Introduction to Cognitive Psychology Chapter 1 PDF

Introduction to Cognitive Psychology Chapter 1 1  The Complexity of Cognition Cognition involves Perception Paying attention Remembering Identifying the category of objects Understanding and producing language Problem solving...

Introduction to Cognitive Psychology Chapter 1 1  The Complexity of Cognition Cognition involves Perception Paying attention Remembering Identifying the category of objects Understanding and producing language Problem solving Decision-making Although we perform these mental activities every day We are unaware of how we accomplish them Often, we are unaware that we are even doing them Psyc 2360 Cognition 2  Early History of Cognitive Psychology Psyc 2360 Cognition 3 The First Cognitive Psychologists Donders (1868) asked a simple question: “How long does it take to make a decision?” Psyc 2360 Cognition 4  Mental Chronometry Mental Chronometry: Measuring how long a cognitive process takes Reaction-time (RT): The interval between stimulus presentation and person’s response to the stimulus Psyc 2360 Cognition 5  Donders (1868) Simple RT task: e.g., participant pushes a button quickly after a light appears Choice RT task: e.g., participant pushes one button if light is on right side, another if light is on left side Psyc 2360 Cognition 6  Donders (1868) A modern version of Donders’ (1868) reaction-time experiment: (a) the simple reaction-time task; and (b) the choice reaction-time task. Psyc 2360 Cognition 7 Psyc 2360 Cognition 8  Determining Decision Time Time to make a decision = Choice RT – Simple RT Choice RT = ~1/10th sec longer than Simple RT Donders concluded that it took 1/10th sec to make the location decision Although mental processes cannot be measured directly, Donders demonstrated that some aspects of these processes can be inferred from the participant’s behaviour Psyc 2360 Cognition 9  Touch Simple RT Task: Squeeze T1 + T2 + T3 + T4 + T5 = RTs Brain Brain Motor Muscles Sensory Perceives Send Signal Signal to Contract Signal Touch To Squeeze Muscles Hand Psyc 2360 Cognition 10  Touch Choice RT Task: Squeeze T1 + T2 + Td + T3 + T4 + T5 = RTch Brain Brain Brain Motor Muscles Sensory Decides Sends Signal Perceives Signal to Contract Signal Which hand To Squeeze Touch Muscles To Squeeze Hand Psyc 2360 Cognition 11  T1 + T2 + T3 + T4 + T5 = RTs Brain Brain Motor Muscles Sensory Perceives Send Signal Signal to Contract Signal Touch To Squeeze Muscles Hand T1 + T2 + Td + T3 + T4 + T5 = RTch Brain Brain Brain Motor Muscles Sensory Decides Sends Signal Perceives Signal to Contract Signal Which hand To Squeeze Touch Muscles To Squeeze Hand Td = RTch - RTs Psyc 2360 Cognition 12  Touch Simple RT Task 2: Simple RT Task 1: Touch Squeeze Squeeze T1 + T2 + T3 + T4 + T5 = RTs Brain Brain Motor Muscles Sensory Perceives Send Signal Signal to Contract Signal Touch To Squeeze Muscles Hand Psyc 2360 Cognition 13  Touch 1 Time for action potential to travel From site of Touch 2 to Touch: Touch 2 RTsensory2->1 = RT1 – RT2 Squeeze Speed of sensory action potential: Speed = (RTsensory2->1) Distance from 2 to 1 Psyc 2360 Cognition 14 Ebbinghaus Ebbinghaus conducted the first scientific studies of memory. He asked: “What is the effect of practice on learning?” “What is the time-course of forgetting?” Psyc 2360 Cognition 15  Ebbinghaus (1885) Read list of nonsense syllables aloud many times to determine number of repetitions necessary to repeat list without errors Tested his ability to accurately reproduce the list Psyc 2360 Cognition 16 Ebbinghaus (1885) Psyc 2360 Cognition 17  Ebbinghaus (1885) After some time, he relearned the list Short intervals = fewer repetitions to relearn Learned many different lists at many different retention intervals (time between learning sessions) Psyc 2360 Cognition 18  Ebbinghaus (1885) Savings = (initial repetitions) – (relearning repetitions) The stronger the memory the less repetitions are required to relearn the list (the greater the savings) Psyc 2360 Cognition 19  Ebbinghaus’s (1885) forgetting curve. Savings as a function of retention interval Psyc 2360 Cognition 20  Wundt (1879): The First Psychological Laboratory Psyc 2360 Cognition 21  Wundt's Approach to Psychological Research Structuralism: Conscious experience is determined by combining elements of experience called sensations Aimed to identify basic