Ap Psychology Chapter 2 Summary

FALL
2011
Psychology 100
Final Exam Notes
Greta Epstein

Chapter 2: RESEARCH METHODOLOGY
What is Scientific Inquiry? * A way of finding answers to empirical questions- questions that are answered by observing and measuring * 4 basic goals: * Describing what happens * Predicting when it happens * Controlling what causes it to happen * Explaining why it happens * Researchers use a general approach known as the scientific method * Scientific method reflects a dynamic interaction of 3 essential elements: 1. A theory - an explanation or model of how something
in the world works 2. A good theory should generate a hypothesis - a specific, testable prediction about the outcome that would best supports the theory. (If the theory is reasonably accurate, the hypothesis should be supported) 3. Once the hypothesis is developed, research must be done- this involved collecting data which tests the hypothesis * Once research is performed, one returns to the theory and evaluates it. * The theory will either be supported, require modification, or discarded fully. Then the process starts again! * Generally, scientific findings that have replicated outcomes are more reliable. * Replication involves repeating a study and getting the same or similar results What Are The Types of Studies in Psychological Research? * 3 main types: 1. Descriptive 2. Correlational 3. Experimental * All research involves variables (=anything that can be measured and that can vary) (1) Descriptive Studies: * Also called observational studies * Involve observing an classifying behavior, either with no intervention by the observer (=naturalistic observation), or with intervention by the observer (=participant observation) * Advantages: valuable in early stages of research, when trying to determine if a phenomenon exists * Disadvantages: errors in observation can occur because of an observer's expectations (=observers bias). The observers presence can change the behavior being witnessed (=reactivity) * Longitudinal studies are a type of study that involves observing and classifying developmental changes that occur over time (either with or without the observers intervention) * Cross-sectional studies are a type of study that involves observing and classifying developmental changes that occur within different groups or people at the same time. This is faster and less expensive than longitudinal studies. * Experimenter expectancy effect is the actual change in the behavior of people or animals being observed because of the observer bias Correlational Studies * Examines how variables are naturally related in the real world-- without attempt to alter them by the researcher * Advantages: relies on naturally occurring relationships and may take place in a real world setting * Disadvantages: can’t be used to support casual relationships, cant show the direction of the cause/effect relationship between variables- a directionality problem, and an unidentified variable may become involved (third variable problem=when the experimenter cannot directly manipulate the independent variable and therefore can’t be confident that another, unmeasured variable, is not the actual cause of the differences in the dependent variable. Instead A causing B, it is possible that there may be a C.) Experimental Studies * Examines how variables are related when they are fully manipulated by the researcher * The investigator has maximum control over the situation * Experiment is a study that tests the casual hypotheses by measuring and manipulating variables * A control/comparison group are the participants in a study that don’t receive any intervention, or the participants that receive an intervention that is different from the one being studied * A experimental/treatment group are the participants in a study that receive the intervention * The independent variable in an experiment is the variable that is being manipulated by the researcher to examine the impact it has on the dependent variable * The dependent variable in an experiment is the variable that changes (or doesn’t change) based on the independent variable. This variable is affected by the manipulation of the independent variable. * The confound of an experiment is anything that affects the dependent variable and May existentially vary the experimental conditions of an experiment or study. (Mrs. Gaeeni always told us to control all of the variables in order to avoid confounds) * Advantages: demonstrates casual relationships because it avoids the directionality problem (=when researchers find a relationship between two variables in a study but cannot determine which variable may have caused changes in the other variable) * Disadvantages: often takes place in an artificial setting Random Assignment is Used to Establish Equivalent Groups * Important issue to be considered when researching is how to select people for the study * A population is everyone in the group the experimenter is interested in * A sample is a subset of the population.
