Chapter 3 Biopsychology and the Foundations of Neuroscience “If I Only Had A Brain” – Wizard of Oz

What is Biopsychology? Biopsychology – The specialty in psychology that studies the interaction of biology, behavior, and the environment Neuroscience – Interdisciplinary field that focuses on the brain and its role in psychological processes

Evolution has fundamentally shaped psychological processes because it favors genetic variations that produce adaptive behavior How Are Genes and Behavior Linked?

Innate – Inborn; present at birth; part of the organism’s biological heritage Evolution – The gradual process of biological change that occurs in a species as it adapts to its environment

Evolution and Natural Selection Natural selection – The driving force behind evolution, by which the environment “selects” the fittest organisms

How Natural Selection Works Environmental pressure (changes in the environment) Competition (for resources) Selection of fittest phenotype (from among a variety of phenotypes) Reproductive success (genotype corresponding to fittest phenotypes passed to next generation) Frequency of that genotype increases (in next generation)

Genes and Inheritance Genotype – An organism’s genetic makeup Phenotype – An organism’s observable physical characteristics

Genes and Inheritance Mutations – Genetic variations, which occur randomly, especially during the recombination of chromosomes in sexual reproduction

Every cell in your body is made up of chromosomes, which are made up of genes, which are made up of strands of DNA.

Chromosomes, Genes, and DNA 1. DNA – A long, complex molecule that encodes genetic characteristics 2. Genes – The functional units of a chromosome Composed of nucleotides Every cell in your body is made up of chromosomes, which are made up of genes, which are made up of strands of DNA.

Sex chromosomes – The X and Y chromosomes that determine our physical sex characteristics Chromosomes, Genes, and DNA 3. Chromosomes – Tightly coiled threadlike structures along which the genes are organized

Genetic Explanations for Psychological Processes Genes influence our psychological characteristics as well as our physical traits

Choosing Your Children’s Genes Scientists already have the ability to control and alter genes of animals and clone animals. Currently, scientists are looking into how to use this information in order to treat disorders like Parkinson’s, heart disease, Down Syndrome, etc. How can stem cells be used to help with these disorders? What are the ethical issues that surround this topic? If we are going to “pick” the best traits, who is to decide what is “the best?”

The body’s two communication systems, the nervous system and the endocrine system, both use chemical messengers to communicate with targets throughout the body How Does the Body Communicate Internally?

The Neuron Types of Neurons Sensory neurons (carry messages from sense receptors towards the CNS) Motor neurons (carry messages from CNS toward muscles and glands) Interneurons (carry messages between nerve cells)

The Structure of a Neuron

The Neural Impulse Resting potential Action potential Synapse Synaptic transmission

All or Nothing in the John – A demonstration on neural transmission.

Seven Important Neurotransmitters – DAN’S EGG Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins

NeurotransmittersDopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Produces sensations of pleasure and reward; used by CNS neurons in voluntary movement Problems with Imbalance: Schizophrenia, Parkinson’s disease Substances that Affect: Cocaine, amphetamines, Ritalin, alcohol

Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Primary transmitter used by neurons carrying messages from CNS; involved in some kinds of learning and memory Problems with Imbalance: Certain muscular disorders, Alzheimer’s disease Substances that Affect: Nicotine, botulism toxin, curare, atropine

Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Controls heart rate, sleep, sexual responsiveness, stress, vigilance and appetite Problems with Imbalance: High blood pressure, depression Substances that Affect: Tricyclic antidepressants, beta blockers

Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Regulates sleep and dreaming, mood, pain, aggression, appetite and sexual behavior Problems with Imbalance: Depression, certain anxiety disorders, obsessive- compulsive disorder Substances that Affect: Prozac, hallucinogenics (e.g. LSD)

Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Pleasurable sensations and control of pain Problems with Imbalance: Lowered levels resulting from opiate addiction Substances that Affect: Opiates: opium, heroin, morphine, methadone

Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Primary excitatory neurotransmitter in CNS; involved in learning and memory Problems with Imbalance: Brain damage after stroke Substances that Affect: PCP (“angel dust”)

