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Another type of bias: We try to find order/patterns in random events
◦ Which sequence of coin flips is statistically more likely?
◦ Random sequences often don't look random

Fallacies of randomness
Hot hand
◦ "on a roll", "hot streak"

Gambler's fallacy
◦ "bound to come up eventually,"
◦ "it's due"
The scientific method helps us overcome our biaseso Many "obvious" findings are not so obvious o We can't always trust ourselves to be good observers of behavior §We'll discuss more biases in thinking throughout the quarterTHE MIND/ BODY PROBLEMHow is your mind (your "internal life"/thoughts/feelings, etc.) related to your brain/body? Hobbes and many others: Mind is what the brain does But how does the brain do it? Thought experiment: What if someone switched your brain with your mom's? Descartes- pineal gland where they interact Dualist- mind body separate, meet at one point Brain damage- they're not themselves What if someone- cut of your pinky, rebuilt your brain, switched your brain with your mom's?NATURE VS. NURTUREHow much of our abilities/knowledge is innate? ◦ Plato argued for some innate knowledge How much is learned from experience? ◦ Aristotle argued for a blank slate (tabula rasa) viewTHE FIRST PSYCHOLOGY LABBorn out of psych and Phil Wilhelm Wundt in 1879 Interested in studying consciousness- subjective experience One method: Reaction time studies ◦ Press a button as soon as the tone sounds vs. ◦ Press a button after you perceive the tone Heard it vs. interpret that you heard it Associated with structuralismSTRUCTURALISMGoal: to discover the mind's structure by breaking down experiences into their underlying components Used the method of introspection ◦ Participants observe and report their own mental states and processes ◦ Potential problems? ◦ How do you do 2+2? ◦ Reliability? Emphasizes the importance of introspection as a research methodologyFUNCTIONALISMGoal: study the purpose of behaviors and mental processes by examining them in terms of adaptation to the environment Studied thoughts, feelings, and behaviors, then asked the following questions: ◦ What function does it serve? ◦ How did it help our ancestors survive? Associated with William JamesBEHAVIORISMPredominant school of thought in American psychology from 1920s to 1960s Redefined psychology as the scientific study of observable behavior ◦ Rejected introspectionCOGNITIVE REVOLUTIONReaction against behaviorism during the 1950s and 1960s Brought back interest in mental processes ◦ Laws of behaviorism cannot explain functions like learning and language ◦ Understanding mental processes is necessary to fully understand behavior Set stage for modern approach to psychologySIGMUND FREUDActive in early 20th century Very influential, but most theories were difficult to study scientifically But idea of unconscious processing is mainstreamWhat makes a good theory?Falsifiable ◦ Piaget's stages of cognitive development vs. Freud's theory of dreams ◦ Only as complex as neededWhat makes a good hypothesis?◦ Specific! Can we make these more specific? ◦ Students who eat chocolate before the Psych 10 exam will do better than students who do not ◦ Drivers who more frequently use a cell phone will get in more accidentsTHE SCIENTIFIC METHOD IS CYCLICALYou get your results Then see how they align with your original theory The data either SUPPORT the theory OR The data DOES NOT SUPPORT the theory ◦ (in which case you need to modify or throw out!) *Keep in mind that no single study can provide a definitive answer, and it is logically impossible to prove your hypothesis Replication!HOW TO TEST HYPOTHESES?o Descriptive/correlational methods o Experimental methodsDESCRIPTIVE METHODSCase studies- Patient HM ◦ Pros and cons? Looks at one participant in great depth Not manipulating anything Patient HM- had epilepsy growing up 1953- certain parts of brain taken out including hippocampus Was not able to form new memories Could gain new motor skills Naturalistic observation ◦ Pros and cons? Not influencing environment Study on tipping at restaurant Self-report- Ex. SurveysCAUTION WITH OBSERVATIONAL STUDIESObserver bias: errors that occur because of an observer's expectations. a problem especially if cultural norms favor inhibiting or expressing certain behaviors Study on interviewees- men more assertive, women more bitchy even though saying the same thing Experimenter expectancy effect: actual change in behavior due to observer's expectations. Rosenthal & Fode's experiment with training rats in the maze Students who were told their rat was fast were able to make it go faster in the maze Double-blind Students shouldn't know which rats were fast, slow so make it double blindCORRELATIONAL METHODSMeasure how closely two factors vary together, or how well you can predict a change in one from observing a change in the other Examples: ◦ In a case study: The fewer hours the boy was allowed to sleep, the more episodes of aggression he displayed. ◦ In a naturalistic observation: Children in a classroom who were dressed in heavier clothes were more likely to fall asleep than those wearing lighter clothes. ◦ In a survey: The greater the number of Facebook friends, the less time was spent studying. Nonetheless... why are correlational methods useful? ◦ Ethics Not changing anything ◦ Establishing relationships/making predictions ◦ Can inspire experimentsCORRELATIONAL STUDIES: DIRECTIONPositive (+) correlation: both variables either increase or decrease together Negative correlation: one variable increases when the other decreases Zero correlation: one variable is not predictably related to the otherTHE THIRD-VARIABLE PROBLEM§The fact that two variables are correlated only because each is causally related to a third variable. §So, there's no causal link between them Texting while driving, dangerous driving are related Risk taking could be