Transcript Document

History of Psychology 2007
Lecture 7
Professor Gerald C. Cupchik
Office: S634
Email: [email protected]
Office Hours:
Wednesdays 1-2 pm
Thursdays 12-1 pm
T.A: Michelle Hilscher
Office: S150
Email: [email protected]
Office Hours:
Thursdays 11-12; 3-4 pm
Course Website: www.utsc.utoronto.ca/~cupchik
“Great Developments in the 19th Century”
One of the two main streams in intellectual development
contrasted Naturalism versus Anti-Naturalism (Greeks) and The
Enlightenment approach to knowledge with that of the German
Rationalists. This is essentially a contrast between atomistic
and holistic approaches. Today we will consider the
implications of the atomistic approach for the development of
scientific psychology.
The atomistic stream can be traced back to Greek
Naturalism. We will recall the basic tenets of this
Materialistic approach:
1. Monistic – rejects mind/matter distinction
- Matter is fundamental
- Explain all by physical laws
2. Atomistic – reduce complex to simple
- Reduce matter to smaller parts which are accepted as
fundamental
3. Reduce quality to quantity
- Qualities such as red and blue, sweet and sour, warm and
cold are reduced to wavelengths of light, chemical reactions
in receptors and transmission of molecular motion.
- Qualities are secondary, to be restated eventually as
quantitative differences in the behaviour of a single primary
substance.
4. Reduce function to structure
- Organisms behave as if trying to maintain
themselves,
seeking
appropriate
food,
defending against danger, selecting mates.
- These are organismic functions with purpose.
- From a materialist viewpoint, purpose cannot exist in
nature.
- Purposive functions must be explained in terms of
structures which have evolved (through natural selection) in
such a way that the species is preserved.
- The structure is inherited or built up through learning
(e.g., structure of the eye)
- The fine distinctions of logicians refer to structural
relations among cortical elements.
This approach was revived during the Renaissance by scholars
in Italy and elsewhere who focused on nature in the absence of
dogma as the real authority; the new naturalism. It was
accompanied by major scientific revolutions including the new
heliocentric theory proposed by Copernicus (1473-1543) and
refined by Kepler’s (1571-1630) laws of planetary (elliptical)
motion, Galileo’s (1564-1642) dynamics of moving bodies, and
Newton’s (1642-1727) principle of gravitation, laws of motion,
and analysis of white light as a mixture of colours.
PHYSIOLOGY
Biological science started as medical science which, with the
Greeks and before them, was a mixture of anatomy, surgery and
knowledge of medicinal plants, supplemented by magic and
other dogmatic principles. The law forbade the dissection of
human bodies so that advances in the correct knowledge of
anatomy depended on animal dissection. So physiological
knowledge was held back by ignorance of anatomy.
Major Figures in the Development of Physiology
1. Hippocrates (ca. 460-370 BC) – He was the “father of
medicine” who showed rare objectivity toward medical facts but
he lacked anatomical knowledge.
2. Galen (ca. 129-199 AD) – He was a good observer and limited
experimenter. He: (i) localized the mind in the brain, and (ii)
distinguished between sensory and motor nerves, an idea which
was lost and rediscovered in the 19th century.
In the 16th century dissection of the body was
being practiced, although with opposition from
the Church. Both Leonardo da Vinci and
Michelangelo performed dissection. In other
words, artists were one step ahead of the
scientists.
3. Andreas Vesalius (1514-1564) – Born in
Belgium. He marked the triumph of observation
over dogma in medicine. By 1537 he was lecturing to large
audiences in anatomy. It took another century to pick up on his
work of which the church disapproved.
Vesalius was born into a family long associated with the
medical care of the imperial dynasty, most notably being his
father who was the pharmacist for Charles V of Germany. From
an early age, Vesalius showed an inclination to follow in the
family tradition through his dissection of dead birds and mice.
He studied at the University of Leuven from 1530 until 1533,
when he began his studies at the University of Paris under
Jacobus Sylvius and Johann Guinter.
At the outbreak of the war between France and the Holy Roman
Empire in 1536, Vesalius returned home to complete his
studies at the University of Leuven, where he received his
medical degree in 1537.
In the autumn of 1537, Vesalius enrolled in the medical school
of the University of Padua, and received his doctorate of
medicine shortly thereafter. Upon his graduation, he was
immediately offered the chair of Surgery and Anatomy
(explicator chirurgiae) at Padua, where he began giving public
lectures. His innovative lectures and course plans were unique
for two reasons. First, he performed his own dissections rather
than reading aloud while a demonstrator did the dissection and
second, because he used drawings to aide his teaching. These
drawings became an integral part in his teaching, and later in
his published works.
