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Department
Psychology
Course
PSYCH 1X03
Professor
Joe Kim
Semester
Fall

Description
What is Psychology? 11-06-03 10:10 PM We will be learning the science of psychology rather than clinical psychology and our goal is to understand the human thought and behavior. What does psychology teach us? Teaches how we think, feel, develop, learn, interact and grow. It also teaches us to use scientific methods to collect and evaluate information and derive a conclusion based upon it. It teaches us not to believe something without solid proof. History of Psychology - Greek words Psyche (soul) and logos (study of) which means study of soul. - Psychology is only about 150 years old. Before this, study of mind was philosophy and physiology (the functions of a organism or any of its parts) Early Century Philosophers influence: Greek Philosophers Aristotle and Plato asked questions: • How do we learn to remember? • Where does knowledge come from? René Descartes: • Mind and Body were two different entities that worked together. • The Mind controlled the mechanical movements of the body and received information about the outside world through sense organs. 1800 Century Physiologist influence: Muller: • Different areas of the brain serve different functions. • Nerves transmit messages in the form of electrical impulses. The impulses travel along different channels • Particular areas of the body are connected to particular areas of the brain and played a role in different functions. Flourens: • used Muller’s technique to destroy certain areas of an animals brain. By doing so, he studied the particular area’s function. • By using the method, he analyzed which areas controlled heart rate, breathing and processing of visual and auditory reflexes. Helmholts: • Nerve impulses do not travel at the same speed an electrical current passes through a conductive wire. Nerve impulses travel at about 90 feet/second. Psychology began to emerge out of roots of Philosophy and Physiology. Birth of Psychology (1879): • Wilhelm Wundt opens first lab devoted to study of psychology. Believed that scientific methods could be used to study conscious experiences. Willhelm Wundt: • 1881 Launched first Scientific journal promoting psychological research. Introduction to Levels of Analysis • Learning, Social Psychology, Cognition, Evolution, Neuroscience, Development Learning: • Ivan Pavlov performed an experiment where he gave a dog food and rang a bell each time. The dog learned to associate food with the sound of a bell. The bell acted as a que for the dog. • Humans also use such que for digestive processes and various other daily activities. We can use this technique to cure phobias. Structuralism: • Focused on breaking down mental processes into their most basic components. • Researches used introspection (analyze own experiences and reported on them) Functionalism: • focused on the purpose of consciousness and behavior. Behaviorism (derived from functionalism): • John B. Watson (Father of Behaviorism) • The mind is a black box that takes input and gives output. The processing information is to complex to understand and is “outside the domain of science.” • BF Skinner -> You can learn everything about an organism by simply studying it’s behavior. Organism will repeat a behavior if it leads to something pleasant Cognition (1960’s): • Proper Scientific methods can be used to unlock the black box (the mind) • Analyzes Thought, Attention, Memory, Language, and Problem Solving • Models used to explain complex processes. Models raise questions and may become outdated when new data is presented. Thus, a new revised model must be made to explain these changes. • Models: Abstract representations of how the mind functions. Can be used to make testable predictions and design experiments. Neuroscience: • early scientists drilled holes into the patients skull to look at the brain. • X-rays, MRI, CT Scanning • Neuroimaging through MRI can allow us to non invasively see the brain. Structural MRI allows us to see the physical makeup of brain. Functional MRI allows us to see what brain is actually doing at the time. • Francis Crick: Where does human Consciousness come from? Why do we behave the way we do? Reductionism: • All behavior can be linked to the brain. Our understanding of the brain is incomplete. Social Psychology: • Influence of individual on a group • Influence of group on a group • Influence of group on individual Social psychologists have to be aware of Ethical considerations as they may have to cause Distress or Deception to create a social situation. Evolution and Development: • Developmental psychologists study the development of behavior over a single lifespan. • Evolutionary psychologists study the development of behavior over a much larger period of time. Thousands to millions of years. • When studying subjects such as infants, special techniques must be constructed to understand behavior correctly (infant + pictures). CASE STUDY ON DEPRESSION TO FIGURE OUT DIFFERENCES BETWEEN EACH TYPE OF PSYCHOLOGY Learning Approach: • What are the behaviors associated with depression and how can they be altered? • They use Therapy to reverse the problem. Cognitive Approach: • What negative thought processes are driving depression? • Therapy to reverse the negative thoughts about ones self. • Aaron beck: depression is fueled by one’s negative thoughts towards self, world, future. Neuroscience Approach: • What changes in the chemical/structural balance of the brain lead to depression? • Potential drug treatment to restore chemical/physical balance • Hippocampus region smaller in individuals suffering from depression. Social Psychologist: • How does a person’s relationship affect their depression? • Study the importance of having a support group such as peers or family to fighting depression. Evolutionary/Developmental Psychologist: • What genetic or environmental factors lead to depression? • Why wasn’t the depression gene eliminated through evolution? • In a social species, depression may be beneficial as it may lead to a increase in peer support. –Marcello Spenilla • Nature/Nurture argument. Introduction to Scientific Research 11-06-03 10:10 PM The Scientific Method: • We