Remembering visual items is important for older adults, whether it requires remembering a new pill or a pot on the stove. There is considerable evidence that visual recognition memory is largely affected by Alzheimer's disease. We used high-densityevent-related potentials (ERPs) to examine whether early pre-clinical physiological changes could be observed in pre-symptomatic individuals who carry a mutation in the Presenilin-1 (PS-1) gene and will go on to develop Alzheimer's disease around the age of 45 (Lopera et al., 1997). 10 PS-1 pre-symptomatic carriers (M age = 34.22 years SD= 6.25) and 11 matched controls (M age = 32.66 years, SD= 6.09) were selected from a Colombian population with familial Alzheimer's disease. Subjects performed a recognition memory test of pictures while 128-channels of event-related potentials were recorded during retrieval. Despite identical behavioral performance, carriers showed significantly less activation in frontal regions compared with controls. These frontal differences began early in the recording interval (~200 ms) and continued throughout most of the recording. Carriers, by contrast, showed more occipital ERP activity than controls in the early and middle periods of the recording epoch. These results suggest that compared to controls, asymptomatic carriers of the PS-1 mutation show changes in brain physiology that can be detected by high-density ERPs. The greater frontal activity in controls and greater occipital activity in carriers may suggest that control subjects use familiarity and other frontally mediated processes to distinguish between studied and unstudied visual items, whereas carriers rely upon perceptual details of the items to make recognition memory decisions. Further studies are needed to determine whether ERP correlates of recognition memory could be used as an early marker of preclinical Alzheimer's disease.