- Describe the significant early developments which contributed to our current understanding of brain-behavior relationships.
- Discuss the phrenology story and indicate the hypotheses that were correct versus those which wern't and explain why.
- What is the current status of the mind body problem?
- Explain the evidence for and against localization of function.
- Explain what Pierre Florens & Karl Lashley meant by equipotentiality.
A. Early Developments Related to Physiological Psychology
Early Egyptians Thought heart & liver were the vital organs; "not the brain"
B. Localization of Function
Alcmacon (5th Century): Thought brain was "seat of the soul"
Plato 4th Century): Also thought brain was "seat of the soul"
Hippocrates (400 BC):
a. Emphasized that the brain was organ of intellect.
Aristotle (3rd century BC): believed function of the brain was to cool the blood.
Herophilus (3rd century BC):
b. Brain controlled senses and movement.
c. Lesion produces a contralateral effect.
a. Brain was organ of intellect.
Galen (2nd century BC): Influenced medical thought for 1000 years.
b. Third ventricle responsible for cognition.
c. Fourth ventricle was seat of soul.
a. First experimental physiologist.
Catholic Church during the middle ages, proposed view of natural & animal spirits.
b. Concluded it was not the
ventricles but the brain that was important.
c. Frontal lobes was seat of soul.
- Franz Joseph Gall (1758-1828) promoted the concept of localization of function.
- Meynert - Frontal - motor and the posterior - sensory.
- Bouilland & Broca (1800's) - left frontal area for expressive language function.
- Wernicke (1800's)- left temporal receptive language function.
- Fritz & Hitzig (1890) - mapped the motor strip (pre-central gyrus of the frontal lobes).
- Helmholtz - measured speed of conduction of nerves (90 ft/sec)
- Ferrier & Munk (1900's) - identified areas for vision, augition, & skin senses
- Overemphasis on localization remained from the 1880's to the 1930's.
a. Faculties located in different organs or centers in the brain.
b. Centers in the cortex were expansions of lower centers.
c. Centers were independent in function but able to interact.
d. Corpus collosum joined the 2 hemispheres.
a. Based on the idea that behavior (mind) can be divided into components (faculties).
Spurzheim (1880's): Elaborated Gall's theory.
b. Specific faculties related to specific cortical areas.
c. Use of faculty related to cell growth.
d. Growth produced a bump on the skull.
a. Initially supported Galen's ideas but overcame this thinking.
Willis (1664): Thought that the corpus striatum was responsible for mental functions.
b. Thought mental functions were in corpus alba.
- Flourens used the experimental method to try to refute the claims of the phrenologists.
- Hughlings Jackson was resistant to localization.
a. He approached the problem from the idea of level of construction rather than specific localization.
b. His ideas were too complex for the time.
- Monakow, Head, & Goldstein
a. Many functions are the result of activity of the whole brain.
b. Categoric behavior - highest level, dependent upon mass of the brain rather than specific localization.
- Marie (1906) examined one of Broca's brains and found widespread damage attacking his theory.
- Lashley (1930's) discovered data which tended to refute localization.
Found size of damage more predictive of effect than specific location.
Mass actionSpecific function is shared by all neurons in association cortex.
Equipotentiality - All neurons within a sensory area share equally in determining function.
- Chapman & Wolff (1950's)demonstrated Lashley's findings with humans.
- Broca (1861)
a. Investigated expressive language area in patient named Tan.
b. Studied 8 patients overall.
c. Found that the posterior 1/3 of the left inferior frontal gyrus functioned as the center for motor images of words
d. This was the first time that a complex mental function had been localized in a particular part of the cortex.
- H. Jackson (1868) Postulated two types of language functions.
- Wernicke (1874)
a. Discovered the receptive language area in the posterior 1/3 of the superior temporal cortex.
b. This area was identified as the area for the sensory images of words.
- Goldstein (1927, 1944, 1948) acknowledged localization but stressed that brain functions such as ability to deal with abstraction resulted from the interctions of the brain as a whole.
- During WWII localization was abandoned for wholistic approach.
- H. Jackson emphasized levels of function.
- Luria discussed functional systems.
- Geschwind held theory of brain function oriented toward connection.
- Functionalism: Natural selection and Evolution
- Functionalism - assumes characteristics of living organisms perform useful functions.
- Mutations - occur frequently and a few offer a selective advantage.
Biological Roots of Physiological Psychology
G. Experimental Physiology
doctrine of specific nerve energies
- Muller - first to advocate use of experimental techniques to physiology. Also developed the
a. First scientific studies related to brain function.
b. Found that the brain functions as if composed of areas of specific function.
c. But specific areas interact to function as a whole.
d. Studying pigeons & chickens, he found that loss of function depends upon the extent of damage (equipotentiality).
Galvani - found that electrical stimulation of nerve caused muscle to contract. Even if separated from nerve, stimulation caused contraction.
H. Philosophical Roots of Physiological Psychology
Animism: Basic theory that all things are controlled by animating spirits.
- Dualism - belief that reality was divided into 2 categories: material & spiritual. (Thought mind and body were separate).
- Aristotle: Thought the mind was separate from the body & could not be destroyed.
a. Believed ventricles controlled body via hollow tubes (nerves).
b. Pineal body was thought to be the controlling mechanism.
c. Thought the soul was in the pineal gland.
- Monism - belief that reality consists of an unified whole. (Belief that mind and body were the same.)
- Free will - able to control our behavior; mind not constrained by physiology. In the lab must act like determinists (look for physical causes of behavior).
- Pluralism - mind, brain, and scientific knowledge.
Psychoneural Identity Hypothesis - mental and brain processes are one and the same (without brain there can be no mind).
I. Contributions of Modern Psychology
The Goals of Research - Two forms of scientific explanation (generalization & reduction)
Physiological research involve both generalization & reduction.
- Generalization - explain behavior as examples of general laws.
- Reduction - explain phenomena in terms of simpler phenomena.
- Levels of Analysis - cellular, intercellular, behavioral, and social.
The Scientific Method:
Independent verification of results.
J. The Value & Ethics of Research with Animals
Terms to Know
Links to Associated Areas