John T. Johnson

Georgia Tech

555 14th St NW

Atlanta, Ga 30318

I am currently researching the neural and behavioral effects of sensory changes on the way we understand and execute reach to grasp actions. This research is applicable to people with limb difference as well as other types of sensory loss, such as stroke or diabetic neuropathy. My research experience runs the gamut from building research equipment for human subjects research, to collecting EEG, fMRI, and motion capture data, analyzing those data, and preparing visualizations, and presenting and publishing results. My previous background in electronics, programming, and field engineering has allowed me to build research equipment for our lab and mentor and assist other grad students in developing their own research equipment. I have also developed equipment that has allowed our lab to collect rich datasets of co-registered data from disparate systems, such as EEG, motion capture, and eye tracking systems.

Nearing the end of my PhD, I am looking for an employer for which I can apply my broad range of research, scientific, and engineering skills to help them address their most interesting and challenging problems.

news

Mar 12, 2022	Brain areas predict upcoming vibrotactile feedback(!)

selected publications

Alpha-Band Activity in Parietofrontal Cortex Predicts Future Availability of Vibrotactile Feedback in Prosthesis Use

Johnson, John T., de Mari, Daniele, Doherty, Harper, Hammond, Frank L., and Wheaton, Lewis A.

Experimental Brain Research Mar 2022

Abs

Prosthesis disuse and abandonment is an ongoing issue in upper-limb amputation. In addition to lost structural and motor function, amputation also results in decreased task-specific sensory information. One proposed remedy is augmenting somatosensory information using vibrotactile feedback to provide tactile feedback of grasping objects. While the role of frontal and parietal areas in motor tasks is well established, the neural and kinematic effects of this augmented vibrotactile feedback remain in question. In this study, we sought to understand the neurobehavioral effects of providing augmented feedback during a reach-grasp-transport task. Ten persons with sound limbs performed a motor task while wearing a prosthesis simulator with and without vibrotactile feedback. We hypothesized that providing vibrotactile feedback during prosthesis use would increase activity in frontal and parietal areas and improve grasp-related behavior. Results show that anticipation of upcoming vibrotactile feedback may be encoded in motor and parietal areas during the reach-to-grasp phase of the task. While grasp aperture is unaffected by vibrotactile feedback, the availability of vibrotactile feedback does lead to a reduction in velocity during object transport. These results help shed light on how engineered feedback is utilized by prostheses users and provide methodologies for further assessment in advanced prosthetics research.