Insensitivity of peripheral vision to spatial phase.

Tolhurst (1973) had suggested that movement-sensitive mechanisms were the human analogues of transient (Y) neurones in the cat (Enroth-Cugell and Robson 1966) and monkey (Gouras 1968) visual system. We challenged this view in a previous study (Rentschler et al. 1981): in strabismic amblyopia the detection of apparent movement of counterphased gratings is impaired considerably more than pattern detection, whereas no such anomaly is found when the sensitivity to temporal transients is tested. This would imply that with a grating target the detection of lateral movement and of transients is not mediated by the same class of mechanisms. Moreover, we have shown that normal peripheral vision suffers qualitatively from the same kind of movement insensitivity as the amblyopic eye. In this study, we have used a wider range of stimulus parameters to seek more definite evidence.