Chapter 1
Introduction to Cognitive Psychology
The Complexity of Cognition
Cognition involves
Perception
Paying attention
Remembering
Distinguishing items in a category
Visualizing
Understanding and production of language
Problem solving
Reasoning and decision-making
All include “hidden” processes of which we may not be aware
The Complexity of Cognition
Cognitive Psychology
The branch of psychology concerned with the scientific study of the mind
Cognition refers to the mental processes, such as perception, attention, and memory, that are what the mind does
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?
How are models used in cognitive psychology?
History of Psychology
Plato (424 – 327 BC)
Greek philosopher who took a rationalist approach to knowledge.
Believed that the route to knowledge was through logical analysis, instrospection and contemplation
Look up, not out for answers
Aristotle (384-322 BC)
Plato’s student who took the empirical approach to knowledge.
Believed that the truth is uncovered only through experience and by careful observation of the external world
Look out, not up for answers
Plato on left, Aristotle on right
Psychology in the Middle Ages
Body is a machine.
Rene Descartes (1596-1650)
Invented analytic geometry.
First to contribute to the science of psychology.
“I think therefore I am”.
Interactive dualism
The mind and body are independent but interact through the pineal gland.
Body is material (involuntary); mind is immaterial (voluntary)
Ideas are innate. Humans are born with instincts.
History of Psychology
Nature vs. Nurture
Heredity vs. Environment
John Locke (1632-1704)
Rejected notion that ideas are innate.
Mind is a tabula rasa.
Immanuel Kant (1724-1804)
We may not be blank slates but we also do not come into the world fully prepared.
History of Psychology
Psychology today is or strives to be a synthesis of the two approaches
without theories, hypotheses, and ideas – what do we do with our empirical observations (data)?
conversely, we can’t just rely on inference, conjecture, or what we think about the way things are – we need empirical observations (data)!
The First Cognitive Psychologists
Donders (1868)
How long does it take for a person to make a decision?
Reaction-time (RT) experiment
Measures interval between stimulus presentation and person’s response to stimulus
The First Cognitive Psychologists
Donders (1868)
Simple RT task:
When you see a light appear, press the button.
Choice RT task:
When you see a light on the left side appear, push the left button.
When you see a light on the right side appear, push the right button.
Reaction time is how fast the participant pressed the button after the light came on.
The First Cognitive Psychologists
*
● FIGURE 1.2 A modern version of Donders’ (1868) reaction time experiment: (a) the
simple reaction time task; and (b) the choice reaction time task. In the simple reaction time
task, the participant pushes the J key when the light goes on. In the choice reaction time
task, the participant pushes the J key if the left light goes on and the K key if the right light
goes on. The purpose of Donders’ experiment was to determine
The First Cognitive Psychologists
*
The First Cognitive Psychologists
Donders (1868)
How long does it take to make a decision?
Choice RT – Simple RT = Time to make a decision
Choice RT = 1/10th sec longer than Simple RT
1/10th sec to make decision
Mental responses cannot be measured directly but can be inferred from the participant’s behavior
The First Cognitive Psychologists
Wundt (1897)
Founded the first psychology laboratory
University of Leipzig, Germany
Also did Reaction Time experiments
The First Cognitive Psychologists
Wundt (1897)
Approach
Structuralism: experience is determined by combining elements of experience called sensations
Our experience of things includes it’s color, taste, structure, smell, sound, etc.
Sensations combine to tell us what the experience or object is.
Method
Analytic introspection: participants trained to describe experiences and thought processes in response to stimuli
The First Cognitive Psychologists
Ebbinghaus (1885/1913)
How long does it take us to forget something we learn?
Read list of nonsense syllables aloud many times to determine number of repetitions necessary to repeat list without errors
NAD, TOC, RET, CAK, ZIF, etc.
One list may have 20 of these. One list may have 50 of these.
Sometimes he recalled them immediately; sometimes after a 1 hour delay. After a delay there always some forgetting.
After some time, he tried to relearn the list and found that:
Short intervals = fewer repetitions to relearn
Learned many different lists at many different retention intervals
The First Cognitive Psychologists
Ebbinghaus (1885/1913)
Savings = (Original time to learn the list) – (Time to relearn the list after a delay)
Savings curve shows savings as a function of retention interval
The First Cognitive Psychologists
*
FIGURE 1.5 Ebbinghaus’s savings (or
forgetting) curve. Taking the percent savings as a
measure of the amount remembered, Ebbinghaus
plotted this against the time interval between
initial learning and testing.
(Source: Based on data from Ebbinghaus, 1885/1913.)
William James’s Principles of Psychology
James was an early American psychologist who taught the first psychology course at Harvard University.
His observations were based on the functions of his own mind, not experiments.
He considered many topics in cognition, including thinking, consciousness, attention, memory, perception, imagination, and reasoning.
Was particularly interested in attention, noting that we are barraged with sensations and experiences all day but not all of them are remembered. Why? We don’t pay attention.
Criticism of the Study of the Mind
Ivan Pavlov (1849-1936)
His contribution was one of the most important ever made to psychology.
Not a psychologist but a physiologist.
Said of psychology “… it is still open to discussion whether psychology is a natural science, or whether it can be regarded as a science at all.”
