CR 3: Biological Bases of Behavior. This Curricular Requirement can be found in Chapters 2 and 3 of Myers Psychology 7 e.

Transcription

1 CR 3: Biological Bases of Behavior This Curricular Requirement can be found in Chapters 2 and 3 of Myers Psychology 7 e.

2 Biological Bases of Behavior: 8-10% Identify basic processes and systems in the biological bases of behavior, including parts of the neuron and the process of transmission of a signal between neurons. Discuss the influence of drugs on neurotransmitters (e.g., reuptake mechanisms, agonists, antagonists). Discuss the effect of the endocrine system on behavior. Describe the nervous system and its subdivisions and functions: central and peripheral nervous systems; major brain regions, lobes, and cortical areas; brain lateralization and hemispheric specialization.

3 Biological Bases of Behavior: 8-10% Discuss the role of neuroplasticity in traumatic brain injury. Recount historic and contemporary research strategies and technologies that support research (e.g., case studies, split-brain research, imaging techniques). Discuss psychology s abiding interest in how heredity, environment, and evolution work together to shape behavior. Predict how traits and behavior can be selected for their adaptive value.

4 Key Terms 1 acetylcholine (Ach) 22 Deoxyribonucleic acid (DNA) 2 action potential 23 electroencephalogram (EEG) 3 adrenal glands 24 endocrine 4 all or none law 25 endorphins 5 amygdala 26 environment 6 aphasia 27 evolutionary psychology 7 association areas 28 fraternal twins 8 autonomic nervous system 29 frontal lobes 9 axon 30 functional magnetic resonance imaging 10 basilar membrane 31 genes 11 behavior genetics 32 genome 12 biological psychology 33 genotype 13 brainstem 34 glial cells 14 Broca's Area 35 heritability 15 central nervous system (CNS) 36 hindbrain 16 cerebellum 37 homeostasis 17 cerebral cortex 38 hormones 18 chromosomes 39 hypothalamus 19 corpus callosum 40 identical twins 20 CT scan 41 interaction 21 dendrite 42 interneurons

5 Key Terms 43 lesion 64 positron emission tomography (PET) 44 limbic system 65 phenotype 45 medulla 66 pituitary gland 46 midbrain 67 plasticity 47 molecular genetics 68 pons 48 motor cortex 69 receptors 49 motor neurons (efferent) 70 reticular formation 50 magnetic resonance imaging (MRI) 71 reuptake 51 mutation 72 sensory cortex 52 myelin sheath 73 sensory neurons (afferent) 53 natural selection 74 somatic nervous system 54 nerves 75 spinal cord 55 nervous system 76 split brain 56 neural networks 77 sympathetic nervous system 57 neuron 78 synapse 58 neurotransmitter 79 temporal lobes 59 norm 80 testosterone 60 occipital lobes 81 thalamus 61 parasympathetic nervous system 82 threshold 62 parietal lobes 83 Wernicke's Area 63 peripheral nervous system

6 Key People Paul Broca Charles Darwin Michael Gazzaniga Roger Sperry Carl Wernicke

7 Biology 101: What is a Neuron Basic Structure of a Neuron Axon Transmit signal Node of Ranvier Myelin Helps speed transmission Nucleus Control center Signal travels in ONE DIRECTION ONLY! The signal DOES NOT STOP!

8 Neural Communication

9 Neurons & Neural Communication Some neurons send messages to the brain, others carry messages away from the brain. Sensory Afferent Motor Efferent Remember, the signal travels in one direction. Dendrites Receive Axons Terminate To the brain Away from brain

10 Neurons & Neural Communication There are several variations of neurons, but the basic structures (dendrites, soma, axon) are all the same. Neurons are highly specialized. Some just see specific colors, some just transmit messages of pain, some just help form memories. Multiple Sclerosis leads to the deterioration of the myelin sheath. The impulse can no longer travel down the axon. Neural impulses can travel as slow as 2 mph and as fast as 200 mph.