the third variable Eating chocolate, poor exam results Unhealthy choices could be third variablePOTENTIAL CAUSALITY"People with low self-esteem are more likely to report depression than those with high self-esteem" Directionality Low self-esteem-Depression? Depression- Low self-esteem Distressing events/ Biological predispositions- Low self-esteem and depression "When ice cream sales go up, more murders are committed" Eating ice cream- Murder? Murder- Eating ice cream Warm weather- Ice cream sales and murderEXPERIMENTAL METHODSResearcher carefully manipulates a limited number of factors (independent variables) and measures the impact on other factors (dependent variables). Looking at the effect of the experimental change on a behavior or mental process. ◦ Manipulate hours studied for a quiz, measure performance on the quiz Avoid confounding factors ◦ Chocolate vs. no chocolate before a quiz Sitting in front of class might lead to better results not studyingTHE CONTROL GROUPWhat is the point of the control group? Importance is to see if there is something wrong with the design § Is there anything wrong with the design below? Pretest- Experimental intervention- Posttest § Also, placebo effect: e.g., An experimental group gets a new drug while the control group gets nothing, yet both groups improve.Why are people hard to study?Reactivity- people sometimes act differently when they know they are being studied Ex. Hawthorne effect- people in workplace knew they were being observed, so productivity increased Need to make conditions blind Individual differencesPARTICIPANTS IN EXPERIMENTSHow do we select participants for the study? ◦ Generalization is important! Population: everyone in the group the experimenter is interested in Sample: a subset of a population ◦Random sampling: every person in the population has an equal chance of being selected ◦Convenience sample: this sample consists of people who are conveniently available for the study Random assignment: placing research participants into the conditions of an experiment in such a way that each participant has an equal chance of being assigned to any level of the independent variable ◦ Increases the chance that the groups are equal WITHOUT RANDOM ASSIGNMENT, Selection bias: ◦ Example: Dividing the class (early arrivals vs late arrivals)ETHICS IN RESEARCHNeed to make sure people are treated in a fair, safe, and informed way (no deception that would induce harm!) ◦ *For ethical and practical reasons, researchers cannot always use the experimental method. Institutional Review Boards (IRBs): Need to make sure it meets the accepted standards of science ◦Takes into account the physical and emotional well- being of research participants Is there risk associated with participating in an experiment? ◦ Cannot put people through( unreasonable) pain or discomfort ◦ IRB weighs tradeoff between risk and benefit before approving any study Informed consent: ◦ Some people cannot legally provide informed consent themselves <18 years old, certain disabilities ◦ Deception: if used, debriefing is NECESSARY!ETHICS IN RESEARCH WITH ANIMALSInstitutional Animal Care and Use Committee (IACUC) judges study proposals to make sure the animals will be treated properly ◦ Similar to an Institutional Review Board, only specific to animals ◦ Every IACUC includes a veterinarian Some animals share similarities with humans ◦They are good "models" for particular human behaviors or conditions* *A balance between animals' lives and humanity's futureIMPORTANCE OF PARTICIPATING IN RESEARCHYou learn firsthand about the research process ◦ Some studies are fun and others are boring (No way around it!) BUT all are important in the understanding of behavior.OKAY, NOW YOU'RE A SKEPTIC ABOUT PSYCHOLOGY...How can a study in a lab tell us anything about real life? § Lab is simplified reality § Experiments test & refine theories, then theories can be used to explain real life § "Field experiments" can test theories in a controlled way in the real worldStudy HabitsStudy Habits pt. 2Study Habits 5 MinsStudy Habits 1 WeekBenefits of TestingRead passage for five minutes then take a break One group given test five minutes after another a week after Read passage for five minutes, then asked to recall as much as possible three times for ten minutes, after five minutes or a week given test SSSS after five minutes recalled more than STTT STTT after a week recalled more than SSSS Benefits of testingRetrieval is a "memory modifier"Retrieval itself has consequences for our memories Memories that get retrieved get strengthenedWHAT ABOUT ERRORS?What is retrieved becomes strengthened ◦ Good, if people get answers correct ◦ Bad, if people get answers wrong Consequences of making errors: ◦ The wrong answer becomes strengthened ◦ Errors persist ◦ And, having now generated an error, this can compete, or interfere, with the correct answer Feedback importantRICHLAND, KORNELL, & KAO, 2009Exp. 1: Test + study group: 2 min pretest on some items + 8 min study ◦ Avg of 5% correct on pretest, items were removed Extended study group: 10 min study Immediate final test Materials: Two-page text about colorblindness caused by brain damage. Results in bar graphTESTING EFFECTTesting is good, not just for assessment, but: ◦ As a learning tool §Testing involves retrieval, and retrieval itself is a powerful memory modifier (strengthens memory) ◦ Even when errors are generated (pre-tests and tests) §As long as corrective feedback is provided §Enables more elaborative encoding of correct answers; makes connection with pre-existing knowledgeWHY IS SPACING GOOD FOR LEARNING?Cramming helps when test is right after, spacing out helps for later Why? Several (not mutually exclusive) theories... § Retrieval: Spacing repetitions = forgetting in between, which means you have to engage in retrieval to remember the prior presentation §Variability: Each presentation