cannot use sources such as Friends, Media or Personal Experiences o Biased information that may not be accurate • Scientists have a 7 Step method with following Goals: o Trying to minimize biases o Making sure information is valid o Avoiding conflicting information o Avoid Overseeing important data o Avoid Confounding Variables. Variables other than independent variable which may have effect on results. The Seven Steps o Theory: By reading the work of other scientists, we can construct a general set of ideas on how the world works. o Hypothesis: A set of statements that form the basis of the experiment you are conducting. These statements guided by theories make predictions about the relationship between variables. o Research Method: Constructing method by which to test the hypothesis. (Hardest Part) o Collecting Data: Taking measurements of the outcomes of the test. (Avoid Bias) o Analyze Data: understand the data collected and discover trends/relationships between variables. o Report Findings: findings are published in scholarly journals after rigorous review. The journals are also tested by the scientific committee for accuracy. o Revise theories: Preexisting theories about the world may be modified to include new research. (Fix what the reviewers tell you to do. Usually reviewers find flaws with findings and we must fix them) Conducting an Experiment Experiment is a scientific tool used to measure the effect of one variable on another. • Testing a Hypothesis: o Anecdotal evidence: Evidence gathered from others or self experience. § Cannot be used to conduct scientific experiment § Your experiences may not be the same as what others in the larger population may have experienced § Your personal experience does not represent the experience of others in the same conditions § Other factors may have played a role in influencing your experience. • Using the Experiment o An experiment is a scientific tool used to measure the effect of one variable on another o Independent variable: the variable manipulated by the scientist. o Dependent Variable: the variable that is being studied and is not under control by scientist. Control Groups • Introducing a subject that is not under the influence of the independent variable. • This subject must have a similar behavior to the subject being tested. For example, is test marks under the influence of caffeine was the research topic, both subjects should be equally motivated and have the same level of intelligence. Using Control Groups o We should have more than one participant in each condition. The experimental subject may possess superior/inferior abilities than that of the control subject. o Experimental group receives the manipulation of the independent variable. The Control group does not receive independent variable. o As discussed before, participants in both groups should be as similar as possible in ability, intelligence and other aspects. Participant Designs o Within-Subject Design: A single participant acts as both the control and the experimental group. He performs some tests using the independent variable, and then performs other tests without using the variable. o Expensive and Time consuming o Practice Effect: Experience leads to better performance over course of experiment. o Subject being tested may be bias and perform better on purpose for the experimental test? Between Subject Designs o One group of subjects is the experimental group whilst the other is the control group o Once again, subjects should be similar as possible in every way Sampling • Population: The general group of people we are trying to learn about. For example, the effects of caffeine on undergraduate students. • Random Sample: Our test subjects should be randomly chosen from this general group of population to represent a majority or group without bias towards one. • Sample: The chosen participants of the population who we conduct tests on. DO NOT PICK A TOO SPECIFIC SAMPLE GROUP as this will not present the general population. • Random Assortment: Assign subjects to the experimental/control group on random to avoid any biases towards a group of subjects. Conducting an Experiment • Subject Biases o Placebo Effect: the experimental group should not know that they are influenced by the independent variable. The placebo effect may occur, in which individuals respond to a treatment that has no medical effect. The experimental group may think that they are being given the miracle drug, will be motivate and perform better for other reasons than the drug itself. § Do not tell participants whether they are in experimental or control group! o Participant bias: participants actions in experiment influence results outside the manipulations of the experimenter. o Blinding: When participants do not know whether they are in experimental or control group or which treatment they are receiving. • Experimenter Biases o Actions made by the experimenter unintentionally or deliberately, to promote the result they hope to achieve o Don’t even tell the experimental which group do the sample belong to! o Double Blind studies: Neither the experimenter or sample know which group they belong to. 11-06-03 10:10 PM Descriptive Statistics Working with Raw Data o Statistics allow for analyzing, summarization, and interpretation of data collected. Types of Descriptive Statistics o Descriptive statistics allow us to view data information at a glance and gives us an overall idea of the results of the experiment. Using Histograms o A Histogram is a type of graph that is used to report the number of times a group of value occurs in a data set. On the x-axis of such a graph is the group of values, whilst on the y- axis is the frequency that dataset occurs. Frequency distribution o Type of graph illustrating the distribution of how frequent values appear in the data set. Normal Distribution o Distribution with a characteristic of Smooth, Bell and symmetrical-shaped curve around a single peak. o Things such as IQ and test scores fall under this typical pattern. Measure of Central Tendency o Mean: The most commonly used. It is found by averaging the data set. It can be misleading when a outlier is present in the system. The value for the mean can drop/increase dramatically depending on outliers