Assessing the Effect of DESC-Feedback on Cognitive Load, Gaze Behavior, and Motor Performance During Manipulation Tasks Performed With Hand Prosthesis

Individuals with upper limb amputation often reported functionality limitations due to poor confidence in myoelectric hand prosthesis control and the lack of tactile and proprioceptive feedback. This is typically associated with increased cognitive demands and compensatory reliance on vision to perform activities of daily living. Such limitations can contribute to user frustration and device abandonment. Providing sensory feedback has the potential to reduce these limitations, but its implementation must be intuitive to avoid adding further cognitive demand on the user. The Discrete Event-driven Sensory feedback Control (DESC) model offers a promising strategy, delivering brief, event-based stimuli that mimic natural sensory encoding. While DESC feedback has been shown to improve motor performance, its cognitive demand and role in modulating visual reliance have not yet been investigated. In this study, we aimed to assess the cognitive load associated with DESC feedback, its effect on visual attention and motor performance during manipulation tasks. To this goal, healthy participants with no prior experience in prosthesis control, performed motor tasks in three conditions: with their intact dominant hand, with a simulated prosthesis with and without DESC feedback. Then the findings obtained from the healthy participants were validated in an experienced prosthesis user. Our results suggest that DESC feedback can enhance prosthesis usability by supporting performance without impacting cognitive load. Conversely, feedback did not consistently reduce participants' reliance on vision during task execution; further investigation is needed to determine whether extended exposure may yield attentional benefits not observable in the short term.