Cognitive Psychology PDF

COGNITIVE PSYCHOLOGY: STUDYING THE MIND WHAT IS THE MIND?  one way to approach the question, “What is the mind?” is to consider how “mind” is used every day: 1. memory 2. problem-solving 3. decision making 4. normal functioning  the mind creates & controls mental functions such...

COGNITIVE PSYCHOLOGY: STUDYING THE MIND WHAT IS THE MIND?  one way to approach the question, “What is the mind?” is to consider how “mind” is used every day: 1. memory 2. problem-solving 3. decision making 4. normal functioning  the mind creates & controls mental functions such as perception, attention, memory, emotions, language, deciding, thinking & reasoning.  the mind is a system that creates representations of the world so that we can act within it to achieve our goals.  cognition is the mental processes, such as perception, attention & memory, which is what the mind creates.  the mind creates representations & enables us to act & achieve goals.  cognitive psychology is the study of mental processes, which includes determining the characteristics & properties of the mind & how it operates. STUDYING THE MIND: EARLY WORK IN COGNITIVE PSYCHOLOGY  in the 1800s, ideas about the mind were dominated by the belief that it is not possible to study the mind; one reason for this belief was that it is not possible for the mind to study itself & the idea that the properties of the mind simply cannot be measured. DONDERS’S PIONEERING EXPERIMENT: HOW LONG DOES IT TAKE TO MAKE A DECISION?  Dutch physiologist, Franciscus Donders, did one of the first experiments that today would be called a cognitive psychology experiment.  the term “cognitive psychology” was not coined until 1967.  Donders was interested in determining how long it takes for a person to make a decision; he determined this by measuring reaction time.  reaction time is how long it takes to respond to presentation of a stimulus.  he used 2 measures of reaction time: 1. simple reaction time  he measured simple reaction time by asking his participants to push a button as rapidly as possible when they saw a light go on.  presenting the stimulus (the light flashes) causes a mental response (perceiving the light), which leads to a behavioural response (pushing the button).  the reaction time is the time between the presentation of the stimulus & the behavioral response. 2. choice reaction time  he measured choice reaction time by using two lights & asking his participants to push the left button when they saw the left light go on & the right button when they saw the right light go on.  the choice reaction time task added decisions by requiring participants to first decide whether the left or right light was illuminated & then which button to push.  Donders reasoned that the difference in reaction time between the simple & choice conditions would indicate how long it took to make the decision that led to pushing the correct button.  since the choice reaction time took 1/10th of a second longer than simple reaction time, Donders concluded that the decision-making process took 1/10th of a second.  mental reponses cannot be measured directly but must be inferred from behavior.  when Donders measured reaction time, he was measuring the relationship between presentation of the stimulus & the participant’s response; he did not measure mental responses directly but inferred how long they took from the reaction times. WUNDT’S PSYCHOLOGY LABORATORY: STRUCTURALISM & ANALYTICAL INTROSPECTION  William Wundt founded the first laboratory of scientific psychology at the University of Leipzig in Germany.  Wundt’s approach, which dominated psychology in the late 1800s & early 1900s, was called structuralism.  structuralism is where our overall experience is determined by combining basic elements of experience the structuralists called sensations.  Wundt wanted to create a “periodic table of the mind,” which would include all the basic sensations involved in creating experience.  Wundt utilized analytic introspection.  analytic introspection is a technique in which trained participants describe their experiences & thought processes in response to stimuli.  analytic introspection required extensive training because the participants’ goal was to describe their experience in terms of elementary mental elements. EBBINGHAUS’S MEMORY EXPERIMENT: WHAT IS THE TIME COURSE OF FORGETTING?  Ebbinghaus was interested in determining the nature of memory & forgetting—specifically, how rapidly information that is learned is lost over time.  Ebbinghaus used a quantitative method for measuring memory.  using himself as the participant, he repeated lists of 13 nonsense syllables such as DAX, QEH, LUH & ZIF to himself one at a time at a constant rate.  he used nonsense syllables so that his memory would not be influenced by the meaning of a particular world.  Ebbinghaus determined how long it took to learn a list for the first time; he then waited for a specific amount of time (the delay) & then determined how long it took to relearn the list.  since forgetting had occurred during the day, Ebbinghaus made errors when he first tried to remember the list but because he had retained something from his original learning, he relearned the list more rapidly than when we had learned it the first time.  he used a measure called savings to determine how much was forgotten after a particular delay.  