elements and create a “periodic table of the mind” Psyc 2360 Cognition 22 Wundt's Approach to Psychological Research Methods: Objective measures (RT, accuracy, & many other) Analytic introspection: participants trained to describe experiences and thought processes in response to stimuli Psyc 2360 Cognition 23  Problems with Introspection Many scientists and philosophers had noted important problems with introspection Primarily: Introspection provided extremely variable results from person to person Results difficult to verify Inner mental processes are not directly observable Whose results should be believed? Psyc 2360 Cognition 24  Behaviourism: Abandoning the Mind Psyc 2360 Cognition 25  John Watson: The Rise of Behaviourism Dissatisfied with the limitations of introspection and the poorly defined mental concepts used by psychologist, John Watson proposed a new approach called Behaviourism. Psyc 2360 Cognition 26  The Rise of Behaviourism Behaviourism: Rejected introspection as a valid technique Studied directly observable behaviour Also rejected the mind as a topic of study Rejected all concepts relating to internal mental processes because they could not be directly observed Psyc 2360 Cognition 27  Watson's Research Approach Watson's research was inspired by the discovery of Classical Conditioning by Ivan Pavlov. Pavlov’s famous experiment paired ringing a bell with presentation of food. Initially, only presentation of the food caused the dog to salivate, but after a number of pairings of bell and food, the bell alone caused salivation. Psyc 2360 Cognition 28  Classical Conditioning Pair a neutral event with an event that naturally produces some response After many pairings, the “neutral” event now also produces the outcome The organism has learned that there is an association between the events Psyc 2360 Cognition 29  Watson & Rayner (1920) “Little Albert” Experiment Demonstrated Classical Conditioning of fear in a human 9-month-old became frightened by a rat after a loud noise was paired with every presentation of the rat Psyc 2360 Cognition 30  “Little Albert” Experiment According to Watson this experiment demonstrated: Behaviour can be analyzed, predicted and understood without any reference to the mind A scientific psychology only needs to measure responses and control stimuli Psyc 2360 Cognition 31  Behaviourism's Peak B. F. Skinner greatly expanded Behaviourist research by investigating: Operant Conditioning: The relationship between behaviours and their consequence Psyc 2360 Cognition 32  Behaviourism's Peak Skinner was interested in behavioural control Shaped behaviour by rewards or punishments Measured changes in behaviour in response to rewards and punishments Behaviour that is rewarded is more likely to be repeated Behaviour that is punished is less likely to be repeated Psyc 2360 Cognition 33 Skinner Interview (4 min) Psyc 2360 Cognition 34 Psyc 2360 Cognition 35  The Decline of Behaviourism Many factors lead to the decline of behaviourism that started in the 1950s Including: Evidence that internal mental states guide behaviour A controversy over language acquisition Demonstrations of the limitations of behaviourist learning principles and behavioural control Psyc 2360 Cognition 36 Latent Learning: Learning without Conditioning Tolman (1938) investigated maze learning in rats Allowed rats to “explore” the maze Did not provide direct reward of specific behaviours Psyc 2360 Cognition 37  Tolman (1938) (a) rat initially explores the maze (b) learns to turn right to obtain food at B when it starts at A In this experiment, precautions are taken to prevent the rat from knowing where the food is based on cues such as smell. Psyc 2360 Cognition 38  Tolman (1938) Two competing interpretations: Behaviourism predicts that the rats learned to “turn right to find food” Tolman believed that the rats had created a cognitive map of the maze and were navigating to a specific arm Psyc 2360 Cognition 39  Tolman (1938) What happens when the rats are placed in a different arm of the maze? The rats navigated to the specific arm where they previously found food Supported Tolman’s interpretation Psyc 2360 Cognition 40  Tolman (1938) Behaviourist learning principles fail to provide a parsimonious explanation for the behaviour of the rats In order to explain the results Tolman proposed the rats had learned the spatial