more likely to be coded in a slightly different state when repetitions spaced apart in time ◦Attention: Massed repetitions get boringTo Cram or Not to Cram?To Cram or Not to Cram? Pt. 2THE CURIOUS CASE OF PHINEAS GAGE•Brain relates to behavior •Localization of function Lessons of the brain- the Phineas Gage case Railroad worker, would blast rocks to lay railroad tracks 25, rod went straight through his brain 1848 Talking and walking minutes after Fell into a coma Personality changes when he woke up Became temperamental, rude, little self control Can lose some cognitive function and live a relatively full life Teaches us how brain relates to behavior, localization of function"COMPASS POINTS" ON THE BRAINForebrain/Midbrain/HindbrainHINDBRAINCerebellum: fine motor skills Medulla: heart rate, circulation, breathing Reticular formation: sleep/wakefulness, arousal Pons: connects to rest of brainMIDBRAINEx. Orienting in response to stimuliForebrain: Subcortical Structures + CortexLeft and Right Cerebral cortex Hypothalamus Amygdala Thalamus- sensory gateway except for smell Hippocampus- memory Limbic system- emotion/motivation/memory Basal ganglia- intentional movementSubcortical StructuresOf Interest- Limbic System: Emotion/motivation/memory Basal Ganglia: Intentional movementLobesFrontal lobe Planning, decision, making, speaking (includes primary motor cortex/prefrontal cortex) Parietal lobe Sensory input for touch and position (includes primary somatosensory cortex) Temporal lobe- auditory processing language Occipital lobe- receives visual informationMajor Reasons of the CortexPREFRONTAL CORTEX, CLOSE-UPPhineas Gage: his accident caused damage to his frontal lobes This led to major personality changes. Lobotomy: a form of surgery that deliberately damages prefrontal cortex Left patients lethargic, done in mental hospitalsMOTOR AND SOMATOSENSORY CORTEXMotor CortexCortical representations of information are weighted by "importance" CORTEXCortical representations of information are weighted by "importance"RIGHT-BRAINED or LEFT-BRAINED?In typical people, hemispheres highly connected ◦ Largely symmetric, but there is some "lateralization" (Ex. Language) ◦ Contralateral organization: Left hemisphere controls right side of body , and vice versa Corpus callosumSPLITTING THE BRAIN SPLITS THE MINDSplit brain: the corpus callosum is cut in surgerySEVERING THE CORPUS COLLOSUM: SPLIT-BRAIN PATIENTS atch?v=ZMLzP1VCANoPLASTICITYBrain can change as a result of experience or injury ◦ Decreases with age, BUT neural connections are made throughout the life spanPHANTOM LIMB◦ Phantom limb demonstrates neural plasticity ◦ Can be taught to manage pain using phantom limb(s) ◦ e.g., survivors of 2010 Haiti earthquake (Miller, Seckel, & Ramachandram, 2012)NEURAL CONNECTIONS AND LEARNINGNeurons that fire together, wire together Ex. repeated behavior good or bad, gets wired in to the brain and becomes more likely to be triggered in the future Neurogenesis- the production of new neuronsTHE NERVOUS SYSTEMNeurons: basic units of the nervous system that operate via electro-chemical signals te via electrochemical signalsTYPES OF NEURONS AND THEIR FUNCTIONSensory neurons: (body to brain) ◦ carry info from sensory receptors to the CNS Motor neurons: (brain to body) ◦ carry info from CNS to muscles & glands ◦ direct muscles to contract or relax (produce movement) Interneurons: ◦ communicate within CNS; intervene between sensory inputs and motor outputs ◦ Think of REFLEXES - neurons are converting sensation to actionPARTS OF A NEURONdendrites: detect incoming signals cell body (soma): collects / sums input; contains nucleus and cellular material axon: transmits signal to axon terminals (and ultimately to other neurons)myelin sheathcovers the axon of some neurons and helps speed up neural impulsesterminal buttons:small nodules at the end of the axon that release chemical signals from the neuron into the synapsesynapsethe space between the axon of a "sending" neuron and the dendrite of a "receiving" neuron THIS IS WHERE/ HOW NEURONS COMMUNICATE!NEURONAL COMMUNICATION◦ Neuron receives signals from other neurons ◦ The threshold is reached when excitatory ("Fire!") signals outweigh the inhibitory ("Don't fire!") signals by a certain amount. ◦ Once reached, action potential starts moving down the axon "All-or-none" ◦ how is intensity communicated? ◦ frequency / firing rate ◦ number of neurons firingRESTING MEMBRANE POTENTIALResting membrane potential = a neuron's at rest electrical charge ◦ Polarized: cell is more negative inside than outside (- 70 mV) More sodium ions (Na+) tend to be outside and more potassium ions (K+) inside of the neuron ◦ Sodium-potassium pumpACTION POTENTIALThe action potential is caused by changes in the electrical and chemical gradients across the cell membrane Recall ➡ action potential is "all or none"ACTION POTENTIAL pt.2NEURON FUNCTIONIn sum, when the integrated signal reaches a threshold, an action potential is generated the neuron is said to "fire" the action potential travels down (propagates along) the axon to the axon terminals by the opening and closing of ion channels along its lengthBETWEEN AXONS AND DENDRITES: SYNAPSESWhen the action potential that is traveling down the axon reaches the axon terminal, it causes the release of neurotransmitters into the synaptic gap/cleft ◦ space where the axon terminal contacts the dendrite ◦ each neuron has ~1000-10,000 synapsesSUMMARY OF A NEURONMS CASE STUDY§Symptoms include: Physical: Vision loss, weakness, clumsiness, slurred speech Cognitive: Inattention, memory loss, fatigue Emotional: Mood swings, depression Jack Osbourne, son of rocker Ozzy Osbourne, was diagnosed with MS in 2012. Can you figure out what is damaged in neurons to cause the symptoms of MS? Multiple Sclerosis (MS) Myelin sheath on neurons is destroyed So neurons can't fire electrical signals Then neurons can't