Prelims-Cognitive-psychology.pdf

Chapter 1: Nervous System [ADN] = Additional Discussion Notes Neurons Specialized cells in NS passes and sends messages and releases neurotransmitter Dendrites = receive info...

Chapter 1: Nervous System [ADN] = Additional Discussion Notes Neurons Specialized cells in NS passes and sends messages and releases neurotransmitter Dendrites = receive information from synaptic receptors on its surface Axon = sends information through axon terminals where neurotransmitters are released action potentials- sodium gated channels regulate = potassium and sodium nutrients Parts: cell body which has the nucleus, dendrite, axon, axon terminals, myelin sheath Glial cells remove waste products nourish and insulate direct growth Astrocytes - wrap around synapses of functionally related axons Microglia - immune system of the neurons Oligodendrocytes - creates myelin sheath in CNS Schwann cells - creates myelin sheath in PNS Synapse = place of action potential conduction Myelin sheath formed by glial cells to insulate neurons in CNS for faster message transmission Space between myelin sheaths = node of ranvier Types of neurons: Neurons vary according to location and function 1. A erent neurons - chain of neurons from sensory receptors to spinal cord and brain (to CNS) - stretch from head to toe 2. E erent neurons - message from brain or spinal cord to muscles and glands (to PNS) - found in hypothalamus, pituitary gland, limbic system - ght or ight fi ff ff fl  [ADN] Multiple sclerosis = caused by degenerated myelin sheaths - lose coordination in body= paralysis Neural impulse electrochemical messages travel within neurons resting potential: neuron not responding to other neurons = slow response action potential: conduction of neural impulse along axon 1. Resting membrane potential = -70mv 2. Excitatory postsynaptic potential high amount at axon initial segment 3. Membrane potential is depolarized 4. Sodium channel open → in ux of sodium ion = membrane potential at +50mv 5. Potassium channel open → potassium ion more out 6. Sodium channel close → end of rising phase 7. Repolarization → rapid moving out /e ux of potassium ion 8. Repolarization achieved potassium channels close slowly leading to hyper polarization = -100mv 9. Potassium channels let some potassium in to return to -70mv 10. Returning to resting membrane potential Easier version: 1. Resting potential= polarized state, inside membrane is negative -70mv 2. Activation = depolarization, membrane inside is positive +50mv , in ux of sodium ions 3. Repolarization = hyperpolarization, inside membrane is negative -100 mv, e ux of potassium ions 4. Back to resting potential ring of neurons = sensitive balance of neurochemicals (potassium and sodium) low sodium = diarrhea capacity for action potential is compromised when you're under in uence of sedatives, anxiolytics, downer, stimulants, cannabis as these upset balance of sodium and potassium [ADN] message travel in the brain by means of electricity ffl  fi fl ffl fl fl  Firing: neuron to neuron conduction of neural impulse along the length of the neuron ring threshold = incoming messages reach a strength at which neuron will re = measured by milivolts levels of fatigue a ect levels of minerals which causes body to ght homeostasis which leads to slow response and sensory Refractory period = rest in between sending of messages for each second - 1-2 milliseconds after action potential initiation that it is impossible to elicit another impulse Relative refractory period = period wherein it is possible to re neuron again but only if the stimulation is higher than normal All or none principle = either it gets red or not; every time a neuron res, it transmits on impulse of the same strength; the threshold of AP should be met for the impulse to be transmitted Synapse uid- lled gap between one neuron to the next where action potentials are conducted = uid is plasma = also called synaptic cleft synaptic bulb: neurotransmitter are stored = lock and key Re ex arc = circuit from sensory neuron to muscle response - re exes automatic muscular responses to stimuli - re exes are slower than conduction along an axon because of synapse, meaning it involves communication between neurons - repeated stimuli within a brief time have a cumulative e ect - synaptic inputs from separate locations combine e ects on neurons Neurotransmitters Chemical substances takes that communicate from one neuron to another Cannot be over produced or under produced unless you take drugs and you have unhealthy lifestyle Synaptic vesicles = stores neurotransmitter Receptor site = dendrite of receiving neuron Reuptake =neurotransmitters that are extra are reabsorbed since too much of this can cause problems Degradation = breaking down of neurotransmitters that are extra i.e. ACTH fl   fl fi fl fl fl ff fi ff fi ff fi fi fi fi  Excitatory neurons = triggers ring of other neurons in action potential; dopamine, epinephrine, norepinephrine - main functions Inhibitory neurons = lessens on stops ring of neurons during action