Haptic vs. Visual Neurofeedback for Brain Training: A Proof-of-Concept Study.

The current practice of administering neurofeedback using the patients' visual and/or auditory channel(s) is known to cause fatigue, excessive boredom, and restricted mobility during prolonged therapy sessions. This paper proposes haptics as an alternative means to provide neurofeedback and investigates its effectiveness by conducting two user studies (Study- I & II) using a novel compact wearable haptic device that provides vibrotactile feedback to the user's neck. Each user study has three neurofeedback modes: visual-only, haptics-only, and visual-and-haptics combined. Study- I examines the participant's performance in a brain-training task by measuring their attention level (AL) and the task completion time (CT). Study- II, in addition to the brain-training task, investigates the participants' ability to perform a secondary task (playing a shape-sorting game) while receiving the neurofeedback. Results show that users performed similarly well in brain-training with haptics-only and visual-only feedback. However, when engaged in a secondary task, the users performed significantly better (AL and CT improved around 11% and 17%, respectively) with haptics, indicating a clear advantage of haptics over visual neurofeedback. Being able to perform routine activities during brain-training would likely increase user adherence to longer therapy sessions. In the future, we plan to verify these findings by conducting experiments on ADHD-patients.