Author ORCID Identifier:
Date of Graduation
12-2025
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Engineering (PhD)
Degree Level
Graduate
Department
Biomedical Engineering
Advisor/Mentor
Jung, Ranu
Committee Member
Abbas, James
Second Committee Member
Leong, Josiah
Third Committee Member
Judah, Matt
Fourth Committee Member
Lin, Wei-Chiang
Keywords
Amputation; Cognitive Load; fNIRS; Nerve Stimulation; Rehabilitation; Virtual Reality
Abstract
Sensory feedback from the hand is fundamental for the coordination of fine motor skills and overall sensorimotor function. Impaired somatosensation during task execution has been associated with the development of inaccurate motor plans, which can hinder motor learning. Virtual Reality (VR) has emerged as a promising tool for motor rehabilitation; however, most VR-based interventions overlook the critical role of tactile feedback in motor control. The absence of touch feedback, which is integral to conventional rehabilitation and training, may limit the full therapeutic potential of VR. Integrating functionally relevant neurostimulation based haptic feedback (neuro-haptic feedback) into VR-based interventions may enhance functional recovery by eliciting neural activity and motor function that more closely resemble those observed in real-world environments. Such integration could improve translatability of VR-training to real-world functional improvements. This dissertation investigates how emulated touch interacts with the sensorimotor system and its influence on user experience and functional performance in rehabilitation and VR contexts. Hemodynamics of the prefrontal (PFC), sensorimotor (SMC) and somatosensory association cortices were recorded from individuals with or without upper-extremity limb difference using fNIRS during three sensorimotor assessments performed in real-world or VR with and without neuro-haptic feedback. Neuro-haptic feedback delivered via a wearable neurostimulation platform (xTouch) employs transcutaneous electrical nerve stimulation to activate peripheral sensory pathways, thereby emulating tactile sensations during virtual object interaction and functional assessments. Our findings demonstrate that xTouch can replicate key characteristics of virtual objects and that cortical activity within the PFC varies according to the emulated object properties. Individuals with limb difference showed distinct cortical patterns compared to controls, including evidence of neurovascular uncoupling during natural touch and increased blood flow to the SMC during emulated touch. While sensorimotor performance and cognitive load were not significantly influenced by emulated touch feedback in VR, haptic feedback enhanced the sense of presence during a VR-based gross motor task. These results underscore the need to establish normative standards for VR-based rehabilitation assessments and inform the design of interventions that incorporate emulated haptic feedback to promote neuroplasticity and neurovascular coupling. Such approaches may optimize sensorimotor recovery and improve clinical efficacy of VR-based rehabilitation.
Citation
Shell, A. K. (2025). Extending Touch: Investigating Sensorimotor Integration, Cognitive Workload, and Presence with Neuro-Haptic Feedback in Virtual Reality. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/6088
