The Effect of Body Positions on Word-Recognition: A Multi-methods NeuroIS Study

Numerous studies have shown that different body postures and positions can differently influence one’s physiology, motivation and emotion processes, and behavioral and cognitive performances. The varying level of autonomic activation in various body positions may explain the differing level of arousal in supine (Lay), seated (Sit), and standing (Stand) body positions. The present study compared for the first time the effect of these three body positions on word-recognition performance (i.e., response accuracy and response time) while simultaneously using electroencephalography (EEG) to watch the brain at work. No significant difference was found among the three body positions for response accuracy. However, the mean response time was significantly faster for the Hit (correct judgment of the repetition of a word-stimulus) response outcome category in the Sit position compared to the Stand position. Moreover, the mean response time was slower for the Miss (incorrect judgment of the repetition of a word-stimulus) category in the Lay position compared to the Sit position. EEG data analysis further revealed interesting trends for the brain potential amplitudes at 180 ms post-stimulus. The amplitude corresponding to the Miss category was significantly different from the Correct rejection category in the Stand position at this timepoint. More importantly though, the differences in brain potential amplitudes between the Miss and the other three categories (Hit, Correct rejection, and False alarm) in the Lay position around this timepoint (180 ms) could be interpreted as a potential neurophysiological correlate underlying the prolonged response time for the Miss category in the Lay position. Possibly, this phenomenon can be linked with the well-known N200 event-related potential (ERP) component.