SAVINGS = ORIGINAL TIME TO LEARN THE LIST – TIME TO RELEARN THE LIST AFTER THE DELAY  if it took 1,000 seconds to learn the list the first time & 400 seconds to relearn the list after the delay, the savings would be 1,000 – 400 = 600 seconds.  longer delays result in smaller savings.  according to Ebbinghaus, this reduction in savings provided a measure of forgetting, with smaller savings meaning more forgetting.  a savings curve is the plot of percent savings versus time.  memory drops rapidly for the first 2 days after the initial learning & then levels off. WILLIAM JAMES’S PRINCIPLE OF PSYCHOLOGY  William James taught Harvard’s first psychology course & made significant observations about the mind.  James’s observations were based not on the results of experiments but on observations about the operation of his own mind.  the observation that paying attention to one thing involves withdrawing from the other things that still ring true today.  James considered a range of cognitive tasks such as: - thinking - consciousness - attention - memory - perception - imagination - reasoning  one of the major forces that caused psychology to reject the study of mental processes was a negative reaction to Wundt’s technique of analytic introspection. ABANDONING THE STUDY OF THE MIND WATSON FOUNDS BEHAVIORISM  Watson became dissatisfied with analytic introspection; his problems were: 1) it produced extremely variable results from person to person 2) these results were difficult to verify because they were interpreted in terms of invisible inner mental processes  in response to what he perceived to be deficiencies in analytic introspection, Watson proposed a new approach called behaviorism.  Watson made 2 key points: 1) he rejected introspection as a method & 2) observable behavior, not consciousness (which would involve unobservable processes such as thinking, emotions & reasoning)  Watson wanted to restrict psychology to behavioral data & rejected the idea of going beyond those data to draw conclusions about unobservable mental events.  Watson’s goal was to replace the mind as a topic of study in psychology with the study of directly observable behavior.  Watson’s ideas are associated with classical conditioning.  classical conditioning is when pairing one stimulus with another, previously neutral stimulus causes changes in the response to the neutral stimulus.  Watson’s inspiration for his experiment was Ivan Pavlov’s research, begun in the 1890’s, which demonstrated classical conditioning in dogs.  Watson used classical conditioning to argue that behavior can be analyzed without any reference to the mind. SKINNER’S OPERANT CONDITIONING  B.F. Skinner introduced operant conditioning.  operant conditioning focuses on how behavior is strengthened by the presentation of positive reinforcers.  like Watson, Skinner was not interested in what was happening in the mind, but focused solely on determining how behavior was controlled by stimuli. SETTING THE STAGE FOR THE REEMERGENCE OF THE MIND IN PSYCHOLOGY  Edward Chace Tolman called himself a behaviorist because his focus was on measuring behavior.  he was one of the early cognitive psychologists, because he used behavior to infer mental processes.  a cognitive map is a mental picture/image of the layout of the physical environment.  Skinner argued that children learn language through operant conditioning; children imitate speech that they hear & repeat correct speech because it is rewarded.  Noam Chomsky pointed out that children say many sentences that have never been rewarded by parents & that during the normal course of language development, they go through a stage in which they use incorrect grammar, even though this incorrect grammar may never have been reinforced.  Chomsky saw language development as being determined not by imitation or reinforcement, but by an inborn biological program that holds across cultures. THE REBIRTH OF THE STUDY OF THE MIND  the decade of the 1950s is recognized as the beginning of the cognitive revolution.  the cognitive revolution was a shift in psychology from the behaviorist’s focus on stimulus-response relationships to an approach whose main thrust was to understand the operation of the mind. PARADIGMS & PARADIGM SHIFTS  Thomas Kuhn defined a scientific revolution as a shift from one paradigm to another.  a paradigm is a system of ideas that dominate science at a particular time.  a scientific revolution involves a paradigm shift.  the paradigm shift from behaviorism to the cognitive approach provided a new way to look at behavior.  psychology was dominated by experiments studying how behavior is affected by rewards & punishments; some valuable discoveries resulted from this research, including psychological therapies called “behavioral therapies,” which are still in use today.  in the 1950s, the new cognitive paradigm began to emerge.  the introduction of the digital computer was a new way of describing the operation of the mind. INTRODUCTION OF THE DIGITAL COMPUTER  the first digital computer was developed in the late 1940s.  in 1954, IBM introduced a computer that was available to the public. FLOW DIAGRAMS FOR COMPUTERS  computers processed information in stages; information was first received by an “input processor” then it was stored in a “memory unit” before it was processed by an “arithmetic unit,” which then created the computer’s output.  