Age-related hemispheric asymmetry in object discrimination.

Young and elderly observers judged whether two sequentially presented images in either the left or right visual field (LVF or RVF) were the same or different. The two objects depicted were always from the same entry-level category, but could differ only in viewpoint (a "same" trial--observers were instructed to ignore viewpoint changes) and/or in exemplar (a "different" trial). Young observers showed no difference in sensitivity across visual fields. Elderly observers were less sensitive overall than young observers, and were less sensitive to stimuli presented in the LVF-RH than in the RVF-LH. The results of this experiment support the hypothesis that one type of visual cognitive functioning declines with age faster in the right hemisphere than in the left hemisphere.