350 Psych Notes PDF

Forensic Psychology Why Developmental Psych? Reason #1: Raising Children - Knowledge could help parents, teachers, professional caretakers, etc. Milestones Optimal/risky influences (daycare? TV?) Practical Advice (e.g. managing problem behaviors…) Ex: Anger M...

Forensic Psychology Why Developmental Psych? Reason #1: Raising Children - Knowledge could help parents, teachers, professional caretakers, etc. Milestones Optimal/risky influences (daycare? TV?) Practical Advice (e.g. managing problem behaviors…) Ex: Anger Management 1950s-60s - Strange that dominated child behavior was through punishment Sometimes even physical punishment… (spanking, belt, etc) Better strategies - Teach empathy (recognize emotional experience they are having as well as that of someone else) - Distraction ( away from things upsetting them) - Boost emotional recognition and control… The Turtle Technique… - Teach children about turtles - When children feel sad, angry, upset, etc… children should do the turtle. - When a turtle feels threatened, it hides away in its shell. - Teaches children to control their emotions and behavior when feeling emotionally overwhelmed. Reason #2: Social Policy Example: Child Testimony - 100,000 children testify each year - 40% are below age 5 - Usually victims of domestic abuse - Reliability? Vulnerability Example: Child Workers  - 5-6 year olds working in coal mines - What effect does this have on child development? Modern Day issues - What are the consequences of phone and electronic use on child development? Reason #3: Child Health - Better diagnoses and treatment of developmental problems E.g. motor difficulties, language impairment, visual impairment, PKU, etc Reason #4: How does it Work? (some things are very complex and hard to learn about…) THE HUMAN MIND - The most complex thing that we know Reason #5: Understanding Human Nature Zebra: What is its true nature? - Are zebras white animals with black stripes or black animals with white stripes? Questions like this can be answered through studying development HUMANS What are we like deep down? How are we the same/different from other animals Human intelligence?”inborn How did it get that way? *Caterpillar camouflage is triggered by what the caterpillar eats. How did YOU get this way? - How is our psychology and phenotype influenced… Traumatic and positive experiences What we consume (food, etc) Technology use Social interactions (making friends and the success rate of making friends) First Developmental Study - Took place in Egypt - A battle over history Ancient Egypt Psammetichus ii - To prove that we are the original people of the world, we are going to raise a child that has never heard any spoken language in their life - Wanting to see what the child's first words would be - Shepard cuts out the tongues of children and is raised in isolation. They are fed and well, but never hear any Egyptian words. - Children’s first words are “Bekos” (phrygian word for bread) *Egyptian was NOT the original language - You can test predictions about different questions using developmental studies by controlling their upbringing and experiences Modern Versions… “Controlled-Rearing” Studies - E.g. how does being deprived of some experience early in life change development - Studies conducted with animals - Human infants… how are children affected when they are not exposed to representation things such as certain toys, books, pictures, etc. What happens to these children… Are they scared of these things? Do they innately know what these things are? - Naturalistic ‘experiments’ Cat Study - Raised in darkness - Can’t see anything, always in darkness - See how this affects Cats when they are exposed to light Depth perception and fear of heights Child Abuse “Genie” Case - Locked in the basement in a cage for the first ten years of her life - Abused horribly by her parents - Deprived of any and all human interaction Nature Vs Nurture Nature: How much of our psychology is based on genetics and our biological makeup? Nurture: How much of our psychology is based on our experiences Philosophical Foundations ~340 B.C Aristotle - All knowledge comes from experience - Not born being able to think or do much at all - Child-rearing should adjust to needs of child - NURTURE Plato - Born with innate knowledge - Strict-discipline and self control always Common Themes: - Influences of nature and nurture - Interested In the proper raising of children The Dark Ages of Development (Pre Modern Europe) - People are distracted from the scholarly writing of raising children - >7 years = similar dress, work and activities as adults Children drink alcohol, smoke, hunt Socialized to be adults by a very young age - Not a lot of effort is being done to see how this affects the development of children. - Psychological outcomes NOT being considered Enlightenment Period - John Locke (1632-1704)  Tabula rasa – a ‘blank slates’ -> believes children and babies to be blank slates Emphasizes “Nurture” As we get older, experiences and memories we have lead to increasingly complex behaviors Importance of early strict parenting -> progressive freedom - Jean-Jacques Rousseau (1712-1778) Innately good – ‘noble savage’ Emphasized “Nature” Child learns via spontaneous interactions with objects and people, NOT instruction Research