PSYCH 3A03 Lecture Notes - Ernst Heinrich Weber, Spectral Mask, Stimulus Modality

• School: McMaster University
• Department: Psychology
• Course: PSYCH 3A03
• Professor: Paul Faure

Document Summary

Stimulus thresholds define the ranges of detection for parameters of acoustic signals (e. g. frequency, intensity, phase, etc. ) Thresholds do not capture a subjects sensitivity to changes in a stimulus parameter. Psychophysicists also interested in measuring the smallest difference between physical stimuli that will just barely cause a difference in sensation (just noticeable difference) 2 famous psychologists looked at the question of how differences in stimulus intensity (magnitude) map on to perception. Devised method for measuring the existence of internal (mental) events; formulated the theory of signs (lokalzeichentheorie); with his brother he studied acoustics and wave motion. Discovered psychology"s 1st empirical constant weber fraction. This concept uses the awareness of a difference in sensation to measure a difference in sensation. Weber fraction: the increase in stimulus intensity necessary to produce an increase in sensation is not a fixed quantity but is a constant proportion of the smaller intensity.