The neural deficit in strabismic amblyopia: sampling considerations.
In order to understand the nature of the neural loss in strabismic amblyopia, we have applied a technique which has been used in the normal periphery to psychophysically probe the sampling properties of the neuronal population. We ask whether there is a 'sampling' deficit and if so whether it is based on either an absolute loss of neurons (i.e. spatial undersampling) or an irregular arrangement of a normal number of neurons (i.e. irregular sampling). Our results suggest that neural pooling restricts the spatial frequency region where sampling considerations are important to a very small part of the visible high spatial frequency range. Within this limited region, irregular sampling rather than spatial undersampling is the greater contributor to the strabismic amblyope deficit.
Demanins
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Department of Ophthalmology, McGill University, Royal Victoria Hospital, Montreal, Quebec, Canada. ritad@bradman.vision.mcgill.ca
Wang
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Hess
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D000550:Amblyopia / Q000209:etiology / Q000473:pathology*; D004192:Discrimination, Psychological; D005403:Fixation, Ocular / Q000502:physiology; D006801:Humans; D009039:Motion Perception / Q000502:physiology; D009410:Nerve Degeneration; D009949:Orientation; D011594:Psychometrics; D012107:Research Design; D013285:Strabismus / Q000150:complications*; D014792:Visual Acuity / Q000502:physiology