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Those who do not know the history of their field are doomed to repeat its mistakes (Santayana). PHILOSOPHY (600BC present). BIOLOGY (15th century present). PSYCHOLOGY (2nd half of 19th century present).
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Those who do not know the history of their field are doomed to repeat its mistakes(Santayana)
PHILOSOPHY (600BCpresent) BIOLOGY (15th centurypresent) PSYCHOLOGY (2nd half of 19th centurypresent)
PRE-GREEK ZEITGEISTPeople observed alternations ofrhythms:day and night, seasons, famines, etc.Awareness and recall of dreams: images of dead people, animals, composites. Concerns about the nature of things, - Cosmologiesdevised as explanations.Motivation for cosmologies was not scientific, e.g., predicting eclipses, droughts, etc. That wasengineering, not science.Cosmologists formulatedhypotheses about the basic units of things:- water, fire, air, earth, numbers. Pythagoras is a well known example. He believed that numbers held the secret of everything.
REDUCTIONISMDemocritus was the first cosmologist to attempt to explain things byreductionism.In about 400 BC, Democritus postulated thatatoms were the basic unit of all matterand that there were two types of atoms:-body atoms(inert)-soul atoms(vital substance)Democritus is also credited with introducing themind-body distinction.
DYNAMIC VS. RELATIONAL COSMOLOGIES:Dynamic (Heraclitus):Things are always in flux. Consciousness is never the same at successive points of time. -A basic problem for all sciences:how do static units change over time?Relational (Anaxagoras):It is not meaningful to talk about elementary units without specifying theirorganization.The whole is greater than the sum of its parts.
REACTIONS TO COSMOLOGIESHow do we know about reality? -Through senses? -Are the senses trustworthy?Epistemology:What is the nature of knowledge?Sophists: There is no absolute knowledge.We only know what our senses tell us.
Plato (Socrates?) & AristotlePlato:Rejected relativism of Sophists and sharpened the mind-body distinction: Reason supplements what we learn through sense organs and functions independently of the senses.The function of the soul is to apprehend idealknowledge of the worldthrough reason, to provide a means of going beyond the imperfect data of the senses and for defining the universals of beauty, goodness, mathematics, etc. (cf. Descartes, Kant, Chomsky).Aristotle:Defined theempiristic point of view [tabula rasa].He did not accept the universals of knowledge that Plato postulated.
Aristotle(384 -322 BC) Mind should be interpreted, not as a thing, but as a process. Perhaps he would prefer to say "minding" as a verb rather than "mind" as a noun.Believed that Mind was in the heart.
GREEK HERITAGEDualism: mind vs. body: What is the nature of each entity? How do they interact? basic question of modern behavioral and cognitive psychology.Materialism vs. Idealism:Materialists: everything is reducible to some physical entity.Idealists: ideas exist independently of any material substance(Descartes, Kant, Chomsky)Nativism vs. Empiricism:Nativists: Knowledge exists independently of experience(knowledge may be material, e.g., brain states as postulated by modern theories of in neuroscience).Empiricists: Knowledge derives from experience.The empiricist view defines a basic question in the study of language, object recognition, etc. Behaviorists regard the concept of tabula rasa as basic.
The Reflex Arc Rene Descartes (1596-1650)
DescartesPostulated two types of substance:1.Material (body) extended substance:Occupies Newtonian space.2.Soul (thinking) unextended matter:Does not occupy Newtonian space. -Thinking matter, unique to man, is the seat of innate ideas. -Body and soul interact in the pineal gland (but do not reside there). -Animals, who have no souls are mere automatons: mechanical robot-like creatures. Two Cartesian heritages: -mechanical action (reflexes)-modern view of innate ideas--picked up by Kant & Chomsky.
CONCEPT OF REFLEXCONCEPT OF THE REFLEXReflex: A correlation between a stimulus and a response.The stimulus releases the response, as pulling a trigger fires a bullet.*Animal spirits: flowed in hollow tubes from sense organ to muscles.*Glisson:Disproved the hypothesis of animal spirits by showing that excised muscle tissue contracts when stimulated (in a dish of saline solution). These experiments gave rise to the concept ofirritabilityandexcitability.*Concept of “Spinal mind”: suggested by results of experiment on the magnitude of the flexion reflex in frogs whose spinal cord were severed (“spinal preparation”)*Pflüger:Inferred spinal mindbecause ofvariability in the magnitude of flexion reflex.*Magnus:Showed that variability was due to uncontrolled shifts in posture.
JOHN LOCKE*Emphasized thebasic role of experience:(1690 Essay Concerning Human Uunderstanding.)*Resurrected Aristotle's concept oftabula rasa.*How does tabula rasa get impressed? *Introduced ideas as the basic unit of the mind and the concept of mentalchemistry: how simple and complex ideas interact.
