Chapter 3 Biological Foundations of Behavior Notes PDF

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Chapter 3 Biological Foundations of Behavior Notes

1.Nervous system-body's electrochemical communication circuitry 1. Field that studies is called Neuroscience 1. Cognitive Neuroscience-links cognitive processes and their underlying neural bases; benefited from fMRI progress 2. Plasticity- brain's special physical capacity for change 1. Brain can change in response to experience as well as injury 2. Collateral Sprouting-process by which axons of healthy nearby neurons to damaged cells grow new branches 3. Substitution of Function-process by which damaged region's functions is taken over by another area or areas of the brain 4. Neurogenesis- process by which new neurons are generated 3. Neuron- nerve cell 1. Means of travel for an impulse 2. Done electrically 3. Handle information processing 4. About 100 billion in the human brain 5. Complex structure with as many as 10,000 physical connections with other cells 6. “One way street” in the nervous system 7. Nerve cells, chemicals and electrical impulses work together to transmit information at speeds of up to 330 miles per hour 8. Specialized; Motor neurons don't respond to sensory info and sensory neurons don't respond to motor information 9. Shape, size and connections can change throughout life span 10. Can and do change 11. Use glucose for energy 4. Afferent Nerves (sensory nerves) 1. carry information about the external environment and the internal conditions to the brain and spinal cord via sensory receptors 2. ex. the sight of a sunrise 5. Efferent Nerves (motor nerves) 1. carry information out of the the brain and spinal cord (i.e. the nervous system's output) 2. Tell muscles and glands to “get busy” 6. Central Nervous System (CNS) 1. Brain and spinal cord make up 2. More than 99% of nerve cells located in 7. Peripheral Nervous System (PNS) 1. Network of nerves connecting the brain and spinal cord to other parts of the body 2. Brings information to and from the brain and spinal cord and carries out commands of the CNS to enable various muscular and glandular activities 3. 2 major division 1. Somatic Nervous System

1. Consists of sensory nerves who conveys information from the skin and muscles to the CNS about about conditions like pain and temperature 2. Also consists of motor nerves that tell the muscles what to do 2. Autonomic Nervous System 1. Takes messages to and from body's internal organs, monitoring processes like breathing, heart rate and digestion 2. Also divided in two parts Sympathetic Nervous System-arouses the body to mobilize for action and is involved in the experience of stress; “fight or flight” Parasympathetic Nervous System-calms the body Acts on endocrine glands to produce important physiological reaction to strong emotions like rage and fear 8. Mirror Neurons 1. Nerve Cells 2. In human and nonhuman primates 3. Activated both when an action is performed and when the organism observes the action being performed by another 4. Respond to both kinds of information-motor and sensory 9. Glial cells (glia) 1. Other type of cell providing support, nutritional benefits and other functions in the nervous system 2. Keep neurons running smoothly 3. Not specialized 4. More than neurons; for every neuron there are about 10 glial cells 10. Neuron Structure 1. Not all are alike;specialized to handle different functions 2. Have common characteristics: 1. Cell body-contains nucleus which directs the creation of substances that the neuron needs for growth and maintenance;maintains neurons chemical balance 2. Dendrites-tree like fibers projecting from a neuron that receive information and direct it toward the cell body; 1. Most nerve cells have multiple dendrites which increases surface area 3. Axon- part of the neuron that carries information away from the cell body and towards other cells 1. Tube encased in a membrane with fluids inside and outside it and inside those fluids are ions(both positive and negative) 3. Very thin cellular membrane surrounds the surface and allows substances to move in and out of the cell 1. Membrane is semipermeable because fluids and ions sometimes flow into and out of it 4. Mylelin Sheath- layer of cells containing fat, encases and insulates most axons 1. Speeds up transmission of nerve impulses 2. Develop as nervous system evolved 3. Nodes of Ranvier- divide sheath into segments 4. Prevents signals from interfering w/ each other