which are extreme points distant from others in the data set. o Median: The median is the centre value in an organized data set. It tells us what the middle point of our data is without influence of outliers. o Mode: Appears most frequently in the set and tells us what the most typical response was. It is the only method out of the 3 discussed that can be applied to something outside of numerical figures. Measures of Variability o Standard deviation: tells us how spread out the data figures are. The higher the standard deviation, the more spread out the graph is. The lower the standard deviation, the less spread out. o The standard deviation of a dataset is essentially the average distance of each data point from the mean. Inferential Statistics • The resulting dataset from the experimental group and the control group must vary to a degree before we can conclude that the independent variable had an effect. • If the experimental and control group perform only slightly different, perhaps the independent variable had no effect. It may have been by random chance that one group may have performed better. • Inferential Statistics: Statistics that allow us to use results from samples to make inferences about overall, underlying populations. Hypothesis Testing • Alternate Populations o In a experiment, we are trying to represent the results of a few individuals to hypothesize the effect of the independent variable on an entire population. o The Control group and an Experimental group may be classified as two different populations. One population represents people under the influence of the independent variable, whilst the other population represents people who are not under the influence of the independent variable. This is referred to as alternate populations. o If the independent variable has no effect, both groups represent a common population. • T-test o Compares each data point from the experimental and control group to calculate the probability of getting results by chance. o Is the difference between my control and experimental group large enough to conclude that the independent variable may have had an effect? • P-Value o A value expressing the probability calculated by the t-test o The p-value must be less than 0.05 to conclude that independent variable had an influence o A p-value of less than 5% means that the probability of receiving results by chance is unlikely o Statistically significant à P-value less than 0.05 • Statistical Significance o Difference between 2 groups is due to some true difference between the properties of the 2 groups and not random variation o The different results obtained are not a result of random chance Observational Research • Introduction to Observational Research o Used for studies that may have ethical concern o Scientists observe the effect of variables of interest on subjects without actually performing any manipulation o Example: Rather than asking subjects to start smoking to study lung cancer, a scientist may use data collected on cancer vs smoking from existing smokers (experimental group) and non smokers (control group) • Correlation o Measure of Strength of the relationship between 2 variables o Correlation Coefficient: Symbolized by letter R it represents the degree with which 2 variables are correlated. o +1 coefficient: variables are perfectly positively correlated. o -1 coefficient: variables are perfectly negatively correlated. o 0 coefficient: As relation between variables get weaker, coefficient correlation approaches zero • Correlation is not Causation o The relationship between two variables does not always prove the hypothesis o An external factor or confounding variable may be the cause of the correlation of two variables. o For example: ice cream and allergies may be correlated but pollen in the air during hotter months when ice cream is eaten is the true reason for this pattern. 11-06-03 10:10 PM Introduction to Learning: Two Types of Learning o Classical Conditioning: Allows us to associate two different events. An organism is able to respond to a signal (stimuli) before a event occurs. For example, a dog presented with a conditional stimuli may salivate even before he is given food. In nature this event produced positive outcomes. For example, salivating may make digestive processes easier. o Instrumental Conditioning: Allows us to associate actions with consequences. Classical Conditioning • Invented by Ivan Pavlov also known as Pavlovian Conditioning • Pavlov discovered that organisms can learn to associate different stimuli to different events and produce a conditional response. • Tested hypothesis on dogs by presenting a conditional stimulus in the form of a metronome. Every time the metronome was activated, the dog was presented with food. Eventually, the dog learned to associate the rhythm of the metronome with food and salivated even when no food was presented. • Contingencies form when a animal learns to associate a signal to a specific event. Terminology • Unconditional Stimulus: Naturally/Automatically triggers a response without any learning required. • Unconditional Response: The response that naturally occurs when a unconditional Stimulus is presented. For example, salivating when food is presented is a unconditional response generated by the body. It is Biologically programmed. • Conditional Stimulus: A stimulus usually paired with the unconditional stimulus. At the beginning, the stimulus is neutral and has no effect. However, through learning we learn to associate a conditional response when presented with a conditional stimulus. The conditional response may be similar to the unconditional response. o The conditional Stimulus must be presented before Unconditional stimuli. Repeated trials of training must be preformed where the CS and US are paired before the CS can generate a response on it’s own. • Conditioned Response: A response generated by the Conditional Stimulus. Acquisition • Acquisition is the process by which a contingency between a CS and US is learned. In other words, it is the rate at which a subject learns to associate conditional stimulus with a unconditional stimulus and thus produce a response. • When conditional stimuli is being learned through repeated trials, evidence shows that