1. The Brain Module 4

2. The Brain: Older Brain Structures
The Brainstem is the oldest part of the brain, beginning where the spinal cord swells and enters the skull. It is responsible for automatic survival functions.
Preview Question 7: What are the functions of the brainstem and its associated structures?

3. Mike the headless chicken

4. Brainstem
The Medulla [muh- DUL-uh] is the base of the brainstem that controls heartbeat and breathing.

5. Brainstem-- PONS Appears just above the medulla
Helps coordinate movements
Houses nerve circuits that regulate sleep and dreaming cycle.
Also acts as the “bridge” that connects the brain stem to the cerebellum.

6. Brainstem
The Thalamus [THAL- uh-muss] is the brain’s sensory switchboard, located on top of the brainstem. It directs messages to the sensory areas in the cortex and transmits replies to the cerebellum and medulla.

7. Brainstem
Reticular Formation is a nerve network in the brainstem that plays an important role in controlling arousal.

8. Cerebellum
The “little brain” attached to the rear of the brainstem. It helps coordinate voluntary movements and balance.

9. The Brain
Techniques to Study the Brain
A brain lesion experimentally destroys brain tissue to study animal behaviors after such destruction.
Hubel (1990)

10. Clinical Observation
Clinical observations have shed light on a number of brain disorders. Alterations in brain morphology due to neurological and psychiatric diseases are now being catalogued.
Tom Landers/ Boston Globe

11. Electroencephalogram (EEG)
An amplified recording of the electrical waves sweeping across the brain’s surface, measured by electrodes placed on the scalp. *Demonstrates activity but not precisely
AJ Photo/ Photo Researchers, Inc.

12. **Demonstrates function
PET Scan
PET (positron emission tomography) Scan is a visual display of brain activity that detects a radioactive form of glucose while the brain performs a given task.
**Demonstrates function
Courtesy of National Brookhaven National Laboratories

13. MRI Scan
MRI (magnetic resonance imaging) uses magnetic fields and radio waves to produce computer-generated images that distinguish among different types of brain tissue. Top images show ventricular enlargement in a schizophrenic patient. Bottom image shows brain regions when a participants lies.
**Structural
Both photos from Daniel Weinberger, M.D., CBDB, NIMH
James Salzano/ Salzano Photo
Lucy Reading/ Lucy Illustrations

14. fMRI
Demonstrates brain function with second-by-second images of blood flow
in-an-fmri-to-love-someone-as-hard-as-they-can

15. The Limbic System
The Limbic System is a doughnut-shaped system of neural structures at the border of the brainstem and cerebrum, associated with emotions such as fear, aggression and drives for food and sex. It includes the hippocampus, amygdala, and hypothalamus.
Preview Question 8: What are the functions of limbic system structures?

16. Aggression as a brain state
Back arched and fur fluffed, this fierce cat is ready to attack. Electrical stimulation of a cat’s amygdala provokes angry reactions, suggesting the amygdala’s role in aggression. Which ANS division is activated by such stimulation?
ANSWER: The cat would be aroused via its sympathetic nervous system.
Aggression as a brain state
David G. Myers: Myers’ Psychology for AP®, Second Edition Copyright © 2014 by Worth Publishers

17. Amygdala
The Amygdala [ah-MIG- dah-la] consists of two lima bean-sized neural clusters linked to the emotions of fear and anger.

18. Hypothalamus
The Hypothalamus lies below (hypo) the thalamus. It directs several maintenance activities like eating, drinking, body temperature, and control of emotions. It helps govern the endocrine system via the pituitary gland.

19. The hypothalamus Involved with many functions, but our focus
will be on the “feeding” element of “The 4 F’s”

21. Lateral hypothalamus: “Lunch!”
(Involved in “hunger messages”)
Ventromedial hypothalamus: “Vomit!!!”
(The “satiety center”; “You’ve had enough!”)

