AVERSION THRESHOLDS AND AVERSION DIFFERENCE LIMENS FOR WHITE LIGHT IN ALBINO AND HOODED RATS

Determined preference thresholds for light vs. darkness and for 1 illumination of light over another for Sprague-Dawley albino and Long-Evans hooded rats, using a simple spatial preference test. Neither strain preferred any illumination level over total darkness and the light aversion thresholds were the same for both strains. The magnitude of the aversion difference limen relative to illumination (Weber ratio) decreased drastically as illumination increased and then leveled off or increased somewhat at higher illuminations, with the Weber ratios of the hooded Ss being about 1 log unit larger than those of the albinos. oars of the Weber ratios of aversiveness with human detection functions revealed that rats are quite sensitive to changes in illumination well within photopic range. (19 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1969 American Psychological Association.