Visual attention modifies spectral sensitivity of nystagmic eye movements.

If we look out of the window of a travelling train our eyes move rapidly back and forth (saccadic movement). With no attention to individual objects, gaze velocity is low but nystagmic frequency is high (stare nystagmus). If we are interested in individual objects, the angular velocity of gaze is high and the nystagmic frequency low (look nystagmus) (Ter Braak, J.W.G. (1936). Untersuchungen ueber optokinetischen Nystagmus. Archives Neerlandaises de Physiologie de L'homme et des Animaux, 21, 309-376) We show that the spectral sensitivities of the two types of nystagmus differ and that the short-wavelength-sensitive cones significantly contribute only to look nystagmus. (C) 1999 Elsevier Science Ltd. All rights reserved