PSYC 212 Chapter Notes -Detection Theory, Power Law, Gustav Fechner

• School: McGill University
• Department: Psychology
• Course: PSYC 212
• Professor: Evan Balaban

Document Summary

We can measure the energy from physical stimuli, but we cannot measure someone"s psychological experience of the stimuli. Provides an estimate of the perceptual quality of a stimulus in numbers. Absolute threshold: minimum intensity level of a stimulus before it is registered in the brain as a perceptual event. Subthreshold: stimuli below absolute threshold that are not detectable by the sensory system. Suprathreshold: stimuli above the absolute threshold where sensation takes place. Difference threshold: the smallest change in stimulus intensity required to produce a discriminable change in sensation. 1860, set out to establish experimental methods for psychophysics. Psychophysics is the study of quantitative relationships between stimuli and psycholog- ical evens. Method of adjustment: participant adjusts intensity of a stimulus until it is barely de- tectable. Method of limits: stimulus intensity is changed in the same direction by a fixed amount until the participant reports that it is perceived.