Structuralist Mental Representation of Dual-action Demands: Mechanisms of Improved Dual-task Performance after Practice in Older Adults

Aim: The present study was designed to investigate how behavioral (dual-action) demands in dual tasks are mentally represented in older adults and how these representations might contribute to the practice-related improvement of dual-task performance. Three different theoretical representation accounts were empirically tested: a structuralist account, a holistic account, and a contextual change account. The first account assumes that component tasks remain structurally intact when combined with another task while the second account assumes that dual-action requirements in dual tasks are represented holistically and entirely distinct from its component (single-action) requirements. The final account assumes that a change in context (e.g., from single to dual requirement) might generally impede response retrieval, similar to repeating a response when the task context switches.Methods: To address this issue of dual-action representations in older adults, we assessed trial-by-trial effects in a single/dual switch paradigm (involving a randomized mix of single- and dual-task trials within blocks). In detail, we re-analyzed a large set of practice data involving seven sessions, in which an auditory-vocal task was combined with a visual-manual task. Results: At the end of practice, the current results were largely consistent with the structuralist account. Conclusions: We conclude that dual-action requirements in the present dual-task setting are mentally represented in a predominantly structuralist fashion at the end of practice in older adults. The results are discussed in the context of other theories on practice-related mechanisms of improved dual-task performance in this age group.