Modality-specific task interference in dual-task sets, funded by the DFG

  • Funding agengy: German Research Foundation, DFG, Priority Program
  • Applicant: Prof. Dr. Iring Koch
  • Co-applicant: Dr. Denise Stephan
  • Responsible staff member: M.A. Edina Fintor
  • Duration: 36 months, 2015-2018


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. Specifically, based on the notion of ideomotor theory that action is preceded by the anticipation of its sensory consequences, stimuli that match the anticipated response consequences in terms of modality are modality compatible, for example vocal responses generate auditory effects, so that an auditory-vocal mapping represents 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 intend to examine first structural aspects of task set more deeply by varying the modality mappings. We also examine second the flexibility of task-set control by assessing the effects of advance task preparation and, additionally, of inhibition of competing tasks on the influence of modality compatibility. We measure inhibition as n-2 task repetition costs, so-called backward inhibition, when switching between tasks defined by three different stimulus and response modalities. Finally, we examine the plasticity of the strength of modality mappings by manipulating short-term practice schedules and, additionally, the influence of age-related cognitive changes as well as of specific expertise with self-produced action effects, for example in musicians. 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

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