Simulating random eye-movement in a P300- based brain-computer interface

Authors' Affiliations

Wheeler, K.M., Shubert, K. N., Kellicut-Jones, M. R., Ryan, D. B., & Sellers, E. W East Tennessee State University, Johnson City TN,USA

Location

Ballroom

Start Date

4-5-2018 8:00 AM

End Date

4-5-2018 12:00 PM

Poster Number

26

Name of Project's Faculty Sponsor

Eric Sellers

Faculty Sponsor's Department

Psychology

Classification of First Author

Undergraduate Student

Type

Poster: Non-Competitive

Project's Category

Social and Behavioral Sciences

Abstract or Artist's Statement

People who suffer from amyotrophic lateral sclerosis (ALS) eventually lose all voluntary muscle control. In the late stages of the disease, traditional augmentative and alternative communication (AAC) devices fail to provide adequate levels of communication. Brain-computer interface (BCI) technology has provided effective communication after all other AAC devices have failed. Nonetheless, EEG-based BCI devices may also fail for people with late-stage ALS due to loss of voluntary eye movement. Specifically, some people may suffer from random eye movement (nystagmus) and/or drooping of the eyelids (ptosis). Presently, it is unclear in the literature whether BCI operation requires voluntary control of eye movement. The current study attempts to simulate involuntary random eye movement in able-bodied individuals employing the P300-based BCI. To simulate involuntary random eye movement, the stimuli shift in the X and Y dimensions. Stimulus movement ‘Jitter’ occurs between each stimulus presentation in increments of 1-5 pixels (Jitter 1), 5-10 pixels (Jitter 2), 10-15 pixels-(Jitter 3), or a no movement control condition. Data collected from a previous study using 22 participants compared the control condition to Jitter 1 and Jitter 2 indicated higher accuracy for control and Jitter 1 than Jitter 2. No significant differences were found in accuracy, selections per minute, or bitrate. Waveform analysis indicated significantly higher P300 amplitude for the control condition and Jitter 1 than Jitter 2. Preference survey scores showed a preference for Jitter 1 as compared to control and Jitter 2. This finding was unexpected and may be due to the slight movement of Jitter 1 forcing participants to be vigilant, but not distracted. Based on our finding in this study, the current study examines the amount of pixel movement that could lead to reductions in performance. Participants completed a control condition and the three levels of Jitter in a counter-balanced design. Preliminary data for the current study was collected from 15 participants. No significant differences were observed between the three conditions in measures of BCI accuracy, selections per minute, and bitrate. Furthermore, preference survey scores indicated no significant difference in condition preference. Based on the findings of the first study, as well as the data collected so far in the current study, it appears that random movement does not have a significant impact on the ability of healthy participants to operate the BCI system. This could indicate that individuals with random eye movement should be able to operate the system with high rates of accuracy.

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Apr 5th, 8:00 AM Apr 5th, 12:00 PM

Simulating random eye-movement in a P300- based brain-computer interface

Ballroom

People who suffer from amyotrophic lateral sclerosis (ALS) eventually lose all voluntary muscle control. In the late stages of the disease, traditional augmentative and alternative communication (AAC) devices fail to provide adequate levels of communication. Brain-computer interface (BCI) technology has provided effective communication after all other AAC devices have failed. Nonetheless, EEG-based BCI devices may also fail for people with late-stage ALS due to loss of voluntary eye movement. Specifically, some people may suffer from random eye movement (nystagmus) and/or drooping of the eyelids (ptosis). Presently, it is unclear in the literature whether BCI operation requires voluntary control of eye movement. The current study attempts to simulate involuntary random eye movement in able-bodied individuals employing the P300-based BCI. To simulate involuntary random eye movement, the stimuli shift in the X and Y dimensions. Stimulus movement ‘Jitter’ occurs between each stimulus presentation in increments of 1-5 pixels (Jitter 1), 5-10 pixels (Jitter 2), 10-15 pixels-(Jitter 3), or a no movement control condition. Data collected from a previous study using 22 participants compared the control condition to Jitter 1 and Jitter 2 indicated higher accuracy for control and Jitter 1 than Jitter 2. No significant differences were found in accuracy, selections per minute, or bitrate. Waveform analysis indicated significantly higher P300 amplitude for the control condition and Jitter 1 than Jitter 2. Preference survey scores showed a preference for Jitter 1 as compared to control and Jitter 2. This finding was unexpected and may be due to the slight movement of Jitter 1 forcing participants to be vigilant, but not distracted. Based on our finding in this study, the current study examines the amount of pixel movement that could lead to reductions in performance. Participants completed a control condition and the three levels of Jitter in a counter-balanced design. Preliminary data for the current study was collected from 15 participants. No significant differences were observed between the three conditions in measures of BCI accuracy, selections per minute, and bitrate. Furthermore, preference survey scores indicated no significant difference in condition preference. Based on the findings of the first study, as well as the data collected so far in the current study, it appears that random movement does not have a significant impact on the ability of healthy participants to operate the BCI system. This could indicate that individuals with random eye movement should be able to operate the system with high rates of accuracy.