Project Summary The primary goal of the proposed work is to determine whether sensory feedback and extended use reduce the cognitive load for controlling an advanced dexterous and sensorized prosthetic limb. Prosthetic technologies for upper-limb amputees are advancing rapidly. The physical improvements involve two components: the robotic limb and the neuromuscular interface. Despite innovations promising increased prosthetic function, high abandonment rates (up to 50%) are seen with upper-limb prostheses. The scientific community is developing advanced control paradigms providing more intuitive control and using haptic sensors to restore the sense of touch. These advancements have the potential to improve satisfaction rates and reduce abandonment rates; however, current metrics do not consider user effort, which is necessary in determining a viable product. Improvements to prosthetic systems, whether through more intuitive control paradigms or sensory feedback are typically quantified through performance in tasks that may or may not represent typical daily activities. Although these metrics are useful, they do not necessarily reflect the preferences of the end-user. Although a particular system may enable fine control, the effort required to achieve such control may be prohibitive to routine use, resulting in a nonviable product. Thus, incorporating measures of effort, herein described as cognitive load, can more completely inform the desirable characteristics of a prosthetic system. The main objective of this proposal is to measure cognitive load during prosthesis use. We propose to adapt cognitive load measures used in other fields (e.g., driving research) to our research with advanced neuromyoelectric prostheses. Our first aim is to develop a robust method for measuring cognitive load through physiological, behavioral, and subject measures, including pupillometry, electrocardiography, and electroencephalography (Aim 1). Aim 1 will expose the advantages and limitations of specific cognitive load measures in prosthetic research. We will then apply these methods to determine if sensory feedback can reduce cognitive load during prosthetic use (Aim 2). Aim 2 elucidates the usefulness of sensory feedback in prosthesis use, a current thrust in the field. Lastly, we will determine if cognitive load decreases during extended (six months) at-home use of an advanced neuromyoelectric prosthesis (Aim 3). Aim 3 will provide the first exploration of the cognitive effects of using an advanced prosthesis in a home setting for an extended period. Success in these aims will establish a fundamentally different yet essential pathway for assessing the viability of prosthesis advancements in a patient-centric manner. Documented effectiveness of sensory feedback and long-term use in prosthetic control is not only of scientific interest, but are also requisite for translating these advanced prosthetic technologies to clinical acceptance and use. Altogether, this p...