Intact functioning of exogenous spatial attention in amblyopic adults
33.545, Sunday, 18-May, 8:30 am - 12:30 pm, Pavilion
Marisa Carrasco1, Mariel Roberts1, Rachel Cymerman2, R. Theodore Smith2, Lynne Kiorpes1,2; 1Department of Psychology, Center for Neural Science, New York University, 2Department of Ophthalmology, Langone Medical Center, New York University
Goal. Amblyopia—a developmental disorder characterized by a deficit in visual acuity, contrast sensitivity and position acuity in one eye following abnormal binocular experience during childhood—is the leading cause of monocular impairment from children to middle-aged adults in the US. Exogenous attention increases contrast sensitivity as assessed by orientation discrimination tasks in adults with normal vision. We explored whether exogenous attention similarly improves contrast sensitivity in amblyopes, is intact whether viewing with the amblyopic or fellow eye, and whether it differentially affects processing at locations across the visual field. Methods. 15 amblyopic (9-strabismic, 6-anisometropic) and 15 control (age- and gender-matched) adults were tested monocularly on a 2-AFC-orientation discrimination task. Four Gabor patches (independently and randomly tilted ±20° from vertical) appeared along the vertical and horizontal meridians. To manipulate attention, participants were presented with either one (valid-cue) or four (neutral-cue) peripheral pre-cues. Participants reported the orientation of the Gabor indicated by a postcue. In the valid-cue condition, the precue and postcue locations matched. Task difficulty was equated between eyes and across observers by adjusting stimulus contrast in the neutral-cue condition. Results. Performance was significantly higher and faster for the valid- than the neutral-cue condition for both groups. There were no 3-way or 2-way interactions among group, attention condition, and eye: The magnitude of the attentional benefit did not differ between the two groups or the two eyes in each group. Moreover, both groups exhibited canonical performance fields–better performance along the horizontal than vertical meridian and at the lower than upper vertical meridian–and similar effects of attention at all locations. Conclusions. The performance benefit of exogenous attention was the same for both eyes of the amblyopic adults at all locations, demonstrating no difference from controls. Although amblyopic eyes process lower-quality visual information, exogenous attention remains functionally intact in amblyopic adults.