communicate with each other. Area of brain where demyelination happens is what causes specific symptoms Problem with myelin on the axons of neurons is the cause of multiple sclerosis symptoms.Excitatory Neurotransmittersmake the receiving neuron more likely to fireInhibitory NEUROTRANSMITTERSmake the receiving neuron less likely to fire (Some NTs can be both excitatory and inhibitory, depending on the situation)Endorphins"Runner's high"- act within the pain pathways and emotion centers of the brain (pain reduction and reward)EpinephrineAdrenaline! Think: bursts of energy after exciting/ threatening eventDopamineInvolved in motivation, reward, and motor control over voluntary movementAGONISTS VS. ANTAGONISTSDrugs act on the existing neurotransmitter systems in our bodyAgonistsincrease effects of neurotransmitter ◦ e.g., Prozac blocks reuptake of serotonin to elevate mood ◦ Serotonin: regulation of sleep (dreaming), eating, mood, impulse controlAntagonistsblock the function of a neurotransmitter ◦ e.g., botulin (Botox) is ACh antagonistParkinson's A CASE STUDYParkinson's Disease Symptoms include: Rigid muscles Tremors at rest Difficulty starting movements and speaking Odd shuffling walk Changes in thought and emotions Lack of Dopamine Actor Michael J. Fox was diagnosed with Parkinson's disease in 1991. Can you figure out which neurotransmitter plays a role in Parkinson's disease? Degenerative and fatal neurological disorder Neurons that produce dopamine slowly die off. Later stages cause people suffering from cognitive and mood disturbances. Patients given L-DOPA, a building block of dopamine, have a temporary recovery.NEURON VIDEO 7AlzK7s&list=PL8dPuuaLjXtOPRKzVLY0jJY-uHOH9KVU6&index=3 1:30- 4:30A FALSE START...PHRENOLOGYFranz Joseph Gall(1796) First attempt at segmenting the brain The notion that bigger=better, and bigger = more bumps against the scalpPET (Positron emission tomography)Assesses metabolic activity by using a radioactive substance injected into the bloodstream ◦ Used for: ◦ Revealing size, shape, & function of brain ◦ Detecting damaged areas and diagnosing dementiaMRI (Magnetic resonance imaging)◦ uses a powerful magnetic field to produce high- quality images of the brain and its structure ◦ e.g., can be used to diagnose a stroke, MS, tumor, dementia, Alzheimer'sfMRI (Functional magnetic resonance imaging)used to examine changes in ongoing brain activity by measuring changes in the blood's oxygen levels ◦ Compares successive MRI images ◦ great for determining location; not so great at determining timingELECTROENCEPHALOGRAPHY (EEG)Because fMRI only measures blood flow, it does NOT provide precise info about the timing of neural activity. EEG can record electrical activity from large populations of simultaneously active neurons at the scalp with millisecond resolution. EEG is a direct measure of neural activity. EEG systems are much cheaper than MRI scannersTranscranial magnetic stimulation (TMS)Strong magnets are used to briefly interrupt normal brain activity as a way to study brain regions ◦ Used for: ◦ Direct testing of function (think back to the video) ◦ Treatment for some neurological & psychological conditionsSensationdetecting physical stimuli and sending this info to the brain Same sensation, different perceptionPerceptionprocessing, organizing, and interpreting sensory infoThere are 4 steps in changing sensory input into our own unique experiencesStimulus A green light emits physical properties in the form of photons (light waves) Sensation Sensory receptors in the driver's eyes detect this stimulus Sensory Coding The stimulus is transduced (translated into chemical and electrical PerceptionTRANSDUCTION (sensation to perception)the process of converting one form of energy to another Sensory transduction converts physical stimuli to neural impulses The senses: ◦ Receive sensory stimulation via specialized receptor cells ◦ Transform that stimulation into neural impulses ◦ Deliver the neural information to the brainBottom-up processingperception based on the physical features of the stimulus ◦ from basic level up to more complex See stop lightTop-down processinghow knowledge, expectations, or past experiences shape the interpretation of sensory information ◦ the context and our expectations affect perception See toy stop light Paragraph with words misspelledAbsolute thresholdthe minimum amount of stimulation needed to detect a stimulus 50% of the time (.....more than chance!) ◦ Stimuli below this threshold are called "subliminal" ◦ Ex. a teaspoon of sugar dissolved in two gallons of waterDifference thresholdthe minimum difference between two stimuli needed to detect a difference between them 50% of the time ◦ Also called a "just noticeable difference" (JND) Ex. hair cut, not noticing that there is a changeWeber's LawIn order to be perceived as different, the intensity of two stimuli must vary by a constant proportion of the intensity of the original stimulus ◦ As intensity increases, we get less sensitive to change Lifting weights, 1 pounds vs 2 pounds- can tell difference 50 pounds vs 51 pounds- can't tell differenceSIGNAL DETECTION THEORYPredicts how and when we detect the presence of a faint stimulus (signal) amid background noise (other stimulation). Assumes that there is no single absolute threshold and detection depends on: • Person's experience • Expectations • Motivation • Level of fatigue • Consequences of missing- radiologistsPAYOFF MATRICES FOR SDTThere are 4 possible outcomes when a participant is asked whether something occurred during a trialSENSORY ADAPTATIONDiminished sensitivity as a result of constant or recurring stimuli ◦ Phone in pocket, wrist watch, smell on the bus, planes overhead Why? Good thing because there is so much sensory information, constantly noticing change is notWHY STUDY VISUAL ILLUSIONS?Illusions reveal constraints/biases on perception ◦ Usually correct/helpful