Foundations - Around this time was the Industrial Revolution When? - 19th and Early 20th Centuries Why? 2 Main forces: 1. Social Reform movement (child labor laws) - Children working 12 hours a day in horrible conditions 2. Sir Charles Darwin 1843: First Child Labor Laws Earl of Shaftesbury: “Children of amiable temper and conduct, at 7 years of age, often return next season from the [coal mine] greatly corrupted with most hellish dispositions.” Charles Darwin - First person to publish a systematic study of child development Theory of Evolution - Examination of human species - Examines humans through the same lens that he did with animals and plants “Biographical sketch of an infant” - Diary of his own child’s development - From son willem’s (it) birth (1839) to 5 years, - Daughter Elizabeth, born 1841 to lesser degree - Meticuois observations about development Emerging Theories of Development Sigmund Frued (1856-1939) - Our unconscious biological drives influence development -> NATURE Psychosexual stages 1. Oral (birth to 1 year) 2. Anal (1-3 years) 3. Phallic (3-6 years) 4. Latency (6-11 years) 5. Genital (Adolescence) - Early nature-nurture tensions affect us throughout our lives Criticisms: - Overemphasis on sexuality - Freud did not study children directly Nature V Nurture - GIANT swings over time A Contrasting Theory John Watson (1878-1958) - Attempt to move away from the subjectivity of Freudian psychoanalysis - Pendulum swings the other way - How BEHAVIOR is shaped by NURTURE Behaviorism: - All behavior can be explained by responses to external stimuli Particularly rewards and punishments Internal (mental) concepts need not be posited - Child development is controlled by conditioning rewards and punishments…Associative learning - Nature CAN OVERCOME nurture Major Themes in Modern Developmental Psychology... 1. Nature vs Nurture - ‘Not and Either-or debate’... ex: Fear can be learned Nurture - innate ability to learn some fears better than others? Nature E.g. The “Little Albert” Study - Children were taught to be scared of rats STILL… we can learn NOT to be afraid, despite our nature Nature AND Nurture? Other Examples 1. Risk and resilience Kauai Longitudinal Study - All 698 children born on the island - Studies for 30 years - Observing things such as child’s personality, IQ, teacher reports, Physicians Records, Police Records Findings: - Early life trauma and stress can negatively affect outcomes -> Nurture - Children’s unique personalities and dispositions can have a positive and ‘insulating” effect -> Nature OTHER Major Themes in Developmental Psychology 2. The Active Child - Individuals play a role in their own development The Active Child: Examples 1. Preferences to attend to certain things - People over objects, Caregiver over others 2. Motivated to learn - Little ‘experimenters’: e.g. dropping food - Practice language when alone - Pretend play 3. Selection of their own environment (increases w age)  - Friends they play with - activities they engage in, places they go, books they read etc 3. Continuity vs. Discontinuity How does development unfold? The Human Mind? - Is the human mind more like a butterfly (stages) OR is it more like a pine tree where all of the basic parts are there as babies. 4. Mechanisms of Dev. Change? How and why does change occur? - Explanation can occur at multiple levels: Perceptual: e.g., auditory system, visual system Brain development: e.g., frontal lobes Strategy use: e.g., problem solving 5. The Sociocultural Context - Physical = house, daycare, school, urban vs rural neighborhood, etc - Social = parents, siblings, other family members, teachers, friends, peers, etc - Economic = national wealth, societal wealth, family/ individual wealth - Cultural = language, values, traditions, attitudes/ beliefs, laws, political structure, technology, etc.  - Historical = influences all these other factors, e.g. traditional practices, policies, economy, technology, etc Cross-cultural studies as methodology 6. Individual Differences Possible sources? - genes - treatment by other people - - subjective reactions to other people’s treatment - choice of environments All vary even within the same family! Prenatal Development Major Themes 1. Nature vs nurture 2. Continuity vs discontinuity 3. Active child 4. Mechanisms 5. Individuals differences 6. Cultural context Continuity vs discontinuity - How does development unfold? Quantitative change (continuity) Qualitative changes; happens in stages; radically different in different stages (discontinuity) Early Ideas #1 Quantitative change “Preformation” A.k.a a homunculus (“little person”) - ‘Ovists’ -> all life starts in the female egg cell - ‘Spermists’ -> the tiny human isn't inside the eggs cell, it is inside the sperm cell  It is what drives the sperm cell When makes contact with egg, eats nutrition in egg and that is how egg is fertilized - Persistent idea until 1800s #2 Qualitative change: - Aristotle: epigenesis Not embraced until modern study of Embryology Idea that we now can embrace, we know what the different stages are that happen after fertilization We begin life in the same way that all other animals do MODERN UNDERSTANDING (all the details) - Neither sperm or egg contains a preformed human - Not one is more important than the other - Both egg and sperm contribute