Johanne Sofie Krog Nedergård, PhD Student, School of Communication and Culture - Department of Linguistics, Cognitive Science and Semiotics 

Abstract: In cognitive psychology, dual-task investigations have indicated that internal language plays a role in a variety of cognitive functions. This preregistered study investigated whether physical endurance as exemplified by cycling performance depends on internal language and internal visual experience. A sample of 50 physically active participants performed 12 cycling trials, each lasting one minute where they were required to cycle as fast as possible while remembering either a sequence of letters and numbers (verbal interference) or locations on a grid (nonverbal interference). We found that participants cycled a numerically shorter distance in the verbal interference condition than in the no-interference and the visuospatial inference conditions, although only the difference to the no-interference task was significant. Further, participants who reported that self-talk helps their sports performance were more negatively affected by verbal interference. Our study suggests that the inner voice plays a causal role in top-down control of sustained physical efforts.