R. Demanins et al., The orientation discrimination deficit in strabismic amblyopia depends upon stimulus bandwidth, VISION RES, 39(24), 1999, pp. 4018-4031
We show that the previously reported orientation deficit in amblyopia (Skot
tun, B. C., Bradley, A., & Freeman, R. D. (1986). Orientation discriminatio
n in amblyopia. Investigative Ophthalmology and Visual Science, 30, 532-537
) also occurs for arrays of randomly positioned Gabor micropatterns for whi
ch explanations based on either neural disarray or local neural interaction
s would not hold. Furthermore, when using Gabors, we show that the deficit
varies with the spatial frequency and orientational bandwidth of the stimul
i used to measure it. We discuss two competing explanations for this, one b
ased on a broader underlying detector bandwidth in amblyopia (both orientat
ion and spatial frequency) and the other based on a selective deficit of fi
rst-order, as opposed to second-order orientation processing in strabismic
amblyopia. Our results favour the latter interpretation. (C) 1999 Elsevier
Science Ltd. All rights reserved.