half of the instructions to form a human being An early sex difference… - Biological males are more often conceived than females; more males at birth - Y chromosome has 25% of the material that the x chromosome has - Y chromosome smaller, leading to more biological males being born Sperm cells that have y chromosomes carry less information -> faster swimmers -> they are more likely to fertilize the egg Biological males more susceptible to genetic based diseases because of this as well Phases of Prenatal Development 1. Germinal Conception - 2 weeks “Zygote” ‘yoked’ or ‘joined” - First split of a fertilized egg; one cell into two cells Germinal Phase - Egg has traveled further up the fallopian tube - Spends time traveling down this tube, into the uterus, and planting on the uterine wall - Undergoing cell division while traveling; mitosis - As it divides more and more, it creates a hollow, spherical structure call a blastocyst - Movement and Cell division Major Developmental Processes  - Cell Division - Cell migration - Cell differentiation (Cell turns to different kind of cell, specific with a specific function) - Cell Death (Apoptosis) Cell Migration Examples - Migration to the uterine wall - Migration within the blastocyst - Migration within embryonic cells within pregnant woman’s bodies (Microchimerism) A Pregnancy Souvenir - Cells continue to travel everywhere in a woman's body - Cells move to the brain, breast tissue, the lungs, heart - Study found that fetal cells travel to every tissue they examined! - Extreme cell migration (Speculation: The migration of these cells might stimulate production of breast milk, blood production from the heart.. etc) 2. Embryonic Phase - 3rd - 8th weeks - “Embryo” Phase is really about specialization, cells becoming more specific (cell differentiation) Cell Differentiation - Zygote -> all cells are identical All cells in zygote are called STEM CELLS They form the “stem” of the flower that grow into the different parts of the plant - Undifferentiated cells depending where they move to, become more specific differentiated cells Depending on which layer they are, they will turn into the skin, parts of the brain, spinal cord, muscle tissue, etc. “Stem Cells” - The power to turn into any other cell in the body Demo: frog eyes - Frog eyes can be formed through the injection of stem cells Stem Cells Gone Wrong Video: doctor found food in child’s brain - Foot formed inside of tumor in the brain - Foot was found early enough not to impact child development - Stem cells end up in the wrong place, growing into the wrong thing. Embryonic Phase - ~22 days: neural tube is a U-shaped groove formed from the top layer of differentiated cells in the embryo. Neural tube defects - Spinal fluid and sometimes the spinal cord itself sometimes grow through hole, outside of where it is supposed to be - Condition is called Spina Bifida Worldwide incidence of about 1/1000 births Cell Death (APOPTOSIS) - Allows for the formation of things like limbs Apoptosis Gone Wrong - Sometimes cells do not die when they are supposed to - Ex: toes stuck together -> cells did not die away when they are supposed to - Sometimes, humans are born with tails, Vestigial tails. Developmental Processes - From this period on, areas near the head develop earlier than those farther away “Cephalocaudal development” Face Development - 5 ½ to 8 weeks - 3 flaps of skin come together to form face - Cleft lip/ palate -> flaps of skin do not come together and fuse correctly, leaving a whole Embryonic Support System Placenta: Permits the exchange of materials between the bloodstream of the fetus and that of the mother Umbilical cord: The tube that contains the blood vessels that travel from the placenta to the developing organism and back again Amniotic Sack: Sack filled with liquid -> protects fetus from collision injuries 3. Fetal phase - 9th week to birth - “Fetus” Protecting the Fetus Placental membrane: barrier against some, but not all toxins and infectious agents Amniotic sac: a protective membrane filled with fluid in which the fetus floats, a protective buffer Fetus at 18 weeks - Some reflexive behaviors … sucking thumb Purpose: to prepare fetus for feeding later on after birth Strengthen mouth and tongue, etc - Great example of The Active Child Individuals play a role in their own development The ‘Active Fetus’ ~ 12 weeks after gestation, most movements present at birth have appeared Swallowing amniotic fluid promotes development of the palate and aids maturation of the digestive system Fetal breathing = inhalation of amniotic fluid, exercise of the lungs and diaphragm; 50% of the time *The fetus is a contributor to its own development* Example #2: Hormones - All human fetuses can develop either male or female genitalia, depending on the presence or absence of testosterone - Active child: They themselves generate the testosterone (~week 8) In rare cases this process can be delayed.. Leading too… - ‘Guevedoces’ (penis at 12) A genetic mutation that inhibits testosterone affects until later (rare but more common in Dominican Republic) Brain Development Structure of the Brain: Neurons - The brain has ~100 billion neurons! Comparison: 100 Billion Hotdogs? ~15 hot dogs for every person on earth Laid end to end, a line of hot dogs 10,061,553 miles long, enough to