potential;serotonin, GABA, glycine - main functions Neurotransmitters for psychology Too little serotonin = depression Too much serotonin and dopamine = schizophrenia Too much ACTH = cause tremors and memory impairment Acetylcholine 'controls muscle contractions; lack of this can lead to paralysis; prevalent in hippocampus that consolidates memory; amyloid plaques takes up ACTH in Alzheimer's disease Role: muscle movements, memory, learning [ADN] hippocampus is part of the limbic system; people who experience trauma at childhood is at risk of underdeveloped hippocampus which leads to low intellect and low creativity to avoid Alzheimer's disease = always stimulate your brain for learning, brain exercises, ful lling social relationships Dopamine pleasure, voluntary movement, learning, memory Reward system A ects muscle contractions → motor control elevated levels: too impulsive ~ schizophrenia, mania Parkinson's disease: too low dopamine; can also be caused by repeated blunt force trauma in the head Low levels = depression, anhedonia Norepinephrine excitatory neurotransmitter Accelerates heart High = PTSD, anxiety, mania Low = depression Serotonin emotional arousal and sleep Mood regulation eating disorders, alcoholism, depression, aggression, insomnia ff   fi fi fi  triggers pineal gland to release melatonin gender di erences: women have higher levels than men raw materials: progesterone and estrogen regulation of mood and aggression here men are more aggressive since they have low levels of serotonin High = mania Low = depression, anxiety, eating disorder GABA: gamma- aminobutyric acid inhibitory may help relax anxiety reactions Lack of this = anxiety too much time pressure to self- leads to lack of this Depression → low concentration of GABA (possible) Low levels → OCD High levels → relaxation Endorphins body's natural pain killer and it naturally occurs within the brain and bloodstream cocaine = Mimics this e ect physical activity elevates levels of this May be connected to indi erence to pain → runner's high Low levels = eating disorder Epinephrine High levels= acute stress Low levels = fatigue Adrenaline Both hormone and neurotransmitter Glutamate Most abundant Cognitive functions in nervous system High levels = psychosis, neuron death Low levels = Huntington's disease Oxytocin Hormone and neurotransmitter Produced by hypothalamus Role in: social recognition, bonding, sexual reproduction Uterus contraction in labor → hormone ff ff ff  Agonists vs Antagonists = Drugs, known as agonists, function by increasing e ects of speci c neurotransmitters while drugs referred to as antagonists, act to block the e ects of neurotransmission Direct vs Indirect E ects = neuro-acting drugs can further be broken down based on whether they cause a direct or indirect e ect. Drugs that have direct e ect work by mimicking the neurotransmitters since they have very similar chemical structure. While those drugs that have an indirect e ect function by acting on the synaptic receptors Parts of the Nervous System Peripheral Nervous System ̶ sensory (a erent) and motor (e erent) neurons ̶ Divisions: PNS: somatic and autonomic nervous system Somatic NS = sensory and motor neurons; transmits messages to brain and purposeful body movements from the brain; senses to brain and vice versa ̶ acute stress = motivates people ̶ chronic stress = not time bound stress; survival mode at all times as it screws up function of ̶ imbalances in neurotransmitters and hormones with behavioral consequences - psychopathology and even physical health Autonomic NS = regulates glands and muscles of internal organs by secreting hormones depending on the perceived stimuli; sympathetic (ight, ight, fawn, freeze) and parasympathetic (at rest) Fawning = people pleasing to the extreme as an act of survival a) Sympathetic NS = most active during emotional response; spend the body's reserves of energy - b) Parasympathetic NS = most active during processes that restore the body's reserve of energy; maintaining body homeostasis Central nervous system ̶ brain and spinal cord Spinal cord - transmits messages from sensory receptors to the brain and from the brain to muscle and glands ff ff    ff   ff fi ff ff ff ff fl  - spiral cord is protected by the spinal column - Gray matter = nonmyelinated neurons - White matter = myelinated neurons * Limbic system (ancient brain,most unsophisticated part) = more gray than white matter - Spinal re ex = simples unlearned response to stimulus = knee-jerk reaction = interneurons How do researchers learn about brain function 1. Experimenting with the brain assessing damage from trauma and disease 2. Brain - imaging techniques  fl  computerized axial tomography = CAT or CT scan positron emission tomography = PET scan magnetic resonance imaging = MRI functional magnetic resonance imaging = MRI Parts of the Brain Major Parts of the Brain: - Cerebrum (frontal, parietal, occipital and temporal lobes plus insula) - Diencephalon - Cerebellum - Brainstem (midbrain, pons, medulla oblongata) A. Cerebral Cortex/ Cerebrum Outermost part, thick piece of