Soon thereafter, Vesalius became interested in the validity of
Galen's findings, and began his study on human anatomy
and his major work, De humani corporis fabrica. In 1539, a
Paduan judge became interested in Vesalius' work, and made
bodies of executed
criminals available for
dissection.
His
collection of detailed
anatomical diagrams
grew,
many
were
produced by artists
and were of better
quality than previous
diagrams.
His
diagrams
became
known as the first
accurate set to be
produced.
4. William Harvey (1578-1657) – He did for physiology what
Vesalius had done for anatomy. Through observation and
experiment, he worked out the exact connection of the cavities
of the heart with each other and with the lungs, the arteries,
and the veins. The connections and the valves showed the way
the blood must be flowing.
Harvey’s work appears very
modern: he experimented and
obeyed the injunction of the
Paduan anatomists to see for
oneself. ‘I profess to learn and
teach anatomy not from
books but from dissections,’
he declared, ‘not from the
tenets of Philosophers but from the fabric of Nature.’ But that
is only half true; certainly he looked for himself (and without
the aid of the microscope), but he saw through Aristotelian
spectacles. Harvey did not, as sometimes supposed, conceive
of the body in a ‘modern’ mechanical fashion: it was too a
machine, but was moved by vital forces.
In discussing the circulation, he wrote, drawing on traditional
macrocosm/microcosm correlations, that it was to transport
life-giving blood to the periphery and then to return it to the
heart where it could be re-enlivened.
There was no burst of good work in scientific physiology right
after Harvey nor in fact in the 18th century. In the 19th century
there was a chain reaction, one discovery making another
possible, one enthusiasm setting off another. This work in the
19th century laid the foundation for experimental physiological
psychology.
Interestingly, this kind of work appealed more to the Germans
than to the English or French scholars. Why did scientific
psychology begin in Germany? It began as taxonomic
description.
While
we
associate
Germans
with
a
phenomenological approach, its real foundation has to do with
description, classification and induction which contrasts with
the mathematical and deductive approaches. This requires the
attitude of a painstaking and methodological culture.
Biology was not yet ready to lend itself to great generalizations.
So the Germans took up the task of collecting observational
facts that were sound, detailed, conscientious and thorough.
So psychology joined the family of sciences because the
Germans had faith in collecting data and welcomed biology
into the circle of science. The French and English hesitated
because biology did not fit with the scientific pattern set by
physics. The holistic attitude of the Germans saved the day.
Physiology in the First Half of the 19th Century
There are 9 major developments between 1800 and 1850 all
but two of which belong as much in the history of physiology.
None of these findings were made by scholars who considered
themselves to be psychologists.
1. Sensory and Motor Nerves
Sir Charles Bell (1774-1842) re-discovered the fact of the
differences between sensory and motor nerves in the spinal
cord – that they were anatomically and functionally discrete.
Rule: The posterior or dorsal roots of the spinal cord contain
only sensory fibres and the anterior roots only motor fibres.
Bell later showed that some cranial nerves are entirely sensory,
some entirely motor, and some mixed.
He later established the law of forward direction in the nervous
system which holds that conduction in a nerve normally flows
in one direction.
The significance of this work:
We could no longer regard the nerves as transmitting both the
powers of sensation and of motion.
[Note that Francois Magendie made the same discovery
independently but later and he had the more convincing
experiment. He was also a notorious vivisector whose shocking
dissections of live animals led in England to anti-vivisection
laws.]
2. Reflex Action
This research was basic to the conception of reflex action and
the reflex arc. Bell published the results privately in 1811 in a
pamphlet (100) for his friends and colleagues.
In 1751, Robert Whytt, a Scot (1714-1766), described
experiments with frogs showing that the spinal cord was both
necessary and sufficient for many automatic movements which
occur in response to stimulation when the spinal cord is
severed from the brain. He distinguished between:
i.
Voluntary movement, which is an act of will
ii. Involuntary spontaneous movement which occurs
instantaneously with no time for the exercise of reason but it
was dependent on sensation in the nervous system.
M. Hall (1790-1857) distinguished between conscious
voluntary movement and involuntary movement dependent
only on the spinal cord, independent of the brain and
consciousness.
The unconscious reflexes were relegated to physiology. The new
physiological psychology, which got under was around 1850,
was organized as a psychology of conscious voluntary action
and reaction time.
The distinction broke down with (1) Pavlov’s demonstration
that unconscious movements can be learned (conditioned
reflex) and (2) Freud’s discovery of unconscious motives and
thinking.
3. Electrical Nature of the Nerve Impulse
The 17th century furnished a means for generating static
electricity and the 18th century made it more available by the
invention of the Leyden Jar (1745).
Galvani began experiments on the
stimulation of frog’s legs by electric
discharges. In 1791 he produced a
kick in the frog’s leg with an electric
charge and concluded that animal
tissues generate electricity.