but occasionally wrong, resulting in illusionsVISIONLight travels at different wavelengths, but we are only sensitive to (can transduce) a small part of the spectrum Different wavelengths are perceived differently (colors) Other organisms can "see" wavelengths we can't because they have receptor cells specialized for those wavelengthsTHE EYEWhen light passes through the cornea and lens, it is bent so that the light waves cross and project an upside down and backwards image on the retina. Top becomes bottom, and left becomes rightTHE RETINAThe light-sensitive inner surface of the eye (back of the eyeball) • Contains receptor rods and cones plus layers of other neurons that process visual informationPHOTORECEPTORS: RODS & CONESFovea: the center of the retina, where cones are densely packedWhat is the best way to view stars at night?Look to the side of it so it is out of the fovea Outer part of retina is where rods are concentrated Night- just detecting a light so cones are uselessYoung-Helmholtz Trichromatic Color TheoryThree types of cones— respond to red, green, or blue light ◦ Other colors formed by mixing some combination of the above three ◦ Colorblind people lack one or more type of coneOpponent Process TheoryThree sets of retinal processes— red/green, yellow/blue, and white/black ◦ Only one of each set can activate at a time ◦ After extended exposure, neurons become fatigued ◦ Looking at white (combination of all colors) makes the opponent color stand out American flag example (stare at different colored flag and actual flag appears)MAKING SENSE OUT OF AMBIGUITIESWhat are some examples of ambiguous stimuli? Why are these often referred to as 'bistable' percepts, and what do these tell us about perception?PERCEPTUAL ORGANIZATIONWe have perceptual processes for enabling us to organize perceived colors and lines into objects: grouping incomplete parts into gestalt wholes seeing figures standing out against background perceiving form, motion, and depth keeping a sense of shape and color constancy despite changes in visual information using experience to guide visual interpretationGESTALT PRINCIPLESGestalt means "shape" or "form" ◦ In psychology, Gestalt means "organized whole" or "unified whole object" ◦ Explains how the brain groups together individual features of an image into one unified whole object rather than a collection of separate parts Figure-ground Grouping Good continuation (see two s, not two v) Similarity (see 5 columns of same color, not 5 rows of alternating color) Proximity (left 6 grouped together, right 6 grouped together) Closure (completing figures with gaps) Common fate (things that move together, go together) The Kanizsa Triangle: example of illusory contoursGestalt Principles PicturesMore Gestalt Principles PicturesMORE GESTALT GROUPING PRINCIPLESThe Kanizsa Triangle (1955) ◦ Example of illusory contoursEDGE DETECTION AND SEGMENTATION CAN BE DIFFICULT...THEORIES OF RECOGNITION: TEMPLATE THEORYAny pattern that fits template (in long term memory) of an object will be recognized as that object See stimuli → search memory for a match What is an existing template that this thing matches?PROBLEMS WITH TEMPLATE THEORYTemplate must be specific to particular size, orientation (in plane and depth), location, etc.? Would need so many templates! Template theory with transformations: every image i have in memory, i have a multitude of snapshots of all different angles and sizes and shapes etc Issue: You're shuffling through all the templates in your head: the more templates you have, the longer it takes you to recognize somethingTHEORIES OF RECOGNITION: RECOGNITION BY COMPONENTS (RBC, Geon)All objects can be described as a collection of several volumetric primitives or geons (geometric icons) and the relations between them Viewpoint independent/viewpoint invariant- can recognize this object from any viewpoint/angle based on geons In ex column B, geons are still intact: corners, features that identify the objectPROBLEMS WITH RBCNot useful for within-category discriminations What kind of chair? Was kind of shoe?DEPTH PERCEPTIONEnables us to judge distances and see objects in three dimensions. Depth- how do we translate a 2D image into a 3D image? Visual Cliff- Glass table, paper over half, infant placed in center and mom stands at one end Pattern on the floor and on top half of table: creates illusion of a drop-off. Part on table larger, part on floor smaller. Child sits at center of board, mother beckons. Child has no problem crawling from center to shallow end Children almost always refuse to go "off the cliff" At a young age, infants have ability to recognize depth and "fall off the cliff" Not born with ability to discriminate and perceive depth, but comes about when we begin to crawl and move and interact with our surroundingsMONOCULAR CUES(for pictures and the real world) Help us perceive depth using one eyeMONOCULAR CUES Pt.2◦ Interposition (or occlusion) = closer objects block farther ones (we don't think the pole is missing, we think the guy is in front of it and blocking it) ◦ Relative height (of object) = lower is closer (lower in a picture usually means closer to you, higher in a picture means something is further away) ◦ Relative size = bigger is closer (appearing bigger means subject closer in the picture) ◦ Relative clarity = clearer is closer ◦ Relative brightness = brighter is closer ◦ Linear perspective = parallel lines appear to converge in the distance (we draw parallel lines as some 3D object to be convergent) ◦ Texture gradient = coarse is close, fine is far away ◦ Motion parallax = faster is closer Light and shadow (gives us idea of underneath vs above) Sidewalk Illusions ?!PONZO ILLUSIONTwo horizontal lines appear to be different lengths when they are the same lengthHow are we able to see?Binocular visionBINOCULAR CUESRetinal disparity—different retinal images each eye