1. Brain Structure and Function

2. “If the human brain were so simple that we could understand it, we would be so simple that we couldn’t”
-Emerson Pugh, The Biological Origin of Human Values (1977)

3. Phineas Gage September 13th, 1848 Phineas 25 years old
Rutland & Burlington Railroad, Cavendish, VT
Paving the way for new RR tracks
“Tamping Iron”
1.25in x 3ft

5. Phineas Gage Accident Months later: “No longer Gage”
Quick Recovery
Months later: “No longer Gage”
Before: capable, efficient, best foreman, well-balanced mind
After: extravagant, anti-social, liar, grossly profane
Stint with P.T Barnum
Died 12 years later
Watch Clip

6. Evolution of the Brain
Reptilian  Paleomammalian  Neomammalian

7. The Brain Brainstem Medulla
responsible for automatic survival functions
Medulla
controls heartbeat and breathing
Brainstem
the central core of the brain, beginning where the spinal cord swells as it enters the skull
responsible for automatic survival functions
Medulla [muh-DUL-uh]
base of the brainstem
controls heartbeat and breathing
Brainstem, controls for heartbeat and breathing—swell is called the medulla.
Vital Functions :
Breathing
Blood circulation
Swallowing
Urination

8. Parts of the Brain BRAINSTEM  Heart rate and breathing THALAMUS
 Relays
messages
amygdala
hippocampus
pituitary
CEREBELLUM
 Coordination
and balance
BRAINSTEM  Heart rate and breathing

9. Reticular Formation Widespread connections
Arousal of the brain as a whole
Reticular activating system (RAS)
Maintains consciousness and alertness
Functions in sleep and arousal from sleep
Reticular formation The brainstem also contains networks of neurons,
known collectively as the reticular formation, that project up into the cerebral
cortex and basal ganglia and affect general arousal. The reticular formation is also
involved in inducing and terminating the different stages of sleep. The autonomy
of the brain stem can be dramatically illustrated by severing an animal’s brain
stem from the entire brain above it, including its entire cerebral cortex. Cats that
receive this treatment can still walk around and direct attacks at noises; if they
then find themselves holding on to food, they will eat it. Some cases have been reported
of humans born without cerebral cortices, and their behaviors are extremely
basic and reflexive. Such infants tend not to develop normally and also do
not tend to survive

10. The Cerebellum helps coordinate voluntary movement and balance
the “little brain” attached to the rear of the brainstem, cerebellum actually means little brain.
Also helps involved in nonverbal learning and memory (will discuss in later chapters), if you injured your cerebellum you would have difficulty walking, keeping your balance, shaking hands.
Note: these lower brain functions occur without any conscious effort.

11. The Limbic System
Hypothalamus, pituitary, amygdala, and hippocampus all deal with basic drives, emotions, and memory
Hippocampus  Memory processing
Amygdala  Aggression (fight) and fear (flight)
Hypothalamus  Hunger, thirst, body temperature, pleasure; regulates pituitary gland (hormones)
The limbic system is an older term for a group of subcortical structures dealing with basic drives, emotions and memory
The diencefpahlon (or between brain) the hypothalamus and thalamus
The hippocampus and amygdala
The basal ganglia
The dreebral cortex

12. The Limbic System Hypothalamus
neural structure lying below (hypo) the thalamus; directs several maintenance activities
eating
drinking
body temperature
helps govern the endocrine system via the pituitary gland
linked to emotion
(show video)

13. The Limbic System Amygdala
two almond-shaped neural clusters that are components of the limbic system and are linked to emotion and fear
Researchers began to find evidence that the amygdala was involved in the emotion of fear in the late 1930s. Monkeys with damage to the brain cluster and surrounding areas had a dramatic drop of fearfulness.
Later, studies showed that rats with targeted amygdala damage would snuggle up to cats.
But if you electrically stimulate the amygdala in a normally placid domestic animal such as a cat, the cat prepares to attach by hissing, arching its back, pupils dilate, and its hair stands up on end.
Accumulating revelations about this fear system led researchers recently to examine the human brain's response to fear with imaging studies. One study showed that pictures of frightening faces initiate a quick rise and fall of activity in the amygdala.
In the future, scientists believe imaging techniques may help determine the course of treatment for disorders involving a malfunction in fear processing. For example, a person with an extreme fear of germs who continuously washes, known as an obsessive-compulsive disorder,

14. August 1st, 1966 Charles Whitman
He killed his wife and mother before going to the top of the university tower and opened fire on persons crossing the campus and on nearby streets. He ended up killing 16 people and wounded 31, before being killed by police officers. The shooting spree lasted 96 minutes.
Post-mortem revealed a brain tumor near his amygdala.
When you see similar cases in the news of people doing horrendous things (eg, Andrea Yates), what’s your reaction? What do you think about the individual? Psychology has changed the way we view such tragedies…now we’re more likely to see evil as pathological.

