PSYCH 111 Chapter Notes - Chapter 4: Retina, Psychophysics
Document Summary
Psychophysics - the study of how physical stimuli are translated into psychological experience. Sensation begins with a stimulus - any detectable input from the environment. Threshold - dividing point between energy levels that do/don"t have a detectable effect. Absolute threshold - minimum stimulus intensity that an organism can detect. Define the boundaries of an organism"s sensory capabilities. Not actually absolute it"s the stimulus intensity detected 50% of the time. Just noticeable difference (jnd) - smallest difference in stimulus intensity that a specific sense can detect. As stimuli inc. jnd between them becomes larger. Signal-detection theory - detection of stimuli involves decision processes as well as sensory processes (both influenced by variety of factors other than stimulus intensity) Responses depend on criterion - standard you set for how sure you must feel. Performance also depends on noise - all irrelevant stimuli in the environment and before reacting neural activity they stir up.
