Chapter 8

Early Developments in Physiology and the Rise of Experimental Psychology

Zeitgeist of the 19th Century

• Except for the 20th, the 19th century saw the greatest amount of change in history
  • chemistry establishes itself as a science
  • discoveries in electricity and magnetism
  • change in transportation technology
    • from horses to trains
  • maturing and spread of the industrial revolution
  • population movement into cities
  • go to Sault Ste. Marie to see 19th century today
• Discoveries in physiology
  • Bell-Magendie Law
    • organization of nervous system into sensory and motor parts
  • Broca
    • localization of speech function
  • Muller
    • doctrine of specific nerve energies
    • see with your ears
  • Helmholtz
    • "greatest scientist of the 19th century"
    • measured speed of nerve impulse and much more
• The German University Model
  • recall the medieval university
    • Trivium
      • logic, grammar, and rhetoric
    • Quadrivium
      • geometry, astronomy, arithmetic, and music
    • Dependent Arts
      • medicine, law, and chronology
  • the new model
    • specialist faculty organized into schools and departments
    • look at SAU
      • Business
      • Education
      • Liberal and Performing Arts
      • Science and Technology
  • other German factors
    • emphasis on description and classifaction as necessary first steps to science
    • science was broadly construed--scientists could attack a wide variety of problems
    • number (24) and prestige of universities and their faculty
• The American University Model
  • most started and remained seminaries
  • faculty were generalists
  • Daniel Coit Gilman and Johns Hopkins University (1876)
    • first American university to use the German model
    • followed by others (University of Chicago, 1892)
    • now a nearly universal model (exception: St. John's of Annapolis and Santa Fe)

Maskelyne and Kinnebrook and the Personal Equation

• Maskelyne was an astronomer and Kinnebrook was his assistant
• They were setting ships clocks, but Kinnebrook was consistently slower.
• Maskelyne warned Kinnebrook, but the discrepancy got worse instead of better
• Kinnebrook was fired
• Bessel, twenty years later, resolved the issue
  • personal equation
  • discovery of individual differences
  • first example of a reaction time study
• Theme of chapter:
  • the replacement of naive beliefs by scientifically-based beliefs
    • Kinnebrook and personal equation
    • Helmholtz and speed of nerve impulse
    • colorblindness

Effect of Phrenology

• Phrenology was a good hypothesis but the data did not support it
• The hypothesis was that as the brain developed, those parts with more development than others distorted the skull accordingly.
• Then, a phrenologist could get an indirect measure of brain's faculties by feeling for the bumps
• Incredibly popular
  • public believe the phrenologists
  • machines were developed to automate the process
  • popularity can still be seen today (ASPS posters, for instance)
• Franz Josef Gall
  • popularized phrenology
  • discovered differences in white and grey matter
• Johann Gasper Spurzheim
  • Gall's student
  • spread term "phrenology" that had been coined by Thomas Foster
  • came to U.S. (and died there)
  • origin of "formal discipline," an influential but wrong view of education
• Pierre Flourens
  • invented ablation method of brain research
  • found evidence for whole brain functioning
• Paul Broca
  • discovered "Broca's area"
  • provided new evidence of localization, but scientifically grounded (unlike phrenology)
  • biased in other research, however (craniometry)
• Further evidence of localization
  • Gustav Frisch and Edward Hitzig discovered motor cortex
  • David Ferrier discovered the sensory cortex

Hermann von Helmholtz

• Studied with Muller, but disagreed with him over vitalism
  • supposedly signed an anti-vitalistic oath in bloodwith other students!
  • Demonstrated that principle of conservation of energy could be applied to animals
• Rate of nerve conduction
  • naive belief: it was instantaneous
  • used both frogs and humans to demonstrate that it could be measured
• Perception
  • sensation and perception defined
  • unconscious inference
    • people unconsciously use what they already know to aid in their perceptions
    • systematically destroyed Kant's categories, showed they were learned
    • agreed with Kant that sensations are converted in mental categories by the action of the mind
• Color vision
  • Young-Helmholtz (or trichromatic) theory
  • three types of cones: red, green, and blue
  • expansion of Muller's specific nerve energies
• Auditory Perception
  • Argued that cochlea and basilar membrane were analogous to eye in action
    • i.e., basilar membrane vibrates sympathetically to sounds of different pitches
• Summary of Helmholtz
  • Assumed an active mind like Kant, but unlike Kant discovered real relationships between mind and stimuli
  • Believed that some kind of "signs", not the world itself, were perceived
  • First to apply rigor of experimental method to philosophy

