Modality-specific task interference in dual-task sets, funded by the DFG (second funding period)

  • Funding agency: German Research Foundation, DFG, Priority Program
  • Applicant: Prof. Dr. Iring Koch
  • Co-applicant: Dr. Denise Stephan
  • Responsible staff member: Erik Friedgen, M. Sc.
  • Duration: 42 months, 2018-2022


Human behavior is usually governed by multiple task constraints. Yet, performance is most often worse in multitasking than in single-task conditions. Specifically, frequent task switching usually leads to switch costs relative to task repetitions. According to reconfiguration accounts, these costs are partly caused by a central bottleneck-like process of reconfiguring the higher-order representation of the cognitive and motor task requirements, the so-called task set. The present project is aimed at examining the nature of this central reconfiguration process. A common conception of reconfiguration is that it refers to an abstract, amodal process that controls modality-specific sensory and motor processes. However, recent evidence revealed that switch costs can vary substantially depending on the specific modality mapping, that is compatibility, even if the degree of sensory and motor interference is equated across switching conditions. We propose that this influence of modality compatibility is not due to intrinsic features of stimulus processing itself but due to constraints of human action control.
Leaning on the ideomotor principle which states that actions are initiated based on the anticipation of their sensory consequences, stimuli that match the anticipated response consequences in terms of modality are modality compatible. For example, vocal responses generate auditory effects, and manual responses typically lead to visible changes in the environment, so that an auditory-vocal and a visual-manual mapping represent a modality-compatible task. Accordingly, switching between modality-compatible tasks should lead to less switch costs than switching between incompatible tasks because the latter invoke more between-task crosstalk at the central mapping level.
In three sets of experiments, we examine the structure, flexibility, and plasticity of task representations in serial task switching. First, we investigate structural aspects of task sets by manipulating processing codes and stimulus-response compatibility. Second, we also examine the flexibility of task-set control by measuring, in experiments with voluntary task choice, the frequency with which participants form modality-compatible vs. modality-incompatible stimulus-response mappings, in addition to measuring switch costs. Finally, we examine the plasticity of the strength of modality mappings by varying short-term practice schedules and comparing the transfer between practicing with single tasks, practicing with task switching, and practicing with dual tasking.
Together, this project is aimed at contributing to the goals of the research framework set by the Priority Program 1772, which seeks to integrate theoretical perspectives differing in terms of their focus on the structure, the flexibility, and the plasticity of task set and its control in human multitasking performance.

Selected references

Fintor, E., Poljac, E., Stephan, D. N., & Koch, I. (2020). Modality compatibility biases voluntary choice of response modality in task switching. Psychological Research, 84(2), 380-388.

Fintor, E., Stephan, D. N., & Koch, I. (2018). Emerging features of modality mappings in task switching: Modality compatibility requires variability at the level of both stimulus and response modality. Psychological Research, 82(1), 121-133.

Fintor, E., Stephan, D. N., & Koch, I. (2019). The interplay of crossmodal attentional preparation and modality compatibility in cued task switching. Quarterly Journal of Experimental Psychology, 72(4), 955-965.

Friedgen, E., Koch, I., & Stephan, D. N. (2020). Modality compatibility in task switching depends on processing codes and task demands. Psychological Research, 1-18. doi:10.1007/s00426-020-01412-2

Stephan, D. N., Josten, J., Friedgen, E., & Koch, I. (2021). Crossmodal Effects in Task Switching: Modality Compatibility with Vocal and Pedal Responses. Journal of Cognition, 4(1): 9, pp. 1–14. doi: 10.5334/joc.129

Stephan, D. N., & Koch, I. (2015). Modality-specific effects on crosstalk in task switching – Evidence from modality compatibility. Psychological Research.

Stephan, D. N., & Koch, I. (2015). Tactile Stimuli Increase Effects of Modality Compatibility in Task Switching. Experimental Psychology. doi: 10.1027/1618-3169/a000291

Stephan, D. N., Koch, I., Hendler, J., & Huestegge, L. (2013). Task switching, modality compatibility, and the supramodal function of eye movements. Experimental Psychology, 60, 90-99.

Stephan, D. N., & Koch, I. (2011). The role of input-output modality compatibility in task switching. Psychological Research, 75, 491-498.

Stephan, D. N., & Koch, I. (2010). Central crosstalk in task switching – Evidence from manipulating input-output modality compatibility. Journal of Experimental Psychology: Learning, Memory, & Cognition, 36, 1075-1081.