It should represent the population. The best way for this to happen is by random sampling (= taken at random from the population- e.g. selecting students from every school in your country) * Most of the time a researcher will use a convenience sample-- taken at random from an available subgroup- people who are conveniently available for the study. (E.g. students at your school) * Selection bias is a condition when the groups aren’t equivalent because the participants differ between conditions in unexpected ways * To make the groups in an experiment as equivalent as possible, random assignment is used. This means that participants are assigned at random to the control group or the experiment group so that each participant of the experiment as an equal chance of being assigned to any level of the independent variable. Random assignment balances out known and unknown factors * Meta-analysis is “a study of studies”. It combines the findings of multiple studies to arrive at a conclusion. (A study of multiple analyses) * Cultural sensitive research are studies that take into account the ways that culture would affect ones thoughts, feelings, and
actions * Cross cultural studies compare groups of people from different cultures * Advantages: examines the effect of culture on some variables of interest-makes psychology more applicable around the world * Disadvantages: some situations and words do not convey the same meaning when translated across cultures and leave room for alternative explanation * Observational techniques involve careful and systematic assessment and coding of overt (obvious) behavior * Reactivity means that the person or thing being observed alters in behavior because of the knowledge that they are being observed * The Hawthorne effect refers to changes in behavior that occur when people know that others are observing them * A case study is a special type of observational study that involves intensive examination of one person or a few individuals (=clinical case studies), or one or a few organizations (=organizational case studies). * Advantages: can provide lots of information about one or a few individuals or organizations * Disadvantages: can be very subjective * A self report method of data collection is a method that involves people providing answers to asked questions about themselves-- a questionnaire or survey * A response performance method of data collection is when researchers quantify perceptual or cognitive processes in response to a specific stimulus-- reaction time, response accuracy * Advantages: a simple way to study cognition and perception, has less observer bias or subject reactivity * Disadvantages: can be costly and time consuming, less likely to be useful in a real world setting Brain and Body Activity Can be Measured Directly * Brain activity methods measure body/brain responses to tasks or events * Advantages: map the brain in various ways to show brain regions involved in different tasks * Disadvantages: show only brain regions active while the tasks are being performed, have the disadvantage of the third variable and directionality problem * An electroencephalograph (EEG) is a device that measures electrical activity in the brain * Brain imaging is a range of experimental techniques that make brain structures and brain activity visible * Positron emission tomography (PET) is a method of brain imaging that assesses the metabolic activity using a radioactive substance that is injected into the bloodstream * Magnetic Resonance Imaging (MRI) is a method of brain imaging that produces high quality images of the brain * Functional Magnetic Resonance Imaging (fMRI) is an imaging technique that is used to examine changes in the activity of the working human brain * Transcranial magnetic stimulation (TMS) uses very fast and powerful magnets to briefly interrupt normal brain activity as a way to study brain regions * Research ethic boards (REBs) are groups of people who are responsible for reviewing proposed research to ensure that its meets the accepted standard of science and provides for the physical and emotional well-being of research participants How Are Data Analyzed and Evaluated? * Good research requires valid, reliable and accurate data: * Validity is the extent to which the data collected addresses the hypothesis in the way it was intended to (do the findings address the question being asked) * Reliability is the stability or consistency of a measure over time * Accuracy is the extent to which an experimental measure is error free. * Descriptive statistics are an overall summary of the data * Central tendency is a measure that represents the typical behavior of the group as a whole * The mean is a measure of central tendency that is the arithmetic average of a set of numbers * The median is a measure of central tendency that is the value of a set of numbers that falls in the middle of all the values * The mode is a measure of central tendency that is the most frequent number of all the set of values * Variability in a set of numbers is how widely dispersed the values are from each other, and from the mean. * Standard deviation measures variability-- measures, on average, how far away each value is from the mean. * Scatter plots illustrate relationship between two variables * Inferential statistics are a set of procedures used to make judgments about whether differences actually exist between sets of numbers or data. * They allow us to decide whether differences between two or more groups are probably just chance in variations or whether they truly reflect difference in the populations being compared.
