Wheelchair control by elderly participants in a virtual environment with a brain-computer interface (BCI) and tactile stimulation

Abstract

Tactile event-related potential (ERP) are rarely used as input signal to control brain-computer-interfaces (BCI) due to their low accuracy and speed (information transfer rate, ITR). Age-related loss of tactile sensibility might further decrease their viability for the target population of BCI. In this study we investigated whether training improves tactile ERP-BCI performance within a virtual wheelchair navigation task. Elderly subjects participated in 5 sessions and tactors were placed at legs, abdomen and back. Mean accuracy and ITR increased from 88.43%/4.5bitsmin^-1 in the 1st to 92.56%/4.98bitsmin^-1 in the last session. The mean P300 amplitude increased from 5.46μV to 9.22μV. In an optional task participants achieved an accuracy of 95,56% and a mean ITR of 20,73bitsmin^-1 which is the highest ever achieved with tactile stimulation. Our sample of elderly people further contributed to the external validity of our results.

Keywords: Aging; BCI; ITR; Learning; Tactile; Wheelchair.