tissue Folded into hills = gyri / gyrus Folded into valleys = sulci / sulcus Has two hemispheres - right and left- separated by a large sulcus Corpus Callosum tough body = thick bundle of bers that connect two hemispheres, allows information to be passed from two sides Functions of left and right hemispheres are redundant but there are some functions that are more localized to one hemisphere than the other Each hemisphere can be broken down to four functionally and spatially de ned lobes Contains the dopaminergic tract, above corpus callosum, this tract shrinks due to overuse in schizophrenia (negative symptoms: anhedonia, avolition) Responsible for thinking and language Cerebral cortex = surface of cerebrum FOUR LOBES OF CEREBRAL CORTEX FRONTAL LOBE Location: front Olfactory bulb: smell Motor cortex: movement planning and implementation Where most of neurons are Neurons: cognitive functions = attention, speech, and decision-making Involved: personality, socialization, risk assessment PARIETAL LOBE Location: top fi fi  Neurons: speech and reading Function: processing somatosensation (touch) and proprioception (sense of body parts space orientation) Pain sensation OCCIPITAL LOBE Location: back Function: vision - seeing, recognizing, identifying the visual world Medulla cascades visual info to other body neurons TEMPORAL LOBE Location: base of brain, by the ears Function: processing and interpreting sounds Contains: hippocampus/seahorse - memory formation structure B. Basal Ganglia interconnected brain areas Role: movement control and posture Damage leads to motor impairments like in Parkinson's Disease (degenerative) Regulate: Motivation C. Thalamus "inner chamber" Gateway to and from cortex Receives sensory and motor inputs from body and receives feedback from cortex Function: regulate consciousness, arousal, sleep states Fatal Familial Insomnia rare genetic disorder; degeneration of thalamic neurons and glia (inability to sleep and eventually fatal) Forms an x shape in medulla D. Hypothalamus below thalamus Secretes hormones that stimulates endocrine hormone release Controls endocrine system by sending signals to the pituitary gland which then releases di erent hormones that a ect other glands and cells Regulates hormone-controlled behaviors Body's thermostat as it keeps body functions at appropriate levels (food and water intake, energy expenditure, and body temperature Neurons: regulate circadian rhythms ff ff E. Amygdala Important structure in the limbic system Temporal lobe structure "Almond" Two amygdala important for: fear sensation and recognition of fearful faces Cingulate Gyrus = regulate emotions and pain Pain and aggression Depressed people have shrunken amygdala since it is overly active hence the person is overly sensitive F. Cerebellum "little brain" Base of brain, on top of brainstem Controls balance Aid in movement coordination and learning new motor tasks memory; Accessed by ears Damage = loss of balance and perception G. Brainstem Connect brain with spinal cord Consists: midbrain, medulla oblongata, pons Motor and sensory neurons extend through the brainstem allowing for the relay of signals between the brain and spinal cord. Coordinates motor signals from brain to body Controls body functions: alertness, arousal, breathing, blood pressure, digestion, heart rate, swallowing, walking, and sensory and motor information integration. Structures and Functions of the Brain Hindbrain Medulla - heartbeat regulation, blood pressure, movement, respiration Pons - respirations attention, sleep, arousal Cerebellum - balance and muscle coordination; little brain Reticular Formation vital to attention, sleep, arousal; from hindbrain ascends through midbrain into lower part of forebrain Sleep and wake Forebrain thalamus = relay station for sensory stimulation  hypothalamus- temperature, motivation, emotion; hunger, thirst, sexual behavior, caring for o spring, aggression; team up with pituitary gland Limbic system = amygdala, hippocampus, parts of hypothalamus(lateral) ; memory and emotion Hippocampus = memory traumatized people= shrunken hippocampus since it is over active overly active hippocampus = learning is compromised since it involves memory and retention [ADN] limbic system is bigger at mid-20s compared to frontal lobe (emotional and impulsive) ; all animals have this but only humans are fully developed hence they're the only one capable of restraint and logic  ff  Thinking, Learning and the Cortex Association areas= responsible for learning, thought memory and language; not involved in sensations or motor activity; more for making sense Association areas in frontal lobe = responsible for executive functions Language Functions two hemispheres of the brain mirror and di er left hemisphere: language functions for all people ̶ if damaged before 13, speech functions transfer to right hemisphere = problems in acquiring number skills learning; nonlinear reasoning two key language areas = damage in either causes aphasia I. Brocaʼs area - frontal lobe; production of speech II. Wernickeʼs area - temporal