Modality-specific crosstalk in multitasking: Evidence from modality compatibility in task switching

• Applicant: Professor Dr. Iring Koch
• Subject Area: General, Cognitive and Mathematical Psychology
• Term: from 2015 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 274800694

Experimental studies revealed robust performance costs in human multitasking. In the present project in the context of the Priority Program "Human Performance under Multiple Cognitive Task Requirements: From Basic Mechanisms to Optimized Task Scheduling", we focus on serial multitasking using variations of the task-switching paradigm. In this paradigm, the basic finding is that performance is worse in task switches than in repetitions. These switch costs have been taken to index the involvement of cognitive control processes at the level of higher-order task representations ("task sets"). The present individual PP project aims at contributing to the goals of the PP by examining issues pertaining to the structure, flexibility, and plasticity of the task representations underlying serial task switching, with a specific emphasis on modality-specific effects ("modality compatibility", MC). We define MC as occurring to the degree that the stimulus modality corresponds to the modality of the intended response effect (e.g. auditory-vocal task mappings would be modality compatible because vocal responses are typically intended to produce auditory effects). In the first funding period, we found that switch costs are larger when switching between two incompatible modality mappings (e.g. auditory-manual and visual-vocal) than when switching between two compatible mappings. Our theoretical account proposes that such effects of MC in multitasking derive from "ideomotor" learning (i.e. learning response-effect contingencies and anticipation of response effects). Rooting the influence of MC in the functional constraints of human action control invites a broad empirical approach that raises research issues referring to the context-specific flexibility and learning-dependent plasticity of human action control and task set. Specifically, this research aims at understanding better (1) how tasks and mappings are represented (structural issue), (2) how tasks and mappings can be selected voluntarily in "free choices" (flexibility), and (3) how task sets can change with short-term and long-term practice (plasticity). In the second project phase, we aim at deepening our understanding of modality-specific interactions in multitasking. First, we generalize the notion of MC to different processing requirements and experimental paradigms, including conditions in which the modality mappings are divided across participants in a “task sharing” situation. Second, we explore the role of MC in free ("voluntary") response modality choices. Third, we examine the boundary conditions for transfer from single-mapping and mixed-mapping practice both in serial task (i.e. mapping) switching and simultaneous dual tasks. Finally, we also aim to extend existing and develop new cooperative links.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1772: Human performance under multiple cognitive task requirements: From basic mechanisms to optimized task scheduling
• Co-Investigator: Dr. Denise N. Stephan