receives based on its different perspective Convergence: when a person views a nearby object, the eye muscles turn the eyes inward Can even create stereopsis (3D perception) with 2D images, if each eye presented with a slightly different imageSTEREOPSIS: 3D MoviesPolarized lenses allow full color viewing (like in Avatar) Filters one image on horizontal plane and one on vertical plane Each eye gets a different perspectivePERCEPTUAL CONSTANCYReal objects don't change at random, so our perceptions of those objects don't change either even though the visual information can change dramatically ◦ Size ◦ Shape ◦ Color ◦ Brightness ◦ Parallel lines & edges Visual illusions take advantage of perceptual constancy by manipulating the monocular cues we rely on to interpret the visual worldSIZE CONSTANCY Seeing a pic of two men: we judge them to be the same size since one is farther back, even though if placed together one is much smaller The Ames Box: misformed room but parallel cues make us think the room is normal, people are weirdSHAPE CONSTANCYPerspective cues make us look at things differentlyBRIGHTNESS CONSTANCYCOLOR CONSTANCYRubix Cube Illusion The Dress"SPLITTING COLORS" TRICK!inattentional/change blindness: failing to perceive objects that are not the focus of attention we treat them like other objects in the world?We are really bad at upside-down facial recognitionFACES ARE SPECIAL, HOUSES ARE NOTYin (1969)How is perception accomplished in the brain? o How can brain damage affect perception?IDK!CATEGORY REPRESENTATIONS?OK BUT...(Chan, 2013)PROSOPAGNOSIAProsopagnosia (face-blindness) is an inability to recognize faces ◦ Must use feature-level clues to tell people apart (hair color/length, blemishes, etc.) ◦ In other words, for prosopagnosiacs, faces are not specialized ◦ Analogy: Like telling rocks apart... Cosmetics can make big changes to the appearance and so can a new haircutVISUAL PROCESSING STREAMSNOTE: we are covering this because this is the "traditional" view, but take it with a grain of saltDorsal/Ventral Streamdorsal stream - where pathway ventral stream - what pathwayACHROMATOPSIAaka cerebral achromatopsia or color agnosia an inability to perceive color despite having a normally functioning eye might not necessarily affect the entire visual field! "Everything looked black or grey. He had difficulty distinguishing British postage stamps of different value which look alike, but are of different colors. He was a keen gardener, but found that he pruned live rather than dead vines. He had difficulty distinguishing certain foods on his plate where color was the distinguishing mark."EVIDENCE FOR TWO STREAMS: DF OBJECT RECOGNITIONWith DF, there is damage and you cannot orient things and identify objects' shapes Ventral stream damaged Cannot tell if two rocks are the same or different Cannot estimate how far apart fingers need to be to pick up the rock But when she actually goes to pick up the rock, she is able to adjust - able to control the actions with info given to her Unable to say "that's an apple" if shown an apple, but able to draw itEVIDENCE FOR TWO STREAMS: PATIENT DFVISUAL NEGLECTAttentional disorder in which patients are unaware or don't respond to objects on one side of space. ◦ Usually declines over several weeks. Patients are often unaware of the neglect. ◦ Fail to compensate by changing orientationVISUAL NEGLECT Described by Sacks (1976)Mrs.S; suffered a severe stroke affecting the right side of her brain. ◦ Neglects the left visual field. Will miss food on the left of her plate, only apply lipstick on the right side. Has learned to swivel to the right to find something that appears missing.HEMISPATIAL NEGLECToften associated with damage to the right parietal lobe Implicit processing of unattended fieldLINE CANCELLATIONCopying figuresDrawings copied by a patient with contralateral neglectIMPLICIT PROCESSING OF UNATTENDED FIELD[Marshall & Halligan, 1988, Nature]RECOVERY FROM NEGLECTMULTISENSORY PERCEPTION: McGURK EFFECTHow are we able to hear?Ex: auditory localizaion We hear things more quickly / can process where it came from better when it's to one of our sidesSOUND LOCALIZATIONThe brain integrates different sensory info coming from each ear. ◦ Ex: Barn owl research subjects Sound always being process by both ears Sound hits our ears at different times depending on where it came from - which side we hear first indicates which side it came fromAuditionhearing; the sense of sound perceptionSound wavea pattern of changes in air pressure during a period of time; produces sound ◦ Amplitude determines loudness ◦ Frequency determines pitch ◦ Hertz (how frequency is measured) ◦ Humans can detect sound waves from ~20 Hz to ~20,000 Hz. a pattern of changes in air pressure during a period of time; produces sound ◦ Amplitude determines loudness ◦ Frequency determines pitch ◦ Hertz (how frequency is measured) ◦ Humans can detect sound waves from ~20 Hz to ~20,000 Hz.Sound waves travel from the outer ear to the eardrumEardrum: vibrates as a result of sound waves Hearing pathway: sound waves eventually travel to the thalamus and then the auditory cortexAmplitude/FrequencySound Class Demo Class Demo Pt. IS LEARNING?What do you think of? School, computer, experience, information, memory, exercising ◦ Effortful? ◦ Academic: Facts/concepts? ◦ Skills: Learn to ride a bike? ◦ How to behave: "I learned my lesson"? Most generally, learning is: "Experience that results in a relatively permanent change in the state of the learner"CLASSICAL CONDITIONING PAVLOV'S DISCOVERYSalivation was (eventually) triggered by what should have been neutral stimuli such as: just seeing the food. seeing the dish. seeing the person who brought the food. just hearing that person's footsteps.Before ConditioningNeutral stimulus (bell) (NS) No responseBefore Conditioning (US)Unconditioned stimulus (dog food) Unconditioned response (UR)- dog