The optokinetic reaction in foveate and afoveate geckos
O.A. Masseck, B. Röll & K.-P. Hoffmann
Vision Res. 48: 765-772, 2008
- To investigate determinants of symmetry of the monocular horizontal optokinetic reaction (hOKR) in vertebrates,
we performed behavioural studies in diurnal foveate, as well as nocturnal afoveate geckos. During binocular viewing
hOKR gain was equal for movement to the left or right, during monocular stimulation, all afoveate geckos (Lepidodactylus
lugubris, Gekko gecko, Eublepharis macularius) and the foveate Lygodactylus spp. exclusively reacted to temporo-nasal
stimulation with stabilising head movements whereas in Phelsuma madagascariensis a naso-temporal component of hOKR
could be elicited albeit much weaker. Thus, neither the presence of a fovea nor lifestyle seems to be decisive
for a symmetrical monocular hOKR.
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