epileptic Seizures – Bursts of abnormal neuron firings that generally occur in one hemisphere and then spread to the other
Subtle effects on brain functions
Ex. Able to describe verbally an object in their left hand but not in their right hand.
Which object do you think the person will be able to recognize verbally?

25. Accidents Phineas Gage 3.5 foot rod shot through his skull
Survived but extreme personality change
Shows that certain parts of the brain control certain aspects of our personality

26. Studying The Brain Computerized axial tomography (CAT Scan)
X-rays beam around the head (3D view)
Pinpoints injuries and brain deterioration

27. Studying The Brain Position Emission Topography (PET Scan)
Can see which areas of the brain are activated when performing tasks
A radioactive solution is injected into the body
Shows activity vs snapshot

28. Studying The Brain Magnetic Resonance Imaging (MRI)
Can see structures in detail, hard to see areas
Magnetic fields and radio waves
More powerful than CAT scan, “slice images”

29. Studying The Brain Electroencephalograph (EEG)
Measures electrical activity of brain using small electrodes pasted to you scalp
The rhythmical patterns produced are “brain waves”

30. Brain Lobes Frontal Lobe (behind forehead)
Executive Center – Higher Mental Processes
Planning, Social Skills, Emotional Control, Problem Solving & Abstract Thinking
Motor Skills - Involved in the coordination of movement
Correct notes for students. In the initial powerpoint Frontal Lobe was labeled as “Forebrain”.