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Flashcards in webers law Deck (26):
1

What is luminance?

Quantity of light

2

What is brightness?

Describe the apparent quantity of light

3

What is a transducer function?

Describes how physical intensity is transformed into perceived intensity

4

What is a transducer?

A transducer is a process whereby physical stimuli are converted into neural signals

5

Who published to first book of psychopysics?

Gustav fechner in 19860s

6

What is the dependant variable ?

What the psychologist measures

7

what is independent variable ?

manipulating the data

8

What is a psychometric function?

A figure which shows relationship between physical quantity and some measurement of behaviour

9

What is noisy?

Observer did not always respond in same way to same stimuli

10

Explain experiment of 2AFC?

Two alternative forced choice test
- sit in the dark
-two beeps both with two bright lights
-lights not same intensity
-one has intensity =L
-one has extra intensity = delta L
-job is to detect the brighter intensity of light

11

Who came up with the wright and wrong case method?

Fechner

12

What is another name for wrong and write cases?

Multiple alternative forced choice test m

13

What are the two independent variable in 2AFC test?

baseline/ pedistal luminance =L
and extra luminance = delta L

14

What would happen if Transduction was flawless

The brighter light would always produce more bright light
however not always flawless its noisy

15

What does alot of overlapping of distribution mean?

The probability of incorrect responses was high correct response probability would be near 1 and half

16

What does little overlapping of distribution mean ?

The probability of correct responses is high the less intense light will never produce,

17

What does having same width on two curves mean?

Mild experience may be variable as intense experience

18

What does average brightness vary with?

Average brightness varies with the logarithm of luminance

19

How can you directly measure appearance?

You cannot it is impossible

20

How do you assign a value to SD of appearance noise?

Indirectly

21

ho demonstrated shadows?

Bouguers

22

Describe Bouguers experiment

-Two candles where light reflects from both candles reflect of the paper and cast shadows of the rod in between the candle and paper
-one candle set at a fixed distance - second candle increased distance until shadow disappeared
-Far enough till shadow just noticeable difference

23

What is just noticeable difference method of ?

Method of limits

24

Noticeability is what?

A judgment call no wrong or right answers

25

What law did Bouguers come up with and when?

Webers law in 1834

26

What is webers law?

Just noticeable of physical intensity over actual physical intensity equals to arbitary constant