PSY-3215 Lecture Notes - Lecture 10: Dark Adapted Eye, Absolute Threshold, Purkinje Effect
Document Summary
Our absolute threshold changes depending on the lighting (dark adaptation curve diagram) Time spent in the dark (minutes) versus light intensity (y-axis) Absolute threshold decreases the longer we spend in the dark. However there is a little notch at about 6-7 minutes (curve isn"t smooth) Light intensity versus time spent in the dark (x-axis) Small decrease to absolute threshold and then levels out to a straight line. Fovia is less sensitive to light (reaches absolute threshold much quicker) Purkinje shift: if you take two colors of equal brightness in the daylight (say red and blue), then as we go into the nightlight they shift their brightness (blue will become much brighter than the red) This suggests that there are color differences in the day versus the night. Varying location (in fovea versus outside) and wavelength. Sensitivity to light (y-axis) [high sensitivity means low threshold] versus wavelength.
