Browsing by Subject "electrodermal activity"

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  • Tammi, Tuisku (Helsingin yliopisto, 2019)
    Objectives. This thesis aims to explore temporal changes in task-related physiological arousal and their connection to performance in repeated trials of a steering task. Moderate physiological arousal is believed to direct attention towards task-relevant stimuli, leading to performance improvements, while too high or low arousal is detrimental (the Yerkes-Dodson law). However, this approach does not explicitly account for changes in arousal over time. In this study, temporal changes in task-related sympathetic arousal are modelled as habituation, which has traditionally been used to describe changes in orienting responses to repeated presentations of non-target stimuli. Habituation during task performance is interpreted in terms of predictability and significance, aiming to describe changes in attentional processing during learning in an evolutionarily plausible manner. Furthermore, connections between performance and individual differences in habituation rate and spontaneous (task-unrelated) sympathetic activity are examined. Finally, habituation is compared to deviations from predicted performance. Methods. Participants (N = 9) played a total of 40 trials of a high-speed steering task in eight sessions over a period of 2-3 weeks. Electrodermal activity during baseline and task performance was recorded in five sessions. Change in task-related skin conductance response (SCR) frequency over trials 1-5 within sessions was used to determine individual rates of habituation whereas SCR frequency during baseline indicated individual spontaneous activity. Trial-level difference scores were used to explore habituation and deviations from predicted performance (a power-law learning curve) within participants. Results and conclusions. Task-related arousal was found to decrease with repeated trials for all participants in nearly all sessions, indicating that a habituation model was successful in capturing changes in arousal in a task situation. Furthermore, sustained task-related arousal (slow habituation) was connected to better performance both between and within participants. High spontaneous activity, on the other hand, was associated with performance decrements. Taken together, these results suggest that temporal changes in task-related arousal during learning are related to the processing of task-relevant cues and may reflect motivational states that direct selective attention, while high spontaneous activity is related to performance decrements, perhaps due to interference from task-unrelated stress.
  • Tammi, Tuisku; Lehtonen, Noora; Cowley, Benjamin Ultan (2019)