circle Earth 404 times. The Neuron - Nucleus - Cell Body - Dendrites - Synapse - Axon - Axon terminals - Myelin sheath Other Brain Cells? Glial Cells - Ancient greek for “Glue” - Perform a variety of support functions They form the myelin sheath around certain axons Guide migration of neurons Remove dead neurons - Glial cells outnumber neurons Neural Development Processes Neurogenesis - Early in development - Prenatally in embryonic period - Starts at about ~6 weeks - Proliferation of neurons via cell division. ~week 6-23 in utero Migration - Movement of neurons from one location to another in the brain (mostly prenatal) Arborization - Increase in size and complexity of dendrites as they branch out - Mainly 1st few years after birth Myelination - Fatty tissue that wraps around the axon to speed up signal transmission - Makes transmission more efficient - Accumulates around nerve cells - Begins before birth and continues into adolescence Synaptogenesis - The process by which neurons form synapses with other neurons, resulting in trillions of connections - One neuron can have 150,000 connections - Many more connections than we need… why? Synapse “Pruning” - Eliminates surplus connections Occurs at different times in different areas Not fully completed until adolescence At peak, 100,000 synapses per second are lost What determines growth, pruning, and maintenance? The Brain and Experience Plasticity: The capacity of the brain to be affected by experience - “Use it or lose it” aka. “Neural darwinism” The strongest connections are the ones that survive and the weak ones do not. Why Design Plasticity? - Allows adaptation to unforeseen environments - Less information needs to be stored in genes - Helps get rid of unnecessary information to make room for more. Experience-Expectant Plasticity - Brain wiring occurs due to normal experiences common across all people and present over the course of evaluation WHY? - The good: efficient design Use normal input from the environment to trigger development Light deprivation example - The bad: vulnerability… If “expected” experience doesn’t occur, unstimulated neurons may be “pruned” and deficits may result E.g. deafness/blindness Sensitive Periods - In experience-expectant plasticity, timing matters! Neural organization that does/does not occur is typically irreversible Compensatory rewiring - E.g. congenital deafness = enhanced visual processing - E.g. congenital blindness = better pitch discrimination Compensatory Rewiring example - Daredevil - He is blind so he has super hearing - He knows to punch bc he can hear you coming Experience-Dependent Plasticity - Neural connections are created and recognized throughout life as a function of individual experience (differs between people) E.g. rats raised in complex vs less complex environments Depending on different experiences - More synapses per neuron in complex cage - More supportive tissues (blood vessels, glial cells, etc) - Perform better in learning tasks in complex cage Human Examples… - Violinists/Cellists - Braille readers  E.g. experts show increased cortical representation for left hands Any learning/memory is a form of plasticity! Neural Plasticity - A genetic blueprint that allows adaptation to the environment - Nature AND nurture Brain Damages and Recovery’ The best time? Early childhood - Neurogenesis complete, Synapse generation and pruning occurring - Plasticity is highest and brain can rewire E.g. damage to language areas in children vs adults The worst time? Early stages of prenatal to 1 year - Interrupts neurogenesis and neuronal migration E.g. radiation and Japanese mothers Correlation w/ lower IQ Causes of Abnormal Development Genetic Abnormalities - 45% of pregnancies end in miscarriage prior to 3rd week (often before knowing one is pregnant) - Due to severe defects (missing or extra chromosome) Environmental influences… Minamata, Japan 1956 - Many cat problems on the island - Sometimes people would see stray cats convulsing, having trouble walking - Would sometimes leap into see to their deaths - Called convulsing cat syndrome Later Discoveries - Convulsions - Slurred speech - Loss of motor control - Significant structural brain damage  - 2000 children, adults, pregnant women with badly deformed babies - Heavy metal from factories polluted water. Cats and humans ate fish swimming in these polluted waters. Methyl-mercuty poisoning Teratogens - Environmental agents that cause harm during prenatal development Minamata Disease - 13,000 people filed for compensation - 3,000 paid (~20,000$ each) - Increased awareness about teratogens - Brought about regulations Warning about what you shouldn't eat when pregnant - TUNA - Tuna has mercury… could lead to birth defects Water teratogens - Lead poisoning in Flint, Michigan - Water supply had been switched using old lead pipes - Pipes carried water that people were drinking and bathing in with high concentrations of lead - ~30,000 children exposed Intellectual disability Behavioral problems Seizures - 28% of city's student now qualify for special education services - Michigan to pay 600M in Flint water crisis settlement; victim compensation Public Health Alert - Lead contamination in applesauce pouches - “Dose-response” relation - Individual/species differences - “Sleeper” effects - Mitigated by a sensitive period…  - f Example: Thalidomide - Drug invented in the 50s seen as a miracle cure to help women - Sedative/sleep aid - Given to pregnant women to ease their morning sickness - By 1960, sales of thalidomide = aspirin in some Euro countries ‘Thalidomide Children’ - About 10,000 cases across 46 countries - ~50% of children survived - E.g. American Horror Story Actor Alcohol: Currently considered the most common human teratogen - Ancient Wisdom… ~1200 BC -> don’t drink wine when you’re pregnant Fetal Alcohol Syndrome - Maternal alcoholism is associated with facial deformity, cognitive deficits, attention problems, hyperactivity and more… - 1 in every 1,000 infants born in the US How much (if any) is safe?  - Damaging in very high, toxic amounts - Mainly from alcoholic pregnant mothers Low levels of alcohol (no more than 2 drinks at a time, and less than 7 a week) linked to changes in face shape - But not visible to the naked eye (used special imaging technique) NOT all or nothing - Smaller amounts of alcohol may have smaller effects - A broad continuum of deficits related to alcohol exposure - One study: As many as 1 in 20 US kids are harmed by alcohol in the womb Continued effects on Brain development… - Decreased myelin in the prefrontal cortex after alcohol consumption during adolescence Myelin devised in the prefrontal cortex in adolescent mice Dads? - Research suggests that father’s drinking habits pre-conception can cause significant fetal abnormalities - Effects the sex cells (sperm) DEHP exposure - Changes in semen quality OTHER teratogens? Cats - There is a parasite that cats can carry that can get into their liter - Pregnant woman changing the cat litter and get the parasite - Toxoplasmosis Toxoplasmosis - Parasite found in ~60 million in the US (no salient symptoms in children and adults) Retarded growth Jaundice Fluid in the brain Visual damage Later cognitive abnormalities In the News…  - “Zika” - Causes description of brain growth and tissues around the brain Toxic Stress - Brain adapts to level of toxicity - Can have life long detrimental effects Genes and Heritability Nature Vs Nurture - Emphasis on genetic or environmental influences have shifted from one extreme to the other over history - Genetic and environmental influences are entangled in complex ways Heredity AND Environment Heredity: Folk Wisdom Nature matters - Selective Breeding - Extraordinary cosmetic and psychological changes Example: Sheep Dogs - ‘Vestigial behavior’ - Innately have behaviors to hear sheep Example #2 - Myotonic Goats Environment matters - Diet, type of training, neglect, etc Gregor Mendel - First modern theory of inheritance 150 years later… - Twin studies - Adoption studies  - DNA testing - MANY NEW TOOLS New opportunities… New questions - As testing improves SHOULD we test for the genes of particular traits in ourselves? Our infants? Behavioral genetics - How does variation in behavior and development result from the interaction of genetics and environment? - How and why do people behave differently from one another Research Designs Family Studies - Correlate trait scores for pairs of individuals with varying degrees of similarity in: Genes (siblings, cousins, 2nd cousins) Similarity of environment Which similarities are more important? Types of environmental influences 1. Shared environment 2. Non-shared environment effects = effects of the environment unique to the individual Birth order Experiencing parents’ behavior differently Being affected different by shared experiences (e.g. divorce) The motivation of siblings to differentiate themselves from one another Isolated trauma Adoption Studies - Allow you to look at people in the same household raised in the same environment, but with different genes - Examines whether adopted children’s scores for given trait are more highly correlated with those of their biological parents/sibs or their adoptive parents/sibs Twin Studies - Identical twins share 100% of genes  - Fraternal twins share 50% of genes (same as non-twin siblings) - How do correlations compare? - Assume same environment Adoptive-Twin-Studies - Compare the similarity between identical twins who grew up together and those reared apart. - The best of both worlds Heritability - The amount of variability in a trait that is attributable to genetic influences in a given population Heritability coefficient (H) = (Corr. identical twins - corr. fraternal twins) x2 Minnesota Twin Study - Extensive study of identical twins (> 100) separated early in life (many have no met until studies) - Give extensive battery of physiological and psychological tests (e.g. IQ, stress response, aggression, traditionalist, reaction time). Strong Heritability - IQ - Some personality (temperantment, leadership) - Life expectancy - Certain attitudes/preferences Weak heritability - Other personality traits: need for intimacy - Spouse similarity What do correlations mean? - Substantial heritability has been reported for several different traits, including… Infant activity level Temperament Reading disability Antisocial behavior Political affiliation Divorce  TV viewing NOT that there are specific genes that underlie particular behaviors or traits - I.e. there is not such thing as a “divorce” gene or a “TV” gene Heritability DOES NOT mean purely based on genes or genetically