Chapter 1 Introduction to Cognitive Psychology The Complexity

Chapter 1 Introduction to Cognitive Psychology

The Complexity of Cognition • Cognition involves – – – – Perception Attention Memory Representation of knowledge Language Problem-solving Reasoning and decision-making • All include “hidden” processes of which we may not be aware

Some Questions to Consider • How is cognitive psychology relevant to • • • everyday experience? Are there practical applications of cognitive psychology? How is it possible to study the inner workings of the mind when we can’t really see the mind directly? What is the connection between computers and the study of the mind?

The First Cognitive Psychologists • Donders (1868) – Mental chronometry • Measuring how long a cognitive process takes – Reaction-time (RT) experiment • Measures interval between stimulus presentation and person’s response to stimulus

The First Cognitive Psychologists • Donders (1868) – Simple RT task: participant pushes a button quickly after a light appears – Choice RT task: participant pushes one button if light is on right side, another if light is on left side

Caption: A modern version of Donders’ (1868) reaction-time experiment: (a) the simple reaction-time task; and (b) the choice reaction-time task.

The First Cognitive Psychologists • Donders (1868) – Choice RT – Simple RT = Time to make a decision • Choice RT = 1/10 th sec longer than Simple RT • 1/10 th sec to make decision

The First Cognitive Psychologists • Donders (1868) – Mental responses cannot be measured directly but can be inferred from the participant’s behavior

The First Cognitive Psychologists • Helmholtz (~1860 s) – Unconscious inference • Some of our perceptions are the result of unconscious assumptions we make about the environment – We infer much of what we know about the world

The First Cognitive Psychologists • Ebbinghaus (1885) – Read list of nonsense syllables aloud many times to determine number of repetitions necessary to repeat list without errors

The First Cognitive Psychologists • Ebbinghaus (1885) – After some time, he relearned the list • Short intervals = fewer repetitions to relearn – Learned many different lists at many different retention intervals

The First Cognitive Psychologists • Ebbinghaus (1885) – Savings = [(initial repetitions) – (relearning repetitions)] / (initial repetitions) – Forgetting curve shows savings as a function of retention interval

Caption: Ebbinghaus’s retention curve, determined by the method of savings. (Based on data from Ebbinghaus, 1885. )

The First Cognitive Psychologists • Wundt (1897) – First psychology laboratory – University of Leipzig, Germany – RT experiments

The First Cognitive Psychologists • Wundt (1897) – Approach Structuralism: experience is determined by combining elements of experience called sensations – Method Analytic introspection: participants trained to describe experiences and thought processes in response to stimuli

The First Cognitive Psychologists • John Watson noted two problems with this: – Extremely variable results from person to person – Results difficult to verify • Invisible inner mental processes

The Rise of Behaviorism • John Watson proposed a new approach called behaviorism – Eliminate the mind as a topic of study – Instead, study directly observable behavior

The Rise of Behaviorism • Watson (1920) – “Little Albert” experiment – Classical conditioning of fear – 9 -month-old became frightened by a rat after a loud noise was paired with every presentation of the rat

Classical Conditioning • Pair a neutral event with an event that • naturally produces some outcome After many pairings, the “neutral” event now also produces the outcome

Pavlov’s Discovery: Classical Conditioning Caption: 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. This principle of learning by pairing, which came to be called classical conditioning, was the basis of Watson’s “Little Albert” experiment.

