International audienceObjective: To differentiate the effect of compounding demands, both corporal and social, on a cognitive task requiring the retrieval of competing lexical items in speech production.Methods: Three experimental groups of adults (ages 18-35) were recruited to complete one of three tasks followed by a questionnaire designed to measure emotion contagion. Experiment 1 had participants in a sitting position to complete a picture naming task. The task consisted of 500 test pictures that included groups of visuo-semantic neighbors (e.g., deer, elk, and antelope) that would lead to greater lexical competition as seen in spoken errors and/or reduced reaction times. A signal-to-noise ratio, known as 1/f noise, was calculated from the picture naming reaction times and used as a descriptor of individual differences. In Experiment 2, participants performed the picture naming task while standing. A 1/f noise ratio was calculated for each participants’ movement tracked online using a Microsoft Kinect. In Experiment 3 participants performed the picture naming task while standing in the same room as an experimenter that recorded the participants’ errors as they were being made. Results: Spoken errors and slower reaction times increased with task complexity, as did the randomness (i.e., white noise) of the 1/f noise ratio. Participants that experienced less lexical competition, succeeded in maintaining greater periodicity (i.e., pink noise) within their 1/f noise ratio for both picture naming reaction times and bodily movement. Participants more susceptible to emotion contagion, as measured in the questionnaire, were more likely to compound the effect of lexical competition in Experiment 3 due to the presence of the experimenter.Conclusion: The ability to control cognitive demands lessons as complexity increases due to online maintenance of cognitive, corporal and social cues. Cognitive control can be seen in those participants able to maintain periodicity within their responses to external stimuli
