Transcript Ch01z

The Spirit of Mechanism
• 17th to 19th century zeitgeist
reflected in:
– Amusement with mechanical
figures
– The universe as a enormous
machine
– Mechanism: all natural
processes are mechanically
determined
Physics (natural philosophy)
• Galileo: matter is comprised of atoms that affect
one another by direct contact
• Newton: Planets moved by invisible forces, not by
actual physical contact
Galileo (1564-1642)
Newton (1643-1747)
Physiology of the Nervous System
• Luigi Galvani (1737-1798)
– Italian Physiologist
– Identified electricity as the
“currency” of the nervous system
– Nephew (Giovanni Aldini)
continued the tradition using
severed heads of criminals
– More Showmanship than Science
Johannes Müller
Doctrine of Specific Nerve Energies
1. The mind is directly aware not of
objects in the physical world but of
states of the nervous system.
2. “The qualities of the sensory nerves
of which the mind receives
knowledge in sensation are specific
to the various senses, the nerve of
vision being normally as insensible to
sound as the nerve of audition is to
light. “
Paul Broca (1824-1880)
– The Clinical Method (1861)
– Broca’s area: the speech center in the 3rd
frontal convolution of the left hemisphere
of the cerebral cortex
Mapping from the Outside
• Franz Josef Gall (1758-1828)
– Used the clinical method to map
the brain and confirm:
• Existence of white and gray matter
• Fibers from each brain side to the
opposite spinal column side
• Fibers connecting the two brain
hemispheres
– “How do the size and shape of
the brain reveal information
about brain facilities?”
– Can it be mapped from the
outside?
Phrenology
• J.G. Spurzheim (1776-1832)
– Gall’s student
– Took specific nerve
energies a little too far
Pierre Flourens (1794-1867)
•
•
Prof. of Natural History-Paris
Used extirpation (ablation)
1. Isolate the parts
2. Remove, when necessary, the
entire parts
3. Always prevent the
complication of the effects on
the lesions due to the effects of
effusions.
Physiology of the Nervous System
• Camillo Golgi (1844-1926)
– Italian neurologist
• S. Ramón y Cajal (1852-1934)
– Spanish neuroanatomist
– Nobel Prize 1906
Hermann von Helmholtz (1821–1894)
• Born in Potsdam, Germany
• Delicate health
• 1838: enrolled at a Berlin
medical institute: free tuition
to future army surgeons
• Seven years in the army
Ernst Weber (1795 – 1878)
– Born in Wittenberg, Germany
– 1815: PhD at university of Leipzig
– 1817 – 1871: taught anatomy and
physiology at Leipzig
– Primary research interest:
physiology of sense organs
– Applied experimental methods to
problems of psychology
– Explored new fields: cutaneous
sensations rather than just vision
and hearing
Ernst Weber (1795 – 1878)
• Thresholds
– Two-point discrimination of the skin
– Predicted layout of sensory cortex
Gustav Theodor Fechner (1801-1887)
– Born in southeastern
Germany
– 1817: began medical studies
at University of Leipzig
– Attended Weber’s lectures
on physiology
– Professor at Leipzig
• By the mid 19th century natural science methods were
being used to study mental phenomena
• British empiricists outlined the importance of
understanding the limitations of the senses
• German physiologists described functioning of the
senses and paved the way for Wilhelm Wundt who
brought them together by founding psychology
Wilhelm Wundt (1832 –
1920)
• Started the first laboratory
and the first journal in
experimental psychology
• Viewed Fechner's work as
the first experimental
psychology
Leipzig Lab Gear
Precision
Chronograph
Tachistoscope
Pulse Generator
Other Developments in
Germany
• Hermann Ebbinghaus (1850-1909)
– Directed clear experiments on
memory (nonsense syllables)
– Influenced by Fechner
• Fechner – Measured senses
indirectly with thresholds
• Ebbinghaus – Measured
memory indirectly by counting
numbers of items recalled after
specific periods of time
Ebbinghaus and Memory
• Ebbinghaus’ Forgetting Curve
– CVC Nonsense syllables (lef, bok)
• Control for familiarity
• Randomized presentation from 2,300 syllables
– Compared nonsense to sense
• 80 nonsense syllables
• 80 syllables of Don Juan
Other Developments in
Germany
• Carl Stumpf (1848-1936)
– Appointed to professorship at
the University of Berlin
– Wundt’s major rival
– Two of his students founded
Gestalt Psychology
• Kurt Koffka
• Wolfgang Köhler
Experimenter Bias & Clever
Hans
Wilhelm von Osten:
Animal intelligence
•
• Oskar Pfungst (Stumpf’s student)
• Spontaneous variability among members of a
species is inheritable – He described genes and
mutations without the benefit of biochemistry!
