Performance and perceptions of workload among young and older adults: Effects of practice during cognitively demanding tasks

Subjective rating scales that measure the mental effort involved in performing tasks have been hypothesized to reveal information about cognitive workload not available from performance-based measures. Thirteen young ( Mean age = 21.6 years) and 18 older ( Mean age = 70.68 years) adults received training that significantly improved their performance of three tasks that involved working-memory processes. Training on the Paced Auditory Serial Addition Task did not influence NASA-Task Load Index (TLX) total workload ratings, training on an attentional-switching task and a response-inhibition task led to age-related changes in TLX ratings. Analysis of TLX subscales suggests that the impact of training on workload ratings is both age and task dependent. Information obtained from subjective rating scales may provide unique insights into developing optimal instructional methods for older individuals.