Neuroscience and Behavior Your brain…and other stuff!

Neuroscience and BehaviorYour brain…and other stuff!

Last time we thought about…• The shift from INTROSPECTIVE psychology to SCIENTIFIC

psychology• Wait…what are the differences again?

• Ways to effectively design an experiment• Wait…how did those work again?

• Common mistakes made in the analysis of data• Wait…what were some of those again?

We also talked about…• The Placebo Effect!

• Question!• What is the Placebo Effect? What causes it?

Neuroscience: Foundations• Paul Broca (1861): describes patient who cannot produce

spoken language• The problem? Damage in a small area in her left FRONTAL lobe• Broca’s Aphasia

Carl Wernicke (1848-1905): describes patient who cannot comprehend language but CAN produce it

Damage to an area in the left TEMPORAL lobeWernicke’s Aphasia

Visuals!

Question!• What do both Broca’s Aphasia and Wernicke’s Aphasia have in

common?

• What can we learn about the brain (and maybe the mind) from both afflictions?

Brains! Brains!• Your brain is made up of over 100 BILLION neurons!• Neurons: cells in the nervous system that communicate with one

another to perform information-processing tasks.

• Question: Are you reducible to your nervous system? Are you just a brain? Are all of your actions, thoughts, and feelings reducible to a bunch of neurons inside your skull?

Neurons: They’re Funny Looking

• Neurons are made up of three parts• Cell body

• The largest part of the neuron• Houses the cell nucleus• Nucleus houses DNA

• Keeps cell alive• Dendrites

• RECEIVE information from other neurons, muscles, or glands and send information to the cell body

• Axons• SEND information from the cell body to other neurons, muscles, or

glands• Axons are long and creepy

Neurons: Close Up!

Oh Syn-APSE!• Synapse: the gap between the axon of one neuron and the

dendrites or cell body of another

• Terminal Buttons: knoblike structures that branch out from an axon

• Neurotransmitter: chemicals that transmit information across the synapse to a receiving neuron’s dendrites

• Receptors: parts of the dendrite that receive neurotransmitters and initiate a new electric signal

Neurotransmitters & Disease• Acetylcholine (Ach)

• Dopamine

• Glutamate

• GABA

• Norepinephrine

• Serotonin

• Endorphins

Alzheimers (ACH-producing neurons deteriorate)

Schizophrenia (high), Parkinson’s (low)

Migraines, seizures (high)

Seizures, tremors, insomnia (low)

Depression (low)

Depression (low)

“Runner’s high” (high)

Dopamine!

Awkward Lecture Ahoy!

But Remember…• Neurotransmitter levels aren’t the only thing that matters:

It’s all about the LOCATION of the receptor sites!

This Is Your Brain on Drugs…• Drugs act like neurotransmitters, tricking your brain into acting

in abnormal ways

• Agonists: drugs that increase the action of a neurotransmitter

• Antagonists: drugs that block the function of a neurotransmitter

• L-dopa: agonist for dopamine, helps fight Parkinson’s symptoms

• Amphetamines: stimulates release of norepinephrine and dopamine

• Prozac: blocks the reuptake of serotonin

Nervous System: Peripheral vs. Central

Split Brain Syndrome• The brain is split into two hemispheres

• The two hemispheres are connected by commissures (bundles of axons that allow the hemispheres to communicate with each other)

• Corpus callosum: the largest commissure; connects large areas of the cerebral cortex on each side of the brain and supports communication of information across hemispheres

Parts of the Brain

Gratuitous Video from Someone Knowledgeable!

Hindbrain & Midbrain

Forebrain: Subcortical Structures

Forebrain: the Most Evolved Part of YOU

• Occiptal Lobe: processes visual information

• Parietal Lobe: processes information about touch, contains the somatosensory cortex

• Temporal Lobe: located at the lower side of each hemisphere, responsible for hearing and language

• Frontal Lobe: specialized areas for movement abstract thinking, planning, memory, and judgment

Cerebral Cortex, One More Time

Cerebellum vs. Frontal Lobes

•Why do zombies shuffle?

Your Brain is Plastic• Plasticity: functions that are assigned to certain areas of the

brain may be capable of being reassigned to toher areas of the brain to accomodtate changing input from the environemnt• Sensory inputs “compete” for representation in each area

• The Woman Without a Cerebellum

But Not THAT Plastic…

•Phineas Gage!

What Happens When…• You cut the corpus callosum?