a significant amount of learning takes place during the first initial trial. Although some learning occurs during the additional trials, it is not as great as what occurred during the initial trial. • Some contingencies can be formed in a single trial. For example, a rat learns to associate a certain food and sickness in a single trial. For the rest of it’s life it will avoid the food. o CS = Taste US = Sickness CR/UR = Aversion o The specific taste of the food is permanently associated with aversion, regardless of whether sickness may occur. Extinction • How long do the effects of a learning trial last? o As long as the Conditional stimuli proves to be a reliable queue to the Unconditional stimuli, the contingency will be maintained. If the Conditional stimuli no longer accurately queues the Unconditional stimuli, the contingency between the two will fade. • Extinction: The loss of the Conditional Response when the Conditional Stimuli no longer accurately predicts the Unconditional stimuli. • If we present the conditioned stimuli multiple times without the presence of the unconditional stimuli, eventually the subject will no longer display a response to the conditioned stimuli. Inhibition • When extinction occurs, the subject does not unlearn the association between the conditioned stimuli and the unconditional stimuli. Rather, a inhibitory response is learned that contradicts with the contingency present between the conditioned/unconditioned stimuli. • After a period of rest, the presentation of a conditioned stimuli will once again trigger a conditional response, proving that the original CS US association is not unlearned. 11-06-03 10:10 PM Generalization and Discrimination • Stimulus Generalization: Stimuli that are similar to the learned conditioned stimulus will also produce a conditioned response. o For example, we may have been bitten by a specific breed of dog and may have learned to associate that breed with the unconditioned stimulus of Dog bite. This means that every time we see that breed of dog, we will produce a response. o However, when we are presented to other breeds of dogs, we will still produce a response even if that breed has never bit us. • The Generalization Gradient o An individual has been conditioned to associate 500hz tone with electrical shock and thus the conditioned response of expecting pain. o As we move away from the 500hz tone either by increasing/decreasing the frequency, we can see that the conditioned response is still present but varying. o Frequencies near the 500hz mark produce a strong response similar conditioned response. Frequencies further away from 500hz produce a weaker conditioned response. o When charting the level of response (y-axis) vs. Frequency tone (x-axis), the highest point is at 500hz and the graph decreases as we move farther away. o Stimulus similar to the conditioned stimulus produce a higher level of conditioned response than those that are not similar. (50hz < 450hz) • Generalization and Extinction o We can diminish the conditioned response to a conditioned stimuli by repeatedly presenting a subject with the conditioned stimulus without presenting the unconditioned stimulus. (For example, present a dog without the dog bite) o When this occurs, the entire Generalized gradient is effected and the strength of the Conditioned response is weakened as a result. (Scared feelings towards dogs weakened) • Discrimination Training o Restricts the range of Conditioned Stimuli that may invoke a Conditioned Response o For example, we may restrict the conditioned response towards a certain breed of dog by continuously showing a picture of it. o Unlike Extinction, the rest of the generalization gradient remains intact. Discrimination just narrows down the conditional stimuli that invoke the conditional response. • CS+ and the CS- o Through discrimination training, we can shape the level of conditioned response generated in a generalized conditioned stimuli. We can completely remove the level of conditioned response towards a certain portion of a generalized stimuli. o CS+ refers to the portion of a generalized conditioned stimuli that predicts the presence of the unconditioned stimuli and produced a response. o CS- refers to the portion of a generalized conditioned stimuli that predicts the absence of the unconditioned stimuli. This is typically the portion which produces zero conditioned response after discrimination training § For example the 500hz (CS+) sound is followed by the unconditional stimulus of shock while the 600hz (CS-) stimuli is followed by nothing. After discrimination testing, the subject will not react to the 600hz stimuli while they will react to all the other generalizations of the conditioned stimuli (ranging from 0hz-580hz) § CS 600hz à US None à UR/CR NONE CS 500hz à US Shock à US/CR Fear of Shock Phobias and Therapies Conditioning and Fear o Phobia: Fear of certain situations, things, activities or people. o Treating of Phobias: Present the conditioned stimulus repeatedly without presenting the unconditioned stimulus. This will fade the conditioned response over time. § For example, present the subject snakes (conditioned stimulus) without the snake bite (unconditioned stimulus) in order prevent Fear or snakes (conditioned response). § This can be difficult as the subject will most likely want to avoid facing their phobia. o Implosive Therapy: subject must confront the phobia in order to suppress conditional response. The conditioned stimulus is presented without the unconditioned stimulus. o Systematic Desensitization: Uses the generalization gradient in order to combat a phobia. § conditioned stimulus that occurs at the far end of the curve are extinguished before moving onto the major stimuli that occur near the middle. § A subject with a fear of dirt might be exposed to paper confetti and other items before being exposed to dirt. Homeostasis and Compensatory Responses • Our body also learns to create conditioned stimuli based on previous experience. • For example, coca-cola increases blood-sugar level which in turn requires insulin to be released. Therefore, the body learns to recognize the sweet taste of cola and produces a conditioned response of releasing insulin automatically, regardless of