11 Synapses & Neurotransmitters Neurons DO NOT TOUCH. The synapse is a gap. Neurotransmitters are like a lock and key they have a specific shape and receptor site. Excess neurotransmitters are sucked up into the presynaptic neuron via reuptake.

12 Dopamine Serotonin Acetylcholine Norepinephrine Glutamate GABA Endorphins Function Lack Excess Pleasure, voluntary movement, learning, attention Memory and movement Mood, appetite, and sleep Parkinson s disease Alzheimer s disease, paralysis Depression, eating disorders, sleep problems Schizophrenia Muscle convulsions Mood and sleep Depression Anxiety Memory & learning (excitatory) Relaxation & sleep (inhibitory) Anxiety disorders, seizures, insomnia Inhibits pain signals Lower pain threshold (use of opiates leads to decreased production of endorphins) Migraines and seizures Higher pain threshold Runner s high

13 Effects of Drugs on Neurotransmitters Psychoactive drugs (both medication and illegal drugs) impact neurotransmission. Agonist drugs work by either blocking reuptake or mimicking the natural neurotransmitters and fitting in to receptor sites on the postsynaptic side. Selective Serotonin Reuptake Inhibitors (SSRIs) such as Prozac for depression, stop the reuptake of serotonin. Xanax, used for treating anxiety, mimics GABA and occupies GABA receptors. Opiate drugs are agonists, and mimic endorphins.

14 Effects of Drugs on Neurotransmitters Psychoactive drugs (both medication and illegal drugs) impact neurotransmission. Antagonist drugs either prevent the release of neurotransmitters or block the receptor sites on postsynaptic neurons. Antipsychotic drugs, such as Thorazine, reduce the symptoms of schizophrenia by blocking dopamine receptors.

15 The Nervous System

16 The Brain: Our Control Center

17 The Hindbrain The Hindbrain is the oldest part of the brain and is basically the same in all animals. Brainstem: located in the top of the spinal cord, it controls all of your automatic survival processes. Severe damage to the brainstem would result in death. Cerebellum: located behind the brainstem and underneath the cerebrum. It helps with balance and coordination, fine motor movements, and your procedural memory. Only 10% of the weight of your brain, but it contains more neurons than the rest of your brain combined.

18 The Hindbrain The Hindbrain is the oldest part of the brain and is basically the same in all animals. Pons: above the medulla and below the thalamus on the brainstem, it helps regulate sleep and arousal, is associated with dreams, and helps us make facial expressions. Medulla: below the pons on the brainstem, it controls basic survival functions (heartbeat, breathing, digestion) and basic reflexes (sneezing, coughing, swallowing).

19 The Midbrain The Midbrain is very small in humans and coordinates simple movements with incoming sensory information. Reticular activating system: this network of nerves runs vertically through the brainstem to the thalamus. It alerts us to incoming stimuli or filters out unnecessary stimuli, and helps with sleep and attentiveness. Basal ganglia: a neural structure that curves around the limbic system & is tucked up under the cerebrum. It helps maintain smooth voluntary muscle activity.

20 The Forebrain The Forebrain is the sophisticated part of the human brain that includes the cerebrum, limbic system and corpus callosum. The forebrain allows for the complex thoughts and behaviors unique to our species. Thalamus: two egg-shaped structures that sit at the top of the brainstem, they filter and relay sensory signals (except smell) to the correct lobe of the brain.

21 The Forebrain The Forebrain (cont). Limbic System: a group of structures between the brainstem and the cerebral cortex. Collectively, the control learning, memory, emotion, and basic drives. Hippocampus: surrounds the thalamus and allows you to form personal memories and retain information. Amygdala: a small structure at the end of each arm of the hippocampus, they control emotional responses (especially fear and aggression).

22 The Forebrain The Forebrain (cont). Limbic System (cont). Hypothalamus: sits below the thalamus and controls the autonomic nervous system, the endocrine system and regulates the 4 Fs of behavior.

