Implicit Processing of Scene Context in Macular Degeneration

PURPOSE. For normally sighted people, there is a general consensus that objects that appear in a congruent context (e.g., a hair dryer in a bathroom) are processed more accurately and/or more quickly than objects in an incongruent context (e.g., a hair dryer in a corn field). We investigated whether people with AMD, who have impairments in recognizing objects embedded in complex scenes, can nevertheless take advantage of contextual information for object detection. METHODS. Twenty-two people with AMD and 18 age-matched, normally sighted controls took part in the study. They were tested in two tasks: (1) an object detection task in which a foreground target object was set within a congruent background or an incongruent background, with no information being given to the participants as to the relationship between the target and its background, and (2) a task in which the participant had to explicitly state whether or not the foreground object was congruent with its background. A go/no-go paradigm was used in both tasks (i.e., a key press when the target is present and no key press when it is absent). The same participants, stimuli, and presentation conditions were used in both tasks. RESULTS. In the context task, the people with AMD exhibited higher sensitivity when the target object was consistent with its background; however, they performed no better than chance in the explicit task. Normally sighted controls benefited from the congruent context in both tasks. CONCLUSIONS. Our results suggest that when central vision is impaired (as in AMD), the contextual information captured by peripheral vision provides cues for object categorization. (Invest Ophthalmol Vis Sci. 2013;54:1950-1957) DOI:10.1167/iovs.12-9680