Chapter 3: BIOLOGICAL FOUNDATIONS
What Is The Genetic Basis of Psychological Science? * Genetics affect thoughts, feelings, and behaviors * The Human Genome Project is an international research effort that is a major development in the new biological revolution * Occurred in February 2001 * Represents coordinated works of hundreds of scientists around the world * This work is the map of the entire structure of human genetic material * The genome is the master blueprint that provides detailed instructions for everything. It provides options and the environment to determine choices made by cues outside the cell * Chromosomes are structures made of genes that exist within the cell body * A gene is a segment of DNA involved in producing a protein, which carries out a specific task. It is the unit of heredity that determines a particular characteristic in an organism. * Heredity is a statistical estimate of the genetic portion of the variation, caused by differences in heredity, on some specific trait. It involves passing along genes through reproduction * A dominant gene from a parent is a gene that is expressed (becomes apparent or physically visible) in the offspring whenever it is present. * A recessive gene is a gene that is only expressed when it is matched with a similar gene from the other parent (don’t interfere with most people’s health) * The genotype is an organism’s genetic formation or constitution determined at the moment of conception. (A genetic combination that is determined upon conception) * The phenotype is that organism’s observable, physical characteristics, which result from both genetic and environmental influences (the appearances that result from genotypes that are formed) * Sexual reproduction: * Most cells in the human body contain 23 pairs of chromosomes—among them are sex chromosomes which are denoted by X and Y (due to shapes) * Females have 2 X chromosomes * Males have 1 X chromosome and 1 Y * In each parent, reproductive cells divide to produce gametes * The egg and sperm cells each contain half of every chromosome pair * After one egg and sperm combine during fertilization, the fertilized cell, called the zygote, contains 23 pairs of chromosomes—half of each pair from the mother, and half from the father * 8 million different combinations are possible * The genotype created at conception accounts for the genetic variation of the human species * The zygote grows through cell division—which is the basis of the life cycle and responsible for the growth and development * Errors that occur during cell division lead to mutations—most are benign but some may cause an advantage or disadvantage (i.e. diseases) * Monozygotic twins (identical) are the result of one zygote dividing into 2, and therefore share the same genes * Dizygotic twins (fraternal) are the result of 2 separately fertilized eggs developing in the mothers womb simultaneously
Summary
* Human behavior is influenced by genetic processes * People inherit both physical characteristics, and personality traits from their parents * Only recently have scientists developed tools that can measure genetic processes and the roles hat various genes play in psychological activity * The Human Genome Project has mapped DNA’s basic sequence; information that will eventually be translated into medical treatments and a greater understanding of individual differences within people. * Among the genetic research tools are methods that enhance or interrupt gene expression by selectively knocking out specific genes to reveal which behaviors are affected.
How Does The Nervous System Operate? * Neurons are the nervous system’s basic units, and operated through electrical impulses, which communicate with other neurons through chemical signals. Their primary task is to take in information, integrate that information, and pass signals to other neurons. * Types of neurons: * Sensory neurons: detect information from the physical world and pass it along to the brain * Motor neurons: direct muscles to contract and relax, thereby producing movement * Interneurons: communicate only with other neurons, typically within a specific brain region * A neuron receives information at the dendrites (= short, branchlike extensions of the neuron that detects information from other neurons) and processes that information in its cell body (= in the neuron, where information from thousands of other neurons is collected and processed). * It passes signals down its axon (= a long narrow outgrowth of a neuron by which information is transmitted to other neurons) and then to other neurons’ dendrites by firing. * Neural firing, also called action potential, is the neural impulse that passes along the axon and subsequently causes the release of chemicals from the terminal buttons (=small nodules at the ends of axons that release chemical signals from the neuron to the synapse/synaptic cleft) * The insulating myelin sheath (= a fatty material, made up of glial cells, that insulate the axon and allow rapid movement of electrical impulses along the axon) surrounding the axon allows the firing, or action potential, to travel, or propegate, very rapidly. * When a neuron is in resting state (the inside and outside of a