5. Ion channels-gates in the membrane 6. Resting Potential-stable, negative charge of an inactive neuron 7. Action Potential- brief wave of positive electrical charge that sweeps down the axon 8. All or Nothing Principle 1. Action potential abides by it 2. Principle that once the electrical impulse reaches a certain level of intensity aka its threshold, it fires and moves all the way down the axon w/out losing any intensity 9. Synapses- tiny spaces between neurons 1. Synaptic gaps are the space between neurons that synapses create 2. Most lie between axon of one neuron and the dendrites/cell body of another 3. Before an impulse can cross the synaptic gap, it must be converted into a chemical signal 10. Terminal Buttons-the end of the numerous fibers an axon branches out into 1. Within the terminal buttons are synaptic vesicles which store neurotransmitters 11. Neurotransmitters 1. Transmit and carry information across the synaptic gap to the next neuron 2. Movements are random 3. After delivering its message, some of the neurotransmitter is used up in energy production and some is reabsorbed by the axon that released it (reuptake) 4. Many different neurotransmitters 1. Excitatory (causes receiving cell to fire) and Inhibitory (causes receiving cell to stop firing) 5. Types of Neurotransmitters: 1. Acetylcholine (ACh)-stimulates firing or neurons;involved in muscle action, learning and memory; found throughout CNS and PNS 2. GABA (gamma aminobutyric acid) found throughout CNS; present in as many as 1/3 of the brain's synapses;key function in brain; helps regulate neuron firing and control the precision of the signal being carried between neurons 3. Glutamate- most prevalent neurotransmitter; key role in exciting neurons to fire and involved in learning and memory;can overstimulate brain and trigger migraine/headaches and seizures in excess; 4. Norepinephrine(noradrenaline)-Stress stimulates release; inhibits firing of neurons in the CNS but simultaneously excites heart, muscle, intestines and urogenital tract; helps control alertness; too much triggers agitation/jumpiness;too little is associated with depression; alerts individual to emergency situations interacting with pituitary and liver; conveys info as a hormone or neurotransmitter

5. Dopamine-helps control voluntary movement; affects sleep, mood, attention, learning and the ability to recognize opportunities for rewarding experiences in the environment 6. Serotonin- involved in the regulation of sleep, mood, attention and learning; 15 known types of serotonin receptors in the brain 7. Endorphins- natural opiates; stimulate the firing of neurons; as opiates shield body from pain 8. Oxytocin- hormone and neurotransmitter; plays important role in love and social bonding experiences 12. Neural Networks-interconnected pathways of nerve cells that integrate sensory input and motor output 1. Can take years to develop 2. Make up most of the brain 3. Working in networks allows neurons to amplify computing power 4. Most information processing occurs when info moves through these networks 13. Study Methods for the Brain and Nervous System-arouses 1. Brain lesioning- abnormal disruption in brain tissue resulting from injury or disease 1. Deep lesioning- electrical current used to destroy brain cells 2. ESB- milder electrical current used to stimulate neural activity in brain 14. Electrical Recording 1. Electroencephalograph (EEG) record brain's electrical activity; can assess brain damage;seizure disorder and other problems 2. Electroencephalogram- chart that records brain wave activity 3. Single-unit recording- provides info about a single neuron's electrical activity 15. Brain Imagining 1. Computerized Axial Tomography (CAT scan or CT scan)-produces 3D image obtained from X rays of the head that are assembled into a composite image by a computer; provides info about location and extent of damage involving stroke,language disorder or memory loss 2. Positron-Emission Tomography (PET scan)- imaging method; based on metabolic changes in the brain related to activity; measures glucose amount in various areas of the brain and sends the info to a computer for analysis; can be used to examine the amount of neurotransmitters waiting to be released into the synaptic gap in neurons in the brain 3. Magnetic Resonance Imaging (MRI)- involves creating a magnetic field around a person's body and using radio waves to create images of their tissues and biochemical activities; generates clear pictures of the brain's interior and doesn't require injecting brain with a substance 4. Functional Magnetic Resonance Imaging (fMRI) allows scientists to see what is happening in the brain while it is working; mental activity is associated with brain changes; exploits changes in blood oxygen that occur in association with brain activity;used to establish links between brain areas and behaviors as well as to understand links among different brain areas