Ewald Hering

• Studied with Josef Breuer (as did Freud later)
• Succeeded Jan Purkinje at University of Prague
• Opponent process theory of color perception
  • three types of color receptors
    • red--green
    • blue--yellow
    • black--white
  • color afterimages
  • color blindness

Ernst Weber

• University of Leipzig (remember this school), Professor of Physiology
• Studied kinesthesis for the first time
• Discovered the two-point threshold
  • report of two points touching varies by location on body
• Weight discrimination research led to JND (just noticeable difference or difference threshold)
• Weber's Law
  • first statement of relationship between physical world and psychological world
  • DI/I = K
    • different K for each psychophysical system
    • the greater the initial value, the greater the difference had to be in order to be perceived

Gustav Theodor Fechner

• University of Leipzig (there's that school again), Professor of Physics
• Worked with electricity first, then had "nervous breakdown"
• After a hiatus of several years, turned to philosophy
• "Dr. Mises"--his pseudonym under which he published satirical articles
• Created psychophysics while trying to "solve" mind-body problem
• Independently discovered Weber's Law as:
  • S = k log R
    • where S = sensation
    • R = stimulus (reiz in German)
  • mathematically equivalent to Weber's Law
• Fechner also developed methods for measuring psychophysical effects:
  • method of limits
    • one stimulus at a time compared to same standard
  • method of constant stimuli
    • pairs of stimuli are presented, one is the standard
  • method of adjustment
    • subject must make a variable stimulus percetually equal to a standard
• Fechner gave Weber credit for priority by naming his own discoveries: "Weber's Law"
• We now give both credit by using "Weber-Fechner Law"
• Modern psychophysics uses "power law"

Summary

• Much changed in physiology in 19th century
• Not yet a true psychology, but stage was set for Wundt

URLs

• The Johns Hopkins University
  • Home of page of Johns Hopkins University. Johns Hopkins was founded in 1876 to explicitly copy the then new model of the German university. http://www.jhu.edu/
• The University of Chicago
  • Home page of the University of Chicago. http://www.uchicago.edu/
• St. John's College
  • Home page of St. John's College of Annapolis and Santa Fe. The college uses a "great books" curriculum. http://www.sjca.edu/
• Psychophysics Defined--text, basic, short
  • Definition of psychophysics from text, Fundamentals of Scaling and Psychophysics. http://www.psychology.su.se/external/ISP/definition.html
• How We See--tutorial, interm., long, links, graphics
  • Complete tutorial on the basic processes of vision, also includes links to related classroom activities. http://www.gene.com/ae/AE/AEC/CC/vision_background.html
• Trichromatic Theory of Color Vision--NEW--text, basic, short, links
  • Describes the basics of the Young-Helmholtz theory of color vision. http://www.yorku.ca/eye/trichrom.htm
• Opponent Process of Color Vision--NEW--text, basic, short, links
  • Short summary of Hering's theory of color vision. http://www.yorku.ca/eye/opponent.htm
• Purkinje Shift--NEW--tutorial, interm., short, links, graphics
  • Short tutorial describes the Purkinje shift (a visual perceptual phenomenon). http://server.esc.cquest.utoronto.ca/psych/psy280f/ch3/purkinje/ps.html
• Introduction to Cochlear Mechanics--tutorial, intermediate, short, links, graphics
  • Tutorial on the cochlea and its action, topics are: location of the cochlea, inside the cochlea, physiological measurements, outer hair cell motility, the cochlear amplifier, and traveling waves. http://www.boystown.org/cel/cm_intro.htm
• Taste and Smell--tutorial, interm., long, links, graphics
  • Basic information with diagrams on the function of the gustation and olfactory systems. http://www.umds.ac.uk/physiology/jim/tasteolf.htm
• Touch Perception--tutorial, interm., long, links, graphics
  • Comprehensive tutorial with graphics on the skin senses, discusses: touch, proprioceptive sensations, pain, and thermal sensations. Also includes graphic of sensory homunculus and table of skin sensitivity by body location. http://www.science.mcmaster.ca/Psychology/psych2e03/lecture11/touch.lecture.html
• The Vestibular System--tutorial, basic, short, links, graphics
  • Five linked pages on the anatomy and function of the human vestibular system, includes animation of pathway of the vestibular-ocular reflex. http://132.206.103.223/lab/vestib1.htm
• Proprioception, Kinesthesia, and Motor Reflexes--tutorial, interm., long, links, graphics
  • Page covers nearly all aspects of: proprioception, kinesthesia, and motor reflexes. Has color graphics included with its explanations. http://nan.drexel.edu/nan/neuroanatomy/lectures/lec12b/lec12b.html