Neurotransmitters Dopamine Serotonin Acetylcholine Glutamine Norepinephrine GABA Endorphins Normal Function: Most prevalent inhibitory neurotransmitter in neurons of CNS Problems with Imbalance: Anxiety, epilepsy Substances that Affect: Barbiturates, tranquilizers (e.g. Valium, Librium), alcohol

Agonists and Antagonists – Various drugs affect communication at the synapse Agonists “excite” They mimic the effects of the neurotransmitter. Opiate class drugs (e.g. vicodin, heroin, morphine) are agonists. Can also enhance the neurotransmitter. Nicotine turns up the volume of ACH – it is why the person gets “amped” up. Prozac and Zoloft are agonists – they block the reuptake of the seratonin to produce more Antagonists dampen or inhibit the release of a neurotransmitter. Botox is an antagonist – doesn’t allow the release of ACH – hence the muscle is paralyzed. Curare then is also an antagonist – paralyzes the body by “turning off” ACH.

Plasticity Plasticity – Ability of the nervous system to adapt or change as the result of experience; sometimes helps the nervous system adapt to physical damage

Glial Cells Glial cells Provide structural support for neurons Help in forming new synapses Form myelin sheath

The Organization of the Nervous System

The Endocrine System (the body’s chemical messenger system)

The Endocrine System Pituitary gland – Master gland that produces hormones influencing the secretions of all other endocrine glands; produces hormone that influences growth; attached to hypothalamus

How Does the Brain Produce Behavior and Mental Processes? The brain is composed of many specialized modules that work together to create mind and behavior

Windows on the Brain EEG (electroencephalograph) – Device for recording brain waves, typically by electrodes placed on the scalp Brain waves – Patterns of electrical activity generated by the brain

Windows on the Brain Brain scans – Recordings of the brain’s electrical or biochemical activity at specific sites CT scanning (computerized tomography)

Windows on the Brain Brain scans – Recordings of the brain’s electrical or biochemical activity at specific sites PET scanning (positron emission tomography)

Windows on the Brain Brain scans – Recordings of the brain’s electrical or biochemical activity at specific sites MRI (magnetic resonance imaging) fMRI (functional magnetic resonance imaging)

Three Layers of the Brain Brain stem and cerebellum Drive vital functions, such as heart rate, breathing, digestion Limbic system Adds emotions, complex motives, increased memory abilities Cerebrum Enables reasoning, planning, creating, problem solving

The Brain Stem and Cerebellum Thalamus Pons Cerebellum Medulla Brain stem Reticular Formation/Reticular Activating System

The Limbic System Hypothalamus – Serves as the brain’s blood- testing laboratory, constantly monitors blood to determine the condition of the body

The Limbic System Amygdala – Involved in memory and emotion, particularly fear and aggression

The Limbic System Hippocampus – Involved in establishing long-term memories

The Cerebrum Cerebrum – Topmost layer of the brain; the bulbous cap over the limbic system Cerebral cortex – Thin gray-matter covering of the cerebrum; carries on thinking and perceiving Cerebral hemispheres – The two walnut shaped halves of the cerebrum, connected by the corpus callosum

The Four Lobes of the Cerebral Cortex Frontal lobes (movement and thinking) Parietal lobes (touch sensation and spatial relationships) Occipital lobes (contain visual cortex) Temporal lobes (process sounds, including speech)

The Cooperative Brain Association cortex – Cortical regions that combine information from various other parts of the brain

Cerebral Dominance Cerebral dominance – Tendency of each brain hemisphere to exert control over different functions Aphasia – The loss of speech caused be brain damage Spatial orientation – Process of locating one’s body or other objects in space

Specialization of the Cerebral Hemispheres Left Hemisphere Right Hemisphere Spontaneous speaking and writing Responses to complex commands Word recognition Memory for words and numbers Sequences of movements Feelings of anxiety Positive emotion Repetitive but not spontaneous speaking Responses to simple commands Facial recognition Memory for shapes and music Spatial interpretation Emotional responsiveness Negative emotion

The Split Brain Split-brain patients – Individuals who have had the corpus callosum surgically severed Duality of consciousness – Condition in which a split-brain patient has a separate consciousness in each hemisphere

Copyright © Allyn & Bacon 2007 Split Brain Research: Roger Sperry and Michael Gazzangia

End of Chapter 3