Detection, discrimination and integration of second-order orientation information in strabismic and anisometropic amblyopia.
To better understand the nature of the cortical deficit in amblyopia we undertook a systematic investigation of second-order processing in 8 amblyopic and 8 normal observers. We investigated local detection, discrimination and global integration. Our local stimulus consisted of a Gaussian patch of fractal noise multiplied by a 1-d sinusoidal modulator. Our global stimulus consisted of an array of such elements. We revealed second-order detection deficits for stimuli with equi-visible carriers. Orientation discrimination for an isolated second-order patch was comparable in normal and amblyopic eyes. We showed that pure integration of second-order patterns can be normal in amblyopia.
Department of Opthalmology, McGill Vision Research Unit, 687 Pine Avenue West, Rm. H4-14, Montreal, Quebec, Canada H3A 1A1. behzad.mansouri@mail.mcgill.ca
Behzad
B
Mansouri
Harriet A
HA
Allen
Robert F
RF
Hess
D000328:Adult; D000550:Amblyopia / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology; D004192:Discrimination, Psychological / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009949:Orientation / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D011601:Psychophysics; D012684:Sensory Thresholds / Q000502:physiology; D013285:Strabismus / Q000503:physiopathology*; D014793:Visual Cortex / Q000503:physiopathology