determined - Ex: # of fingers and toes have low heritability score Groups not individuals - They describe differences within populations, scores do not apply to the “make-up” of individuals More limitations… - They apply only to a particular group living at a particular time - Can differ markedly for groups of people who grow up in very different environments - High heritability does not imply immutability They say nothing about the meaning of differences between groups (e.g. race, IQ) - Many reasons why between group measurements differ Heredity Part 2 Genotype: Genetic material you inherit Phenotype: expression of genotype (appearance, behavior, etc) Environment: every aspect of your surroundings Chromosomes - The packaging for our genetic material (DNA) - The spool of thread the DNA is wrapped around Genes - Sequences of DNA - Blueprints or instructions for particular features - 60’s guess = ~2,000,000 - ONLY 30,000! How many separate mice from humans?? - Only 300 How similar is the human genome to chimpanzees? - >95% of genes are the same How similar are humans? 1-1.5% difference between any two people How many chromosomes in each cell of our body? - 46 Sex Cells “gametes” - Sex cells have 23 chromosomes (haploid) - When two sex cells meet, they combine the number of chromosomes to get 46 Mitosis vs. Meiosis Mitosis: normal cell reproduction Meiosis: sex cell reproduction Normal karyotype - All 46 seen on screen Abnormal Karyotype - Trisomy 21 3 chromosomes This leads to down syndrome Extra chromosome on the 21st pair Many others - Trisomy 18… Edwards syndrome Meiotic Errors Aneuploidy: an abnormal number of chromosomes Trisomy: an extra chromosome e Monosomy: a missing chromosome (e.g. Turner’s syndrome) How does normal meiosis lead to genetic diversity? Why aren’t siblings more alike? Mechanisms of genetic variation - Mutations: changes in sections of DNA caused by random or environmental factors - Random assortment: shuffling of the 23 chromosome pairs; chance determines which member of the pair goes into the new sperm and egg. 64 Trillion combinations in reshuffling - Crossing over Genetic Variation Key Fact: Only SOME of the genes you inherit are expressed Alleles - Different forms of genes that influence the same trait - A person who inherits two of the same alleles for a trait is described as homozygous - A person who inherits two different alleles for a trait is described as heterozygous Gene Expression (simplest) Dominant recessive pattern - The dominant allelE is the form of the gene that is expressed if present - The recessive allele is not expressed if a dominant allele is present Dominant inheritance - Everyone with the abnormal gene has the disease - E.g. Huntington’s disease Recessive inheritance - Inheriting one copy of the gene does not lead to disease bc the normal allele predominates - If both parents are carriers, their child has a 1 in 4 chance of receiving a recessive allele from each parent and inherit the disease - E.g. sickle-cell anemia Lipodystrophy - Older looking people when they are young Sex-Linked Inheritance Sec linked traits  - Alleles passed to child on sex chromosomes - Most inherited sex-linked characteristics carried on X chromosomes (b/c larger than y) - Males more susceptible to genetic defects Females XX: If one X is bad, the other can take over Males: only have one X chromosome - E.g. male pattern baldness, Red-green color blindness, hemophilia, muscular dystrophy Complications… Other patterns: only a few traits follow simple dominant-recessive pattern - Codominance: a single gene with > 1 dominant allele - E.g. single gene can affect multiple traits - Both alleges can be expressed, or blended - Different expression depending on whether they came from mom or dad Polygenic: “many genes” (can also then interact with environmental factors) - E.g. shyness, aggression, empathy - Schizophrenia, ADHD How can identical twins ever be different? - Environmental effects Relationship between environment and phenotype Norm of reaction: refers to all the phenotypes that could theoretically result from a given genotype, in relation to all the environments in which it could survive and develop Environment and gene expression - Even parts of the same individual grow differently in response to different environments Example: Himalayan Rabbits - Shave the back of the bunny and put ice where you shaved - Grows black patches in this location - Genotype expressed phenotype differently based on environment The effect of environment on expression of a gene for fur color: - Normal conditions = feet, tail, ears, and nose are black - Cold local environment = new fur grows in black Human Example: PKU  - Phenylketonuria (PKU) Defective gene on chromosome 12 Unable to metabolize phenylalanine Negative effects can be avoided by early diagnosis and properly restricted diets The case of MAOA - X-linked gene that inhibits brain release of brain chemicals associated with aggression - The “Warrior” Gene Nature and Nurture Mechanisms of Developmental Change - How and why does change occur?? Perceptual Brain development Strategy use Gene regulation - A given gene influences development and behavior only when it is turned on - Activation is affected by the genes’ environment - Multiple factors control the continuous switching on and off of