1. AP Psychology Sept. 16th
Objective
Opener
Identify the purposes for different methods of measuring the brain.
Understand the importance of the corpus collosem and the difference between the left and right brain by participating in a demonstration.
Presentations

2. Electroencephalogram
EEG
Detects brain waves through their electrical output.
Used mainly in sleep research.

3. Magnetic Resonance Imaging
MRI
More detailed picture of brain using magnetic field to knock electrons off axis.
Takes many still pictures and turns images into a movie like production.
3D MRI

4. Computerized Axial Tomography
CAT Scan
3D X-Ray of the brain.
Good for tumor locating, but tells us nothing about function.

5. Positron Emission Tomography
PET Scan
Measures how much of a chemical the brain is using (usually glucose consumption).

6. Functional MRI
Combination of PET and MRI

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

8. The Corpus Callosum
Divides the 2 hemispheres.

9. Split Brain Patients
Those who dues to epilepsy, have their corpus callosum removed.

10. Testing the Divided Brain

11. Split-Brain Surgery- Severe Epilepsy
Corpus Callosum attaches the two hemispheres of cerebral cortex.
When severed you have a split- brain patient.
Michael Gazzaniga & Roger Sperry studied these split-brain patients

12. Split Brain Demo Was this task difficult or easy? Why?
VOLUNTEERS: Tie the shoe with only the hand you have on the desk. Right Hemisphere=left hand Left Hemisphere=right hand
Difficult b/c: The volunteers are trying to coordinate the movements of 2 independent hands.
Split brain patients experience some numbness & coordination problems immediately after surgery
Practice & Habituation will improve performance over time.

13. Split Brain Demo
ENTIRE CLASS: Draw each shape with the assigned hand at the same time
SPLIT BRAIN PATIENT: Now you give it a try….

14. Split Brain Demo
Was this task easier for the split brain patient or the people with “normal” brains? Why?
EASIER FOR THE SPLIT BRAIN PATIENT b/c of the disconnect between the two hemispheres – each hemisphere sees something different & can operate independently to draw it with ease.

15. Left Hemisphere (right hand)– wear the blinders & look down at the paper & pen in front of you (NO PEAKING!)
Right Hemisphere (left hand)– take the pen in hand…draw a picture of what’s on the flashcard.
Why can’t the left hemisphere answer initially?
Why can’t the Right Hemisphere answer verbally?
What is on the card???
Left Hemisphere = Language center
The right Hemisphere is unable to SAY what he saw but he can draw it.
B/C the Right Hemisphere “saw”
the card...but the Right Hemisphere can’t share that info with the Left Hemisphere internally (No Corpus Callosum)
The Left Hemisphere literally doesn’t know what was on the card until he sees it drawn in front of them…with his own left hand by the right hemisphere!

16. Living with half a brain

17. Neural Plasticity
The brain has the ability to be changed by experience.
Rosenzweig (1984) demonstrated the importance of experience to neural development Rats raised in more complex environments had larger neurons and more synaptic connections. Other research has found those rats raised in more complex environments are better at solving problems
The brain changes in response to experience. This appears to happen as a response to expertise (e.g. practicing the violin)
Neural plasticity
The ability of the brain to be changed structurally and chemically by experience.
Rosenzweig (1984) demonstrated the importance of experience to neural development
Rats raised in more complex environments had larger neurons and more synaptic connections
Other research has found those rats raised in more complex environments are better at solving problems
The brain changes in response to experience.
This appears to happen as a response to expertise (e.g. practicing the violin)
The strength of the response varies as well as the amount.
Adult brains are capable of neurogenesis, the creation of neurons over the course of one’s lifetime
This finding has lead to new research into the potential to grow cells to replace damaged cells,
or finding ways to encourage damaged cells to repair themselves.
Morris, (c) 2006, Prentice Hall

18. 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.

19. Homework Review
Watch Crash Course #3-4 and complete viewing guides.