The Rise of Behaviorism • Watson (1920) – “Little Albert” experiment – Behavior can be analyzed without any reference to the mind – Examined how pairing one stimulus with another affected behavior

The Rise of Behaviorism • Skinner (1950 s) – Interested in determining the relationship between stimuli and response – Operant conditioning • Shape behavior by rewards or punishments • Behavior that is rewarded is more likely to be repeated • Behavior that is punished is less likely to be repeated

Caption: Timeline showing early experiments studying the mind in the 1800 s and events associated with the rise of behaviorism in the 1900 s

The Decline of Behaviorism • A controversy over language acquisition • Skinner (1957) – Argued children learn language through operant conditioning • Children imitate speech they hear • Correct speech is rewarded

The Decline of Behaviorism • Chomsky (1959) – Argued children do not only learn language through imitation and reinforcement • Children say things they have never heard and can not be imitating • Children say things that are incorrect and have not been rewarded for – Language must be determined by inborn biological program

The Decline of Behaviorism • The Misbehavior of Organisms (1961) – Attempts to condition animal behavior did not work – Animals’ built-in instincts prevailed

The Decline of Behaviorism • Tolman (1938) trained rats to find food in a • four-armed maze Two competing interpretations: – Behaviorism 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

The Decline of Behaviorism • 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 – Did not support behaviorism interpretation

Caption: Maze used by Tolman. (a) Rat initially explores the maze; (b) then learns to turn right to obtain food at B when it starts at A; (c) when placed at C, the rat turns left to reach the food at B. In this experiment, precautions are taken to prevent the rat from knowing where the food is based on cues such as smell.

Studying the Mind • To understand complex cognitive behaviors: – Measure observable behavior – Make inferences about underlying cognitive activity – Consider what this behavior says about how the mind works

The Cognitive Revolution • Shift from behaviorist’s stimulus-response relationships to an approach that attempts to explain behavior in terms of the mind

The Cognitive Revolution • Information-processing approach – A way to study the mind created from insights associated with the digital computer

Caption: (a) Flow diagram for an early computer. (b) Flow diagram for Broadbent’s filter model of attention.

The Cognitive Revolution • Early computers (1950 s) – Processed information in stages • How much information can the mind absorb? • Attend to just some of the incoming information?

The Cognitive Revolution • Cherry (1953) • Dichotic listening – Present message A in left ear – Present message B in right ear – To ensure attention, shadow one message • Participants were able to focus only on the message they were shadowing

The Cognitive Revolution • Broadbent (1958) – Flow diagram representing what happens as a person directs attention to one stimulus – Unattended information does not pass through the filter

FIG 1. 12 Caption: Timeline showing events associated with the decline of the influence of behaviorism (above the line) and events that led to the development of the information-processing approach to cognitive psychology (below the line).

Researching the Mind • Behavior approach measures relationship between stimuli and behavior • Physiological approach measures relationship between physiology and behavior • Both contribute to our understanding of cognition

Researching the Mind – Memory Consolidation • Memory for recent events is fragile • If processing is disrupted, recent memories • can fail to be consolidated New information can interfere with memory consolidation

Researching the Mind – Memory Consolidation • Behavior approach • Muller and Pilzecker (1900) had participants learn two lists of words – Independent variable: • One group learned the second list immediately after the first list • The other group experienced a six-minute delay between learning the lists – Dependent variable: • Memory (recall) for the first list of words

Researching the Mind – Memory Consolidation • Behavior Approach • Gais et al. (2007) the effect of sleep on memory consolidation – Independent variable: • One group learned a list of words shortly before going to sleep • The other group, many hours before going to sleep – Dependent variable: • Memory (forgetting) for the list of words measured two days later

Caption: Results of the Gais et al. (2007) experiment in which memory for word pairs was tested for two groups. The sleep group went to sleep shortly after learning a list of word pairs. The awake group stayed awake for quite a while after learning the word pairs. Both groups did get to sleep before testing, so they were equally rested before being tested, but the performance of the sleep group was better.

Researching the Mind – Memory Consolidation • Physiological approach • Gais et al. (2007) the effect of sleep on • memory consolidation – Brain activity at encoding and retrieval – Measured using brain imaging (f. MRI) Results – Found differential brain activity between the two groups

Cognitive Science • Interdisciplinary study of the mind • – Psychology – Computer science – Cognitive anthropology – Linguistics – Neuroscience – Philosophy Goal: finding ways to study and understand the inner workings of the mind