Abstract
BackgroundAccidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate (locked-in state). Brain-computer interfaces (BCI) based on electroencephalography represent an important approach to establish communication with these patients. The most common BCI for communication rely on the P300, a positive deflection arising in response to rare events. To foster broader application of BCIs for restoring lost function, also for end-users with impaired vision, we explored whether there were specific time windows during the day in which a P300 driven BCI should be preferably applied.MethodsThe present study investigated the influence of time of the day and modality (visual vs. auditory) on P300 amplitude and latency. A sample of 14 patients (end-users) with ALS and 14 healthy age matched volunteers participated in the study and P300 event-related potentials (ERP) were recorded at four different times (10, 12 am, 2, & 4 pm) during the day.ResultsResults indicated no differences in P300 amplitudes or latencies between groups (ALS patients v. healthy participants) or time of measurement. In the auditory condition, latencies were shorter and amplitudes smaller as compared to the visual condition.ConclusionOur findings suggest applicability of EEG/BCI sessions in patients with ALS throughout normal waking hours. Future studies using actual BCI systems are needed to generalize these findings with regard to BCI effectiveness/efficiency and other times of day.
Highlights
Accidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate
Follow-up analysis indicated that latencies in the auditory modality were always shorter than in the visual modality at all electrodes, but the latency difference between the two modalities was larger at Fz than at Pz (t = 3.48, DF = 48, p = .003, d = 0.68) with no significant differences between either Fz and Cz and Cz and Pz
These results indicate that in patients with ALS P300 amplitudes comparable to those of healthy participants can be elicited in both modalities, which supports the feasibility of a P300 Brain-computer interfaces (BCI) in late stage ALS
Summary
Accidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate (locked-in state). In addition to the visually based P300 speller, there have been efforts to design a BCI solely relying on Erlbeck et al BMC Neurology (2017) 17:3 auditory stimuli for users with impaired vision or eye gaze control [9,10,11,12,13,14,15]. Patients are left unable to move or breathe while being fully aware of themselves and the environment For these patients a BCI solely relying on brain activity may be the only way to communicate their thoughts and wishes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