23 The Forebrain The Forebrain (cont). Nucleus Accumbens: a region of the forebrain near the limbic system, it contains the pleasure/reward pathways of the brain and is associated with drug dependency. Suprachiasmiatic Nucleus: a small region IN the hypothalamus, it regulates your circadian rhythm. Corpus Callosum: a bundle of neural fibers that connects the 2 hemispheres of the cerebral cortex, it allows information to cross between the 2 sides.

24 The Forebrain The cerebrum is the upper area of the brain, and it s actually made up of 2 layers. The inner layer is made up of glial cells (which help in neural transmission but don t generate any action potentials) is called the white matter. The top layer, the cerebral cortex, is ¼ of an inch thick and is called the grey matter.

25 The Forebrain Frontal Lobes Functions: higher level thinking, reasoning, planning, judgement, and impulse control. Specific Areas: Prefrontal Cortex: in front of the motor cortex, it controls conscious thoughts and actions, working (short-term) memory, and short and long term memory planning. Broca s Area: front of the LEFT lobe, it controls the facial movements required for speech. Primary motor cortex: extending from ear-to-ear (like a headband) it s at the rear of the frontal lobe and controls voluntary movement. Note: the left lobe controls the right side of the body and the right lobe controls the left side of the body.

26 The Forebrain Frontal Lobes Specific Areas: Motor Homunculus: symbolic representation of the motor cortex (not an actual brain area), it s the distorted figure that represents the proportions of brain area dedicated to each body part in relationship to movement. More cortical area is devoted to highly controlled body parts.

27 The Forebrain Parietal Lobes Functions: receives sensory information about the somatic senses of touch, pain, and temperature. Also controls spatial abilities Specific Areas: Sensory Cortex: front of the parietal lobe, parallel to the motor cortex, extending from ear-to-ear. It receives all somatosensory information for touch and body position. Left side of the brain receives sensory information from the right side of the body, and the right side of the brain receives sensory information from the left side of the body.

28 The Forebrain Parietal Lobes Specific Areas: Sensory Homunculus: symbolic representation of the sensory cortex (not an actual brain area), it s the distorted figure that represents the proportions of brain area dedicated to each body part in relationship to sensitivity of stimuli. More cortical area is dedicated to highly sensitive body parts.

29 The Forebrain Occipital Lobes Function: visual processing Specific Areas: Primary visual cortex: located at the bottom of the occipital lobes, it decodes the sensory stimulation from our retinas. Visual information from our left visual field (right side of each retina) goes to the right side of the brain. Visual information from our right visual (left side of each retina) field goes to the left side of the brain.

30 The Forebrain Temporal Lobes Function: auditory processing, olfaction, and recognition of faces. Specific Areas: Primary auditory cortex: located in the upper areas of each temporal lobe, it processes most auditory information from the opposite ear. Wernicke s Area: top left of the LEFT temporal lobe, it is responsible for language comprehension (written and spoken), as well as creating meaningful statements.

31 More Stuff About Your Brain Aphasia loss of language abilities. Broca s Aphaisa can t form words. If Broca s is broken, no word can be spoken. Wernicke s Aphasia can say nonsense words. Split-Brain when the corpus callosum is severed. Typically done to prevent seizures. The hemispheres of the brain can t communicate. Hemispherectomy partial removal of one cerebral hemisphere of the brain.

32 More Stuff About Your Brain Plasticity the brain's ability to change and adapt as a result of experience. When one sensory function is gone, other sensory functions may invade that area of the brain. Phantom Limbs the sensory experience of feeling a limb that has been amputated. The nerves that connect to that area of the body have been removed, but the area of the brain dedicated to that limb are still there.

33 Ways of Studying the Brain Case Studies in-depth study of an individual AFTER a traumatic brain injury (TBI). Phineas Gage railroad worker who had part of his frontal lobe destroyed in an accident. It s really had to make generalizations from a case study. Lesion intentionally or unintentionally destroying brain tissue. Typically done on animals. On humans, it s usually done to stop the spread of a tumor.