salivatesDURING CONDITIONINGNeutral stimulus and Unconditioned stimulus Unconditioned response- dog salivatesAFTER CONDITIONINGConditioned (formerly neutral) stimulus- bell Conditioned response- dog salivates The UR and the CR are the same response, triggered by different events. The difference is whether conditioning was necessary for the response to happen. The NS and the CS are the same stimulus. The difference is whether the stimulus triggers the conditioned response.ACQUISITIONAcquisition refers to the initial stage of learning/conditioning ◦ What gets "acquired"? ◦ How can we tell that acquisition has occurred? Can also have second-order conditioning ◦ E.g., Square predicts bell, so square to salivation ◦ Money predicts buying fun things, so money to funEXTINCTIONWhen US (food) and CS (bell) are paired repeatedly, the CR (salivation) gets stronger Extinction occurs when the US and CS stop appearing together ◦ Bell rings, food doesn't appear Over time, the CR gets weakerSPONTANEOUS RECOVERYFollowing a rest period (after extinction), presenting the CS (bell) may lead to spontaneous recovery of the CR (salivation)GeneralizationOnce a response has been conditioned, similar stimuli can elicit the same response ◦ Ex. Different bell tones still produce salivationDiscriminationability to distinguish between similar but distinct stimuli ◦ Ex. If dog shows less salivation to a different bell toneLITTLE ALBERTCan classical conditioning explain complex behaviors? Video available at Before Conditioning NS-rate: no fear US-steel bar hit with hammer: unconditioned response- fear During Conditioning NS- rat and US- steel var hit with hammer: Unconditioned response- fear Acquisition phase: learning to associate rat with loud noise NS + US → URAfter ConditioningNS becomes CS- rat: Conditioned response- fearJohn Watson's claims:It is possible that complex reaction like fear can be conditioned using Pavlovian techniques ◦ So emotions are not necessarily the products of unconscious process or early life experiences (as Freud had claimed). Was Albert treated ethically? No What happened to Little Albert? Unclear Think about implications for therapy for phobias... If you have a fear of spiders but love cake, maybe seeing cake alongside a picture of a spider enough times will make you not be so scared ◦ How could we decrease fear of helicopters in people who have experienced war? ◦ Decrease fear of heights?Little PeterHad a fear of white rabbits Loved graham crackers Would put rabbit in corner of room as eating crackers Over time kept eating and they kept bringing the rabbit closer and closer And he was okay with it. Reverse conditionUNDERSTANDING CLASSICAL CONDITIONINGRescorla-Wagner model ◦ Conditioned stimulus sets up expectation ◦ Easier to condition unfamiliar stimuli ◦ Why didn't dogs salivate to Pavlov? He was in the room every time Taste aversions ◦ Can be learned in a single trial! Get food poisoning and don't want to eat there again, etc. ◦ Delay to response can be long ◦ Adaptive role?Classical conditioningreactive behaviorsOperant conditioningvoluntary behaviors ◦ An operant behavior is one that has some impact on the environment A type of learning in which the consequences of an organism's behavior determine whether it will be repeated in the futureThorndike's Law of Effect◦ Behaviors followed by favorable consequences become more likely ◦ Behaviors followed by negative consequences become less likelyCatsPut a cat in a box and food outside (the cat can see it) How many trials does it take for the cat to realize that if he presses the level, he gets the food?Thorndike's catsSKINNER BOXRat in a box with food and water dispensers, speaker that can come on, and a light that can blinkPositive/Negative Reinforcement/PunishmentTYPES OF CONSEQUENCESSam's mom only stops nagging him when he cleans his room, so he learns to clean it more often.Negative ReinforcementDiscrimination and generalizationWhere/when are behaviors desired? ◦ Ex. Children should be loud during recess and quiet during class. Extinction ◦ What happens when you no longer reinforce behavior? ◦ Affected by initial schedule of reinforcement...SCHEDULES OF REINFORCEMENTReward every time vs. intermittently Continuous vs. partial Intermittent schedules can be: Fixed vs. Variable ◦ Fixed: Reinforcement after a given amount of time or responses ◦ Variable: On average, you get reinforcement after a given amount of time or responses, but the exact reinforcement is random. Interval vs. Ratio ◦ Interval: Based on TIME intervals ◦ Ratio: Based on number of behaviors, (i.e., ratio of responses to reinforcements)SCHEDULES OF REINFORCEMENT PICTURERESPONSE RATES FOR EACH SCHEDULEFixed ratio > variable ratio > Fixed interval > variable intervalWHICH SCHEDULE IS BEST?"Best" = most resistant to extinction. Intermittent reinforcement resists extinction more than continuous reinforcement ◦ Ex. Broken vending machine vs. broken slot machine Variable ratio is most resistant to extinctionSHAPINGAnother example: OPERANT CONDITIONINGTolman: Stimulus to cognitive state (knowledge, beliefs) to behavior, not stimulus to behavior ◦ Some evidence: Even without reward, rats explore and learn about maze- latent learningMore evidence for cognitive explanations (Tolman):Evolutionary elements ◦ After finding food, rats look other places, not the same place they found food beforeCLASSICAL VS. OPERANT CONDITIONINGBEHAVIORISM and LEARNING"Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select -- doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors." --John Watson, Behaviorism, 1930 Can behaviorism account for all learning?OBSERVATIONAL LEARNINGBobo Doll Experiment Could viewing media violence can lead to increased expression of aggression in viewers? BUT, others can model good behavior too! Learning by observing others ◦ Also happens in animalsModelingthe process of observing and imitating