using this approach as their inspiration, some psychologists proposed the information-processing approach to studying the mind.  the information-processing approach is an approach that traces sequences of mental operation involved in cognition.  according to the information-processing approach, the operation of the mind can be described as occurring in several stages. FLOW DIAGRAMS FOR THE MIND  Colin Cherry (1953) presented participants with two auditory messages, one to the left ear & one to the right ear & told them to focus their attention on one of the messages (the attended message) & to ignore the other one (the unattended message); the result of the experiment was that when people focused on the attended message, they could hear the sounds of the unattended message but were unaware of the contents of that message.  Donald Broadbent (1958) proposed the first flow diagram of the mind.  “input” would be the sounds of both the attended & unattended messages; the “filter” lets through the attended message & filters out the unattended message & the “detector” records the information that gets through the filter.  Broadbent’s flow diagram provided a way to analyze the operation of the mind in terms of a sequence of processing stages. CONFERENCES ON ARTIFICIAL INTELLIGENCE & INFORMATION THEORY  John McCarthy defined the artificial intelligence approach as “making a machine behave in ways that would be called intelligent if a human were so behaving.”  Herb Simon & Alan Newell succeeded in creating the program, which they called the “logic theorist;” this program was a real “thinking machine” because it used humanlike reasoning processes to solve problems.  George Miller presented the idea that there are limits to a human’s ability to process information & that the capacity of the human mind is limited to about seven items.  Miller’s basic principle was that there are limits to the amount of information we can take in & remember. THE EVOLUTION OF COGNITIVE PSYCHOLOGY WHAT NEISSER WROTE  the first cognitive psychology textbook was “Cognitive Psychology” by Ulrich Neisser (1967).  Neisser did not consider “higher mental processes” such as thinking, problem solving & long-term remembering until later in his book because he said that in 1967, we just did not know much about higher mental processes.  there was also the complete absence of physiology; he argued that he was interested in how the mind operates, but not in the physiological mechanisms behind this operation. STUDYING HIGHER MENTAL PROCESSES  a big step toward the study of higher mental processes was Richard Atkinson & Richard Shiffrin’s (1968) model of memory.  the model of memory pictures the flow of information in the memory system as progressing through 3 stages: 1) sensory memory  sensory memory holds incoming information for a fraction of a second & then passes most of this information to short-term memory. 2) short-term memory  short-term memory has limited capacity & holds information for seconds. 3) long-term memory  long-term memory is a high-capacity system that holds information for long periods of time.  by distinguishing between different components of the memory process, this model opened the way for studying each part separately; once researchers discovered more details about what was going on inside each of the model’s boxes, they were able to subdivide these boxes into smaller units.   Endel Tulving proposed that long-term memory is subdivided into 3 components: 1) episodic memory  episodic memory is memory for events in your life. 2) semantic memory  semantic memory is memory for facts. 3) procedural memory  procedural memory is memory for physical actions. STUDYING THE PHYSIOLOGY OF COGNITION  physiological research provided important insights into the “behind the scenes” activity in the NS that creates the mind.  2 physiological techniques that dominated early physiological research on the mind were: 1) neuropsychology  neuropsychology is the study of the behavior of people with brain damage. 2) electrophysiology  electrophysiology is measuring electrical responses of the NS.  a procedure called positron emission tomography (PET) was introduced in 1976 & it made it possible to see which areas of the human brain are activated during cognitive activity; a disadvantage was that it was expensive & involved injecting radioactive tracers into a person’s bloodstream.  PET was replaced by functional magnetic resonance imaging (fMRI) which did not involve radioactive tracers & which was capable of higher resolution.  there was also a shift in how people do science (for e.g., new developments in technology). NEW PERSPECTIVES ON BEHAVIOR  current cognitive psychology involves more-sophisticated flow diagrams of the mind, a consideration of higher mental processes & also a large amount of physiological research.  researchers began taking research out of the laboratory.  it became clear that to fully understand the mind, we must also study what happens when a person is moving through the environment & acting on it.  modern cognitive psychology features an increasing amount of research on cognition in “real-world” situations.  researchers also realized that humans are not “blank slates” that just accept & store information, so they began doing experiments that demonstrated the importance of knowledge for cognition.