Volta showed that this kind of
electricity can be had without animal tissues by creating an
inorganic battery. He thought that he had disproved animal
electricity.
du Bois-Reymond developed a theory of the polarization of
animal tissues in 1848-49. He argued that muscles and nerves
consist of electrically charged particles with a positive charge
on one face and a negative charge on the opposite one, oriented
like a magnet. This relates to the modern concept of
polarization. He brought the nervous impulse out of the
mystical realm of animal spirits and into material science
suggesting to Helmholtz that the activity of the impulse may
not be instantaneous but finite and measurable.
4. Velocity and Conduction of the Nerve Impulse
It had been supposed that the velocity of the nervous impulse
was so rapid as to be practically immeasurable.
i. 9000 ft/min
ii. 32,400 ft/min
iii. 57,600 ft/sec which is 60 times the velocity of light.
Haller’s estimate of 150 ft/sec is close to the truth which is 3400 ft/sec depending on the diameter of the conducting fibre.
It is important for psychology to determine that transmission is
not instantaneous but relatively slow.
To separate the movement of a finger in time from the event of
will that caused it was in a sense to separate the body from the
mind.
So bodily motion becomes part of a series of events and this
contributed to the materialist view of the psycho-physical
organism that was the essence of 19th century science.
Other developments:
Electrical depolarization – Bernstein (1866)
-Wave of negativity passing along the nerve.
All or none principle – Bowditch (1871)
-A nerve fibre supplies the energy for an impulse and is
completely discharged when excited.
5. Specific Energy of Nerves
Müller (1826) – The central principle is that (1) we are directly
aware, not of the object, but of our sensory nerves themselves.
So the idea is that the mind is the result of a reaction excited
in the eye or brain and not of anything received. The operation
of the mind is determined by the kinds of senses that we have.
(2) There are five kinds of nerves (specificity); each kind imposes
its specific quality on the mind.
So the quality of sensation depends not upon the nature of the
cause but upon the nature of the nerve which the cause
affects.
Now we know that qualitative differences lie not in the nerve
excitation themselves but rather different central effects.
6. Phrenology
Phrenology relates to the problem of where the mind is located
in the body. It was not commonly held that the mind was in
the brain. Phrenology tried to establish that:
(1) The brain is the organ of the mind.
(2) Particular parts of the brain are associated with separate
mental faculties.
HISTORY
Aristotle: Mind 
Egyptians: Thought 
; Judgment 
Pythagoras: Seat of mind and intellect 
Plato: Seat of mind    
Alexandrian anatomists: Seat of mind  Also brain
Descartes: Soul  in the entire body but specifically the pineal
gland; did not identify the brain with the mind.
The modern idea of the brain as the seat of the mind emerged
in the 19th century. It was prepared in the late 18th century by
Jean Baptiste Pinel. After Pinel, possession was treated as
a disease. To recognize the mind as subject to disease
orients us towards the idea of the mind’s dependence on
the body, the usual seat of disease.
A Little History
The first humane impulse of any considerable importance in
this field seems to have been aroused in America. In the year
1751 certain members of the Society of Friends (Quakers)
founded a small hospital for the insane, on better principles, in
Pennsylvania. To use the language of its founders, it was
intended “as a good work, acceptable to God.‘” Twenty years
later Virginia established a similar asylum, and gradually
others appeared in other colonies.
But it was in France that mercy was to be put upon a scientific
basis, and was to lead to practical results which were to
convert the world to humanity. In this case, as in so many
others, from France was spread and popularized not only the
scepticism which destroyed the theological theory, but also the
devotion which built up the new scientific theory and endowed
the world with a new treasure of civilization.
In 1756 some physicians of the great hospital at Paris known
as the Hotel-Dieu protested that the cruelties prevailing in the
treatment of the insane were aggravating the disease; and
some protests followed from other quarters. Little effect was
produced at first; but just before the French Revolution,
Tenon, La Rochefoucauld-Liancourt, and others took up the
subject, and in 1791 a commission was appointed to
undertake a reform.
By great good fortune, the man selected to lead in the
movement was one who had already thrown his heart into it Jean Baptiste Pinel. In 1792 Pinel was made physician at
Bicetre, one of the most extensive lunatic asylums in France,
and to the work there imposed upon him he gave all his
powers. Little was heard of him at first. The most terrible
scenes of the French Revolution were drawing nigh; but he
laboured on, modestly and devotedly - apparently without a
thought of the great political storm raging about him.
His first step was to discard utterly the whole theological
doctrine of ``possession,'' and especially the idea that insanity
is the result of any subtle spiritual influence. He simply put in
practice the theory that lunacy is the result of bodily disease.