resting neuron differ electrically—this phenomenon is called the resting membrane potential), it is slightly negatively charged. * A neuron fires depending on the excitatory and inhibitory signals that the dendrites receive * Excitatory neurotransmitters (neurotransmitter= a chemical substance that carries signals from one neuron to another) make the postsynaptic neuron more likely to fire, and the inhibitory neurotransmitters make the postsynaptic neuron less likely to fire. * The firing results from the changes in the electrical charge across the cell membrane: * Sodium ions rush in when the sodium channels open * Potassium ions rush out when the potassium ions stop exiting * This allows the neuron to return to it’s resting state * The intensity of the excitatory signal affects the frequency of neural firing, but does NOT affect its strength—neurons fire on an all-or-none basis (= the principle whereby a neuron fires with the same potency each time, although frequency can vary; it either fires or not—it can’t partially fire) * Action potentials cause vesicles to release neurotransmitters into the synaptic cleft (= the site for chemical communication between neurons which contains extracellular fluid) * Neurotransmitters diffuse across the synaptic cleft and bind with specific postsynaptic receptors (= specialized protein molecules found in neurons, on the postsynaptic membrane, that neurotransmitters bind to after passing across the synapse) * These signals are terminated through reuptake (= the process whereby a neurotransmitter is taken back into the presynaptic terminal buttons, thereby stopping its activity), enzyme deactivation, or the actions of auto receptors * Substances that enhance neurotransmitters’ actions are called agonists. * Substances that inhibit neurotransmitters’ actions are called antagonists. * There are now more than 60 known substances that act as neurotransmitters, and the number is still growing! * Certain neurotransmitters are especially important for psychological research: * Acetylcholine is involved in motor movement and complex mental processes (e.g. learning, memory, sleeping, dreaming) * Epinephrine is responsible for adrenaline rushes, bursts of energy caused by its release throughout the body * Norepinephrine is involved in states if arousal and awareness * Dopamine is involved in reward, motivation, and motor control * Serotonin is important in mood regulation, impulse control, and dreaming * GABA (gamma-aminobutyric acid) is the primary inhibitory transmitter in the nervous system * Glutamate is the primary excitatory transmitter in the nervous system * Endorphins are involved in natural pain reduction and reward * Substance P is involved in pain perception
What Are The Basic Brain Structures and Their Functions? * The nervous system’s different parts all have essential roles: * It is divided into 2 functional units: * The central nervous system (CNS): consists of spinal cord and brain * The peripheral nervous system (PNS): consists of all other nerve cells in the body * The spinal cord is involved in basic moment and reflexes * The brain stem (= a section of the bottom of the brain, housing the most basic programs of survival, such as breathing, swallowing, vomiting, urination, and orgasm) is connected to the cerebellum (= a large, complex protuberance at the back of the brain stem, essential for coordinated movement and balance), which is a workhorse tat learns routine habits of movement and possibly thought. * Beneath the cortex, the thalamus serves as gateway to the brain, and receives almost all-incoming sensory information before that information reaches the cortex. * The left frontal region of the brain is called Broca’s area and is crucial for the production of language * The hypothalamus is the brains master regulatory structure—it is indispensible as it regulates body function and is vital for temperature regulation, emotion, sexual behavior, and motivation. * The hippocampus is involved in the formation of memory * The amygdala is a brain structure that serves a vital role in our learning to associate things with emotional responses and in processing emotional information * The basal ganglia is a system of subcortical structures that important for the initiation of planned movement) * Finally, the cerebral cortex is the outer layer of brain tissue, which forms the intricate surface of the brain. It is divided into occipital, parietal, temporal, and frontal lobes. * Each lobe serves specific functions: * Occipital lobes: important for vision (regions of the cerebral cortex, back of the brain) * Parietal lobes: important for the sense of touch and the spatial layout of an environment (regions of the cerebral cortex, in front of occipital lobes, behind frontal lobes) * Temporal lobes: important for processing auditory information and for memory (lower region of cerebral cortex) * Frontal lobes: concerned with thought, planning, and movement (region at the front of the cerebral cortex) * Prefrontal lobes: especially prominent in humans, important for attention, working memory, decision making, appropriate social behavior, and personality (region of the frontal lobes)
