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Flashcards in Week 1 Deck (14):
1

What is psychophysics?

A study of the quantifiable relationship between a stimulus and perception.

2

The minimum stimulus magnitude at which a stimulus can be reliably detected is know as the _____?

absolute threshold

3

Describe the procedure involved with a method of constant stimuli?

1. Construct a set of stimuli with a range of magnitudes.
2. Present stimuli in random order
3. Plot the results
4. Threshold is taken as the magnitude at which the stimuli is detected at a pre-determined proportion of the time. (e.g. 50%)

4

Describe some ads and disads of the method of constant stimuli.

Ads- allows shape of psychometric function to be established, provides an accurate estimate of threshold.
DisAds- time consuming, requires pre-testing to establish threshold region, wastes trials, difficult to measure changes over time.

5

Describe method of limits protocol.

Asc or desc, presents stimuli at sub threshold level, increase until the participant can detect. this is the threshold

6

Describe some ads and disads of the method of limits

Doesn't plot shape of psychometric function. Quicker. Habitual 'yesses' or 'nos' not so accurate, still wastes trials.

7

Describe the adaptive staircase procedure

staircase run until a reversal is evident. Staircase direction changes. procedure is terminated after a criterion number of reversals.

8

The mathematical formula for determining what threshold the adaptive staircase is measuring is:

n square root 0.5

9

The two conditions in Signal Detection Theory are:

Catch Trials, Signal Trials

10

Activity that stimulates our sensory system and results in a positive response during a catch trial is called:

Noise

11

What does dprime measure in signal detection theory?

The sensitivity, the difference between the noise and signal + noise distribution. Big prime means the experiment is easy - the trial is easy to detect or reject - big distinction.

12

Why might you use the double adaptive staircase method?

If you suspect there might be strong participant bias - prevents against anticipation

13

How do you measure d prime?

The difference between correct rejection and hits.

14

What do the receiver operating curves signify?

The relationship between false alarms and hits.