It is a curious matter for reflection, that but for this sway of
the destructive philosophy of the eighteenth century, and of
the Terrorists during the French Revolution, Pinel's blessed
work would in all probability have been thwarted, and he
himself excommunicated for heresy and driven from his
position. Doubtless the same efforts would have been put forth
against him which the Church, a little earlier, had put forth
against inoculation as a remedy for smallpox; but just at that
time the great churchmen had other things to think of besides
crushing this particular heretic: they were too much occupied
in keeping their own heads from the guillotine to give attention
to what was passing in the head of Pinel. He was allowed to
work in peace, and in a short time the reign of diabolism at
Bicetre was ended.
What the exorcisms and fetiches and prayers and processions,
and drinking of holy water, and ringing of bells, had been
unable to accomplish during eighteen hundred years, he
achieved in a few months. His method was simple: for the
brutality and cruelty which had prevailed up to that time, he
substituted kindness and gentleness. The possessed were
taken out of their dungeons, given sunny rooms, and allowed
the liberty of pleasant ground for exercise; chains were thrown
aside. At the same time, the mental power of each patient was
developed by its fitting exercise, and disease was met with
remedies sanctioned by experiment, observation, and reason.
Thus was gained one of the greatest, though one of the least
known, triumphs of modern science and humanity.
Phrenology emerged due to the work of
Franz Joseph Gall (1758-1828) who was
an anatomist. As a schoolboy, he observed
a relationship between mental qualities of
his school mates and shapes of their heads
(e.g., prominent eyes and good memories).
His doctrine gained public attention and
the church tried to have the government of
Austria force him to discontinue his
lectures. He moves to France!
The Basic Propositions
1. Phrenologists must show conformation of exterior to interior
skull and brain.
2. The mind can be meaningfully analyzed into a number of
faculties or functions.
3. Faculties and powers of the mind are localized in the brain
and an excess of any faculty is correlated with an enlargement
of the corresponding place in the brain. So a protrusion of the
brain would indicate an excess in the particular faculty.
Phrenology flourished for a century. There were 29 societies in
Great Britain and several journals. But it was never accepted
as a science even though it retained popular appeal even
though knowledge of the brain physiology rendered it
impossible.
The importance of phrenology lies in its effect on
scientific thought of the period.
From a negative standpoint:
(1) Physiologists disbelieved the relation of the skull to the
brain.
(2) Philosophers objected to analysis of the mind into faculties
because it violated the principle of unity of mind.
But, while essentially wrong, it furthered scientific thought by:
(1) Establishing the brain as the organ of the mind.
(2) It suggested localization of function in the brain.
It mediated between the Cartesian concept of an
unsubstantiated soul and the concept of mere material neural
function. Phrenology was wrong only in detail.
7. Physiology of the Brain
A. The French physiologist Bichat (1771-1802) assumed a
connection between the mind and brain. He felt that the brain
is the centre for intelligence, perception, imagination and
judgment but that emotions are centred in the internal organs.
Gall’s specific psychophysiology made a radical but less
extreme view seem conservative. He prompted Pierre Flourens
to associate different functions with the cerebrum, cerebellum,
medulla and spinal cord. So Flourens mediated between the
too vague tradition of Descartes and the too specific doctrine of
the phrenologists. His conclusions were based on
experimentation.
Moment in scientific wisdom. He said “There is a great secret
behind being brief. That is to be clear.” Flourens substituted
carefully planned experiments for nature’s experiments that
occur in accidental lesions and disease. Using animals, his
method was the extirpation of parts and he looked for a
correlation between brain area and function. For example, the
function of the cerebral cortex is willing, judging, and seeing.
He distinguished six parts.
He also distinguished “action propre” from “action commune”.
“Action propre” or exact localization implies a special function
for each of the 6 parts (in the direction of Gall).
“Action commune” or field theory implies a general function
such that the removal of one part reduces the energy of every
other. This is related to the unity of mind which philosophers
had contended.
B. The improvement of the microscope around
1830 led to histological research. Luigi Rolando
first thought (1824) of cutting thin sections of
brain tissue chemically hardened for microscopic
examination. This procedure was important
because Flourens had divided the brain into a few
gross parts each with its own function. But he
didn’t analyze further within each part.
The histological work led the brain to be considered as
composed of an almost infinite number of separate cells
which connect in a complicated network. This view of the
brain bore a close resemblance to the picture of the mind
adhered to by the Associationists, the dominant psychology of
the period which held that the mind consisted of an infinitude of
ideas. These ideas are bound together into more complex ideas
by association, just as the nerve cells are connected by fibres. In
sum, the new knowledge of the division of the brain into many
tiny interconnected units implied that further separation of
localized mental functions should be sought. Later research
localized functions such as hearing, somesthesis, and sensation.