psy·cho·phys·ics noun pl but singular in constr \ˌsī-kō-ˈfiz-iks\
: a branch of psychology concerned with the effect of physical processes (as intensity of stimulation) on the mental processes and especially sensations of an organism
Seen & Heard
What made you want to look up psychophysics? Please tell us where you read or heard it (including the quote, if possible).