22. Reward Center
Rats cross an electrified grid for self-stimulation when electrodes are placed in the reward (hypothalamus) center (top picture). When the limbic system is manipulated, a rat will navigate fields or climb up a tree (bottom picture).
Sanjiv Talwar, SUNY Downstate

23. Hippocampus Processes memory
Connects your present to your past and remember the location of things in space.

24. The Hippocampus Picture a hippo college student who
can’t recall where his class is…..
(The hippo – campus is responsible for
the formation of new memories)

25. The Cerebral Cortex
The intricate fabric of interconnected neural cells that covers the cerebral hemispheres. It is the body’s ultimate control and information processing center.

26. Structure of the Cortex
Each brain hemisphere is divided into four lobes that are separated by prominent fissures. These lobes are the frontal lobe (forehead), parietal lobe (top to rear head), occipital lobe (back head) and temporal lobe (side of head).
Preview Question 9: How is the cerebral cortex organized?

27. Functions of the Cortex
The Motor Cortex is the area at the rear of the frontal lobes that control voluntary movements. The Sensory Cortex (parietal cortex) receives information from skin surface and sense organs.
Preview Question 10: What are the functions of the cerebral cortex?

29. Penfield did open brain surgery to map this area.
Talk about contralateralization
Plasticity: these parts “invade” areas that are not being used

30. The Homunculus

31. Frontal Lobes Higher Mental functions Includes the motor Cortex
Pre-frontal Cortex—decision-making and reasoning skills.

32. Parietal Lobes Sensory Cortex
Right Lobe: helps keep track of your body parts.
Left Lobe: specialized in locating the source of speech sounds, as when someone calls your name.
It also works with the temporal lobe to extract meaning from speech, and writing.

33. Occipital Lobe You have eyes in the back of your head!!
Receives stimulation relayed from the eyes to the visual cortex, which constructs our moving picture of the outside world.

34. Temporal Lobes
Auditory Cortex Helps make sense of sounds.

35. Visual Function
The functional MRI scan shows the visual cortex is active as the subject looks at faces.
Courtesy of V.P. Clark, K. Keill, J. Ma. Maisog, S. Courtney, L.G.
Ungerleider, and J.V. Haxby,
National Institute of Mental Health

36. Auditory Function
The functional MRI scan shows the auditory cortex is active in patients who hallucinate.

37. Language
Aphasia 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) or in the Angular Gyrus that leaves people unable to read aloud.

38. Also note:
Aphasia

39. Broca’s Area: ‘boca’ means ‘mouth’ in Spanish (Broca’s Area is largely
responsible for expressive language) or
Broca comes before Wernicke
alphabetically, and expression comes
before understanding alphabetically

40. Specialization & Integration
Brain activity when hearing, seeing, and speaking words

41. The Brain’s Plasticity
The brain is sculpted by our genes but also by our experiences. Plasticity refers to the brain’s ability to modify itself after some types of injury or illness. Our Brains are more plastic when we are children Constraint-Induced Therapy Neurogenesis: formation of new neurons
Preview Question 11: Is the brain capable of reorganizing itself if damaged?

42. Hemispherectomy

43. Jody's Hemispherectomy

44. Our Divided Brain
Our brain is divided into two hemispheres. The left hemisphere processes reading, writing, speaking, mathematics, and comprehension skills. In the 1960s, it was termed as the dominant brain.

45. Splitting the Brain
A procedure in which the two hemispheres of the brain are isolated by cutting the connecting fibers (mainly those of the corpus callosum) between them. *band of fibers that connect/carry the messages between the hemispheres.
Corpus Callosum
Preview Question 12: What is a split brain, and what does it reveal about brain functioning?
Courtesy of Terence Williams, University of Iowa
Martin M. Rother

46. Split Brain Patients
With the corpus callosum severed, objects (apple) presented in the right visual field can be named. Objects (pencil) in the left visual field cannot.

47. Divided Consciousness

48. Try This!
Try drawing one shape with your left hand and one with your right hand, simultaneously.
BBC

49. Split Brain Patient

50. Non-Split Brains
People with intact brains also show left-right hemispheric differences in mental abilities.
A number of brain scan studies show normal individuals engage their right brain when completing a perceptual task and their left brain when carrying out a linguistic task.