34 Scan Definition Purpose Advantages/ Disadvantages EEG PET CT Measures electrical activity of the neurons below the electrodes placed on the scalp. Used to see electrical activity during sleep or seizures. Injection of a small amount of radioactive material (usually glucose) into the bloodstream to observe fuel consumption during cognitive activities Multiple x-ray scans taken from various angles to form a 3D picture of the brain. Function Function Structure Adv: noninvasive, abnormal patterns indicate neurological disorders. Dis: difficult to determine which specific areas of the brain are producing the electrical activity. Adv: observation of specific tasks associated with mental illness, Alzheimer s, epilepsy & drug use. Dis: radioactive materials, difficult to pinpoint EXACT location of activity. Adv: can show large brain anomalies, more sensitive than x-ray. Dis: radiation, incapable of locating small brain anomalies. MRI A magnetic field causes different molecules in the brain to vibrate at different frequencies, producing detailed images of the brain. Structure Adv: greater clarity than CT Scan, no exposure to radiation. Dis: cannot be used on people with metallic implants, pacemakers, must remain still for a long time. fmri Produces images of the brain but also tracks blood flow to active regions of the brain. Structure & function Adv: no exposure to radiation, ability to track quick mental processes Dis: cannot be used on people with metallic implants, pacemakers,

35 The Endocrine System The endocrine system consists of glands that secrete hormones into the bloodstream. Hormones are chemical messengers (like neurotransmitters) that work on the body in a different way. The endocrine system is controlled by the pituitary gland, which receives its signals from the hypothalamus.

36 The Endocrine System Pituitary Gland Hormones: growth, prolactin, oxytocin, hormones to stimulate action in other glands. Function: regulates growth, breastmilk production, childbirth, and bonding, and communicates to other glands. Dysregulation: extremes in height, malfunction of other glands. Note: there is concern over some in the medical community that bovine growth hormone is affecting human development.

37 The Endocrine System Pineal Gland Hormone: melatonin Function: sleep/wake cycles Dysregulation: Seasonal Affective Disorder. Thyroid and Parathyroid Glands Hormones: thyroxine, calcitonin, parathyrin Function: metabolism, calcium levels in blood stream. Dysregulation: hyperthyroidism (thin, excessive energy) or hypothyroidism (overweight, lethargic).

38 The Endocrine System Adrenals Hormones: cortisol, epinephrine, norepinephrine Function: Fight-or-flight response of the sympathetic nervous system (increase heart rate & respiration, decreased digestion. Dysregulation: excessive activity leads to a weak immune system. Pancreas Hormone: insulin Function: regulates sugar metabolism. Dysregulation: diabetes, low blood sugar.

39 The Endocrine System Gonads (testes/ovaries) Hormones: androgens (including testosterone), estrogen, progesterone. Men and women produce all three hormones, just is varying amounts. Function: primary sex characteristics (sexual maturity and reproduction), and secondary sex characteristics ( looking masculine or feminine). Dysregulation: low levels = reproductive difficulties, high testosterone = aggression, high estrogen = optimal cognitive functioning.

40 Heredity, Environment & Evolution Behavioral genetics attempts to explain the influences of heredity, the environment and evolution in terms of the effect on human behavior and mental processes. Heredity the passing on of physical or mental characteristics genetically from one generation to another. The nucleus of each human cell (except eggs and sperm) contains 46 chromosomes, 23 donated by each parent.

41 Heredity, Environment & Evolution Heredity The 23 rd pair determines the sex of the offspring. The mother donates one X chromosome, and the father donates either an X or a Y chromosome. If the combination is XX, the child is a girl. If the combination is XY, the child is a boy. Each chromosome contains genes (a region on the chromosome), which are made of a chainlike molecule called deoxyribonucleic acid (DNA). The entire genome of a human has more than 3 billion DNA base pairs (and its in every cell in your body that has a nucleus).

