PSY 323: Cognition Chapter 1: Introduction to Cognitive Psychology

Cognition and Cognitive Psychology The mental processes that are involved in perception, attention, memory, problem solving, reasoning, and making decisions Cognitive Psychology Branch of psychology concerned with the scientific study of cognition

Challenges of Cognitive Ψ Often times, “the processes involved in cognition are complex and hidden from view” Take a moment and think about all that is happening around you (perception, attention, memory, reasoning)

History of Cognitive Ψ: 1st Cognitive Psychology Experiment Donders (1868) Franciscus Donders, Dutch physiologist Measured reaction time: time b/w presentation of stimulus and person’s response to that stimulus Simple reaction time The length of time it takes to push a button after the presentation of a stimulus Choice reaction time Push one of two buttons in response to a stimulus Inferred mental process of perception Mental response cannot be measured directly, but can be inferred from behavior (choice reaction time – simple reaction time = length of time to make a decision) All research in cognitive psychology deals with inferred mental processes

A pioneer of the scientific study of memory: Hermann Ebbinghaus  (1850 – 1909) Worked as philosopher at University in Berlin Performed experiments on himself published in classic volume entitled: ‘Über das Gedächtnis’ (1885)

Memory experiments of Ebbinghaus: Focus on retention of newly learned material Invented lists of 16 nonsense syllables to minimize influence of meaningful associations and learner’s history His goal: study memory in ‘pure’ form Introduced criterion for successful learning

Hermann Ebbinghaus Ebbinghaus founded the experimental study of memory Serial Learning Experiments A list of items presented one at a time; you must recall them in order Memorizing lists in sequence until they can be recalled perfectly Ran tests on himself for six years Memorized thousands of lists of nonsense syllables (ZAB, VUB, etc.) Invented 2300 of these syllables, arranged them in random lists and tested them after various delays What problems do you see with this methodology?

Ebbinghaus' Experiments Serial Learning Experiments Learning to criterion Ebbinghaus would repeatedly attempt to learn the material until he achieved a perfect reproduction (every item memorized in the order originally presented) “Method of savings“ Subtracting the number of repetitions required to relearn material to a criterion from the number originally required to learn the material to the same criterion Savings = (Initial Repetitions – Relearning Repetitions)/ Initial Repetitions

Ebbinghaus' Experiments: Important Findings List-length effect Ease of learning and amount of information not related in linear one-to-one fashion Disproportionate increase in difficulty with more than 7 syllables Distributed practice Beneficial effects of distributed practice for repetitions

Ebbinghaus' Experiments: Important Findings Forgetting Curve Recollection of words drops dramatically during the first hour of learning

Structuralism Wilhelm Wundt 1879, founded first laboratory of scientific psychology at the University of Leipzig, in order to study the mind scientifically Carried out reaction-time experiments Developed analytic introspection Procedure used in which trained participants described their experiences and thought processes elicited by stimuli presented under controlled conditions Problematic: introspection did not seem to reveal the structure of thought; results from different laboratories often disagreed

Abandoning the study of the mind… Behaviorism John Watson Developed new approach to psychology by studying actual behaviors in their own right and not worrying about consciousness Argued behavior is observable and objective Studied impact of stimulus conditions on behavior (stimulus-response) Most famous study: Little Albert 

Abandoning the study of the mind… Behaviorism B.F. Skinner  Studied operant conditioning: believe reinforcements, not free will, determined behavior Published book on verbal behavior that claimed language developed through imitation and reinforcement

Reemergence of the mind… Cognitive Learning Focus on the role of thinking processes in learning Theory based on unseen internal factors rather than on external factors

Latent Learning Tolman and Honzik (1930) Took three groups of rats and had them run a maze Group 1 Reinforced every time they found their way out of the maze (food box) for ten days Group 2 Never reinforced (no food at the end) Group 3 Reinforced only after day 10 of the experiment

Latent Learning On day 11, they timed the three groups to see which group would make it through the maze the quickest… Which group do you think was the fastest?

Cognitive Psychology Scientific study of mental processes Simply put “it is the study of thought” Behavior is examined by cognitive psychologists the same way that physicists infer the force of gravity from the behavior of objects in the world. Mental Processes: remembering, attention, producing and understanding language, solving problems, and making decisions Thinking is something that is constantly happening, yet we rarely stop to think about it

Cognitive Processes Perception and Sensory Memory Attention Organize and interpret incoming information (e.g., first lecture) Sensory memory holds information, like an information buffer, just long enough to determine whether it seems worthwhile Attention Set of processes through which you focus on incoming information Ability to attend is flexible—can divert (cocktail party effect, police car) Attention is also limited

Rebirth of Study of the Mind Cognitive Science Study of the mind (mental processes) as carried out by many different disciplines Disciplines: cognitive psychology, and research on the mind within the fields of computer science, linguistics, neuroscience, anthropology, artificial intelligence, and philosophy

Modern Approaches to Study the Mind Behavioral Approach Measure behavior and explain cognition in terms of behavior e.g., reaction time Measuring mental rotation exercise

Modern Approaches to Study the Mind Physiological Approach Measure both behavior and physiology and explain cognition in terms of physiology e.g., reaction time and brain wave activity or brain activation Davachi experiment (words that were remembered on the memory test had more brain activity when words were first exposed 

Models of the Mind: Introduction of Digital Computer Flow Diagrams for the Mind Rise of the Information Processing Metaphor Broadbent’s flow diagram depicted the mind as processing information in a sequences of stages Information processing models conceive of cognitive activities as involving a series of steps, procedures, or processes that take time (e.g., 1/10 second)

Credits Some slides of this presentation prepared with the help of the following websites: www.cogsci.rpi.edu/courses/cogpsy/spr09/lectures/Chapter%201.ppt