Patients with amnestic Mild Cognitive Impairment (aMCI) who are at risk for further cognitive decline and development of Alzheimer’s dementia show deficits in visual attention. In the present study, we evaluated whether parameters of visual attention, estimated based on theory of visual attention (TVA; Bundesen, 1990) explain variance of performance in a standard battery assessing cognitive functions in patients at risk for dementia. More precisely, we assessed whether visual short-term memory (vSTM) capacity and visual processing speed are significant factors in regression models including group (aMCI vs. healthy controls) with total and composite scores derived from the Consortium to Establish a Registry for Alzheimer's Disease (CERAD+).

When comparing aMCI patients to a sociodemographically matched healthy control group, we found significant impairments in visual processing speed and vSTM capacity. Furthermore, vSTM capacity, but not visual processing speed, significantly contributed to standard task performance. Apart from group and age, it significantly predicted variance in the total as well as in the memory and the executive functions composite scores of the CERAD.

These results indicate that the reduction in vSTM capacity is an early indicator of cognitive decline in patients at risk for Alzheimer’s disease and significantly contributes to their declining performance in standard neuropsychological tasks.