Behind the Scenes of Noninvasive Brain–Computer Interfaces: A Review of Electroencephalography Signals, How They Are Recorded, and Why They Matter

Abstract

Purpose Brain–computer interface (BCI) techniques may provide computer access for individuals with severe physical impairments. However, the relatively hidden nature of BCI control obscures how BCI systems work behind the scenes, making it difficult to understand “how” electroencephalography (EEG) records the BCI-related brain signals, “what” brain signals are recorded by EEG, and “why” these signals are targeted for BCI control. Furthermore, in the field of speech-language-hearing, signals targeted for BCI application have been of primary interest to clinicians and researchers in the area of augmentative and alternative communication (AAC). However, signals utilized for BCI control reflect sensory, cognitive, and motor processes, which are of interest to a range of related disciplines, including speech science. Method This tutorial was developed by a multidisciplinary team emphasizing primary and secondary BCI-AAC–related signals of interest to speech-language-hearing. Results An overview of BCI-AAC–related signals are provided discussing (a) “how” BCI signals are recorded via EEG; (b) “what” signals are targeted for noninvasive BCI control, including the P300, sensorimotor rhythms, steady-state evoked potentials, contingent negative variation, and the N400; and (c) “why” these signals are targeted. During tutorial creation, attention was given to help support EEG and BCI understanding for those without an engineering background. Conclusion Tutorials highlighting how BCI-AAC signals are elicited and recorded can help increase interest and familiarity with EEG and BCI techniques and provide a framework for understanding key principles behind BCI-AAC design and implementation.

Investigating NIBS for language rehabilitation in aphasia

“…Recently, it has been used to detect neural activity for speech and translate it into commands for a speech synthesizer (Brumberg et al, 2010;Rabbani, Milsap, & Crone, 2019). Neural activity is non-invasively measured through electroencephalography and transferred to the BCI that aggregates all the EEG detected neural signals, sorts through them, finds the signal of interest and uses that as a command to instruct a speech generating device (Pitt et al, 2019). EEG technology capitalizes on the models of neuroplasticity by picking up neural potentials from the remaining perilesional brain.…”

Identifying Thematics in a Brain‐Computer Interface Research

“…EEG is a portable noninvasive monitor of the neuron electrical activity of the brain with the use of electrodes that are attached to the scalp [ 4 , 5 , 51 ]. Attached electrodes are used to detect and capture signals that are emitted from the brain.…”