How to measure distinct components of visual attention fast and reliably

Measuring different attentional processes in a fast and reliable way is important in both clinical and experimental settings. However, most tests of visual attention are either lengthy or lack sensitivity, specificity, and reliability. To address this we developed a ten minute test procedure for the Swedish Betula-project, a longitudinal study investigating changes in cognitive functions over the adult life span (Nilsson et al., 2004). The test consists of a computer-based letter recognition task with stimulus displays of varied durations followed by pattern masks or a blank screen. The temporal threshold of conscious perception (t₀), visual processing speed (C), and storage capacity of visual short-term memory (K) are estimated by use of Bundesen's (1990) Theory of Visual Attention, and the standard error of each estimate is calculated using a bootstrapping procedure. The results from the first sample of 100 participants (55-85 years of age) confirm that both t₀, C and K are negatively affected by age and that C and K are highly correlated. Furthermore, the standard errors of the estimates are remarkably small considering the limited duration of the test. Thus, it seems possible to obtain precise and stable estimates of visual attention using only a very brief test.