Poster C36, Sunday, March 26, 5:00 – 7:00 pm, Pacific Concourse
The impact of interruptions on task performance: Comparing younger and older adults in an event-related spectral perturbation study
Stefan Arnau1, Kristina Küper1, Edmund Wascher1; 1Leibniz Research Centre for Working Environment and Human Factors (IfADo)
The ability to maintain task performance, even if a task is interrupted by an unrelated and interfering task, is crucial for reliable information processing. With increasing age, cognitive processing becomes especially vulnerable to irrelevant information. However, does this phenomenon also appear when cognitive resources have to be distributed across two unrelated tasks? We used a nested task design. For the primary task, subjects had to memorize a specific stimulus feature, which could either be displayed by the first or the second of two sequentially presented stimuli. In one third of the trials, this sequence was interrupted by a math task. As expected, the nested math task strongly affected older participants’ performance on the primary task. Time-frequency analysis of the EEG uncovered the use of different strategies across age groups. Older participants showed a larger frontal theta amplitude in response to the cue that signaled the relevant task feature of the primary task. This may reflect higher mental effort when encoding the task itself. In younger participants, on the other hand, induced theta was larger in response to the cue preceding the interruption task, suggesting that younger subjects had sufficient resources available for strategic task execution. The strategic allocation of top down resources is also reflected by an occipital alpha decrease, which was stronger in response to the presentation of relevant compared to irrelevant task features. The data support the notion, that processing capacities decrease with increasing age, leading to a strategic allocation of resources in favor of a primary task.
Topic Area: EXECUTIVE PROCESSES: Development & aging