CHAPTER 6 – GERMAN

PSYCHOLOGISTS OF THE 19TH

& EARLY 20TH CENTURIES

Dr. Nancy Alvarado

German Rivals to Wundt

Ernst Weber & Gustav Fechner -- psychophysicists

Hermann Ebbinghaus -- memory

Franz Brentano

Carl Stumpf

Oswald Kulpe

Weber & Fechner

Ernst Weber (1795-1878)

Weber published “De tactu” describing the minimum

amount of tactile stimulation needed to experience

a sensation of touch – the absolute threshold.

Using weights he found that holding versus lifting them

gave different results (due to muscles involved).

He used a tactile compass to study how two-point

discrimination varied across the body.

On the fingertip .22 cm, on the lips .30 cm,

on the back 4.06 cm.

Just Noticeable Difference (JND)

Weber studied how much a stimulus must change in

order for a person to sense the change.

How much heavier must a weight be in order for a

person to notice that it is heavier?

This amount is called the just noticeable difference JND

The JND is not fixed but varies with the size of the

weights being compared.

JND can be expressed as a ratio:

where R is stimulus magnitude and k is a constant and

R means the change in R ( usually means change)

kR

R

Gustav Fechner (1801-1887)

Fechner related the physical and psychological

worlds using mathematics.

Fechner (1860) said:

“Psychophysics, already related to physics by name

must on one hand be based on psychology, and [on] the

other hand promises to give psychology a mathematical

foundation.” (pp. 9-10)

Fechner extended Weber’s work because it

provided the right model for accomplishing this.

Fechner’s Contribution

Fechner called Weber’s finding about the JND

“Weber’s Law.”

Fechner’s formula describes how the sensation is

related to increases in stimulus size:

where S is sensation, k is Weber’s constant and R is the

magnitude of a stimulus

The larger the stimulus magnitude, the greater the

amount of difference needed to produce a JND.

He used catch trials to study guessing.

RkS log

Relationship of JND to Stimulus

S.S. Stevens modified

Fechner’s Log Law to a

Power Function in the

early 1950’s.

Fechner’s Legacy

His methods are still used in psychophysics.

Ideas from signal detection theory have been

applied to a wide variety of other topics.

Threshold for criminal behavior.

Scaling techniques, including rating scales, were

placed on a sound scientific basis, especially by S.S.

Stevens later work, continued by Luce & Narens.

His speculations about split-brain studies were

confirmed by Sperry.

Hermann Ebbinghaus (1850-1909)

Ebbinghaus was inspired by finding a copy of

Fechner’s “Elements of Psychophysics.”

He wanted to apply Fechner’s methods to study of

higher mental processes.

In 1877, he began developing procedures for

studying memory.

His major work, “Fundamentals

of Psychology,” is dedicated to

Fechner.

Early Academic Career

Ebbinghaus had no mentor to teach him techniques

so he developed his own, highly original methods.

He had no lab, no access to subjects, so he performed

most experiments on himself.

He followed rigorous experimental rules and spent

4 years replicating his first series of experiments.

These were well received and widely recognized.

His nonsense syllables were developed to avoid

word familiarity, using a permutation formula.

Consonant, vowel, consonant

Ebbinghaus Experiments

First, he studied the relationship between the

amount of material to be memorized and the time

needed to learn it to complete mastery.

His measure was number of repetitions needed.

Second, he studied the effects of different amounts

of learning on memory.

His measure was savings – repetitions needed to

relearn the original items after a delay.

As repetitions increase, so does relearning time saved –

overlearning helps.

Ebbinghaus Forgetting Curve

His best known experiment studied the effects of

passage of time on memory – his forgetting curve.

In addition to graphing his

data he developed a

mathematical model by

writing a logarithmic

equation and deriving the

parameters using the

least squares method.

He also compared means

and variability and tested

whether their differences

exceeded chance.

Other Investigations

Ebbinghaus studied the relative effects on memory

of spaced versus massed practice, part versus

whole, and active versus passive learning.

Active, spaced learning was most effective.

He found that meaningful material was much easier

to learn and remember than material without

meaning.

Lists learned before sleep were better retained.

Ebbinghaus’s Contributions

This was the first time a higher mental function had

been studied experimentally.

His book is “one of the most remarkable research

achievements in the history of psychology” Roediger.

His success established a paradigm for studying

memory that was used for the next 90 years.

An ecological approach later challenged this:

Ulric Neisser challenged validity of lab approaches.

Bahrick studied long-lasting memories.

Banaji & Crowder defended lab-based studies.

An Applied Problem

Breslau schools were concerned that children were

too tired during an uninterrupted 8-1 school day.

Griesbach tested mental fatigue and irritability

using a two-point discrimination task.

He proposed the day be broken into 2 short segments.

Ebbinghaus disagreed because the measurement of

sensory discrimination has little to do with mental

activity, introducing the concept of content validity.

He developed analogy and completion test items to

measure intelligence, later included in IQ tests by Binet.

Franz Brentano (1838-1917)

Brentano was a Dominican priest and lecturer at the

Univ. of Wurzburg who left his position after writing

a scholarly critique of papal infallibility.

During the next 6 years he taught at the University

of Vienna and published a textbook

“Psychology from an Empirical

Standpoint.”

Comparison to Wundt

Brentano studied Aristotle and put more emphasis

on logical examination than experimental results.

As a result, Brentano’s ideas were fixed and did not

change, because neither logic nor premises change.

Instead of studying the products of mental actions,

as Wundt did, Brentano’s act psychology studied

the processes and mental actions themselves.

Brentano did not use introspection (inner observation) –

it was impossible because the act of observing changes

what is observed, retrospection (memory) was possible.