15. The Brain
Thalamus
the brain’s sensory switchboard, located on top of the brainstem
it directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla
Thalamus- located on top of the brainstem, a joined pair of egg-shaped structures,
Receives sensory info, routes it to higher brain regions that deal with seeing, tasting, touching etc.
directs messages to the sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla

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

17. The lobes of the cerebral hemispheres
Figure page 110
The lobes of the cerebral hemispheres: parietal, occipital, temporal, and frontal.

18. The lobes of the cerebral hemispheres
Planning, decision making speech
Sensory
Figure page 110
The lobes of the cerebral hemispheres: parietal, occipital, temporal, and frontal.
Vision
Auditory

19. The Cerebral Cortex Frontal Lobes Parietal Lobes
involved in speaking and muscle movements and in making plans and judgments
the “executive”
Parietal Lobes
include the sensory cortex
The cerebral cortex is organized or divided into 4 regions or lobes.
frontal lobe- behind your forehead, executive functions.
-parietal lobe- at the top and to the rear of the head

20. The Cerebral Cortex Occipital Lobes Temporal Lobes
include the visual areas, which receive visual information from the opposite visual field
Temporal Lobes
include the auditory areas, each of which receives auditory information primarily from the opposite ear
Occipital lobe- at the back of your head
-Temporal lobe- just above your ears; receives auditory info primarily from the opposite ear.
The lobes are separated by prominent fissures or folds. Important to note that although each lobe carries out different functions, many of our functions require the interplay or involvement of several lobes.
Temporal lobes -- each of which receives auditory information primarily from the opposite ear

21. The Cerebral Cortex Frontal (Forehead to top)  Motor Cortex
Parietal (Top to rear)  Sensory Cortex
Occipital (Back)  Visual Cortex
Temporal (Above ears)  Auditory Cortex

22. Motor/Sensory Cortex
Contralateral
Homunculus
Unequal representation

23. The Cerebral Cortex Aphasia Broca’s Area Wernicke’s Area
impairment of language, usually caused by left hemisphere damage either to Broca’s area (impairing speaking) or to Wernicke’s area (impairing understanding) –see clips
Broca’s Area
an area of the left frontal lobe that directs the muscle movements involved in speech
Wernicke’s Area
an area of the left temporal lobe involved in language comprehension and expression

24. Language Areas Broca  Expression
Wernicke  Comprehensionand reception
Aphasias
LEFT HEMISPHERE

25. Suggested localization
Paul Broca [1800s]
Observed “Tan” (named so because he could only utter the sound ‘tan-tan’)
In 1861 Broca did a post-mortem showing that Tan had a superficial lesion in the left frontal lobe of his brain, in exactly the area that controlled speech.
Largely on the basis of this case, Broca postulated that expressive language function was located in the posterior left frontal lobe ("Broca's Area").
Suggested localization

26. Techniques to examine functions of the brain
1. Remove part of the brain & see what effect it has on behavior
2. Examine humans who have suffered brain damage

27. 3. Stimulate the brain
4. Record brain activity

28. Brain Lateralization

29. Our Divided Brains
Corpus collosum – large bundle of neural fibers (myelinated axons, or white matter) connecting the two hemispheres

30. Hemispheric Specialization
LEFT
Symbolic thinking
(Language)
Detail
Literal meaning
RIGHT
Spatial perception
Overall picture
Context, metaphor

31. Contra-lateral division of labor
Right hemisphere controls left side of body and visual field
Left hemisphere controls right side of body and visual field

32. Split Brain Patients
Epileptic patients had corpus callosum cut to reduce seizures in the brain
Lives largely unaffected, seizures reduced
Affected abilities related to naming objects in the left visual field

33. Brain Plasticity

34. Brain Plasticity
The ability of the brain to reorganize neural pathways based on new experiences
Persistent functional changes in the brain represent new knowledge
Age dependent component
Brain injuries

35. Environmental influences on neuroplasticity
Impoverished environment
Enriched environment

36. Sensation
The process by which the central nervous system receives input from the environment via sensory neurons
Bottom up processing

37. Perception
The process by which the brain interprets and organizes sensory information
Top-down processing

38. The psychophysics of sensation
Absolute threshold  the minimum stimulation needed to detect a stimulus with 50% accuracy
Subliminal stimulation  below the absolute threshold for conscious awareness
May affect behavior without conscious awareness
Sensory adaptation/habituation  diminished sensitivity to an unchanging stimulus

39. The five major senses Vision – electromagnetic Hearing – mechanical
Occipital lobe
Hearing – mechanical
Temporal lobe
Touch – mechanical
Sensory cortex
Taste – chemical
Gustatory insular cortex
Smell – chemical
Olfactory bulb
Orbitofrontal cortex
Vomeronasal organ?

40. And the seventh…and eighth…and ninth…
The sixth sense
And the seventh…and eighth…and ninth…
Vestibular  balance and motion
Inner ear
Proprioceptive  relative position of body parts
Parietal lobe
Temperature  heat
Thermoreceptors throughout the body, sensory cortex
Nociception  pain
Nociceptors throughout the body, sensory cortex

41. Thresholds of the five major senses

42. The Retina
The retina at the back of the eye is actually part of the brain!
Rods – brightness
Cones – color