whether the cola contained sugar or not. • Our body uses Classical conditioning in order to prepare the body for challenges to homeostasis. Addictions • Environmental queues play a role in promoting drug intake. • When drug intake occurs, the body counters the effect of the drug in order to maintain homeostasis. These effects include increase of pain sensitivity and respiration and become the Unconditioned Responses to the drug. • Drug intake usually occurs at a particular period of the day, at a certain location, under a certain mood. The body learns to associate these environmental factors and turns them into a Conditioned Stimuli. • When the subject is present in such environment, the body automatically initiates processes that promote homeostasis, regardless of whether the subject has taken the drug or not. The body has learned that the environment conditions usually result in drug intake and performs homeostatic activities to counter the drug effects. This body has created Conditioned Response. • This is why addicted individuals tend to crave a certain drugs only when present in a certain environment. Their bodies are initiating processes that have the opposite effect of what the drug had. Withdrawal and Environmental Specification • As an individual increases his intake of a drug in a specific familiar environment, his tolerance (CR) towards the drug builds up and the effect of the drug weakens. o Exposure to Drug taking Environment (CS) produced a counter-adaptation effect (CR) which generates desire to take drugs Overdose • Usually occurs when drug users intake a type of drug in a new environment. • When taking drug in a new environment, no conditioned response occurs as the body has no conditioned stimuli. Therefore, only natural unconditioned processes act on the body and no built up tolerance is present. This increases the risk of overdose. 11-06-03 10:10 PM Instrumental Conditioning: Involves explicit training between voluntary behaviour and their consequences. It is not naturally formed contingency unlike the ones found in Classical Conditioning examples. Learning the contingency between behaviour and consequences. Thorndike's Experiment (puzzle box) • Placed cat in a box with a door which could be opened by pulling a string • The cat must open door in order to reach food outside the box (motivator) • The action of pulling on rope must be learned through many attempts • Each attempt, the time it takes vs the number of trials decreases gradually. • Random behaviour that did not lead to escape occurred less and less. • The POSITIVE BEHAVIOUR was motivated, whilst negative was inhibited. • Animals = No consciousness applied to behaviour unlike humans. The Law of Effect Stamped in: -Thorndike experiment, behaviour like rope pulling stamped in - Stamped in behaviour produces a favourable consequence. Stamped Out: - Behaviour that do not produce a favourable consequence. - These behaviour are typically eliminated through learning. - Animal will learn to favour the stamped in behaviour over this. Eventually, the cat will form a contingency between pulling rope and reward. The Law of Effect: - Behaviours with positive consequences will be stamped in - Behaviours with negative consequences will be stamped out. Types of Instrumental Conditioning Four Consequences - Reinforcer: Any stimulus presented after a response. - Positive Reinforcers may promote a certain response. - Negative Reinforcer may inhibit a certain response. - Presenting/Removing positive and negative reinforcer modifies behaviour Reward Training - Presentation of positive reinforcer - Increases a certain behaviour - Presenting puppy with treat every time it sits on command will increase behaviour Punishment - Presentation of a Negative reinforcer - Leads to a decrease in behaviour - Punishment by parents decreases unwanted behaviour - Controversial due to ethical implications - B.F. Skinner: When punishment is used, authority figure may become signal for pain. Omission Training - Removing a positive reinforcer - Decrease in a certain behaviour as a response - Removing positive reinforcer is a situation a person wants to avoid - Example. Time out in kindergarten. All the other kids can play but you can't. Escape Training - Removal of negative reinforcer - Constant negative reinforcer presented that the learner wants to remove. - Increase in the Target Behaviour. The response must be presented soon after the behaviour is performed. If the response is presented later, contingency may not form between behaviour and response may not form. Acquisition and Shaping - Contingencies: Learns between a stimulus and a biologically important event - instrumental: Contingency between a response and consequences. Graphing Responses - Response rate for a new behaviour. - Accumulive Recorder --> Like a lie detector - Graphing responses: X-axis (time), Y-axis ( # of Responses per Trial) Autoshaping - The subject learned the contingency between behaviour and response by itself. - Example: Pigeon will learn to peck keyhole in order to get a grain of seed. - Behaviour and Response learned without explicit training by researcher Shaping - Complex behaviour and responses cannot be effectively auto- learned. - Shaping takes a complex behaviour, splits it into components and then through reward training builds up to the final complex behaviour - B.F. Skinner --> Pigeons playing ping 11-06-03 10:10 PM Generalization and Discrimination The discriminative Stimulus o The discriminative stimulus tells the subject when a certain contingency is present between a response and it’s reinforcement. o For example, a particular environment or person may signal the activation of a certain behaviour in order to receive a particular response. The Discriminate stimulus is the environment/person. o S-Delta is a queue that indicates when a contingency between the conditioned stimulus and response is not valid to obtain a reinforcement. o Unlike a conditioned stimulus, which autonomously produces a conditioned response through reflex, the discriminative stimulus simply sets the occasion when a response is valid and likely to generate a positive reinforcement. The response is typically voluntary by the subject. Generalization o Like in classical