Measurement of Cognitive Load in Lower Limb Prosthesis Wearers: The P3 Event-Related Potential in Sitting, Standing, and Walking.

다국어 초록 (Multilingual Abstract)

Elevated cognitive load is a hindrance commonly reported in lower limb prosthesis wearers, and it holds potential as a vital clinical measure for assessing prosthesis effectiveness. While previous works have focused on self-reports and dual task metrics such as reaction time for evaluating cognitive load, we lack a comprehensive neurophysiological measure that is robust to bias and precise in the time domain. We utilized the P3 (or P300) event-related potential, a neurophysiological signal derived from dry EEG data, to measure cognitive load during stationary and mobile activities of daily living. The P3 amplitude, which is inversely related to cognitive load, is well documented in EEG studies. Using an auditory oddball paradigm, we elicited P3 responses during five-minute trials of sitting, standing, and walking in individuals with transtibial and transfemoral amputation, as well as those with intact limbs. In the first study, we characterized the P3 potential in intact limb subjects and examined the impact of head motion using accelerometer data. In the second study, we compared the P3 values between participants with transtibial and transfemoral levels of amputation. Our results suggest that P3 is an effective marker of cognitive load in intact limb participants and that it is robust to head motion artifacts. In those with lower limb prostheses, we saw a greater degree of variance among the participants in the transfemoral group compared to the transtibial group. While the small sample sizes in both studies may limit the generalizability of the results, they point towards the potential of P3 as an effective rehabilitative outcome measure of cognitive load. Furthermore, the dry EEG's rapid setup time, negating the need for gel application, suggests its suitability in fast-paced clinical environments. Future work could examine the long-term or short-term changes in cognitive load, which may be instrumental in evaluating and enhancing rehabilitative approaches or prosthesis selection. While this research aimed primarily at enhancing the lives of prosthesis wearers, this work is broadly generalizable to those who use other rehabilitative assistive devices, such as wheelchairs and exoskeletons. The overarching goal is to improve the holistic well-being of all users of assistive devices by understanding and addressing the complexities of their physical and cognitive experiences and abilities.