Finish: Overview of the History of Cog Psych Psychology 355: Cognitive Psychology Instructor: John Miyamoto 04/01 /2015: Lecture 01-3 This Powerpoint presentation may contain macros that were used to create the slides. The macros aren’t needed to view the slides. If necessary, you can disable the macros without any change to the presentation.

Outline History of Cognitive Psychology: How did cognitive psychology become a major focus within psychology? Overview of Physiological Methods in Cognitive Psychology Single cell recordings of neural activity Event-related potentials (ERP) Positron emission tomography (PET) Functional magnetic resonance imaging (fMRI) ♦ Example of fMRI applied to localization of perceptual function Psych 355, Miyamoto, Spr '15 2 Lecture probably ends here Overview of the Historical Development of Cognitive Psychology

Psych 355, Miyamoto, Spr '15 3 Overview of the History of Cognitive Psychology Precursors to cognitive psychology ♦ Aristotle, Plato – epistemology, theory of ideas and their relation to human action Experimental psychology begins in 19th century Germany ♦ Franciscus Donders (response time analysis, method of subtraction) ♦ Hermann von Helmholtz (perception, unconscious inference) ♦ Hermann Ebbinghaus (experimental study of memory) ♦ Wilhelm Wundt (analytic introspection, analysis of conscious experience) Behaviorist hiatus in America: roughly 1920 – 1960 ♦ During the behaviorist period ( ), cognitive psychology continued to be studied in Europe. Revival of cognitive psychology in America (1950 – 1970) 1970 – present: Cognitive psychology plays a major role in psychology pretty much everywhere in the world Donder’s Mental Chronometry

Psych 355, Miyamoto, Spr '15 4 Early Cognitive Psychology: F.C. Donders ( ) Mental chronometry: Measuring the duration of a cognitive process Reaction-time (RT) (a.k.a. response time): RT = the time interval between stimulus presentation and the response to the stimulus Method of Subtraction: Used to infer how long a mental process takes when the process is not directly observable. ♦ Method of subtraction is an example of a behavioral research method. Definition of Simple RT and Choice RT "Donders, Franciscus Cornelis ( )" by Alexander Seitz (Photographic company) - SIL14-D4-14a.jpg from the Scientific Identity: Portraits from the Dibner Library of the History of Science and Technology (reworked). Licensed under Public Domain via Wikimedia Commons _(1818_-_1889).jpg#/media/File:Donders,_Franciscus_Cornelis _(1818_-_1889).jpg TIME Stimulus Presentation Response RT

Psych 355, Miyamoto, Spr '15 5 Simple and Choice Reaction Time and Measuring the Time It Takes to Choose Simple RT task: Participant pushes a button quickly after a light appears. Choice RT task: Participant pushes one button if light is on the right side, and a different button if light is on left side Donder’s goal: To measure how long it takes a person to decide which button to press in the choice RT task. How long is the decision process? Diagram Showing Time Course of Simple RT

Diagram of Cognitive Processes During Simple RT Simple RT = (Response Completion) – (Stimulus Onset) In a simple RT task, the subject does not have to decide how to respond. Psych 355, Miyamoto, Spr '15 6 Diagram Showing Time Course of Choice RT Time

Diagram of Cognitive Processes During Choice RT Choice RT = (Response Completion) – (Stimulus Onset) In a choice RT task, the subject has to decide which response is appropriate. Psych 355, Miyamoto, Spr '15 7 Time Diagram showing the Decision Stage in the Information Process

Psych 355, Miyamoto, Spr '15 8 Decision time = the length of time that it takes to decide which response is appropriate. Diagram of Cognitive Processes During Choice RT Question for the Class: How to Measure Decision Time? Decision Time

Question for the Class: How Can We Measure the Duration of the Decision Stage in a Choice RT Task? Donder’s goal: Measure how long it takes a person to decide which button to press in the choice RT task. How long is the decision process? Psych 355, Miyamoto, Spr '15 9 Diagram comparing simple and choice RT

Method of Subtraction: Compare Simple RT to Choice RT Method of Subtraction: Duration of Decision Stage (red) = Choice RT – Simple RT Psych 355, Miyamoto, Spr '15 10 Simple RT Choice RT Diagram Showing that the Perceiving Stages are Identical

Method of Subtraction: Compare Simple RT to Choice RT Psych 355, Miyamoto, Spr '15 11 Simple RT Choice RT Diagram Showing that the Responding Stages are Identical Same

Method of Subtraction: Compare Simple RT to Choice RT Psych 355, Miyamoto, Spr '15 12 Simple RT Choice RT Diagram Showing that the RT Difference Measures the Duration of the Decision Stage Same