• Natural selection: process that leads to survival
of organisms which adapt to the environment;
Elimination of those which do not
Edward Lee Thorndike (1874–1949)
• Cats and Puzzle Boxes
– Trap a cat…random behavior will evolve in to a
specific behavior aimed at generating results
– Consequences led to the “stamping in” or
“stamping out” of responses (Trial-andAccidental-Success-Learning)
Ivan Petrovitch Pavlov (1849-1936)
• In general
– His work helped shift of
associationism from
subjective ideas to
objective physiological
responses
– Provided Watson with a
new method
Sigmund Freud (1856-1939)
Three shocks to the human ego (Freud, 1917)
1. Copernicus: Earth not center of universe
2. Darwin: Humans not a distinctive species
3. Freud: Unconscious forces rather than rational
thought govern our lives/moods
John B. Watson (1878-1958)
• Watsonian Behaviorism
– Ultra-Scientific
– Dealt solely with observable
behavioral acts
– Objective descriptions of the data
– Rejection of mentalistic concepts
and terms
– Consciousness comparable to
soul, introspection irrelevant
Skinner
• Operant Conditioning (Type I) vs.
Respondent Conditioning (Type II)
• Skinner Box was similar to
Thorndike’s Puzzle Box
• The purpose of psychology is to
understand individuals – single
subject designs.
• Behavior is the focus – no black
Boxes!
• Behavior is controlled by its
consequences.
The phi phenomenon: A challenge to
Wundtian Psychology
• A product of Wertheimer's 1910
research
– Developed riding a train while on
vacation
– Involved seeing movement when
no actual physical motion occurs
Wolfgang Köhler (1887- 1967)
• 1913-1920: unable to leave Canary
Islands during WWI
• Studies the behavior of chimpanzees
• 1917: The Mentality of Apes
• 1922: succeeded Stumpf at U. of
Berlin
– Static and Stationary Physical
Gestalts (1920) Suggested Gestalt
theory as general law of nature
War and Science
Artificial Intelligence
• Is the intelligence of the computer
the same as that of the human?
• Initially, idea eagerly accepted
• 1950 Turing test: can a subject
interacting with a computer be
persuaded that he/she is
communicating instead with a
human?
Alan Turing (1912-1954)
• Chinese Room Problem
• Deep Blue vs. Kasparov
Properties of a Hebb Synapse
Hodgkin and Huxley
• Alan Lloyd Hodgkin and Andrew
Huxley explain the mathematics
and chemistry in the squid giant
axon in 1952
• If one neuron can be explained
with math, perhaps the same is
true for the whole system (brain)?
• This discovery corresponded with
advances in computer technology
Rosenblatt Perceptron (1958)
• Learned to categorize
– The perceptron had to be trained
• If it was wrong, connections were adjusted
The Founding of Cognitive Psychology
• No single founder
• George Miller: Seven +/- 2
• The computer and brain
– Both electric
– Process information in stages
– Software can be modified (like
synapses)
Darwin’s Theory
• Variations in traits are the norm
– They are inherited (through
genes)
– New variations appear
spontaneously (genes mutate)
• Changes in the environment will
put selective pressures on these
traits. Some will survive, some
won’t
Some Sociologists Did Not
• Looking for Utopia
– Margaret Mead in Samoa
– Described a culture in which
• Gender roles were reversed
• No sexual jealousy
• No rape, murder or war
• Results were appealing to those
who were concerned about trends
in Western societies
• Results were later challenged
Common Misunderstandings about Evolution
1. Human behavior is genetically determined
–
Environment plays a large role
2. If it is evolutionary, we can’t change it
–
We have the power
3. Current mechanisms are optimally designed
–
–
Environments change faster than genes. We
are stone -age people in a modern world
(McDonalds Effect)
Every adaptation has a cost and perfecting one
system will probably compromise another
Limitations of Evolutionary
Psychology
• You can explain the physical properties of an
animal with fossils, but behavior can only be
inferred.
• Physical properties often evolve to facilitate
behavior, so we can take some guesses
• Evolutionary psychology relies on genetics and the
assumption that all current behaviors served a
survival-based purpose in the past, if not currently.
• So what do you do…?
Observe, Hypothesize and Test
• Phobias
– Behaviorist approach (Everything is learned)
• If you fear snakes, you must have been bitten
– Evolutionary approach
• Phobias represent an exaggeration of a useful survival tool
• An inborn fear of snakes provides a survival advantage
• Most phobias have a legitimate basis (spiders, snakes,
heights, strangers, closed spaces, open spaces)
• Phobias to modern threats (guns, electrical outlets) are rare
Choosing a Mate
• Observe behavior and look for an
explanation
– Men and women both get jealous, but men
are much more likely to get violent about it
– An evolutionary explanation:
• Men face the problem of paternity uncertainty
• It is important to defend the “genetic territory”
• Men are, of course, generally more aggressive
Who’s Manlier?
Who’s Ovulating?
What about this?
Evolutionary Psychology may
be the Unifying Principle
• It has tackled
– Law
– War
– Religion
– Economics
– Advertising
– Architecture
– Cognition, Education, Sociology, etc.