layout of the maze (a “mental map”) In other words, they relied on an unseen internal mental representation of the maze Psyc 2360 Cognition 41 A Controversy Over Language Acquisition Skinner (1957) argued children learn language through operant conditioning Children imitate speech they hear Correct speech is rewarded Psyc 2360 Cognition 42 A Controversy Over Language Acquisition However: Children say things that are incorrect and have not been rewarded for (e.g., bringed instead of brought) Children say things they have never heard and can not be imitating Chomsky (1959) argued: Children do not only learn language through imitation and reinforcement Concluded language development must be determined by an inborn biological program Psyc 2360 Cognition 43  Limitations of Operant Conditioning “The misbehavior of organisms” (Breland & Breland, 1961) Operant condition does not always succeed: Animals drift towards their biologically predisposed instinctive behaviours. Biological constraints predispose organisms to learn associations that are naturally adaptive. Psyc 2360 Cognition 44 Cognitive Revolution: Return of the Mind Psyc 2360 Cognition 45  Return of the “Mind” Most psychologists now believe that in order to understand complex cognitive behaviours we must: Measure observable behaviour Make inferences about underlying cognitive activity Inferences are tested by generating testable predictions Inferences that fail to provide accurate predictions are rejected This transformation of psychology is now referred to as the “Cognitive Revolution” Psyc 2360 Cognition 46  The Cognitive Revolution: Major Milestones Conferences in Artificial Intelligence (1956) Evidence that computers can process information in a seemingly human like manner Newell and Simon created the logic theorist program that could apply rudimentary logic to creating mathematical theorems Ulrich Neisser (1967) coins the term “cognitive psychology” Psyc 2360 Cognition 47 Information Processing Approach Information Processing Approach describes mental processes in terms of the storage, transfer and manipulation of information. Inspired by advances in computer technology in the 1950s Psyc 2360 Cognition 48  Information There are many technical definitions of information: Information is any type of pattern (interconnections between neurons, state of transistors in a microchip) that influences the formation or transformation of other patterns. Information cannot be touched or seen. However, it can have observable effects. Psyc 2360 Cognition 49  Information Processing Models Information processing models (AKA Process models) are functional models. They provide explanations in terms of theoretical processes, they don't specify how these processes are implemented in the brain. Information processing models are often depicted using Flow Diagrams. Psyc 2360 Cognition 50 Flow Diagrams (AKA Box & Arrow Diagrams) Inspired by diagrams describing computer designs Boxes: functional units that process &/or store information Arrows: connections that transfer information Psyc 2360 Cognition 51 Early Information Processing Model an Example: Auditory Attention Dichotic listening (Cherry, 1953) One message in each ear Attend and Shadow (repeat) one message Participants were: Able to shadow the attended message without interference from the other message Unable to remember information in the unattended message Psyc 2360 Cognition 52 Early Information Processing Model an Example: Auditory Attention Broadbent's Filter Model (1958): Early theory that attempted to explain Cherry's data Flow diagram represents the flow of information from the senses Unattended information does not pass through the filter Psyc 2360 Cognition 53  Structural Models Structural Models: Representation of the physical structure of the brain Represent the structures involved in the function we are attempting to understand Different structures are associated with different components of the function Psyc 2360 Cognition 54 Psyc 2360 Cognition 55  The Value of Models Models are an important part of theory development Integrated the findings from many experiments Provide a framework for understanding the complex systems of the mind by providing simplified systems that attempt to describe the major processes involved Aid in the formulation of new hypotheses for future research Psyc 2360 Cognition 56