5. Functional Connectivity- the correlation between different brain areas or the degree to which their operation is dependent on each other 6. Transcranial Magnetic Stimulation (TMS)- combined with brainimaging techniques to establish casual links between brain activity and behavior to examine neuronal functioning following braininjuring events, like accidents or strokes; even to treat neurological/psychological disorders 7. Brain Organization 3 major regions 1. Hindbrain, Midbrain and Forebrain Hindbrain1.located at skull's rear 2.brain's lowest portion 3. 3 main parts are medulla, cerebellum and pons 4. Medulla-spinal cord enters skull; controls many vital functions like breathing and heart rate; regulates reflexes 5. Pons- Bridge in the hindbrain connecting the brain stem and the cerebellum; contains several clusters of fibers involved in deep sleep and arousal 6. Cerebellum- extends from the rear of the hindbrain; consists of 2 rounded structures thought to be important to motor coordination Brain stem- Stem like brain area that includes much of the hindbrain (minus the cerebellum) and the midbrain; connects w/ the spinal cord at its lower end and then extends upward to encase the reticular formation in the midbrain Midbrain 1. located between hindbrain and forebrain 2. Relays info between the brain, eyes and ears 3.Substantia Nigra- contains a large number of dopamine producing neurons; located near the bottom of the midbrain; feeds dopamine into the striatum, the central input station for the basal ganglia 4. Rich in dopamine receptors; especially involved in reward experiences, pleasure and addiction 5. Reticular Formation- Diffuse collection of neurons involved in stereotyped patterns of behavior like walking, sleeping and turning to attend a sudden noise Forebrain 1. Brain's largest division and most forward part 2. Cerebral Cortex- forebrain structure that covers both the hindbrain and midbrain structures 3. Most important structures are the limbic system, thalamus, basal ganglia, hypothalamus and cerebral cortex Limbic System- loosely connected network of structures under the cerebral cortex; important in memory and emotion; 1. Amygdala- almond-shaped structure located inside brain toward the base; basic principle structure of limbic system; on each side of the brain; involved in discrimination of objects that are necessary for survival (mates, food, rivals); size of both amydalae is linked to size of person's social network 2.Hippocampus- special role in memory; structure in limbic system Prefrontal Cortex- associated with planning, self control and decision making Thalamus- forebrain structure; sits on top of brain stem in brain's central core; servers as relay station (sorts info and sends it to appropriate places in forebrain for processing) Basal Ganglia- Above thalamus;under cerebral cortex; large clusters of neurons; works with cerebellum and cerebral cortex to control and coordinate voluntary movements

Hypothalamus-- small forebrain structure; below thalamus; monitors rewarding activities-eating, drinking, sex as well as emotion, stress and reward; helps direct endocrine system; regulator of body's internal state Cerebral Cortex- most recently developed part of brain, evolutionary wise; brain's outer layer; responsible for most complex mental functions (thinking and planning); Divided in 2 halves (hemispheres) 1. Neocortex- outermost part of cerebral cortex; size related to social group Lobes- four regions of the brain's two hemispheres (occipital, temporal, frontal and parietal);part of cerebral cortex 1. Occipital Lobes- back of head; visual stimuli; process info to do with visual stimuli like color, shape and motion 2. Temporal Lobes- just above eyes; involved in hearing, language processing and memory 3. Frontal Lobes- behind forehead; involved in personality, intelligence and voluntary muscles control 4. Parietal Lobes- top/toward head rear; register spatial location, attention and motor control; also involved in perception of numerical info Somatosensory cortex- important region of cerebral cortex; processes info about body sensations; located in front or parietal lobes Motor Cortex- other important region of cerebral cortex; located at the rear of frontal lobes; processes info about voluntary movement Association Cortex aka Association area- regions of cerebral cortex that integrate sensory and motor info (applies to material that is not somatosensory or motor cortex but not filler space); throughout brain; sensory systems have area in cerebral cortex;Intellectual functions, like thinking/problem solving, occur here; makes up 75% of the cerebral cortex; involved in linguistic and perceptual functioning 1.Executive functions- planning and problem solving Expressive Aphasia (Broca's Aphasia)- language disorder involving inability to produce language 1. Broca's Area- precise area of the left hemisphere that plays important role in speech production Wernicke's Area- important role in language; injured parts can produce words but may not be able to understand Corpus Callosum- large bundle of axons connecting the brain's two hemispheres; relays info between them Brain Hemispheres 1. Right Hemisphere receives info from the left side and vice versa 2. Most language processing/production occurs in the brain's left hemisphere 3.Left Hemisphere recognizes words and numbers; comprehends syntax and grammar and right does not; keenly involved when singing words of a song, can direct in solving basic spatial puzzles Right Hemisphere not as verbally oriented but plays role in language;Adept at picking up meaning of stories and voice tones;excels at song melodies; involved in conversation processing; real strength is processing nonverbal info (spacial perception, visual recognition and emotion) Endocrine System 1. Interconnected with nervous system via hypothalamus and works closely with it 2. Made up of a set of glands which regulate certain organs' activities by releasing their chemical products into blood stream 3. Not all parts are connected like the nervous system and works more slowly Glands 1. Organs or tissues in the body that produce chemicals that control many bodily functions 2. Pituitary Gland-pea sized; beneath hypothalamus; controls growth and regulates other glands; 1. Anterior (front) of pituitary=master gland; almost all its hormones direct target glands activities elsewhere; controlled by hypothalamus

