Psychophysics Essay Research Paper An Approximate psychological

Psychophysics Essay, Research Paper

An Approximate psychological law relating the degree of response or sensation of

a sense organ and the intensity of the stimulus. The law asserts that equal

increments of sensation are associated with equal increments of the logarithm of

the stimulus, or that the just noticeable difference in any sensation results

from a change in the stimulus, which bears a constant ratio to the value of the

stimulus. Ernst Heinrich Weber (1795-1878) Weber was the first German anatomist

and physiologist to introduce the concept of the just-noticeable difference,

which is the smallest observable difference between two similar stimuli. From

1818 until 1871 Weber was a professor at the University of Leipzig. Weber is

best known for his work on the sensory response to weight, temperature, and

pressure. Weber stated that, in order for any increase in the intensity of the

stimulus a threshold of sensation must be passed. This increase would create the

just-noticeable difference. The ratio Weber discovered was the total intensity

of sensation, rather than an absolute figure. Greater weight had to be added to

heavier objects in order for the person to notice the change. Weber’s

observations were formed mathematically by Gustav Theodor Fechner, which he

later called Weber’s law. Gustav Theodor Fechner (1801-1887) Fechner was a

German physicist and philosopher; he was an influential figure in the

development of psychophysics. He was concerned with the quantitative relations

between sensations and the stimuli producing them. When Fechner was 16, he began

medical school at the University of Leipzig where he studied anatomy under

Weber. Fechner upon graduation discovered his interested lead more toward

physics and mathematics than medicine. Fechner by the end of the 1830’s had

written several papers on the perception of complementary and subjective colors.

In 1840 his article on subjective afterimages was published. The same year he

suffered a nervous collapse. Fechner had to quit his job at the University due

to his temporary blindness from staring at the sun during his experiments. He

returned in 1848 he completed when Nanna, which is a metaphysical treatise that

explains the philosophical treatment of relationship of mind to body. This left

a future program for psychophysics by linking increased bodily energy with an

increase in mental intensity. From 1851 and 1860, Fechner worked on his

psychophysical methods: just noticeable differences, right and wrong cases and

average error. He also did experiments on visual distance and brightness.

Fechner also lifted weights that lead to the first two volumes of the Elemente

der Psychophysik. The Elemente der Psychophysik was to distinguish an exact

science between physical and mental phenomena. The relationship between

sensation and nerve excitation was known as the inner psychophysics. The outer

psychophysics was referred to as the relationship between sensation and physical

simulation. He developed his famous principle: the intensity of a sensation

increases as the log of the stimulus (S = k log R) to characterize outer

psychophysical relations. Fechner believed this was demonstrating a fundamental

philosophical truth: mind and matter are simply different of conceiving of one

and the same reality. The philosophical message of the Elemente was widely

ignored while; its orderly and practical contributions were not. Fechner was a

well trained, rational experimentalist and a skillful mathematician and the

influence of his work on scientists was accurate. Terms of physical events could

be linked to the measures of mental events. Fechner showed the potential for

quantitative, experimental exploration of the phenomenology of sensory

experience and established psychophysics as emerging scientific psychology. I

decided to write my paper on psychophysics because I really do not know much

about it. The article I read was very interesting. Denis Leri the author of The

Fechner Weber Principle asked a few questions at the beginning of her article.

In bright midday sun you light a candle. Does anyone notice it getting brighter?

I would have never thought the candle would make the outside brighter. Will you

identify my voice if I call you on a cellular phone at a rock concert? I do not

think I could pick out a familiar voice because the noise level would be too

loud. If you are carrying a refrigerator up a flight of stairs and someone puts

a hammer on it do you notice the difference? I would have said the weight of the

hammer would have made a difference. After reading this article I would now say

the ratio between the hammer and the refrigerator is greatly different and would

not cause a noticeable difference. I found psychophysics pretty interesting and

I plan on reading more about it.

The Fechner Weber Principle @1997 Denis Leri Microsoft Bookshelf 98 Edition I

found my information by looking up psychophysics on the Internet and I found the

article by Denis Leri to be the most interesting. The italicized words are her

exact words are close to them.