conditioning, the subject may react to stimulus that is similar to the discriminative stimulus. o The closer in resemblance the discriminative stimulus is, the higher the rate of response. The further the resemblance of discriminative stimulus, the lower the rate of response. o In the presence of adults that resemble a child’s parents, the child may behave more politely in order to get praise. § Adults: Discriminative stimulus § Politeness: Response § Praise: Reinforcement Discrimination and Extinction o Discriminative Stimulus Extinction § If the Discriminative stimulus is present and generates a response but, the response does not generate a positive reinforcement, the subject will unlearn the contingency between a DS and a response and will not display a certain behaviour. o Generalization Extinction § Stimulus that appear to be similar to the Discriminative stimulus do not present positive reinforcement to a generated response in behaviour. Eventually the subject will learn to disassociate the generalized stimulus and not perform a particular response. § The response will only be generated in this case when the exact Discriminative stimulus is present. SD and S-Delta o Experiments conducted with S-Delta and SD produce more effective results that can be analyzed by a generalization gradient. Schedules of Reinforcement o Continuous vs. Partial Reinforcement § Continuous reinforcement occurs when a response leads to a reinforcement on every single occasion. This is generally rare in the real world. § Partial Reinforcement schedule is one where a particular response does not always initiate a reinforcement. o Fixed Ratio vs. Interval Partial Reinforcement § Ratio Responses: reinforcement given based on the number of trials made by the subject. ú FR1 Reinforcement = each response initiates a th reinforcement. FR10 = every 10 response initiates a reinforcement. § Interval Time: This type of schedule presents the subject with a reinforcement after a certain set period of time since the last response was reinforced. ú FR1minute = reinforcement after every response initiated after 1 minute period. FR10minute = reinforcement after 10 minute response. o Fixed Constant vs. Variable § Random Reinforcement based on some sort of a mean. § For example, on a VI10 schedule, although the time when reinforcement is given are random, the average time between response and reinforcement will be 10 minutes. o Fixed Ratio § A schedule with a very high FR may result in a loss of response § Cumulative Record: Time (x-axis), # of responses per trial (y-axis) § Following reinforcement, a subject will pause with inactivity before once again responding. § The pause with inactivity may be a result of the subject lacking motivation to performing a response. o Variable Ratio § Reinforcements are made on a random response basis around a average figure. § The Lower the Variable ratio, the higher the rate of response and thus the larger the slope between # of responses and Time. o Variable Interval § Reinforcement is delivered on a random time basis around a average figure. § For example, a machine may have a VI of 10. This means that the average of all the responses by a subject in which reinforcement was present must equal to 10. Extinction and Schedule • Partial reinforced behaviour is less prone to extinction than continuous reinforced behaviour. • When continuous reinforcement stops, the subject immediately realizes of this abrupt change and will decrease responding • In a partial reinforcement schedule, abrupt changes take a while for a subject to realize. • Partial Reinforcement better option if we want a behaviour to be maintained. 11-06-03 10:10 PM Introduction to Memory • Thoughts, representations, mental processes make up cognition • Cognitive factors provide qualities which allow humans to be classified as humans. • What is memory? o The fundamental process which allows us to store and recall information. o Memory is a result of complex processes. • Common Memory Metaphors o NOT ACCURATE REPRESENTATIONS OF HUMAN MEMORY. They can be misleading in various ways. § Video Camera ú Memory may be classified using a video-camera analogy. We store information in a medium and replay it at a later moment in time ú Accurately preserves moments to be played back at a later time § Filing Cabinet ú We store information and organize it to be accessed at a later time. § Computer Metaphor of memory ú RAM (Random Access Memory) = Short term memory ú Hard Disk = Long term memory ú Specialized components responsible for handling memory at different times. • Problems with memory Metaphors o Video Camera § The memory captured through the video camera remains the same. This type of memory does not change and is Vivid and accurate despite the amount of time in past. § Human memory is varying and certain moments may become vague or disappear entirely. Also, memories may vary depending on the interpretation made by individuals and personal details. Studying memory through scientific means • The Questions we must ask: o How does memory acquisition function? o How are we able to store memory? o How are we able to retrieve memory from the system? • The importance of Cues o We can navigate through the vast array of memory stored in our brain with relative effortlessness. o Environmental cues, social cues and other factors may spark the recall of a particular memory. § For example, during conversations we recall various moments that may be buried deep in the mind. In this case, one memory acts as a cue to trigger another memory. o Early memory interpreters of memory relied on the Behaviorist theory in order to test memory functions. These individuals nevertheless studied the relationship between cues and encoding and retrieval mechanisms. • Hermann Ebbinghaus o Memory is a serial learning task. o Each word in a word list served as a cue to trigger the recall of the consequent word which followed. Each word in a list connected to a word before and after it. o The experiment: § Exposed himself to a list of random words with no meanings. During the encoding phase he tried to memorize the words. During the recall phase he tried to recall the list of words. § Used nonsense words to minimize the affect of learning the words due to prior