42 Disorder Genetic Cause Symptoms Colorblindness Down s Syndrome Phenylketonuria (PKU) Fragile X Syndrome Tay-Sachs Syndrome Huntington s Disease Turner Syndrome Klinefelter s Syndrome Recessive gene on the X chromosome = lack of cones. Additional 21 st chromosome. Recessive gene = inability to process a specific amino acid a build up of toxins in nervous system. Mutation of an X chromosome in a weak area = abnormal brain development. Recessive gene = lack of a protein needed to break down chemicals in nervous system. Defect on a dominant gene = a portion of the DNA repeats more often than it should. Females missing all or part of one of their 2 X chromosomes. Males with an additional X chromosome (XXY) Inability to see or differentiate between colors Intellectual disability Distinctive facial features Intellectual disability resulting from permeant brain damage. Note: diet may prevent damage Intellectual disability Distinctive facial features Progressive and fatal nerve damage. Death typically occurs between 3-5 years of age. Progressive and fatal nerve damage. Impaired behavioral & mental functioning. Onset between years of age. Short stature Webbed neck Alters physical & sexual dev. Low testosterone & lack of secondary sex charac. Excessive shyness & reserved pers.

43 Heredity, Environment & Evolution The Environment Most psychologists accept the combination of nature and nurture, and the effect both have on human behavior and mental processes. How can psychologists attempt to isolate the relative contributions of nature OR nurture on humans? Identical Twin Studies Identical twins (monozygotic) are the result of one egg and one sperm that split into 2 embryos. They share 100% of their DNA. In theory, any differences that exist between them should be a product of the environment.

44 Heredity, Environment & Evolution The Environment Adoption Studies Are adopted children more similar to their adoptive parents of their biological ones? Adoptive political and religious views, taste in music or interest in arts or sports. Biological intelligence, personality, psychological disorders.

45 Heredity, Environment & Evolution Evolutionary Psychology Based on the work of Charles Darwin Natural selection those genes that contribute to increased survival and reproduction are the ones that are passed to the next generation. Genetic diversity comes from mutations of the gene sequence. Some are adapted for all humans (capacity to learn) and some for specific groups (broad rib cage and large lungs for people who live at high altitudes). The process has taken thousands of years.

46 Heredity, Environment & Evolution How Evolution Helps Explain Human Behavior: Why do infants start to fear strangers about the time they become mobile? Why are unrelated boyfriends more likely to abuse the children with whom they share a home? Why do so many more people have phobias about spiders & snakes than they do about guns & electricity? How do men and women differ? Why are men quicker than women to perceive friendliness as sexual interest? Why are men quicker than women to initiate sexual relations? Why are more likely than women to feel jealous rage over a mate s having sex with someone else?

47 Heredity, Environment & Evolution Evolution and Sexuality Human mating preferences seem to be rooted in evolution. How can I best pass on my genetic material to the next generation? Men improve their chances if they mate widely. Women improve their chances if they mate wisely.

48 Heredity, Environment & Evolution Evolution and Sexuality The features we find attractive in a mate are based in evolution. Men prefer women who appear youthful, with soft, round features, large breasts & wide hips. Indications of high levels of estrogen so she must be fertile. Women prefer men who appear mature, with square or rugged features, and developed musculature. Indications of high levels of testosterone, so he must be strong and will be able to provide for an protect me and his offspring.

49 Heredity, Environment & Evolution Evolution and Sexuality I contend that nature has given males the heaviest burden of all: the burden of always having to Make the First Move, and thereby risk getting Shot Down. I don t know WHY males get this burden, but its true throughout the animal kingdom It s always the male bird who does the courting dance, making a total moron of himself, while the female bird just stands there, looking aloof, thinking about what she s going to tell her girlfriends. ( And then he hopped around on one foot! Like, I m supposed to be impressed by THAT!) Dave Barry

50 Heredity, Environment & Evolution Evolution and Psychology What physical and personality traits have helped humans survive? Increased brain size compared to other human species. Aggression in men hunting, protecting families or tribes. Sociability making connections with other humans. How do nature and nurture work together? Heritability - to what extent is a trait influenced by genetics. ex: Intelligence seems to be 40-60% heritable. Genetics provide a PREDISPOSITION for a trait, the environment provides the means for developing it.