lobe Angular gyrus - translates visual into auditory information; damage impairs reading ability ff  Three Major Types of Aphasia 1. Brocaʼs Aphasia understand language but speak slowly and laboriously Slow, laborious, non- uent speech Lesions in the left inferior frontal region (Broca's area), head of caudate nucleus, thalamus, etc. Non uent, labored, and hesitant speech (articulation) Most also lose the ability to name persons or subjects (anomia) Can utter automatic or overlearned speech (ello; songs) Have di culty with function (the, in, about) vs content words (verbs, nouns, adjectives) (agrammatism) Comprehension relatively intact when other cues available (The man swat the mosquito vs the horse kicks the cow) Most also have partial paralysis of one side of the body (hemiplegia) if extensive, not much recovery over time 2. Wernickeʼs Aphasia impairs ability to comprehend speech and think of words to express own thoughts Fluent speech but unintelligible Lesions in posterior part of the left superior temporal gyrus, extending to adjacent parietal cortex Unable to understand what they read or hear (poor comprehension) Unaware of their de cit Fluent but meaningless speech Can use function but not content words Contains many paraphasias Syntactical but empty sentences Cannot repeat words or sentences Usually no partial paralysis 3. Global Aphasia Total loss of language Left Brain, Right Brain Left-brained = logical and intellectual Right-brained = intuitive, creative and emotional fl ffi fi fl  Hemispheres do not act independently = functions overlap and they respond simultaneously Handedness Left-handed = somewhat greater than average probability of language problems and certain health problems; more likely than right-handed people in gifted artists, musicians and mathematician Origins of handedness = genetics Split-brain Experiments severe cases of epilepsy may require split -brain operations examples of "two brain" phenomenon - inability vision problems with two brain issues Since the left hemisphere of the brain controls the right side of the body, any injuries in it could lead to right-sided weakness. The following problems could arise: = Di culty understanding both written and spoken words. = Di culty expressing both written and spoken words. = The person nds it di cult to coordinate or program motor movements for speaking or medically called apraxia. = Slurred speech or change in the sound of the voice (dysarthria). = Di culties with numbers. = Di culty in dealing with complex problems. The right hemisphere of the brain controls the left side of the body. Any injuries on the right side of the brain could result in left-sided weakness. The following problems could arise: = The patient nds it challenging to focus on concentrate on a task. = The left side of the body canʼt attend to things. = Di culty in processing the information on the left visual eld. = The patient canʼt recall the previously learned information as well as di culty in learning new information. = The person fails to identify problems or even generate solutions. ffi ffi ffi ffi ffi fi fi ffi fi ffi  = The personʼs social communication skills are a ected such as interpreting abstract language, understanding jokes, making inferences, and understanding non-verbal cues. = Di culty in recalling signi cant events such as the time, date, and place. = Di culty in organizing things such as arranging information and planning. Chapter 2: Endocrine System - comprised of ductless glands that release hormones into bloodstream - Hormones - regulate growth(HGH), metabolism (leptin, ghrelin) and some behaviors - maintain steady bodily states ̶ set point in metabolism - Very potent which means despite its low secretion its e ects are felt - Body takes time to replenish its supply of hormones - Control body processes at every level - There are 50 hormones made by 12 endocrine glands that secrete them directly into the blood - Regulate: breakdown of chemical substances, uid balance and urine production, growth and development, sexual reproduction we - body stops secreting HGH at 25 years old - Body must maintain overall homeostasis → balanced bodily functions such as heart rate, body temperature ffi ffi fi fl ff ff Pituitary and the Hypothalamus Pituitary gland - lies below hypothalamus - "master gland" - anterior pituitary gland = Adrenocorticotrophic hormone (ACTH), Thyroid-stimulating hormone (TSH), Luteinising hormone (LH), Follicle- stimulating hormone (FSH), Prolactin (PRL), Growth hormone (GH), Melanocyte- stimulating hormone (MSH) - posterior pituitary gland = vasopressin, oxytocin, antidiuretic hormone Hypothalamus - regulates pituitary gland activity - The hypothalamus and the pituitary gland are part of the diencephalon region of the brain. - The hypothalamus connects the nervous system to the endocrine system. It receives and processes signals from other brain regions and pathways and  translates them into hormones, the chemical messengers of the endocrine system. - These hormones ow to the pituitary gland, which is connected to the hypothalamus