1. THE BRAIN
September 18, 2013

2. Ways we Study the Brain 52-54
CAT Scan
PET Scan
MRI
Functional MRI

3. Lesions Removal or destruction of some part of the brain.
Frontal Lobotomy

4. What IS IT? Jellylike mass of fat and protein
Weighs about 3 pounds (1/45th of the body’s weight)
100 billion neurons make up the "gray matter”
Millions of dendrites and axons are the "white matter"

5. Brain Structures 54-62 Hindbrain Midbrain Forebrain
Cerebral Cortex (part of forebrain)

6. “Older” Brain Structures-hindbrain
Brainstem
Oldest and innermost part
Where spinal cord enters brain (medulla)
Controls heartbeat, breathing, & blood pressure
Crossover point for nerves
Injury results in death

7. Older Brain Structures, cont’d.-hindbrain
Cerebellum
Extends from back of brainstem (bottom rear of brain)
Means “little brain”
Involves coordination of voluntary movement
Coordinates fine muscle movements.
Habitual motor skills

8. Older Brain Structures, cont’d.-hindbrain
PONS
Located just above the medulla.
Connects hindbrain with midbrain and forebrain.
Involved in facial expressions.

9. Midbrain If stimulated If Destroyed
Coordinates simple movements with sensory information.
Most important structure in Midbrain is the Reticular Formation: controls arousal and ability to focus our attention.
If Destroyed

10. MIDBRAIN Cont’d Thalamus Located at top of brainstem
Sensory “switchboard” of brain
Receives sensory signals from the spinal cord and sends them to other parts of the forebrain.
Every sense except smell.

11. Midbrain cont’d Limbic System
Border between older brain and two halves
Amygdala – aggression and fear
Hypothalamus – hunger, thirst, body temperature, sex
Hippocampus - memory

12. Amygdala Involved in how we process memory with emotions.
Emotions connected to survival: anger, fear, disgust
The emotion of anger has not changed much throughout evolution.

13. Hypothalamus The most powerful structure in the brain.
Maybe most important structure in the brain.
Controls and regulates
Body temperature
Sexual Arousal
Hunger
Thirst
Endocrine System
The most powerful structure in the brain.

14. Rat with an Implanted Electrode in pleasure center of Hypothalamus

15. Hippocampus
Involved in the processing and storage of new memories.

16. In what brain region would brain DAMAGE BE MOST LIKELY TO …
… disrupt your ability to jump rope?
… disrupt your ability to hear sounds?
… leave you unable to move faster in a threatening situation?
… leave you unable to breathe?

17. Forebrain 58-62 What makes us human. Largest part of the brain.
Made up of the Cerebral Cortex.

18. CEREBRAL CORTEX
Layer of densely packed neurons “gray matter” and “glial cells”(glue), that support brain cells & cover the cerebral hemispheres.
Wrinkles are called fissures.
80% of brain’s weight
Divided into four regions
Frontal lobes
Parietal lobes
Occipital lobes
Temporal lobes

20. Frontal Lobes Abstract thought and emotional control.
Contains Motor Cortex: sends signals to our body controlling muscle movements.
Contains Broca’s Area: responsible for controlling muscles that produce speech.
Damage to Broca’s Area is called Broca’s Aphasia: unable to make movements to talk.

21. Parietal Lobes
Contain Sensory Cortex: receives incoming touch sensations from rest of the body.
Most of the Parietal Lobes are made up of Association Areas.
Where would this girl feel the most pain from her sunburn?

22. Occipital Lobes Deals with vision.
Contains Visual Cortex: interprets messages from our eyes into images we can understand.

23. Temporal Lobes Process sound sensed by our ears. NOT LATERALIZED.
Contains Wernike's Area: interprets written and spoken speech.
Wernike's Aphasia: unable to understand language: the syntax and grammar jumbled.

24. CEREBRAL CORTEX, CONT’d.

26. Association Areas
Any area not associated with receiving sensory information or coordinating muscle movements.

27. Cerebral cortex, cont’d.
MOTOR FUNCTIONS
Sends messages out to body
How do scientists know what it does?
electrical stimulation of different parts
neural prosthetics

28. Cerebral cortex, cont’d.
SENSORY FUNCTIONS
Receives information from skin’s senses
More sensitive body regions have greater area of sensory cortex devoted to them

29. Motor and Sensory Cortexes

30. LOCALIZATION OF BRAIN FUNCTION
How do scientists know the functions of different parts of the brain?
“Old” methods
phrenology
Brain damage case studies
Example: Case of Phineas Gage
Modern technology
EEG, CT, MRI, PET

31. Accidents Phineas Gage Story Personality changed after the accident.
What does this tell us?
That different part of the brain control different aspects of who we are.

33. Specialization and Integration in Language

34. Hemispheres Divided into two hemispheres.
Contralateral control: right controls left and vice versa.
In general,
Left Hemisphere: logic and sequential tasks.
Right Hemisphere: spatial and creative tasks.

35. Brain Activity when Hearing, Seeing, and Speaking Words

36. Brain Plasticity
The idea that the brain, when damaged, will attempt to find news ways to reroute messages.
Children’s brains are more plastic than adults.

37. The Corpus Callosum
Divides the 2 hemispheres.

38. Split Brain Patients
Those who suffer from epilepsy, have their corpus callosum severed partially.

39. Testing the Divided Brain