Reading for today’s lecture

B. M Thorne & T. B. Henley, Connections in the History and Systems of Psychology:

Pages 100-107, 211-216, 301-306, 318-323

Dr. Paul Dockree, History of Psychology: PS1203, 2009

Early Associationism and Connectionism

A natural neural network. The Golgi method of staining brain tissue renders the neurons and their interconnecting fibres visible in silhouette

Dr. Paul Dockree, History of Psychology: PS1203, 2009

Associationism: Learning and Memory

• Tabula rasa – “blank slate”

• Repeated experiences become habitual patterns (associated ideas and behaviours) that form our character

• First associationist – Aristotle

• Aristotle proposed three laws of association in memory:• 1. similarity - (cows and horses)• 2. dissimilarity - (hot and cold)• 3. closeness in time and space - (lightning and thunder)

• Aristotle’s biological or naturalistic account of how memories are formed: impressions and traces.

David Hartley (1705-1757)• Observations on Man (1747/42) • Physiology of Associations: Hartley undertook

to define the physiological facts upon which memory images and their sequences depend

• application of atomistic Newtonian philosophy to physiological psychology

• Vibrations of "white medullary substance of the brain" and miniature vibrations that reach the brain are faint copies or traces of a sensation

• Different vibrations become associated upon being repeatedly linked together (re: law of contiguity)

• A series of sensations A, B, C, D forms such a pattern in the brain (through miniature vibrations) that later arousal of A alone will set going B, C, D – i.e., the memory images of B, C, D

• By Hartley rationale, clusters and sequences of sense impression are the clue to mental life

James Mill• James Mill (1773-1836)• Analysis of the Phenomena of the Human

Mind (1829/56) • single principle of association contiguity:

• the more frequent sensations and idea are paired the higher the strength of association between them.

• He reduced mental life down to elementary sensory particles • Perception is a process by which a number

of bits are put together to make a whole through additive summation

• the process of association of elementary parts is passive and is demonstrated through ‘trains of thought’

James Mill

John Stuart Mill• John Stuart Mill (1806-1873)• phenomenally precocious (IQ of 190)

• a free-thinker (“On the Subjection of Women,” 1869/66)

• active conception of mind: “mental chemistry”

• JS Mill notes that chemical compounds often represent qualitatively new things, not the summation of single components

• In psychology, qualitatively different ideas could be created by combinations of smaller parts

John Stuart Mill

Hermann Ebbinghaus (1850-1909)

• PhD in Philosophy aged 23!• Gustav Fechner's book Elements

of Psychophysics spurred him to conduct his famous memory experiments. Ebbinghaus dedicates his work Fundamentals of Psychology to Fechner.

• University of Berlin appointment in 1880 but lost his seat

• Ebbinghaus set a new direction in psychology introducing experimental control, and quantitative analysis.

Ebbinghaus and Associative Memory

• Father of associative memory• Ebbinghaus devised the nonsense

syllable: To avoid the pre-established associations of ordinary verbal materials, he devised some 2,300 trigrams: • E.g, "WID" and "ZOF".

• Ebbinghaus initial experiments using trigram-word pairs (e.g., ZOF-APPLE, WID-SHOE)• How many iterations of the list was

needed to get the participant to errorless performance in learning?

Graph showing average number of repetitions required (on y axis) for first errorless reproduction of increasing numbers of nonsense syllables (on x axis)

From “Memory: A Contribution to Experimental Psychology” Chapter V Hermann Ebbinghaus (1885)

Ebbinghaus’ normal forgetting curve

•The forgetting curve exhibits an exponential curve that illustrates how fast we tend to forget the information we have learned.

•The sharpest decline is in the first twenty minutes, then in the first hour, and then the curve evens off after about one day.

Ebbinghaus and Savings•Another technique that Ebbinghaus used to determined the strength of memory was through a measure he called Savings

•So savings becomes a measure of the persistence and efficiency of memory

•Effective practice starts with massed practice for fast learning and proceeds to distributed practice later for retention.

Ebbinghaus and Savings

• Savings upon relearning (even after 100% forgetting) implies subconscious influences.

• Ebbinghaus’ savings imply the memorial records are intact but inaccessible

• Drawing a parallel between cognitive and psychoanalytic theories

Ebbinghaus and the Serial Position Curve

• The earliest and most recent items are best recalled and the intermediate items are least recalled

• On theory that explains this is one of interference between items in the list.

• Interference effects are greatest over the middle range and are least at the beginning and at the end of the list.

Primacy effect

Recency effect

Edward Lee Thorndike (1874-1949)

• A very diligent and prodigious American psychologist raised in New England in a Methodist family with a keen interest in science.

• Doctoral dissertation in 1898 (aged 24): Animal Intelligence: An Experimental Study of the Associative Process in Animals

• Approximately 507 publications!

• Basic View of Psychology: the mind is a “connection system”

Studied animal behavior using puzzle boxes; formulated the “law of effect,” a precursor to later Skinnerian operant or “instrumental” conditioning paradigm.

Edward Lee Thorndike (1874-1949)

Four of Thorndike’s cat puzzle boxes

Thorndike’s basic data was the learning curve: the time needed to escape in increasing numbers of trials

Thorndike formulated two “laws”:

1) “Law of effect”:Behaviors followed by rewards/punishments become more/less frequent The greater the reward or punishment, the greater the change in “connection” between S - R

2) “Law of exercise”A response is more strongly connected to a situation in proportion to the number of times it has been connected to the situation, and to the average vigor and duration of the connection

Thorndike and beyond

• ‘‘Complex as human life is, it is at bottom explainable by a few principles’’. More pointedly, ‘‘it has been shown that in great measure the intellects and characters of men are explainable by a single law [the law of effect]’’

• Thorndike influenced the beginnings of behaviourism and anti-mentalism

• Behaviourism produced some useful principles but., as we will see, historical developments led to opposition to this extreme position and new schools emerged

• Association and connectionism are alive today in a different guise: explaining connections of neural networks in animals and in artificial intelligence or computational models that mimic neural networks.