A deficit in strabismic amblyopia for global shape detection

Using a task which relied upon the detection of sinusoidal deformations fro m circularity, we show that strabismic amblyopes exhibit deficits which are not critically dependent on either the scale of deformation or the spatial frequency characteristics of the stimulus (circular D4) itself. We show th at this loss is not due to the restricted passband of the amblyopic eye. Fu rthermore, in a pedestal distortion experiment, we show that the suprathres hold form of this loss is consistent with an elevated level of 'intrinsic n oise' rather than a loss in 'sampling efficiency'. (C) 1998 Elsevier Scienc e Ltd. All rights reserved.