Mental ChemistrySimpleideas(sensations).Complex ideas(reflection, thought, perception). Ideas can have either of the following qualities:-Primary qualities:quantitative properties of an object (e.g., mass, motion, temperature, etc.).-Secondary qualities:in the "eye" of the beholder (qualitative differences: colors, sounds, tastes, etc.).
British School of EmpiricismBerkely:claimed that all ideas were secondary in nature. God insures stability of world because He has primary ideas.Hume:Doubted existence of mind and God. All we have is a collection of ideas. What we must discover are the principles of association of those ideas (Aristotle), Hume proposed as principles of association (after Aristotle): resemblance, contiguity, and cause and effect (temporal succession).Hartley:Placed ideas in nervous system and hypothesized that they obey Newtonian laws.James Mill:All ideas are reducible to simple sensory elements.
Ronald Knox: There was a young man who said, God must think it exceedingly odd if he finds that this tree continues to be when there is no one about in the Quad.Reply: Dear Sir: Your astonishment’s odd: I am always about in the Quad and that is why the tree will continue to be since observed by Yours faithfully, God
RELEVANT DEVELOPMENTS IN BIOLOGY *Reflexology *Sensory physiology *Theory of evolution
SENSORY PSYCHOLOGY Developed out of ancient concern to understand senses. Knowledge of sensory psychology was facilitated by: - assumption that the body obeyed mechanical laws. - advances in resolution of the microscope. - the discovery of nervesBell and Megendie:Discovered independently the difference between sensory (dorsal) and motor (ventral) nerves.Müller:How many types of sensory nerves are there? Law of Specific Nerve Energies.Helmholtz:Hypothesized specific nerve energies for primary colors - red, green, blue.Gall:Phrenology.
TABLE OF SENSATONS eye 32,820 ear ? nose 4 tongue 4 skin 2 muscle 1 tendon 1 joint 3 alimentary canal ? blood vessels 1? lungs 1 sex organs 1 ear (static sense) 1 -------Total: 44,435(From E. B. Titchener “An Outline of Psychology”, NY: Macmillan, 1896 pp. 74-75.
PSYCHOPHYSICSSensory psychologists often asked subjects to make judgments. This gave rise to various mathematical generalizations about sensory function.Weber’s Law: ∆I/I = K[DIFFERENCE THRESHOLD] I = Physical magnitude of stimulus ∆I = Physical magnitude of change needed to produce a just noticeable difference (jnd) K = constantFechner’s Law: S = Klog IS = Subjective magnitude of stimulus I = Physical magnitude of stimulus K = constantStevens Law: S = KInS = Subjective magnitude of stimulus n = exponent whose value varies with sense modality K = constant I = Physical magnitude of stimulus
Theory Of EvolutionThree aspects relevant to psychology:-Variation -Continuity of Structure-Functionalism Charles Darwin
“We have seen … [that] man bears in his bodily structures clear traces of his descent from some lower form; but it may be urged that, as man differs so greatly in his mental power from all other animals, there must be some error in this conclusion....It can be shown [that] there is no fundamental difference of this kind. We must also admit that there is a much wider interval in mental power between one of the lowest fishes, as a lamprey or lancelet, and one of the higher apes, than between an ape and man; yet this interval is filled up by numberless gradations. ” (Darwin, 1871/1982a, p. 445 )
VARIATIONCharles Darwinand his discipleHerbert Spencer, argued that the logic of variation and selection also applied to behavior. Note the similarity with respect to the logic of reinforcement theory.Galton:Observed that intellectual ability varied between individuals (just as structural features vary). -Asked how can variation of intellectual ability be measured? -Argued for sensory ability as a measure of intelligence. -Experiments on individual differences led to development of I.Q. and other psychological tests. -Assumed that intelligence is innate.
BEHAVIORAL ADAPTATIONSExamples of Continuity of Biological Structure: -eyes -breathing apparatus -digestive systems -camouflage -musculatureComparative psychologistsask, is there continuity of mental ability and consciousness between animal and man? Modern examples of continuity: a. instincts - study ofethologyb. reflexes -conditioned & unconditioned reflexesClever HansMorgan’s Canon of Parsimony
FUNCTIONALISMDarwin:Structures are adaptive because they assume a certain function. -Search for structure can be facilitated by studying function. -Structure can be inferred from function, e.g., research in physiological psychology.William James: What is the function of consciousness? That topic is central to modern psychology.
PLATO NEWTON HARVEY DESCARTES REFLEXOLOGY SENSORY PSYCHOLOGY THEORY OF EVOLUTION BRITISH EMPIRICISM INTROSPECTION PSYCHOPHYSICS COGNITIVE PSYCHOLOGY