Cognitive Psychology Lectures: By Stephen R. Schmidt, MTSU

Historical Introduction to Cognitive Psychology

Updated 8/20/2002


Outline:

I.  Metaphors for the Mind

  A.  Analogies and Metaphors
  B.  Prominent Metaphors
  C.  Conclusions on metaphors

II.  Methodological Developments

 A. Introspection
 B. Performance Measures
 C. Computer Modeling
 D. Physiological methods

III.  Conclusions


I.  Metaphors for the Mind

Thesis:
  The analogies and metaphors we use to  understand the human mind have greatly changed in the last 3000 years.  By viewing the history of these metaphors we can trace a brief history of cognitive psychology.
 

A. Analogies and Metaphors


1. purpose of analogy: aid understanding

Metaphorical description:  electrons orbit the nucleus.

2. Limitations of analogies - - But, these analogies are often imprecise.

The electron cloud model of the atom


 

B.  Prominent metaphors


Writing Systems
 

Plato: wax tablet carried by his student
"that our minds contain a wax block, which may vary in size, cleanliness and consistency in different individual . . ." Socrates

  - impressionability
  - wax could be too hard, soft, of full of impurities.
 

Writing was the dominant metaphor for memory for many years.  This was extended to scrolls, books, and libraries of knowledge.

John Locke (1600ís)  "tabula rasa"

Photography
Daguerre (1839) published a description of a process for producing photographs (Daguerrotypes).
Draper (1856) ganglion cells store "impressions"

Examples of the Photography metaphor


Telephone

Neo-behaviorism (Hull)
Electrochemical model for the conditioned reflex:

Examples of the Telephone metaphor

Computer
Computers were developed during WWII in attempts to crack the Axis Powers coded messages.

Turing (1950)
    General "Turing machine"

         Any process that can be defined by a series of precise steps can be programmed to be performed by a general machine that processes symbols.
  William James (1842-1910) Philosophical foundation of the computer metaphor
Functionalism:  description of mental processes in terms of their function, or adaptive significance.
The mind is what it does?
 Turing's test: provided an operational definition of "thought"
        Philosophical Foundation of Artificial Intelligence

U. Neisser (1966) Cognitive Psychology

Cognitive Psychology and the computer metaphor:
"The task of a psychologist trying to understand human cognition is analogous to that of a man trying to discover how a computer has been programmed."
Examples of the computer metaphor
Neural Networks
Hopefield (1982)
Described a method of storing information that was more "neurologically realistic" than traditional computers.

Memory consisted of a set of homogeneous components connected in layers.

Simple Pattern Associator (Rumelhart & McClelland, 1986)

Neural Networks had a number of properties that made them attractive as a metaphor:

C.  Conclusions on metaphors

a. Long succession of metaphors for mind
b. Metaphors are closely tied to discoveries and technologies of the day
c. These metaphors help us understand our mental processes by tying them to everyday experiences.

II.  Methodological Advancements

A.  Introspection

1) definition

"looking inward"
"reflection"

2) Examples

                    a) William Wundt (1832-1920)

                            Structuralist School

                  b) Sigmund Freud (1856-1939)

Developed Psychoanalytic theory
id, the ego, and the superego
Levels of Awareness:
 Conscious
 Pre-conscious
 Unconscious

3) Evaluation of  introspective evidence.

Strengths:
1) easy
2) intuitive appeal
Weaknesses:
1)  How do we resolve disagreements?
2)  Introspections are often wrong
3)  Cognitive processes may be hidden from consciousness

B. Performance Methods

1)  Relearning: Ebbinghaus (1885)  methodical study of memory using number of trails to relearn a list.
Variations include: number correct
2) Pattern of errors

Example:  errors  in auditory recognition of letters

stimulus          responses    percent
    c                    "c"               80
                         "p"               10
                         "b"                 6
                         "v"                 2
What does this tell us about letter perception?

3)  Reaction Time
Mental Chronometry
Donders (1850ís):  method of subtraction


 
 

        Sternberg (1960's) (see Ch. 4)

C. Computer Modeling

        Newel, Shaw, & Simon (1963) General Problem Solver
        Miller, Galanter, & Pribram (1960)
            Three Steps in Computer Modeling

                Step 1:  Analyze the task
                Step 2:  Develop a "sufficient model"
                Step 3:  Evaluate the model

D.  Physiological methods


 1) magnetic resonance imaging (MRI)

 2) functional magnetic resonance imaging(fMRI)
 - dynamic
 - high resolution (can see individual blood vessels

MRI's taken two years apart from a patient with Alzheimer's Disease.  The photo on the right shows the progression of the disease with loss of brain matter.
 


 
 

3) Positron emission tomography (PET)
 

III.  Conclusions

Philosophical and Technological developments have driven how we think about our minds and how we think about ourselves.

This can be seen in the metaphors we use to describe mental processes, the theories we develop, and the methods we use to study the human condition.
 
 

Return to course outline.


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