The Lingraphica Blog

Tutorial on Brain-Computer Interfaces for AAC

Jan 22, 2019 | by Richard Steele, PhD

Lingraphica Co-founder and Chief Scientist, Dr. Richard Steele, summarizes a tutorial on brain-computer interfaces (BCI) for augmentative and alternative communication (AAC) by rehabilitation specialists from universities in Kansas and Missouri. 

Broadly, the goal of this tutorial is to familiarize AAC practitioners with advanced technologies that help severely physically involved persons communicate via AAC, thereby expanding appropriate BCI utilization.

The authors organize their material into six topic areas: (1) how BCI users interact with computers, (2) what the factors for BCI user candidacy are, (3) the effectiveness and efficiency of BCI in different populations, (4) fatigue considerations among various users, (5) BCI as an addition to conventional AAC access technologies, and (6) limitations of BCI presently and future directions. Through literature reviews, the authors found the relevant information to identify and analyze articles on BCIs for restoring communication.

Briefly, by topic areas:

(1) They identify four non-invasive BCI approaches: first, visually- or aurally-inducing brain activity patterns detectable by electroencephalogram (EEG) as outlier event potentials; second, analyzing steady-state brain rhythms for modulations associated with directing attention to particular visual or aural stimuli; third, using motor-based BCI, which detects various neural activation patterns associated with intended bodily movements; and fourth, using biofeedback to train BCI users volitionally to change amplitude and polarity of the slow cortical potential for detection by EEG.

(2) Persons with acquired neurological and neuro-motor impairments leading to paralysis with minimal cognitive involvement are the best BCI candidates.

(3) Current BCI operations for AAC are generally slower than existing non-BCI methods.

(4) Operational fatigue that degrades user performance during extended use can be an issue.

(5) Combinations of BCIs with conventional AAC access technologies are infrequent.

(6) Technologies implanted surgically in the brain may improve BCI performance, but costs vs. benefits to users have not been clarified.

The tutorial is informative. It gives clinicians and others a useful introduction to the fundamentals of BCI for AAC, identifies and explains technologies now available and supported, outlines characteristics of good user candidates, and discusses trade-offs encountered in practice. In summary, it is an accessible, practical, and current resource for AAC practitioners.

For more on this topic, watch the interview below with Dr. Steele and authors of the tutorial, Jonathan Brumberg and Kevin Pitt.


For further reading:  J.S. Brumberg, K.M. Pitt, A. Mantle-Kozlowski, & J.D. Burnison. Brain-computer interfaces for augmentative and alternative communication: a tutorial. American Journal of Speech-Language Pathology, 27(1-2):1-12, 2018.