Response-Code Conflict in Dual-Task Interference and Its Modulation by Age

Abstract

Difficulties in performing two tasks at once can arise from several sources and usually increase in advanced age. Tasks with concurrent bimodal (e.g., manual and oculomotor) responding to single stimuli consistently revealed crosstalk between conflicting response codes as a relevant source. However, how this finding translates to unimodal (i.e., manual only) response settings and how it is affected by age remains open. To address this issue, we had young and older adults respond to high- or low-pitched tones with one (single task) or both hands concurrently (dual task). Responses were either compatible or incompatible with the pitch. When responses with the same level of compatibility were combined in dual-task conditions, their response codes were congruent to each other, whereas combining a compatible and an incompatible response created mutually incongruent (i.e., conflicting) response codes, potentially inducing detrimental crosstalk. Across age groups, dual-task costs indeed were overall highest with response-code incongruency. In these trials, compatible responses exhibited higher costs than incompatible ones, even after removing trials with strongly synchronized responses. This underadditive cost asymmetry argues against mutual crosstalk as the sole source of interference and corroborates notions of strategic prioritization of limited processing capacity based on mapping-selection difficulty. As expected, the effects of incongruent response codes were found to be especially deleterious in older adults, supporting assumptions of age-related deficits in multiple-action control at the level of task-shielding. Overall, our results suggest that aging is linked to higher response confusability and less efficient flexibility for capacity sharing in dual-task settings.

Authors 5

1. Lya K. Paas Oliveros

   Forschungszentrum Jülich · Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institute of Neuroscience and Medicine (INM-

   Institute of Systems Neuroscience , Heinrich Heine University Düsseldorf , Düsseldorf , Germany

   Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Forschungszentrum Jülich, Jülich, Germany

   Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf, Germany

2. Aleks Pieczykolan Aachen Human Technology Center

   RWTH Aachen University · University of Würzburg

   Affiliation as printed

   Human Technology Center , RWTH Aachen University , Aachen , Germany

   Institute of Psychology , University of Würzburg , Würzburg , Germany

   Human Technology Center, RWTH Aachen University, Aachen, Germany

   Institute of Psychology, University of Würzburg, Würzburg, Germany

3. Rachel N. Pläschke

   Forschungszentrum Jülich · Heinrich Heine University Düsseldorf

   Affiliation as printed

   : Brain and Behaviour) , Forschungszentrum Jülich , Jülich , Germany

   Institute of Systems Neuroscience , Heinrich Heine University Düsseldorf , Düsseldorf , Germany

   Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf, Germany

4. Simon Bodo Eickhoff

   Forschungszentrum Jülich · Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institute of Neuroscience and Medicine (INM-

   Institute of Systems Neuroscience , Heinrich Heine University Düsseldorf , Düsseldorf , Germany

   Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Forschungszentrum Jülich, Jülich, Germany

   Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf, Germany

5. Robert Langner

   Forschungszentrum Jülich · Heinrich Heine University Düsseldorf

   Affiliation as printed

   Institute of Neuroscience and Medicine (INM-

   Institute of Systems Neuroscience , Heinrich Heine University Düsseldorf , Düsseldorf , Germany

   Institute of Neuroscience and Medicine (INM-7: Brain and Behaviour), Forschungszentrum Jülich, Jülich, Germany

   Institute of Systems Neuroscience, Heinrich Heine University Düsseldorf, Düsseldorf, Germany