A Radial Zoom Motion-Based Paradigm for Steady State Motion Visual Evoked Potentials

Abstract

Background: In steady state visual evoked potential (SSVEP)-based brain-computer interfaces, prolonged repeated flicker stimulation would reduce the system performance. To reduce the visual discomfort and fatigue, while ensuring recognition accuracy, and information transmission rate (ITR), a novel motion paradigm based on the steady-state motion visual evoked potentials (SSMVEPs) is proposed. Methods: The novel SSMVEP paradigm of the radial zoom motion was realized using the sinusoidal form to modulate the size of the stimuli. The radial zoom motion-based SSMVEP paradigm was compared with the flicker-based SSVEP paradigm and the SSMVEP paradigm based on Newton's ring motion. The canonical correlation analysis was used to identify the frequency of the eight targets, the recognition accuracy of different paradigms with different stimulation frequencies, and the ITR under different stimulation durations were calculated. The subjective comfort scores and fatigue scores, and decrease in the accuracy due to fatigue was evaluated. Results: The average recognition accuracy of the novel radial zoom motion-based SSMVEP paradigm was 93.4%, and its ITR reached 42.5 bit/min, which was greater than the average recognition accuracy of the SSMVEP paradigm based on Newton's ring motion. The comfort score of the novel paradigm was greater than both the flicker-based SSVEP paradigm and SSMVEP paradigm based on Newton's ring motion. The decrease in the recognition accuracy due to fatigue was less than that of the SSSMVEP paradigm based on Newton's ring motion. Conclusion: The SSMVEP paradigm based on radial zoom motion has high recognition accuracy and ITR with low visual discomfort and fatigue scores. The method has potential advantages in overcoming the performance decline caused by fatigue.

Comparison of Modern Highly Interactive Flicker-Free Steady State Motion Visual Evoked Potentials for Practical Brain–Computer Interfaces

“…Our findings on the subjective discomfort, that the SSMVEP approach is less exhausting and more comfortable—according to the questionnaire—are in-line with the literature [ 20 ]. We did not find any significant differences between the user questionnaire responses of the SSVEP against SSMVEP1 or SSMVEP2 (details in Supplementary Figure S3 and Table S1 ).…”

“…The statistical results of the achieved accuracies show that all tested SSMVEP stimuli were as accurate as the standard SSVEP stimulation. This proves that all of the tested SSMVEP stimuli can easily induce a strong steady-state response [ 29 ], as discussed in [ 18 , 19 , 20 ]. We also examined a broader frequency response of the tested SSMVEP designs, where we compared the responses with an additional recording utilizing the CCA maximum correlation coefficient spectrum (see Figure S4 ).…”

“…The findings of this study suggest that SSMVEP can be applied when SSVEP is found to be annoying, confusing or destructive [ 20 ] like in a virtual reality environment, while keeping the overall performance at a similar level to the SSVEP. For this application, our results suggest that the optimal movement would incorporate translational components in their movement behaviors.…”

“…An overwhelming majority of the reported studies utilizes the CCA method for data analysis (e.g., [ 14 , 15 , 18 , 19 , 20 , 21 ]). Based on our previous experience with the minimum energy combination (MEC) method [ 7 , 8 , 25 , 26 ], we decided to evaluate it with the filter banks (FB) in a practical scenario (spelling task), similar to our previous studies implementing the SSMVEP1 or SSMVEP2 stimuli, where the FB-CCA [ 22 ] or CCA [ 6 ] methods were utilized.…”

“…For the online experiment, the trial duration varied between 2 and 4 s with an additional 0.5 s for gaze shifting. On average, all eighteen participants reached an accuracy of 94.0% and an ITR of 91.2 bpm, with a mean trial length of 2.8 s. In 2019, Chai et al tested a radial zoom stimulation in a motion presentation pattern [ 20 ]. The authors compared this radial zoom stimuli to the typical on/off flickering and to the modulated Newton’s ring motion (e.g.…”