Psychophysics Flashcards
What is psychophysics?
-what you experience when something happens to your sensory organs
What is a stimulus?
-something that provides input to any of the sense organs
What are the quantitative measures of behaviour in psychophysics?
-observer makes judgement about one or more stimuli and records their decisions
Define precision
- How consistent your judgements about a stimulus are
- the higher your precision, the less your judgements vary
- high precision, low variability
Define accuracy in psychophysics
- how close, on average, your judgements are to the true value
- calculated as an average
What is a standard stimulus?
-a stimulus that is a baseline to the comparison stimulus
What is a comparison stimulus?
-a stimulus you compare to the standard stimulus
What is a trial?
-a single time you judge a comparison of the comparison stimulus and standard stimulus
What is the method of constant stimuli?
-observer decides whether comparison stimulus has greater or smaller magnitude than standard stimulus
What is the method of adjustment?
-observer adjusts the magnitude of the comparison stimulus so it matches that of the standard stimulus
What is the point of objective equality?
-when the standard and comparison stimulus are the same magnitude
What is the point of subjective equality!
-when the observer perceives that the standard and comparison stimulus are the same magnitude
What is the just noticeable difference?
-the smallest difference in stimulation that is reliably discriminated from the standard stimulus
What is the interval of uncertainty?
-the range of values of the comparison stimulus in which the comparison stimulus are not noticeably different from the standard stimulus
Define Weber’s law
-where magnitude change is much more noticed in something with great magnitude than in something with small magnitude