experiences and other factors. § How long could memories be maintained? ú Number of remembered words plotted against a time graph. ú Highest # of words at beginning, fewer and fewer words near the end. The forgetting curve. Testing memory theories using scientific models • Cognitive models are generated in order to explain complex functions like memory. • Models organize and describe data and make testable predictions that can be studied in the controlled settings of the lab. • Phases of cognitive model o Encoding phase § A subject is exposed to a list of items, words, pictures. The control group is distracted while exposed to this list. The test group is focused and is told to learn the list of words. o Retrieval phase § Subjects asked to recall the presented information from the encoding phase. o Recall test § Subject asked to freely recall as many items of the list as they could remember. o Recognition test § Ask the subject to identify whether the item is new and not presented in the encoding phase, or whether it was old and presented during the encoding phase. o Both the Recall and Recognition methods test the ability to remember items from the encoding phase Popular memory models • The multi-store model o Memory is composed of short and long-term storage systems o New information is initially stored in a short term memory buffer (similar to RAM in computer). o The long term memory system can store memories transferred from the short term buffer (Similar to transfer of data from RAM to Hard disk Log files). o Rehearsal may influence memory transfer from short-tem to long-term. • George Miller o Short term memory has typical capacity of 7 +- 2 items. § This is why phone numbers are 7 digits long! o Short term memory fades as soon as rehearsal of info stops. o Chunking § We may be override the capacity of 7+-2 items by reorganizing information into meaningful packets or “chunks.” § For example, letter groupings that form words pack a large amount of information without straining short- term memory • Models have a strong ability to make testable predictions about how memory functions. • If short term and long term memory are distinct, we should be able to manipulate variables and observe the effect produced on each system The Serial Position Curve • When a recall test is performed, a common trend shows that memory performance is better for items early and later in the list. • Primacy o Memory performance is good for items encoded earlier in the list. o In relation to Multi-store model, the items at the beginning of the list have most opportunity to be rehearsed. These items may have the best potential to enter long-term memory and be permanently stored. § This can explain why memory performance for these items is stellar. o Items at the middle of the list have less opportunity for rehearsal. Items at the end of the list are the most recent and are present in the current short term memory. This can explain why their recall rate is high. • Recency effect o Last 7 items remain in the short-term memory. This results in their performance. • Improving Primacy o If the primacy effect depends on our ability to rehearse, then we should see a change in the primacy effect by influencing this ability. o For example, the primacy effect should change depending on the interval of time given to practice the list of words. Reducing the amount of time given to memorize a list of words would decrease the rehearsal level and reduce primacy. • Diminishing Recency o Disruption after the encoding stage should effect the recency significantly. Disruptions would affect the content of the short term memory storage. Levels of Processing • The levels at which items are encoded has a direct effect on the ability to recall them. o Shallow Level § Items encoded at this level require little effort and is often directed at the physical characteristics of a stimulus. ú Is the word capitalized? § Memory performance is poor o Deeper Level § More effort given in order to memorize the item. A great deal of semantic (meaning based characteristics). ú Does this word fit into the sentence, I walked my ______? § Memory performance is much better. • Levels of processing principle o The more we try to understand and organize material, the better we remember it. Storage and Retrieval related • Memories in reality are not simple lists of items but are richly detailed and in context with the world around us. • Environmental cues are incorporated in addition to learned items. Encoding specificity • Memory encodes all aspects of specific experiences • For example, when we encode a word in a memory experiment, we encode various aspects such as: o The properties of the room o The chair that you’re sitting on o The font-type • When recalling a item in the future, the items mentioned above can act as cues. Loftus and False Memories (Tricking people into believing memory) • Elizabeth Loftus and false memories experiments o Subjects presented to 4 experiences. 3 were real whilst the fourth was fake. § The fake memory was made up by the experimenter and was described in great detail. o On the first interview, all subjects identified fake experience as fake. o By the third interview however, the fake experience was classified as real by over 20% of the subjects. o Shows that MEMORY IS HIGHLY CONSTRUCTIVE. • False memory implantations (Bizarre fake memories) o Could people be tricked into believing a bizarre and fake memory? o Repeatedly imagining à False memory generation o Memory can be tricked into believing bizarre events. Memory and it’s flaws (Attributive view of Memory) • Memory is a Reconstructive process • Memory is a open interpretation of a event altered suggestions Fluency • The ease with which a experience is processed • Familiar processes are processed more fluently than non-familiar processes. • A sense of familiarity increases fluency and the ease by which we may recall an event. Attribution • Ties together causes with effects. Fluency must be present in order to create a attribution. Memory Illusions (modification of attribution of fluency and effect on memory) • Being Famous Overnight o Individuals were made to read a list of names. Next, the individuals waited 24 hours and were told to identify famous names