Finish: Overview of the History of Cog Psych
Psychology 355: Cognitive Psychology
Instructor: John Miyamoto
04/01/2015: Lecture 01-3
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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
Lecture probably
ends here
• 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
Overview of the Historical Development of Cognitive Psychology
2
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 (1920-1960), 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
Psych 355, Miyamoto, Spr '15
Donder’s Mental Chronometry
3
Early Cognitive Psychology: F.C. Donders (1818-1889)
• 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
TIME
"Donders, Franciscus Cornelis (1818 - 1889)" 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 http://commons.wikimedia.org/wiki/File:Donders,_Franciscus_Cornelis
_(1818_-_1889).jpg#/media/File:Donders,_Franciscus_Cornelis
_(1818_-_1889).jpg
RT
Stimulus Presentation
Response
• 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.
Psych 355, Miyamoto, Spr '15
Definition of Simple RT and Choice RT
4
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?
Psych 355, Miyamoto, Spr '15
Diagram Showing Time Course of Simple RT
5
Diagram of Cognitive Processes During Simple RT
Time
• 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
Diagram Showing Time Course of Choice RT
6
Diagram of Cognitive Processes During Choice RT
Time
• 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
Diagram showing the Decision Stage in the Information Process
7
Diagram of Cognitive Processes During Choice RT
Decision Time
• Decision time = the length of time that it takes to decide
which response is appropriate.
Psych 355, Miyamoto, Spr '15
Question for the Class: How to Measure Decision Time?
8
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
Diagram comparing simple and choice RT
9
Method of Subtraction: Compare Simple RT to Choice RT
Simple RT
Choice RT
• Method of Subtraction:
Duration of Decision Stage (red) = Choice RT – Simple RT
Psych 355, Miyamoto, Spr '15
Diagram Showing that the Perceiving Stages are Identical
10
Method of Subtraction: Compare Simple RT to Choice RT
Simple RT
Same
Choice RT
Psych 355, Miyamoto, Spr '15
Diagram Showing that the Responding Stages are Identical
11
Method of Subtraction: Compare Simple RT to Choice RT
Simple RT
Same
Choice RT
Diagram Showing that the RT Difference Measures the Duration of the Decision Stage
Psych 355, Miyamoto, Spr '15
12
Method of Subtraction: Compare Simple RT to Choice RT
Simple RT
Same
Choice RT
• Method of Subtraction:
Duration of Decision Stage (red) = Choice RT – Simple RT
Psych 355, Miyamoto, Spr '15
What does Donder’s Method Show About Cognitive Psych?
13
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
fMRI Method of Subtraction
14
Subtraction Methods in fMRI Brain Imaging
Activations are regions of significant change
from a control condition to a test condition.
Test Condition: Subject views picture.
Control Condition: Subject fixates a blank
screen.
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.
Psych 355, Miyamoto, Spr '15
Helmholtz & Unconscious Inference
15
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
Diagram that Illustrates Unconscious Inference (Occlusion)
16
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.
Psych 355, Miyamoto, Spr '15
Repeat this Slide without the Rectangles
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.
Psych 355, Miyamoto, Spr '15
Example of Unconscious Inference: An Occluded Cube 18
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.
Psych 355, Miyamoto, Spr '15
Example of Unconscious Inference: Craters versus Mounds
19
Example: Craters or Mounds?
Craters
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?
Psych 355, Miyamoto, Spr '15
Same Image + Light from Above Assumption
20
Example: Craters or Mounds?
Craters
Mounds
“Light comes from above” assumption guides perception.
Psych 355, Miyamoto, Spr '15
Why Idea of Unconscious Inference Is Important for Cog Psych
21
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.
Psych 355, Miyamoto, Spr '15
Other Early Cognitive Psychologists – Ebbinghaus & Wundt
22
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
Psych 355, Miyamoto, Spr '15
Return to Slide Showing the Overview of History of Cog Psych
23
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
♦
♦
♦
♦
Done!
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 (1920-1960), 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
Psych 355, Miyamoto, Spr '15
Behaviorist Hiatus in America
24
To-Be-Continued on Thursday
Psych 355, Miyamoto, Spr '15
25