Brentano’s Ideas About Mental Acts

Three fundamental classes of mental acts:

Ideating, judging, loving (versus hating)

Mental acts may have as their objects past

sensations (an idea of an object not present) using

memory and imagination (Locke’s Reflection).

It is possible to feel an emotion when the object of that

emotion is not present.

One mental act may have as its object another mental

act – judgments about judgments.

Brentano in Perspective

Brentano is not as well-known as Wundt because he

wrote less and had personal problems.

He did very little experimental research.

His main importance is his formulation of a rival

approach to Wundt’s.

His psychology of acts was a precursor to the

American functionalists.

Two of his students (Stumpf & von Ehrenfels)

influenced the later Gestalt psychologists.

Carl Stumpf (1848-1936)

Stumpf was a talented musician who composed and

performed throughout his life, mixing with musicians.

Brentano changed his life by teaching him to think

logically and empirically.

Brentano encouraged him to transfer and study under

Lotze, a German perceptual theorist.

He became a priest but left the seminary over

papal infallibility, but not the church like Brentano.

Lotze got him a job at the Univ. of Gottingen where he

worked with Weber and Fechner.

The Golden Section

Two quantities are in the golden ratio if the ratio of

the sum of the quantities to the larger quantity is

equal to the ratio of the larger quantity to the

smaller one:

Stumpf conducted experiments studying whether this

“golden section” ratio was aesthetically pleasing.

b

a

a

ba

Stumpf’s Early Work

Stumpf gained a reputation for youthful brilliance

by publishing a nativist explanation of depth

perception.

He opposed Berkeley, Helmholtz, Wundt & Lotze.

He proposed that although “local signs” contribute

to depth perception they are of secondary

importance.

The interpretive action of a higher center in the brain is

most important.

He paralleled Kant’s view of the nature of space.

Stumpf’s Tone Psychology

Like Brentano, Stumpf distinguished between

phenomena and mental functions.

He called sensory images, tones, colors phenomenology.

Seeing, hearing, perceiving, thinking are cognitive acts.

He studied sounds of musical instruments, melody,

tonal fusion and consonance/dissonance of tones.

He compared musical and non-musical people.

His volume “Tone Psychology” appeared in 1883.

This led to prestigious academic appointments.

Debunking Sensational Phenomena

In 1903-4, Stumpf challenged the likelihood of a

machine that could change photographs of sound

waves into sounds.

In 1904 he chaired a commission to investigate the

claims of Clever Hans, the horse who could count.

His student, Oskar Pfungst, tested Hans when his owner

knew the answer and again when he did not.

The horse was correct 98% of the time in the first

condition but 8% correct in the second condition.

He was correct 89% without blinkers, 6% with blinkers.

Clever Hans & Von Osten

Von Osten was

convinced that

horses had inner

speech and thus

could do math.

Stumpf’s Later Years

His later years were sad.

WWI emptied the university of young men who left

to serve in the armed forces.

War also disrupted his relationships with colleagues

throughout Europe, including British, American and

Russians, and caused his work to be overlooked.

He was asked to organize psychologists to support

the war effort but his heart wasn’t in the task.

He retired in 1921, succeeded by Kohler.

Oswald Kulpe (1862-1915)

Kulpe studied history but became interested in

psychology after hearing Wundt speak at Leipzig.

At Wundt’s recommendation he went to Gottingen to

study with Muller (Lotze’s successor as chair).

Muller followed Fechner’s psychophysics and studied

memory (interference) with Ebbinghaus – developing

techniques for avoiding experimenter bias & demand.

After graduating, he performed experiments

challenging assumptions of Wundt & Titchener,

although he had warm affection for Wundt.

Kulpe’s Experimental Psychology

Kulpe was influenced by Mach’s positivist

philosophical views – all science is based on

experience and naturalistic sensory observation.

Mentalistic conceptions and attributions of mental

entities are to be avoided.

Psych needs objective descriptions of mental events.

Kulpe tried to demonstrate that higher mental functions

could be studied experimentally.

Kulpe’s research provided a foundation for

contemporary cognitive psychology.

The “Wurzburg School”

Founded by Kulpe & his students.

Subjects were asked about free associations using a

method of questioning called “Ausfrage.”

Marbe studied “conscious attitudes” of subjects

judging weights – doubt, hesitation, searching.

Kulpe & Bryan (Clark University) showed that

subjects could abstract features of nonsense

syllables as an active mental act “apprehension.”

Count the “F”s in a sentence.

Investigations of Reaction Time

Wurzburg psychologists asked how very fast,

volitional reaction times could occur without being

part of the subject’s mental experience.

Watts used a more precise Hipp chronoscope &

broke reaction times into four parts:

(1) preparatory period, (2) stimulus presentation, (3)

striving for the response, (4) the response itself.

Based on introspection, the thinking takes place

during the preparatory period (instructions),

establishing a subject “set.”

More Wurzburg Findings

Using systematic experimental introspection, Ach

found consistent differences between subjects –

called decision types.

Binet claimed priority based on descriptions of his kids.

Later (1907), Buhler asked questions requiring

thoughtful replies, not just “yes/no” answers.

Subjects described imageless thought, where answers

just came to them.

Wundt claimed he was not using introspection correctly.

Kulpe & Moore claimed meaning is distinct from image.

Lost German Psychologists

Why are only Ebbinghaus, Weber & Fechner well

known?

WWI disrupted others’ work and international contacts.

WWII destroyed the German universities.

Politics prevented communication between German and

American psychologists.

Cognitive psychology might have developed much

sooner without this interruption.

Only Gestalt psychology took root because some

fled Nazi Germany and took refuge in America.