from a new list presented. o The individuals interpreted the names from the list before and interpreted them famous names. Group A, which did not have the delay did not do this. o False Fame Effect: § Old fictional names create a processing fluency. § Immediate test group do not produce fluency associated with names presented. Overnight test group developed a fluency for the names. Memories are not necessarily something we store and recall in a system, memories are reconstructed upon demand. We actively construct memories. • The memory system is a pile of basic building blocks • Memory system able to construct experiences that may have not occurred 11-06-03 10:10 PM Introduction to attention • Attention allows one to navigate through a world filled with information. • Without being able to focus a limited amount of our resources, we would not be able to perform simple tasks such as converse with others, enjoy a piece of music, understand a joke or learn new things. Attention • We need to identify what Attention is, Build a cognitive model which we can use to test our theories, and explain the hypothesis • Unfortunately, Attention covers a area of a wide range of topics. We cannot simply generate one theory or hypothesis in order to explain it. NO SINGLE DEFINITION FOR ATTENTION. • Our conscious ability to attend to something that is relative to our goals. • William James o Attention implies withdrawal from some things in order to deal effectively with others. Selection • Attending something (focusing) causes the object tot be inattentive to other objects in the surrounding. • We may be attentive of something at first but may become inattentive if more important stimuli are present during a time. • Some stimuli have a stronger grasp towards our attention than others do. • Irrelevant background information makes it increasingly difficult to attend and identify the important information. o We usually turn radio down when we are driving and need to make important decisions. The radio creates a background noise that needs to be minimized. Automatic and Controlled Attention Automatic process o Involuntary attention o Something that automatically grasps your attention. o Fast, efficient manner and grab attention o Some ques are more noticeable and lead to stronger and quicker association when paired with events. § SALIENT information is anything that naturally pops out at us. o Autonomic processes influenced by learning. For example, we learn to drive a car almost autonomously and regulate various different functions (clutch, accelerator, brake) without specifically attending to them. • Controlled process o Conscious attention o We may decide whether to pay attention to or ignore. Usually slow due to more cognitive effort required. The spotlight model • Our attention spotlight focuses on only part of the environment at a time. • Attention can be directed across a visual scene. This occurs when we are looking for a particular person in a crowd of people. Spatial Cueing Paradigm • Three squares present on the screen. • One of these squares is highlighted. Shortly after, one of the three squares is filled in. • Researchers found that when the highlighted square is the one which is also filled in, the response time is faster than when the highlighted square differs from the square that was filled in. • The highlighted box is quick due to it’s use of automatic process. The Consciously controlled is slower. • THE QUE AUTOMATICALLY ATTRACTS SPOTLIGHT to the location. If the target is displayed in the que, the perception is amplified and the response is quick. If the target appears in the unqued location, the target is acquired more slowly because the attention spotlight was towards the automatic location. • Attention moves faster than the eye. We may be attentive towards something even before we see it. Filter Models • At situations such as parties, there may be a lot of background noise competing for attention. Despite this, we are able to single out a specific noise to focus our attention towards. • Collin Sherry: cocktail party effect o Subjects exposed to 2 speakers, both producing a different message o Subjects told to focus on one message over the other. o Gender, pitch of speech and various other factors effect ability to filter. Difference between Filter and spotlight model • The Filter model assumes that we tune out everything besides the object of focus. • The spotlight model suggests that the point of focus is enhanced and thus our focus is leans toward that point. Broadbent’s single filter model • The attention filter selects sensory information on the characteristics of physical basis. • This information is further processed. • Information that does not pass through the initial filter is irrelevant and is completely voided from further analysis. • Broadbent’s test: o Dual speakers, each displaying a different message. o Subject told to focus to message being relayed by only one of the speakers. o The subject has no problem recalling data from the ear which was attentive. o Subject seems to completely ignore the message from the opposite ear. o According to Broadbent, the attentive ear is the only one which allows information to enter and undergo deeper processing. The information from the inattentive ear is discarded. • Von Wright. o A stimulus was presented each time a certain word was relayed during a conditoning paradigm. o When the word was presented in the unattended ear after conditioning, a response was generated. This showed that the information from the unconditioned ear was also processed. o Some information about sound and meaning is able to pass through the initial filter. Triesman’s Dual Filter Model • In contrast to Broadbent’s test, the Triesman’s model proposes two filters, one filters physical things, whilst the other filters Symantic things. • Information first passes through physical filter • Semantic filter evaluates information for meaning. What is the deeper meaning and relevance of the stimuli? Shadowing Paradigm: • Participant receives an input in one ear completely opposite to the input received in the other ear. The Stroop Task: • Subjects presented to a colored word and asked to name the color
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