Related Experiment Video
Updated: May 1, 2026
Eye-Tracking Control to Assess Cognitive Functions in Patients with Amyotrophic Lateral Sclerosis
Published on: October 13, 2016
Comparing tactile and visual gaze-independent brain-computer interfaces in patients with amyotrophic lateral
M Severens1, M Van der Waal2, J Farquhar2
1Sint Maartenskliniek Nijmegen, Research Department, The Netherlands; Radboud University Nijmegen, Donders Institute for Brain, Cognition and Behaviour, The Netherlands.
Objective:
Brain-computer interfaces (BCI) tested in patients often are gaze-dependent, while these intended users could possibly lose the ability to focus their gaze. Therefore, a visual and a tactile gaze-independent spelling system were investigated.
Methods:
Five patients with amyotrophic lateral sclerosis (ALS) tested a visual Hex-o-Spell and a tactile speller. Six healthy participants were also included, mainly to evaluate the tactile stimulators.
Results:
A significant attentional modulation was seen in the P300 for the Hex-o-Spell and in the N2 for the tactile speller. Average on-line classification performance for selecting a step in the speller was above chance level (17%) for both spellers. However, average performance was higher for the Hex-o-Spell (88% and 85% for healthy participants and patients, respectively) than for the tactile speller (56% and 53%, respectively). Likewise, bitrates were higher for the Hex-o-Spell compared with the tactile speller, and in the subjective usability a preference for the Hex-o-Spell was found.
Conclusions:
The Hex-o-Spell outperformed the tactile speller in classification performance, bit rate and subjective usability.
Significance:
This is the first study showing the possible use of tactile and visual gaze-independent BCI spelling systems by ALS patients with mild to moderate disabilities.
