History & Systems Of Sensation & Perception

Question 0

Fechner (mid-1800s)

Answer 0

Formulated Weber’s Law

Question 1

Ernst Weber (1834)

Answer 1

Introduced jnd

Question 2

Sir Francis Galton

Answer 2

Measured the sensory ability of 10,000 people; studied individual difference in sensation

Question 3

Max Wertheimer (1880-1943)

Answer 3

Gestalt psychology, beginning with visual illusion: phi phenomenon
Phi phenomenon: Visual perception of a whole may be different from the sum of its parts
Therefore, breaking conscious experience into its parts is not a valid way to study psychology

Question 4

Absolute threshold

Answer 4

Minimum of stimulus energy necessary to activate a sensory system; minimal energy necessary for perception
(“Limen” is another word for threshold)

Question 5

Difference threshold

Answer 5

How different two levels of stimulus must be in order for difference to be perceived.

Question 6

Jnd

Answer 6

Similar to difference threshold, in different units
Amount of unit between standard stimulus and comparison stimulus = just noticeable difference, whereas difference threshold is a ratio
(One jnd unit needs to be added to or subtracted from stimulus for individual to notice the difference. If 2 oz. equals difference threshold, 2 oz. = 1 jnd. Then, dt= 2 oz and jnd= 1)

Question 7

Weber’s law

Answer 7

Stimulus energy needed to produce jnd increases proportionally to stimulus intensity. Ex. Candle brightness, weber’s constant = 0.1 so with 10 candles, +/-1 candle will produce jnd, with 1,000 candles, +/-100 candles will produce jnd

Question 8

Fechner’s Law

Answer 8

Describes relationship between stimulus intensity and intensity of sensation
Found that sensation increases more slowly as higher intensities increase

Question 9

Steven’s Power Law

Answer 9

Also relates intensity of stimulus to intensity of sensation, differs from Fechner’s Law

Question 10

Signal detection theory

Answer 10

Nonsensory factors (like experience, motives, expectations) may influence what a subject reports to sense

Question 11

Response bias

Answer 11

Tendency of subjects to respond a certain way based on nonsensory factors (ex. Wanting to be certain before affirming a response may cause someone to respond positively less often than someone who doesn’t want to “miss” a stimulus)

Question 12

Receiver operating characteristic curves

Answer 12

Graphically summarize a subject’s responses by measuring the operating characteristics (sensitivity) of a subject receiving signals
Refined by John A. Swets

Question 13

Steps of sensory information processing

Answer 13

Reception, transduction (translation of energy), electrical signal to projection areas (area that analyzes the sensory input)