Psychology 1000 Lecture Notes - Lecture 13: Retina, Vitreous Body, Power Law

• School: Western University
• Department: Psychology
• Course: Psychology 1000
• Professor: Dr.Mike

Document Summary

Psychophysics: relation between physical stimulus and psychological response. Threshold: value of a stimulus characteristic required to produce some response. Absolute threshold: lower limit (ie, auditory threshold is 20hz- Smell: 1 drop of perfume in a 6 room apartment. Touch: wing of a fly falling on cheek from 1cm. Difference threshold: the amount of change necessary for jnd. Relation: brightness & perceived brightness, not a 1-1 relation intensity of test is constant: di/i = c (d=delta) C value test could be 90 or 110 db. Weber"s law: size of difference threshold relative to physical. Ie, if i=50db, and jnd is reported at 55db, 5/50=1/10, this is the. Predict jnd at 100db, di/100 = 1/10, therefore dl = 10db, new. Only works for small changes, not very generalizable. Value of jnd is not constant, but the relative difference is constant better. Can compare sensitivity of different system, smaller the c, the. S = k log i (don"t need to know)