by the infundibulum. - Some hormones are stored in the pituitary stores for later release; others spur it to secrete its own hormones. The hormones released by the pituitary gland and the hypothalamus control the other endocrine glands and regulate all major internal functions. Pineal Gland Secretes melatonin Helps regulate sleep-wake cycle The pineal gland is small and pine cone- shaped, (which is how it got its name)located at the back of the diencephalon region in the brain. At night, in the absence of light, the pineal gland secretes the hormone melatonin. In the morning, when light hits the eye, photo receptors in the retina send signals to the pineal gland, which then decreases melatonin production and we wake up. May a ect onset of puberty ̶ sleep deprived children are late bloomers Melatonin = secreted naturally at sunset since one's body is sensitive to the time of day → diurnal creatures Only during sleep can the body creates hormones needed for development Revenge bedtime procrastination = people squeeze in a lot of leisure time during late night hours because of their busy morning schedule; common among female, early to mid twenties, with highly stressful work and single Thyroid Gland produces thyroxin which regulates metabolism → how the body utilize ATP (adenosine triphosphate) The thyroid gland sits in the throat region, just below the larynx, served by large arteries with many branches and a dense network of capillaries. The hormones it secretes, travel in the bloodstream throughout the body to: ~Increase metabolism ~Regulate glucose use ~Protein synthesis ~Nervous system development. ff fl  ~It also releases Calcitonin, which helps maintain blood calcium homeostasis by causing calcium to be removed from the blood and deposited into bones when blood (calcium) levels are too high. A ects body's metabolism - hypothyroidism:thyroxin de ciency; under active thyroid gland, gain weight,enlarged throat, hair thinning, always cold → because you have slow metabolism (having this also makes one prone to autoimmune disorders like lupus) - hyperthyroidism: too much thyroxin - cretinism: secreted too much too early, before the body could handle it; mental development in children is hampered until adulthood Adrenal Glands Located above the kidneys - pyramid shaped Each adrenal gland consists of two structures: an outer adrenal cortex and an inner adrenal medulla. The adrenal cortex is a network of ne connective tissues that makes up most of the gland. It secretes a range of steroid hormones. Cortisol which manages protein and glucose levels. Aldosterone which adjusts our levels of water and salt. Androgens and estrogens are secreted by the adrenal cortex in small amounts by both sexes. The adrenal medulla (inside the gland) produces epinephrine and nor- epinephrine (NE). These chemicals promote “ ght-or- ight,” the bodyʼs initial response to stress. Cortical steroids [corticosteroids] - increase resistance to stress - promote muscle development - released during the ght and ight response - if under acute stress, body release corticosteroids, ght and ight response is activated. - corticosteroids are released to burn glycogen/fat in fat cells Epinephrine and norepinephrine - helps arouse body in threatening situations - maintains muscles and organ health Steroids Increase muscle mass ff fi fi fi fl fi fl fi fl  Heighten resistance to stress Increase body's energy supply By product of protein Anabolic steroids enhance athletic prowess Connected with self-con dence, aggressiveness, memory function Thymus Gland The thymus gland produces progenitor cells, which mature into T-cells (thymus- derived cells). The body uses T-cells to help destroy infected or cancerous cells. T-cells created by the thymus also help other organs in the immune system grow properly. These cells are so vital, they are often donated to those in need. The Thymus gland is the primary donor of cells for the lymphatic system, much as bone marrow is the cell donor for the cardiovascular system. Kidneys 2 HORMONES MADE BY THE KIDNEYS The kidneys make two main hormones, vitamin D and erythropoietin. Vitamin D is essential for a number of di erent functions in the body. Most of the vitamin D that is in the blood is inactive and it is modi ed by the kidney and other tissues to activate it. Active vitamin D stimulates the uptake of calcium from food, is important for the maintenance of healthy bones and also helps to regulate the response of the immune system to infection. Erythropoietin is produced when oxygen levels in the blood are low. It acts in bone marrow to stimulate the production of mature red blood cells and to maintain healthy oxygen levels in our tissues. Sex Glands The main sex glands are the ovaries in females and testes in males. fi ff fi  The sex hormones they produce stimulate the production of eggs and sperm respectively and in uence the early development of the embryo into a boy or girl. After birth, the circulating levels remain low until puberty. Then, in males, the testes increase their output of androgens (male sex