3. Adrenal Glands- At top of each kidney; regulate mood, energy level and ability to cope with stress; secretes epinephrine and norepinephrine 1. Epinephrine (adrenaline) helps by getting a person ready for emergency; smooths muscles, the heart, stomach, intestines and sweat glands; also stimulates reticular formation which then arouses sympathetic nervous system which then excites adrenal glands to produce more epinephrine 4. Pancreas- under stomach; dual-purpose gland; performs both digestive and endocrine functions; the endocrine part produces hormones like insulin (Islets of Langerhons) 1. Insulin-essential; controls glucose (blood sugar) levels in body; related to weight, obesity and metabolism 5. Ovaries(females)-in pelvis on either side of uterus and Testes(males)-in scrotum: Sex related endocrine glands that produce hormones involved in sexual development and reproduction Hormones 1. Chemical messengers produced by the glands 2. Carried by bloodstream throughout body-contains 3. Membranes of every cells has receptors for one or more hormones Brain Tissue Implants 1. Brain Grafts-Implants of healthy tissue into damaged brains 2. Stem Cells-Unique Primitive cells that have the capacity to develop into most types of human cells Genetics and Behavior 1. Chromosomes- 46 in nucleus of each human cell; threadlike structure that comes in 23 pairs;one member of each pair comes from each biological parent 2. Deoxyribonucleic Acid (DNA)- in chromosomes; molecule contains genetic information 3. Genes- Units of hereditary info; short chromosome segments composed of DNA; hold code for creating proteins out of amino acids and they direct and regulate their production; don't operate independently but work with one another and in collab with hormones and environment to direct body functions 1. Humans have about 20,500 genes 4. Genome- Organism's complete genetic material Genetics 1. origins in mid 19th century 2. Dominant-recessive genes principle- if one gene is dominant and one recessive, the dominant will override the recessive one 1. Recessive genes only appear if both genes in a pair are recessive 3. Polygenic Inheritance- the influence of multiple genes on behavior 4. Molecular Genetics- manipulation of genes using technology to determine their effect on behavior 5. Selective Breeding- genetic method in which organisms are chosen for reproduction based on how much of a certain trait they display 1.genes are important influence on behavior but doesn't mean experience isn't important 2. Eugenics- application of selective breeding to humans 6. Genome-Wide Association Method 1. Used to identify genetic variations linked to certain diseases like cancer, heart disease or Alzeheimers 1. Linkage analysis- uses link between genes to help identify location of certain genes by referring to other genes whose position is already known 2. Key challenge is replication Behavior Genetics 1. Study of the degree and nature of heredity's influence on behavior 2. Less invasive

3. Twin studies- examination of the extent to which individuals are shaped by their heredity and their environmental experiences Genes and the Environmental 1. Genotype- individual's genetic heritage. The actual genetic material present in their cells (brown eye person with a gene for blue eyes) 2. Phenotype- individual's observable characteristics (brown eyes) 1. Influenced by genotype AND environmental factors 2. Applies to physical AND psychological traits 3. Genetic Expression- refers to gene activity that affects body's cells; influenced by genes environment Health and Wellness 1. Stress- individuals response to stressors 1. Stressors- circumstances and events that threaten individuals and tax their coping abilities 2. Causes physiological changes to ready the body to handle assault of stress 3. Stress begins with “fight or flight” response 4. Acute Stress- stress that occurs in response to an immediate perceived threat; ends when threat ends; adaptive 5. Chronic Stress- Continuous stress; may lead to persistent autonomic nervous system arousal; constant production of adrenaline and norepinephrine (stress hormones) can cause breakdown of immune system...