Understanding the Cerebral Cortex and Research Strategies in Neuroscience

1. Modules 3-6 Research Strategies Neural & Hormonal Systems Tools of Discovery/brain structures The Cerebral Cortex & our divided brain

2. Research Strategies • Scientific Method • *operational (objective) definitions • *replicate the study • *valid (tests what it is supposed to) • *reliable (consistent results) • Correlation vs. Causation

3. More about research … Wording – important! Random sample Population size & make-up Correlation coefficient (strong vs. weak) (Positive vs. negative) Scatterplot (revealing)

4. Experimentation Control Group & Experimental Group Dependent Variable (depends on what you do to the other one!) Independent Variable (manipulated by researcher) Confounding Variables (other factors that can impact results) Blind Study – participants don’t know if they get the “treatment” Double Blind Study – participant and researcher don’t know if participant gets “treatment”

5. *great summary on page 37. I highly recommend! Statistics (YEAH!!!) Measures of central tendency (mean/median/mode) Measures of variation (range/standard deviation) Normal Curve (bell curve) Pay special attention to page 41 Remember – differences may be significant but still not important.

6. Just a bit more about statistics… Representative samples are better than biased samples Less-variable observations are more reliable than those that are more variable More cases are better than fewer

7. Module 4 – Biology… • Phrenology & Dr. Gall • Neurons – cell body, dendrite fibers (receive information), axon fibers (send messages) • “Dendrites Listen & Axons Speak” • Myelin Sheath = insulator • No insulator = multiple sclerosis – degenerative loss of muscle control • ~ Action potential – electrical impulse (2-180 mph) ~ Threshold – if this is exceeded, the party’s on! All or nothing response, though. One neural impulse doesn’t get stronger - more neurons fire

9. Previous slide taken from: http://www.kizoomlabs.com/products/the-adventures-of-ned-the-neuron/ Other images from: Google Images

12. Neurotransmitters Synapse=meeting point between neurons Neurotransmitters – chemical messengers. Enable the connections between neurons. When fired, neurotransmitters are released and connect (like lock & key) to another neuron. This excites (or inhibits) the continued firing of the message. Reuptake is when the sending neuron reabsorbs the excess chemical.

13. Neurotransmitters, continued • Please look at the table on page 52 • Endorphins – neurotransmitter similar to morphine • Drugs/other chemicals affect brain chemistry by exciting or inhibiting the firing of neurons. • Agonist molecules – mimic neurotransmitters • Antagonist molecules – inhibit/block transmitter functions • Read about Botulin (Botox) on page 53.

14. Nervous System

15. Previous slide taken from: • http://www.rhsmpsychology.com/ • I would recommend visiting this site. This instructor uses the same textbook and has some relevant handouts and study materials that may help you. ~I will let you know if I find helpful resources for you to use – if you find any, I would appreciate it it you would please share them with me.

16. Central Nervous System • Reflexes – a warm headless body can do it. • What about paralysis and sex? • Direct stimulation (reflex) vs. images/feelings…(mental)

17. Endocrine System and Hormones Hormones – chemical messengers that travel in the bloodstream. Sex/Food/Aggression Slower than neurotransmitters but some are similar. If it takes time to effect you, also may take longer to dissipate. “Simmer Down” In times of stress/danger – Autonomic Nervous System (ANS) tells adrenal glands to release epinephrine and norepinephrine (adrenalin/noradrenaline) ~ Raises BP, HR and blood sugar

18. Pituitary Gland Growth hormones Oxytocin – aids birth and … Master Gland – impacts other glands.

19. Brain Scans EEG – electroencephalogram Shower-cap-like hat filled with electrodes & conductive gel No direct access to brain Stimulus – see changes due to stimulus “Listen to the hum”

20. Brain Scans PET – Positron emission tomography Shows brain’s consumption of glucose – active neurons eat it up! Radioactive glucose tracked by machine – shows “hot spots” where brain is most active

21. Brain Scans MRI – Magnetic Resonance imaging Person’s head is put in a strong magnetic field then radio-wave pulse disrupts aligned atoms and when the atoms return to a normal spin, they provide a picture of the soft tissues

22. Brain Scans fMRI – functional MRI Where the brain is especially active, blood goes. Repeated MRI scans can show where the blood is going as a patient performs different functions Mind Reading?

23. Structures of the Brain • Brain Stem • Cerebellum – base of skull – “little brain” • Nonverbal learning & memory • Time / emotions • Balance / walking / shaky hands Limbic System Amygdala – aggression / fear Hypothalamus – hunger / thirst / body temp / sexual behavior

24. Module 6 Cerebrum=85% of brain’s weight Cerebral Cortex – like the bark on a tree. “Thinking Crown” Size of a large pizza Ultimate Control Center 20-23 billion nerve cells 300 trillion synaptic connections

25. 4 lobes of the brain • Frontal • Parietal • Occipital • Temporal • All these interplay

26. Cortex Motor Cortex – mapping brain activity – every thought is a neural event Sensory Cortex – occipital lobe – sensory area – bash=blindness – stimulation=flashes of light (see stars) Auditory Cortex – Schizophrenia auditory hallucinations seen via MRI Association areas: stimulation doesn’t result in any observable response – more difficult to map

27. Phineas Gage – page 74 Plasticity – ability of brain to repair itself following injury. Neurogenesis Split Brains We don’t know much about the brain!

28. Brain Damage • Sometimes brain can re-route pathways. • Plasticity • Neurogenesis • Stem Cells • May change personality

29. Everything psychological is also biological.