How Are Neural Messages Integrated into Communication Systems? * The peripheral nervous system has two primary components: * Somatic nervous system: transmits sensory signals to the CNS via nerves * Autonomic nervous system: regulates the body’s internal environment by stimulating glands and by maintaining internal organs such as the heart, gall bladder, and the stomach. A division of the ANS that prepares the body for action is called the sympathetic division of ANS, and the division of the ANS that returns the body to it’s resting state is called the parasympathetic division of ANS * The central nervous system, consisting of the brain and spinal cord, attends to the body and the environment, initiates actions, and directs the peripheral nervous system and endocrine system (= a communication system that uses hormones to influence thoughts, behaviors and actions) to respond appropriately * Hormones are chemical substances, typically released from endocrine glands, which travel through the bloodstream to targeted tissues, which are subsequently influenced by the hormones. * Gonads are the main endocrine glands that are involved in sexual behavior: in males, the testes, and in females, the ovaries. * All three systems (PNS, CNS, and endocrine system) use chemicals to transmit their signals, but transmission in the nervous system occurs across the synapses, while transmission in the endocrine system uses hormones that travel through the bloodstream * Gonadal hormones (estrogen, progesterone, and testosterone) are important in the development of secondary sex characteristic and in the sex drive * The hypothalamus controls the endocrine system by directing the pituitary to release specific hormones.
* The various communication systems are integrated and promote behavior that is adaptive to the environment
How Does The Brain Change? * Although neural connections are intricate and precise, they are flexible. * Plasticity is a property of the brain that allows it to change as a result of experience, drugs, or injury. * The human genome, the blueprint for normal development, is affected by environmental factors, such as injury, sensory stimulation, sensory deprivation, and life experiences. * During development and throughout our lifetimes of learning, the circuitry is reworked and updated * Culture, as context for experience, affects the organization and structure of the brain * The brain can reorganize after a brain injury, though children’s recovery is far greater than adults’. * An understanding of genetic transmission and of brain organization, along with the knowledge that the brain regions are specialized for different perceptions, has allowed researches to unravel the puzzle of synthesia * Females’ and males’ brains differ in several ways, although similarities are more
obvious * Males’ brains tend to be larger * Evidence suggests that females’ brains are organized more bilaterally
Chapter 5: SENSATION AND PERCEPTION
How Do We Sense Our Worlds? * Psychological scientists often divide the way we experience the world into two distinct phases: * Sensation: the sense organs’ detection and responses to external stimulus energy (e.g. light, air vibrations, odors, etc.) and the transmission of these responses to the brain * Perception: the brain’s further processing of these detected signals that results in internal representations of the stimuli—representations that form a conscious experience of the world. * The study of sensation focuses on the way our sense organs respond to and detect external stimulus energy * Our sensory organs’ translations of stimuli’s physical properties into neural impulses is called sensory coding * Sensory coding begins with transduction—stimuli need to be transduced (= a process by which sensory receptors, specialized neurons in the sense organs, produce neural impulses when they receive physical or chemical stimulation) for the brain to use their information. In other words—in order for the brain to use the information given from the stimuli, the stimuli must go through a process, transduction, where special neurons in the sense organs produce and pass on neural impulses after having received physical or chemical stimulation * Qualitative aspects of stimuli, such as colour and bitterness, are coded by the combination of the specific receptors each activates. (Sensory receptors respond to qualitative differences by firing in different combinations) * Sensory coding for quantitative factors, such as intensity and loudness, depends on the number of neurons firing and how frequently they fire. (Sensory receptors respond to quantitative differences by firing at different rates) * The development of psychophysical methods has allowed scientists to study psychological thresholds (limits) for detecting events and for noticing change: * Absolute threshold is the minimum intensity of stimulation that must occur before you experience a sensation or the stimulus intensity detected above chance—the absolute threshold for hearing is the faintest sound a person can detect 50% of the time * Difference threshold is the just noticeable difference between two stimuli—the minimum amount of change-required for a person to detect a difference. * These thresholds can be influenced