Prior research yielded conflicting findings regarding
whether older adults show a greater processing cost than
younger adults when encountering unpredicted semantic
material during language processing. Here, we
investigated whether age-related differences in recovery
from prediction error are influenced by increased
demands on working memory. We used a dual task
design: a primary sentence comprehension task in which
semantic predictions were fulfilled or violated, and a
concurrent driving task, thought to limit working memory
resources in resolving prediction errors. In the dual task,
older participants showed an increase in comprehension
accuracy for sentences with semantic violations, while
demonstrating a decrease in driving accuracy. Thus, when
working memory resources were limited, older adults
focused exclusively on the language task and neglected
the driving task. This could be related to an age-related
increase in generating semantic predictions, or to a
general inability among older adults to divide attention
between two cognitively demanding tasks.