hormones), such as testosterone. In females, the ovaries produce more oestrogens and progesterone. Testosterone produced by testes (smaller amounts from adrenal gland) Male sex characteristics Estrogen and progesterone produced by ovaries (smaller amount from testes) Female sex characteristics Parathyroid Gland On the posterior (back) surface of the thyroid sit much smaller, separate glands: the parathyroids. Typically there are four parathyroid glands, a superior and inferior pair on the left and right sides of the thyroid. They secrete parathyroid hormone (PTH), which stimulates bones to release calcium into the blood when blood (calcium) levels are low. PTH also causes the kidneys to reduce calcium secretion into urine to further elevate calcium levels in the blood. Together, calcitonin and PTH act in complementary ways to maintain blood calcium homeostasis, which is one of the most tightly controlled physiological parameters in the body. Heart and Stomach: Gut Hormones The gut hormones work in association with the gutʼs extensive nervous system and play a coordinating role in: ~The control of appetite ~The digestion of food ~The regulation of energy balance ~The maintenance of blood glucose levels. The gut continuously sends information to the brain regarding the quality and quantity of the food that is consumed. fl  Ghrelin is produced in the stomach, and its function is to tell the brain that the body has to be fed. It increases appetite. Gastrin is produced in the stomach when it is stretched. It stimulates the release of gastric juice rich in pepsin and hydrochloric acid. Secretin is produced in the duodenum and has the e ect of stimulating the pancreas to produce alkaline secretions as well as slowing the emptying of the stomach. Cholecystokinin (CCK) is produced in the duodenum. It reduces appetite, slows down the emptying of the stomach and stimulates the release of bile from the gall bladder. Peptide YY (PYY) is produced in the last part of the small intestine known as the ileum as well as parts of the large intestine. It plays a role in slowing down the passage of food along the gut, which increases the e ciency of digestion and nutrient absorption after meal. Glucagon-like peptide 1 (GLP-1) is produced in the small intestine and colon and has multiple actions including inhibition of gastric emptying and appetite as well as the stimulation of insulin release. Pancreas-Dual Purpose Gland It is also a part of the digestive system. It excretes pancreatic juice into the small intestine via the pancreatic duct. Scattered within the pancreas there are also tiny cell clusters called pancreatic islets (or islets of Langerhans) that release hormones into the bloodstream. These islets make up less than 2% of pancreatic tissue, but their specialized cells regulate blood glucose levels (or blood sugar). When blood sugar is low, alpha cells in the islets release glucagon. Glucagon spurs the liver to break down glycogen and release more glucose into the blood. When blood sugar is high, beta cells in the islets release insulin, which increases glucose reuptake. Darwin's theory of evolution - struggle for existence = competition for same resources ( inherently important for survival) - Natural selection = adaptive genetic variations that aid in survival - Genetic variations is important for survival since too much commonalities can lead to weaker body/ birth defects ff ffi - Mutations= sudden charges in genes; positive mutation/windfall̶ unforeseen ; negative mutation̶ albinism - Chimpanzee, humans, neanderthal → human skeletons and skeletal relatives (inserrt diagram comparison) Evolutionary Psychology - ways in much adaptation and natural selection connected to behavior and brain processes - Behavior patterns evolve and transmitted genetically - Instinctive or species speci c behaviors = pair bonds - Instinct = stereotyped patterns of behavior triggered by a speci c situation (low survival instincts) - Species speci c = Heredity and Genetics - Heredity = transmission of traits from parents to o spring (genes) - Genetics = sub eld of biology → study of heredity - Behavioral genetics = contributions of genes inherited to behavior - Diathesis - stress model = neuroticism (anxiety) factor is inherited Genes and Chromosomes - Gene: basic unit of heredity - Chromosomes: inside cell nucleus carrying the genes (46,23); formed by DNA, that contains genetic code - Nucleotides: Adenosine, Guanine, Thymine, Cytosine, Uracil - Genes regulate development of speci c traits - Dominant gene (traits determined by one gene) or polygenic (traits determined by many genes) - schizophrenia is a dominant gene - Genotype: individual genetic makeup - Phenotype: actual appearance based from genotype and environmental factors - Down syndrome: chromosomal abnormality → late pregnancy and paternity Kinship studies - focus on presence of traits and behavior patterns in people who are or not related biologically - Twin studies = monozygotic twins and dizygotic twins - Adoption studies = trying to prove nurture and nature fi fi fi fi ff fi