genes that underlie development across the lifespan Epigenetics! - An analogy Computer hardware (the genome) Computer software (the epigenome) What is the epigenome? Before: Genes don’t change Epigenetics: The environment can change your genes (i.e. how they’re expressed) Good news! - The environment we select can compensate for ‘bad’ genes Bad news - The environment we select may be inherited by our children Darwin  - Some born with longer necks - More successful traits are passed down Lamarck - Neck stretches and becomes longer - Driven by ‘inner need’ - Trait passed down to offspring - Wrong, but maybe some experiences can be passed down Inheriting your Epigenome - Long term effect of feast and famine during the 1800s 100 people born 1905 Determined food supply for relatives from records Kids who went from normal eating to gluttony in a single season has sons and grandsons who lived shorter lives 6-32 year life expectancy difference Smoking mother - 1.5x more likely to develop asthma - Grandmother -> 2.1 x more likely - Non-smoking mother/smoking grandmother -> 1.8x likely A controlled example… - Reaction to small was 200% stronger if their father was trained with that smell before they were conceived - Even grandchildren without any prior experience with blossoms - Genes are being controlled by environmental factors Epigenetic Summary - The epigenome controls the expression of genes - The epigenome can be changed - Epirgenoe can be inherited and passed down Heredity Video - Monozygotic twins reared apart are just as similar as monozygotic twins reared together Plasticity is highest and thus recovery from brain damage is highest during synaptic pruning Perception - More than it appears… Sensation - The low level processing of basic information from the external world by sensory receptors (e.g. eyes, ears, skin, nose, tongue) - The ‘output’ of our senses Sensation vs Perception Sensation = two things Perception= one thing Vision Sensation = unspide own and only two dimensions Perception - The process of organizing and interpreting sensory information about the objects, events, and spatial layot - The mind makes educated guesses…vision is an illusion “Low-level” - Acuity - Color - Brightness “Mid-level” - Depth - Pattern Objetcs High Level - Recogntion - Categorication Infant Perception Developmental Origins?  - John Locke ~1670 ‘Tabula rasa’ aka a blank slate - William James ~1890 [The infant’s world] is “one” great blooming buzzing confusion - Piaget ~1930 The [infants’ world is a world of pictures, lacking in depth and consistency, permanece or identity which disappear or reappear capriciously How to Test? - Problem? Infants can’t do much… Eat, sleep, poop Look Around Perfer to look at interesting things to boring things Solution: test how long babies look at things 2 Main Testing Methods Method 1: - Preferential Looking Babies should look at more complex images Measure looking time to each side Does the baby have side preferences? Do two trials, switching sides Sample Results - 2-3 months of age babies perceive patterns well Preference for patterns Infants can see well! Experimental Logic - Vary stripe width - FInd smallest’ Acuity results - The sharpness of visual discrimination dveleops rapidly, approaching that of adults by age 8 months; reaches full adult acuity by 3-6 years. Method 2: - Habituation Visual Acuity; Brian Mehtods - Measure degree of electrical activity evoked by different displays More sensitive What causes change? Astigmatism: stimuli at different orientations perceived with different level of acuity - Adults: irregularly shaped lens - Infants Nature and Nurture - Retina growth determined by brain wiring and experience - Chicks with contacts - Breif exposures: just 10 minutes - Critical period Color Vision - Limiations in early months (0-3 months) Poorer in 1st month, highly saturated red at birth 3 months + is adult like Habituation Method: Visual habituation procedure - Downward trend = habituation curve - Habituation= getting bored - Dishabituation = getting excited Visuomotor Abilities Depth perception… How does it develop? Learning? - E.g. classical conditioning Learning by Association?  - Less effort to focus can touch - More effort to focus can’t touch An Incidental Discovery… - Newborn goats on a rock won't step off - Vision or touch? The Visual Cliff Results: Animals - 100% of baby goats stay on the shallow side Using vision - No goats crossed to the deep side - Most animals stayed on the deep side - An inmate capacity to previrce/avoid cliffs Comparative Development ‘ - Test; Human infant Infants tend to stay on the shallow side Humans behave like other animals on visual cliff How Do We See Depth? Binocular Cues - Binocular disparity/Parallax (stereopsis) Pictorial Cues - Aka monocular cues Linear perspective Overlap/ “interposition” Texture gradient Relative size - ~7 months - Never before this age - Suggests you need experience in order to interpret artistic cues such as this Dynamic Cues - Motion parallax - Optical expansion Developmental pattern - Motion cues are present extremely early on from birth or just after birth - The next cues to develop are binocular cues - The next cues to develop are pictorial cues Object Perception Question - How would you test whether infants perceive this as a single continuous rod? 4 month olds - Habituation - Test - No motion = equal looking - Motion = longer looking Pattern perception - Ability analyze/inetgrate seperate elements of a display into a coherent pattern - Subjective or “illusory’ contours Innate Pattern Perception? - Developmental study with baby chickens - Same pattern Hak towards chick Goose away from chick - Nature built in patterns to help avoid predators Innnate Pattern Recognition in Humans - Face Perception We are constabntly looling for one another out in the world - o find love, avoid danger, connect… Sink - Predominantly percieved as male Face Perception in newborn infants - Newborns look at faces longer Paddle - Each display starts in front, move slowly to left or right.  - Measure: how far will infants turn to follow it? - Newborn babies more likely to follow paddle with face configuration as opposed to the scrambled configuration - Infants have an innate template of a human face Face Recognition - Infants recognize and prefer their mother’s face after about 12 cumulative hours of exposure General Face recognition? - Familiarize - Test - Babies recognize the new faces they havent seen before by 9 months of age - At nine months, longer looking at the novel face Results differ for things other than humans - Babies cannot differentiate between monkeys for example - No difference looking at the two faces, at 9 months Species-specific recognition - Hypothesis(obvious): infants learn to distinguish human faces over the first 9 months of life Test - 9 months good at human faces bad at monkey faces - 6 months, good at human faces and good at monkey faces Infants learn NOT to distinguish between monkey faces! - Between 6 and 9 months, a narrowing of face processing Perceptual Narrowing’ - A developmental process during which the brain uses environmental experiences to shape perceptual abilities Why? Similarities? - Improves the perception of things that people experiences often - A decline in the ability to perceive some things to which they are not often exposed The ‘Other Race’ Effect  - As adults, you make more mistakes and you are slower if the person is not part of your race - 9 month old infants are more lieklt to misperieve 2 different people from the same race as rhe same - 3 month old infants have an easier time telling people apart, regardless of race. Are Babies Racist? - NO - But some perceptual biases exist very early The Senses - Sight - Smell - Hearing - Touch - Taste Auditory Perception - Begins prenatally - Newborn baby remembers cat in the hat and looks towards speaker playing familiar story Development - Well developed @ birth (mid range, localization reflex) - Adult like by ~6 months (frequency range, intensity, adv. Localization etc) Sound Localization - Experiments in the dark Side Distance Position Object type Music Perception Changes in beat (newborns! In their sleep!) Changes in melody (~7 mos; relative and some absolute pitch) Irregular musical phrases (~4 mos; e.g, clipped Mozart minuets) Culture-specific Rhytm patterns (e.g. Western vs Balkan) Caveat: The ‘Mozart Myth’  - No evidence for a link between listening to classical music and cognitive achievement - Lawsuit even led to refund… but other benefits Cross Modal Perception - In addition to perceiving things by senses must come Two Hypotheses 1. You have to learn the correspondence between A test - Tactile familiartization’ One month olds were allowed to mouth either a nubby or a smooth pacifier Preferential looking at the pacifier - bInfants looked longer at the pocyure matching how the pacifier felt Ability to detect correspondence between tactual Intermodal perception Ex2 - Show two videos with many marbles vs one large marble - 3 months of age expect different sounds to come from different cylinders Cross-Speices Comparisons - Example of cross modal perception A Dancing Test - 120 infants (5mos to 2 years old) - Heard rhythmic beats, classical and speech - Babies move in response to music - More in-sync they were = more smiling Synesthesia - Our senses may overlap early on in development - The overlapping of different senses - Ex: people hear certain sounds see certain images Feel something on their bodies and a sound is associated Tasting in color Developmental Synesthesia - Some data suggests that we are all partially born synesthetic - Born with an overlap between senses  - Over development, synaptic pruning helps to separate senses - 3.g.g 2-3 month olds show significant shape color associations - Weaker at 8 months - Gone in most adults Prenatal Sensartions - Taste Fetus at 28 weeks - A taste test - Mothers with polyhydramnios (too much amniotic fluid) - Puts pressure on developing fetus - Mothers ate foods of certain types and injected sugar water into amniotic fluid - Inject sac with saccharin and colored dye or dye alone - Measure amount of dye in mother’s urine - Experiment show that the fetus can taste and prefers sweet things Sensory learning - E.g. mothers drank carrot juice - 4 days a week for 3 weeks - Found that baby matched fetal experienced to what they preferred after they were born - Food preferences can develop even before the fetus is born Example: Newborns Cry in their Native Language Difference? German as tonal falling language French as more high toned - Babes have distinguish patterns of cries