Note on stimulus error and the experienced subject in psychophysical research.
Experienced subjects participate in some psychophysical research. While they may be more responsive to experimental stimuli than naive subjects, they may not be immune from stimulus error, the tendency for subjects to bias their responses given known physical characteristics of the stimulus. A brief examination of the literature concerning processing of changing sound-level and visual spatial frequency may support this contention.
D006805:Human Experimentation; D006801:Humans; D008144:Loudness Perception; D011603:Psychophysiology; D012106:Research; D014796:Visual Perception