by situational factors and by biases in human judgment—the difference threshold increases as the stimulus becomes more intense * Weber’s law states that the just noticeable difference between two stimuli is based on a proportion of the original stimulus, rather than a fixed amount of difference. * Thinking critically: context affects judgment—understanding the situation for any comparison is the key to making a sound judgment related—positively, or negatively—to that comparison. * Classical psychophysics was based on the idea of a sensory threshold—either you saw something or you did not, depending on whether the intensity of the stimulus was above or below the sensory threshold (limit). As time went on—it was clear that psychophysicists disregarded an important variable—human judgment. * After realizing that their methods of testing were flawed, researchers formulated signal detection theory (SDT), a theory of perception which states that the detection of a stimulus requires a judgment about it’s presence or absence—it isn’t an all-or-none process. * Sensory adaptation is a decrease in sensitivity to a constant level of stimulation. In other words, when you don’t notice a stimulus anymore because it is constant and you become used to it.
What Are The Basic Sensory Processes? * In taste, the stimuli are chemical substances from food that dissolve into saliva * Gustation = our sense of taste * Taste buds = sensory receptors that transduce taste information * In taste, taste buds detect chemicals * Sense of smell has the most direct route to the brain, but may be the least understood * Olfaction = the sense of smell, which occurs when receptors in the nose respond to chemicals * Olfactory epithelium = the thin layer of tissue, within the nasal cavity, that is embedded with smell receptors * Olfactory bulb = the brain centre for smell, located below the frontal lobes * In smell, the nasal cavity gathers odorants * Sense of touch conveys sensations of temperature, pressure, pain, and a sense of where our limbs are in space * Haptic sense = our sense of touch * In touch, sensors in the skin detect pressure, temperature and pain * Hearing is second only to vision as a source of information about the world for humans * Audition = our sense of sound perception * Sound wave= the pattern of the changes in air pressure through time that results in the precept of sound * Eardrum (tympanic membrane) = a thin membrane, which sound waves vibrate, that marks the beginning of the middle ear * In hearing, the ear detects sound waves * If we acquire knowledge through our senses, then vision by far is the most important source of knowledge. * Cornea = the clear outer covering of the eye * Retina = the thing inner surface of the back of the eyeball. The retina contains the photorceptors that transduce light into neural signals * Pupil = the small opening in the eye; it lets in light waves * Iris = the coloured muscular circle on the surface of the eye; it changes shape to let in more or less light * Rods = retinal cells that respond to low levels of illumination and result in black and white perception * Cones = retinal cells that respond to higher levels of illumination and result in colour perception * Fovea = the centre of the retina, where cones are densely packed * Receptive field = the region of visual space to which neurons in the primary visual cortex are sensitive * Lateral inhibition = a visual process in which adjacent photoreceptors tend to inhibit one another. This effect emphasizes changes in visual stimuli * Subtractive colour mixing = a way to produce a given spectral pattern in which the mixture occurs within the stimulus itself and is actually a physical, not psychological, process. Physical process of colour mixing that happens with the stimulus * Additive colour mixing = a way to produce a given spectral pattern in which different wavelengths of light are mixed. The percept is determined by the interaction of these wavelengths with receptors in the eye and is a psychological process. Mixing that happens when the eye perceives lights of different wavelengths. * In vision, the eye detects light waves * Humans and animals have other sensory systems—some animals can use sound waves and disruption in an electrical field to navigate * Humans have several internal sensory systems in addition to the five primary ones: * Kinesthetic sense: refers to sensations we gather from receptors, in muscles tendons, and joints, that pinpoint the position in space and the movements o both our body and our limbs. This information helps us coordinate voluntary movement and helps us avoid injuries. Perception of our limbs in space * Vestibular sense: uses date from receptors in the semicircular canals of the inner ear. It contains a liquid that moves when our head moves, and ultimately controls our perception of balance. * The evidence for extrasensory perception (ESP) is weak or nonexistent * Refers to a “sixth sense” * Reports of an ESP are based on anecdotal cases * Anecdotes are not science—thus psychological scientists reject claims supported by anecdotes as such evidence is too difficult to disprove and ordinary thought processes could explain many of the claims.
