Contrast Sensitivity of Cats and Humans in Scotopic and Mesopic Conditions

• Published in: Journal of neurophysiology 2009-08, Vol.102 (2), p.831-840
• Main Authors: Kang, Incheol, Reem, Rachel E, Kaczmarowski, Amy L, Malpeli, Joseph G
• Format: Article
• Language: English
• Subjects: Adult; Animals; Cats; Darkness; Female; Humans; Lighting; Linear Models; Night Vision; Photic Stimulation; Psychometrics; Psychophysics; Pupil; Vision, Ocular; Young Adult
• ISSN: 0022-3077; 1522-1598
• DOI: 10.1152/jn.90641.2008

1 Neuroscience Program, University of Illinois, Urbana; and 2 Department of Psychology, University of Illinois, Champaign, Illinois Submitted 4 June 2008; accepted in final form 15 May 2009 Human contrast sensitivity in low scotopic conditions is regulated according to the deVries–Rose law. Previous cat behavioral data, as well as cat and mice electrophysiological data, have not confirmed this relationship. To resolve this discrepancy at the behavioral level, we compared sensitivity in dim light for cats and humans in parallel experiments using the same visual stimuli and similar behavioral paradigms. Both species had to detect Gabor functions (SD = 1.5°, spatial frequencies from 0 to 4 cpd, temporal frequency 4 Hz) presented 8° to the right or left of a central fixation point over an 8 log-unit range of adaptation levels spanning scotopic vision and extending well into the mesopic range. Cats had 0.74 log unit greater absolute sensitivity than that of humans for spatial frequencies 1/8 cpd. Cats had better contrast sensitivity overall for spatial frequencies