Mental Strategies in a P300-BCI: Visuomotor Transformation Is an Option

Abstract

Currently, P300-BCIs are mostly used for spelling tasks, where the number of commands is equal to the number of stimuli that evoke event-related potentials (ERPs). Increasing this number slows down the BCI operation because each stimulus has to be presented several times for better classification. Furthermore, P300 spellers typically do not utilize potentially useful imagery-based approaches, such as the motor imagery successfully practiced in motor rehabilitation. Here, we tested a P300-BCI with a motor-imagery component. In this BCI, the number of commands was increased by adding mental strategies instead of increasing the number of targets. Our BCI had only two stimuli and four commands. The subjects either counted target appearances mentally or imagined hand movements toward the targets. In this design, the motor-imagery paradigm enacted a visuomotor transformation known to engage cortical and subcortical networks participating in motor control. The operation of these networks suffers in neurological conditions such as stroke, so we view this BCI as a potential tool for the rehabilitation of patients. As an initial step toward the development of this clinical method, sixteen healthy participants were tested. Consistent with our expectation that mental strategies would result in distinct EEG activities, ERPs were different depending on whether subjects counted stimuli or imagined movements. These differences were especially clear in the late ERP components localized in the frontal and centro-parietal regions. We conclude that (1) the P300 paradigm is suitable for enacting visuomotor transformations and (2) P300-based BCIs with multiple mental strategies could be used in applications where the number of possible outputs needs to be increased while keeping the number of targets constant. As such, our approach adds to both the development of versatile BCIs and clinical approaches to rehabilitation.

The application of hybrid feature based on local mean decomposition for motor imagery electroencephalogram signal classification

“…Yu et al [9] proposed a computer classification system that can cross‐discipline recognize multidisciplinary examination of MI, mental imagery, slow cortical potentials, epilepsy, and alcoholism can be used as an effective automated neurorehabilitation system. Syrov et al [10] proved the possibility of increasing the number of commands in classical P300‐BCI, based on the requirement of imaginary movement which can be further enriched by quasi‐movements and covert speech, increasing the development of multifunctional BCI and clinical rehabilitation methods. Numerous studies have shown that EEG signals have the characteristics of non‐stationarity, randomness, nonlinearity, weak signals, and easy interference [11, 12].…”

Lateralized Sensorimotor Evoked Potentials during Visuomotor Transformation in Real and Imagined Movements

“…Additionally, motor cortex readiness to execute a movement is known to be influenced by internal factors (Kunzendorf et al, 2019;Al et al, 2021) and stochastic processes (Murakami et al, 2014;Murakami et al, 2017;Aflalo et al, 2022). In particular, an increase in LRP duration associated with RT slowing has been documented in the elderly population (Falkenstein et al, 2006), which on the one hand suggests a deterioration of different stages of sensorimotor transformation with aging, and on the other hand makes BCI paradigms such as the one proposed in (Syrov et al, 2022) a useful tool for monitoring and possibly treating such age-related changes.…”