Psychology 1000 Lecture Notes - Lecture 14: James Vicary, Optic Nerve, Retina

• School: Western University
• Department: Psychology
• Course: Psychology 1000
• Professor: Terry Biggs

Document Summary

Psychophysics: relation between physical stimulus and psychological response. Cannot determine difference but can determine a just noticeable difference. Value of a stimulus characteristic required to produce some response. Absolute: lower limit, when we can detect it: eg. Of i = 50db and a jnd is reported at 55db then 1/10 = 5/50: we can predict other jnd"s when we have the constant. From previous example: at 100db jnd would occur at 110db or 90db: the value of jnd is not constant, the relative difference of jnd is constant, we can compare sensitivity of different systems, the smaller. Fechner"s law: sensation increases with the logarithm of intensity. James vicary (1957): claimed 50% increase in popcorn sales when there was a subliminal message inserted into the movie, concern about the use of subliminal cuts . In general, there is no evidence that subliminal cuts influence consumer behaviour. Apple is flashed on screen 30ms: sperdin: minimum presentation time for neural response: