PSYA01H3 Chapter 5: Chapter 5 Notes - Part two
Document Summary
Smallest difference between two similar stimuli that can be distinguished; aka difference threshold. Weber fraction: the ratio between a just-noticeable difference and the magnitude of a stimulus; reasonably constant over the middle range of most stimulus intensities. Psychophysical methods rely heavily on threshold: the line between not perceiving and perceiving. Just-noticeable difference can also be called a difference threshold: the minimum detectable difference between two stimuli. Absolute threshold: minimum value of a stimulus that can be detected that is, discriminated from no stimulus at all. By convention, it is the point at which a participant detects the stimulus 50% of the time. Signal detection theory: every stimulus event requires discrimination between signal (stimulus) and noise (consisting of both background stimuli and random activity of the nervous system) Response bias: tendency to say yes" or no" when you are not sure whether you detected the stimuli.