Summary
* All the senses share similar processes * Each sense has receptors that respond to different physical or chemical stimuli by transducing them into some pattern of brain activity * Typically, different receptors respond to different types of stimuli, and most sensory systems integrate signals from these different receptors into and overall sensation * This system allows a relatively small number of receptors to code a wide variety of stimuli * Visual stimuli can interpret the entire range of colours with only three cone types * All the taste sensations are produced by five primary taste receptors * These various sensory receptors help the perceptual system receive important information that assists in solving adaptive problems * Sensory information, although obtained from the outside world, is processed entirely in the brain to produce sensory experience through perception
What Are the Basic Perceptual Processes? * Perception occurs in the brain * Neural activity in the primary auditory cortex gives rise to hearing * Touch is mediated by neural activity in the primary somatosensory cortex * Other than sense of smell, all sensory information is relayed to areas of the brain through the thalamus * Object perception requires construction—the neural computations for object perception begin in the early stages of visual processing * The primary visual area in the brain is called V1 * Bottom-up processing is a hierarchical model of pattern recognition in which data are relayed from one processing level to the next, always moving to a higher level of processing. Data being relayed from lower to higher levels of processing * Top-down processing is a hierarchical model of pattern recognition in which information at higher levels of processing can also influence lower; “earlier” levels in the processing hierarchy. * Perception is a combination of bottom-up and top-down processing * Context affects perception * Depth perception is important for locating objects * Binocular depth cues are cues of depth perception that arise from the fact that people have 2 eyes—available from both eyes together * Monocular depth cues are cue of depth perception that are available to each eye on its own * Binocular disparity is a cue of depth perception that is caused by the distance between a person’s eyes, which provides each eye with a slightly different image * Culture influences perception—cross cultural studies have shown that people who grew up in, and live in a carpentered world—who have interacted with carpentered structures—are more prone to illusions based on cues, such as linear perspective, than people who are raised in a non carpentered world * Size perception depends on distance perception—the size of an object’s retinal image depends on that objects distance from the observer—the farther away, the smaller its retinal image. * Motion perception has internal and external cues—the brain perceives motion because we have neurons specialized for detecting movement—they fire when movement occurs. * Perceptual constancies are based on ration relationships * Perceptual constancy is when people correctly perceive objects as constant in their shape, size, colour, and lightness, despite raw sensory data that could mislead perception. * The changing of an objects angle, distance, or illumination doesn’t change our perception of that object’s size, shape, colour, or lightness
Summary
* The perceptual system is very intelligent * Takes ambiguous sensory information and constructs rich and meaningful experiences that allow us to navigate the world around us. * All perception occurs in the brain, where various perceptual processes take incoming sensations and construct them into meaningful perceptions * Information first arrives in the primary sensory regions, such asV1, for visual experience, and A1 for audition, but multiple brain regions contribute to our unified perceptual experience * The perceptual system uses cues from the person’s environment to help interpret sensory information—visual cues help provide information about what object are and where they are located, as well as information about depth and motion * Contemporary theorists emphasize that perceptions are not faithful reproductions of the physical world, but rather are constructed through multiple processes that allow us to taste, smell, hear, touch and see
Chapter 6: LEARNING
How Did The Behavioral Study of Learning Develop? * Learning is a relatively enduring change in behavior, one that results from experience. * Behaviorism, founded by John B. Watson focuses on observable aspects of learning. * Psychologists study 2 types of conditioning (= how associations are developed): * Classical/Pavlovian conditioning: occurs when we learn that two types of events go together—a type of learned response that occurs when a neutral object comes to elicit a reflexive response when it is associated with a stimulus that already produces that response. * Unconditioned stimulus (US) is a stimulus that elicits a response, such as a reflex, without any prior learning (e.g. in Pavlov’s experiment the US is the food) * Unconditioned response (UR) is a response that is not learned, such as a reflex (e.g. in Pavlov’s experiment the UR is salivation from the food) * Conditioned stimulus (CS) is a stimulus that elicits a response only after learning has taken place (e.g. in Pavlov’s experiment the CS is the clicking of the metronome after learning has taken place) * Conditioned response (CR) is a response to a conditioned stimulus that has been learned—an acquired, learned response (e.g. in Pavlov’s experiment the CR is salivating after hearing the metronome) * The CR is usually weaker than the CR * Hundreds of possible stimuli can be associated with the unconditioned stimulus to produce a conditioned response * Pavlov was greatly influenced by Darwin * Acquisition is the gradual formation of an association between conditioned and unconditioned stimuli * Extinction is the process in which the conditioned response is weakened when the conditioned stimulus is repeated without the unconditioned stimulus. The CR is eventually extinguished * Spontaneous recovery is the process in which a previously extinguished response re-emerges following the presentation of the conditioned stimulus. It is temporary and will fade quickly unless the CS is again paired with the US * Stimulus generalization occurs when stimuli similar but not identical to the CS produce the CR * Stimulus discrimination is a differentiation between two similar stimuli when only one of them is consistently associated with the unconditioned stimulus * Phobias and addictions have learned components to them * A phobia is an acquired fear that is out of proportion to the real threat (e.g. dogs, heights, bugs) * According to the classical conditioning theory, phobias develop through the generalization of a fear experience (e.g. a person stung by a be develops a fear of all bugs) * Conditioned drugs effects are common and demonstrate conditioning’s power * Classical conditioning involves more than events occurring at the same time—a number of challenges to Pavlov’s theory suggested that some conditioned stimuli would more likely produce learning than other and that contiguity was not sufficient to create CS-US associations * The Rescorla-Wagner model is a cognitive model of classical condition; it states that the strength of the CS-US association is determined by the extent to which the unconditioned stimulus is unexpected.
How Does Operant Conditioning Differ from Classical Conditioning? * Operant conditioning, also known as instrumental conditioning, is a learning process in which the consequences of an action determine the likelihood that it will be performed in the future. Behaving in certain ways results in rewards, and behaving in other certain ways results in punishment. We learn based on the outcome of our actions. * B.F. Skinner is the psychologist most closely associated with this type of learning, as he selected the term operant to express the idea that animals operate on their environments to produce effects. * Thorndike’s general theory of learning, called the law of effect, which states that a “satisfying state of affairs” will more likely occur again, and any behavior that leads to an “annoying state of affairs” will less likely occur. * Reinforcement increases behavior—influenced by behaviorism * The reinforcer refers to the stimulus that follows a response and increases the likelihood that the response will be repeated. Behaviors such as studying, eating, driving on the right side of the road, occur because these behaviors have been reinforced. * The Skinner Box was Skinner’s operant chamber—as he called it. It was used to assess operant conditioning on rats and other animals. He would keep them in a box and expose them to repeated conditioning trials and observe * Shaping is a process of operant conditioning; it involves reinforcing behaviors that are increasingly similar to the desired behavior. * Both reinforcement and punishment can be positive or negative * Reinforcement and punishment have opposite effects on behavior * Positive reinforcement increases the probability that a behavior will occur again, as it sometimes involved a reward. Rewarded behaviors increase in frequency * Negative reinforcement increases behavior through removal of a stimulus * A punishment decreases the likelihood of a behavior all-together. * Positive punishment decreases a behaviors probability through the administration of a stimulus. (E.g. rat getting a shock for pressing the lever) * Negative punishment decreases a behavior’s probability through the removal of a pleasurable stimulus.