How can we have a “science” if we are studying something like the “mind”.
Criticism of the Study of the Mind
Pavlov discovered 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
See this video for an explanation.
https://www.youtube.com/watch?v=bRrBsoU3PVI
Showed that we can only study behavior, not mental processes.
The First Cognitive Psychologists
John Watson was very influenced by Pavlov.
He noted two problems with Wundt and James’ approaches:
Extremely variable results from person to person
Results difficult to verify
Invisible inner mental processes
The Rise of Behaviorism
Watson proposed a new approach called behaviorism
The goal was to eliminate the mind as a topic of study.
Instead, study directly observable behavior because that is all we can know for sure.
We can never know what another person is thinking unless they tell us, and even then they could be lying.
Said psychology has failed to establish itself as a natural science.
Believed psychology should be a truly experimental discipline that studied only observable phenomena.
Rather than you tell me that you are nervous, I would observe your behavior (finger tapping, nail-biting, sweating, heart rate, etc.).
The Rise of Behaviorism
Watson and Rayner (1920) – “Little Albert” experiment
Classical conditioning of fear
They hypothesized that if a stimulus that automatically produces a certain emotion such as fear is repeatedly experienced at the same moment as something else, that stimulus will eventually become a conditioned stimulus for the fear.
Little Albert was a physically and psychologically healthy little boy borrowed from an orphanage at the age of 9 mo.
The Rise of Behaviorism
Several items were presented to Little Albert
white rat, rabbit, dog, fur coat
mask with and without hair
He initially had no fear of any of the objects.
So then they started scaring him after showing him the object
The Rise of Behaviorism
Albert was very afraid of loud noise.
Following a loud noise he began to cry.
The Rat (neutral stimulus) or other objects was presented to Albert followed by loud noise.
After 7 pairings, the rat began to elicit fear and crying.
He used this study to show that what was going on in the babys’ mind was irrelevant. You only had to observe behavior.
=
The Rise of Behaviorism
B.F. Skinner (1940s through 1960s)
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
The Rise of Behaviorism
The Reemergence of the Mind in Psychology
Tolman (1938) trained rats to find food in a four-armed maze
The first time they took a long time to find the food; after several trials they would run directly to the food
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” in their mind of the maze and were navigating to a specific arm
The Reemergence of the Mind in Psychology
Tolman (1938)
What happens when the rats are placed in a different arm of the maze?
The rats didn’t just turn right from where they were.
They navigated to the specific arm where they previously found food.
Supported Tolman’s interpretation
Did not support behaviorism interpretation
The Reemergence of the Mind in Psychology
*
The Decline of Behaviorism
A controversy over language acquisition
Skinner (1957) – Verbal Behavior
Argued children learn language through operant conditioning.
Children imitate speech they hear
Their mom says “Mama” to them.
If the baby repeats it she screams in delight and says “Good boy” or “good girl”.
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
I runned away (instead of ran).
He taked it away from me (instead of he took it away).
Language must be determined by inborn biological program
Studying the Mind
So how can we study the unobservable 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
A new device was invented…..…..the computer!
This changed the way people thought about information processing
people started talking about the mind in computer terms:
input, encoding information, storing information ~ memory store, & output
information codes: representing information as symbols
limitations in processing capacity
The Cognitive Revolution
Early computers (1950s) processed information in stages
Information-processing approach
A way to study the mind created from insights associated with the digital computer
The Cognitive Revolution
Cherry (1953)
“Dichotic” listening
Present message A in left ear
Present message B in right ear
To ensure attention, focus attention on only one message
Participants were able to focus only on the message they were focusing attention on.
The Cognitive Revolution
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
The Cognitive Revolution
*
FIGURE 1.9 (a) Flow diagram for an early computer.
FIGURE 1.9 (b) Flow diagram for Broadbent’s filter model of
attention. This diagram shows that many messages enter a “filter”
that selects the message to which the person is attending for
further processing by a detector and then storage in memory. We
will describe this diagram more fully in Chapter 4.
The Cognitive Revolution
Artificial Intelligence and Information Theory
Artificial Intelligence
“making a machine behave in ways that would be called intelligent if a human were so behaving.” (McCarty et al., 1955)
attempts to construct machines that show intelligence
revealed that there are many different types of intelligence
designed computer chess games that have “intelligence”
Newell and Simon created the logic theorist program that could apply rudimentary logic to creating mathematical theorems
Artificial Intelligence and Information Theory
Although the mind / computer analogy was beneficial, it soon became clear that computers and humans do not process information the same
When it comes to this problem, 123,456,789 X 987,654,321, the computer has the advantage
-When it comes to recognizing a familiar face, humans have the advantage
Modern Research in Cognitive Psychology
How research progresses from question to question
Start with what is known
Ask questions
Design experiments
Obtain and interpret results
Use results as the bases for new research questions and experiments
The Role of Models in Cognitive Psychology
There are two kinds of models to be aware of:
Structural Models
Process Models
Structural Models
Representations of a physical structure
Mimic the form or appearance of a given object
Structural Models
Process Models
Represent the processes that are involved in cognitive mechanisms, with boxes usually representing specific processes and arrows indicating connections between processes
Process Models