Psych 355, Miyamoto, Spr '15 13 Method of Subtraction: Duration of Decision Stage (red) = Choice RT – Simple RT Method of Subtraction: Compare Simple RT to Choice RT Simple RT Choice RT What does Donder’s Method Show About Cognitive Psych? Same

Why is Donder’s Method of Subtraction Important for Cognitive Psychology? It combines a behavioral study with a simple computational model of a cognitive process. ♦ The combination yields an important conclusion. ♦ Mental chronometry Example of a purely or strictly behavioral study – no physiological measurements; no brain imaging. Method of subtraction is a valid measure of mental duration if all of the assumptions are valid. ♦ Unfortunately, the assumptions of this method are often not valid. ♦ But Donder's ideas inspired improved methods that do lead to valid measurements of the duration of mental processes. Psych 355, Miyamoto, Spr '15 14 fMRI Method of Subtraction

Subtraction Methods in fMRI Brain Imaging Activations are regions of significant change from a control condition to a test condition. Psych 355, Miyamoto, Spr '15 15 Brain image shows regions of significant activation when comparing Test Condition to Control Condition. (Slice of brain is viewed from above.) The purpose of this slide is simply to show that subtraction methods are used in modern fMRI studies. Specific details are not important. Test Condition: Subject views picture. Control Condition: Subject fixates a blank screen. Helmholtz & Unconscious Inference

Early Cognitive Psychology: H. L. F. von Helmholtz (1821 – 1894) Great mathematician, physicist, psychologist Contributions to psychology: perception, especially color vision, hearing, optics, unconscious inference Helmholtz invented idea of 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 Psych 355, Miyamoto, Spr '15 16 Diagram that Illustrates Unconscious Inference (Occlusion)

Psych 355, Miyamoto, Spr '15 17 Unconscious Perceptual Inference The display in (a) looks like (b) a gray rectangle in front of a light rectangle; but it could be.... … (c) a gray rectangle and a six-sided figure that are lined up appropriately or (d) a gray rectangle and a strange-looking figure that are lined up appropriately. Repeat this Slide without the Rectangles

Psych 355, Miyamoto, Spr '15 18 Unconscious Perceptual Inference The display in (a) looks like (b) a gray rectangle in front of a light rectangle; but it could be.... … (c) a gray rectangle and a six-sided figure that are lined up appropriately or (d) a gray rectangle and a strange-looking figure that are lined up appropriately. Example of Unconscious Inference: An Occluded Cube

Psych 355, Miyamoto, Spr '15 19 Another Example of Unconscious Inference We rapidly and automatically infer that there is a cube behind a screen with holes in it. Your knowledge of cubes and occlusion (seeing through holes) determines what you perceive in this figure. Example of Unconscious Inference : Craters versus Mounds

Where is the light coming from on the left and on the right? What is the shape of the sand on the left and on the right? Example: Craters or Mounds? Psych 355, Miyamoto, Spr '15 20 Same Image + Light from Above Assumption Craters Mounds

Example: Craters or Mounds? “Light comes from above” assumption guides perception. Why Idea of Unconscious Inference Is Important for Cog Psych Psych 355, Miyamoto, Spr '15 21 Craters Mounds

Psych 355, Miyamoto, Spr '15 22 Why Is the Idea of Unconscious Inference Important? Unconscious inferences contribute in many ways to our perceptions and beliefs. Cognitive psychology attempts to discover: (a) what unconscious inferences occur in the formation of our beliefs; (b) the processes by which such inferences are made. Other Early Cognitive Psychologists – Ebbinghaus & Wundt

Psych 355, Miyamoto, Spr '15 23 Other Important Early Cognitive Research Ebbinghaus (1850 – 1909) and the Method of Savings ♦ Important memory research ♦ We will talk about this later in the course Wundt (1832 – 1920) ♦ How sensations combine to form percepts ♦ Analytic introspection Return to Slide Showing the Overview of History of Cog Psych

Psych 355, Miyamoto, Spr '15 24 Overview of the History of Cognitive Psychology Precursors to cognitive psychology ♦ Aristotle, Plato – epistemology, theory of ideas and their relation to human action Experimental psychology begins in 19th century Germany ♦ Franciscus Donders (response time analysis, method of subtraction) ♦ Hermann von Helmholtz (perception, unconscious inference) ♦ Hermann Ebbinghaus (experimental study of memory) ♦ Wilhelm Wundt (analytic introspection, analysis of conscious experience) Behaviorist hiatus in America: roughly 1920 – 1960 ♦ During the behaviorist period ( ), cognitive psychology continued to be studied in Europe. Revival of cognitive psychology in America (1950 – 1970) 1970 – present: Cognitive psychology plays a major role in psychology pretty much everywhere in the world Behaviorist Hiatus in America Done!

To-Be-Continued on Thursday Psych 355, Miyamoto, Spr '15 25