Brightness discrimination in the harbor seal (Phoca vitulina)

• Published in: Vision Research
• Main Authors: Scholtyssek, Christine, Kelber, Almut, Dehnhardt, Guido
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2008
• Subjects: Zoology; brightness discrimination; harbor seal; animal psychophysics; contrast; Phoca vitulina
• Online Access: https://lup.lub.lu.se/record/1193671; https://doi.org/10.1016/j.visres.2007.10.012

The brightness discrimination ability of a mate harbor seal was investigated at an ambient illumination of 0.9 lx. The visual stimuli consisted of circular gray discs that were presented on a black background on a TFT monitor. Eight standard intensities were tested against sets of lower comparison intensities. In accordance with Weber's law we observed a constant gain of the just noticeable intensity difference with increasing intensity of the standard stimulus. The calculated Weber fraction is 0.14. This result indicates that the brightness discrimination ability of the harbor seal is comparable to that of humans.