Neuroscience and Behavior Your 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 lobe Wernicke’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 Alzheimers (ACH-producing neurons deteriorate) Schizophrenia (high), Parkinson’s (low) Migraines, seizures (high) • GABA Seizures, tremors, insomnia (low) • Norepinephrine Depression (low) • Serotonin Depression (low) • Endorphins “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?