a certain behavior ◦ Often very useful! ◦ How did you learn to tie your shoes? How did your dentist learn how to extract wisdom teeth? MIRROR NEURONS?THE "DOOR" STUDY EXAMPLES?Just because we "see" something, doesn't mean it is in memory (failures to encode) ◦ Where's the nearest fire extinguisher? ◦ What color shirt was your friend wearing yesterday?DVD-IN-THE-HEADoEncoding: Record on an electronic disk oStorage: Store the DVD in a drawer oRetrieval: Play the disk back on a DVD player Why is it a bad analogy? ◦ Perception does not equal memory ◦ Memory is susceptible to distortions and misinformation ◦ Forgetting is not all-or-none: How well you can retrieve a piece of information depends on many different factorsEncoding/Storage/RetrievalEncoding: the information gets into our brains in a way that allows it to be stored Storage: the information is held in a way that allows it to later be retrieved Retrieval: reactivating and recalling the informationEVIDENCE FOR LEVELS OF PROCESSING Craik & Tulving (1975)DEEPER PROCESSING to BETTER ENCODING• Semantic encoding • "Mnemonics" = using mental imagery & other well- known cues, method of loci • Making memory personally meaningful • Hierarchies = organizing information • Distributed Practice to spacing effect!WANT TO BE A MEMORY CHAMP? MODELSENSORY MEMORY◦Iconic memory is the visual sensory register ◦Echoic memory is the auditory sensory register We very briefly capture a sensory memory, analogous to an echo or an image, of all the sensations we take in. ◦ 3 to 4 s. echo ◦ 1/20th s. imageSHORT TERM MEMORYUsed to keep track of what is currently relevant ◦ Limited capacity ◦ Short durationCAPACITY OF SHORT TERM MEMORYGet a pencil ready! About 7 + 2 chunks of information What is a chunk? ◦ Information grouped into a meaningful unit ◦ Words are chunks of letters ◦ Multi-digit numbers are chunks of single digit numbers ◦ Routes are chunks of locationsWORKING MEMORYSTM- the space used to hold information presently required WM- manipulation of that information for whatever task you are doing Maintenance vs. elaborative rehearsal Phonological Loop EpisodicLONG TERM MEMORY (LTM)oMemory that persists over time without conscious activation oEvents in your life, facts about the world, motor skills, etc. o"Long term" sometimes means a few minutes- doesn't have to be years oCan last indefinitely oCan be retrieved and brought into working memory (but we might lose the ability to access that memory)SERIAL POSITION EFFECTSerial position effects can be evidence for separate short versus long term memory systems.What would happen to primacy and recency effects if you had to do something else in between hearing the end of the list and recalling the words?With a delay between study and test... Primacy effect, no recency effect, WHY?How is memory involved in doing mental arithmetic?Short-term and working memory ◦ holds information about the particular problem ◦ applies the rules and strategies retrieved from long-term memory to the present information ◦ transiently stores intermediate outcomes and final solution Long-term memory ◦ rules of arithmetic ◦ learned strategies for solving problemsThe critical lureDRM ResultsUnlike a video recording, how we store our experiences in memory depends on our interpretations and expectations of themSchemas are organized knowledge structure or mental model that we've stored in memory ◦ What happens when you go to a restaurant? ◦ Useful, but can oversimplify!RETRIEVALNOT like playback of a video ◦ Remember the testing effect? Retrieval depends on cues/hints that help bring information to mind ◦ They can be more or less effective Evidence: ◦ Transfer appropriate processing ◦ Encoding specificity ◦ State dependent learning ◦ Context effectsTRANSFER APPROPRIATE PROCESSING Morris, Bransford & Franks (1977)Compatibility between encoding and retrieval processes Deep, semantic not inherently better, just more compatible with typical memory tests E.g., want to improve pronunciation of words ◦ attention to phonology better than attention to meaning Study phase- yes/no judgments 1. "The ____ had a silver engine" TRAIN 2. "____ rhymes with legal." EAGLE Test phrase- old/new judgments 1. old if occurred in study phase, e.g. EAGLE 2. old if rhymes with studies word, e.g. REGALCONTEXT AND MEMORYContext helps retrieval ◦ Context may be many different things ◦ Other words on list ◦ Internal state at the time of encoding ◦ Environmental cues such as odors or sounds The more similar the retrieval situation is to the encoding situation, the better retrieval ◦ Similarity of retrieval to encoding can override level of processing ("transfer-appropriate processing")ENCODING SPECIFICITYCONTEXTThe effects of studying and context ◦ Test taking and similar context of rooms ◦ Use of imagery and mental time travel... Are there benefits of different context? ◦ Always study at the same place? ◦ Different context leads to more retrieval cues?RETRIEVAL PT.2How to measure what you know? Recall ◦ Name everything you need to buy at the market Recognition ◦ You see a tomato and decide whether it was on your list Savings/Reaction time measures ◦ Can you learn something faster the second time around?Declarative Memory• knowing "what" • expressed verbally • conscious awareness • a.k.a. "Explicit Memory"Non-Declarative Memoryknowing "how" • expressed behaviorally • awareness not necessary • a.k.a. "Implicit Memory"EPISODIC MEMORYdiscrete events • specific time, place • personally experienced • "What did you eat for breakfast?" •Prospective memory?: future events o return book (event-based) o doctors appt (time-based) DeclarativeSemantic Memoryfacts • general knowledge • e.g. "Who was the first US president? DeclarativePROCEDURAL SKILLS• motor - bike riding • cognitive - reading Non-DeclarativePRIMINGincreased fluency perceptual conceptual Non-Declarative MemoryCONDITIONINGNon-Declarative Memory