The effects of age and extended practice on divided attention performance

The present study examined the effects of repeated practice on the divided attention performance of young and old adults. Six young and 6 older adults performed two perceptual-motor tasks under both single- and dual-task conditions across six 1-hr sessions. Absolute levels of performance improved reliably over sessions for both young and old participants, but divided attention performance remained poorer in old than in young adults. Relative divided attention costs (Somberg & Salthouse, 1982) were consistently higher for the older adults across experimental sessions. These results confirm previous suggestions that older people are particularly vulnerable to the effects of divided attention. The findings are discussed further in terms of the validity of single-session studies of age differences in divided attention performance.