14.4: Polychromatic High‐Frequency Steady‐State Visual Evoked Potentials for Brain‐Display Interaction

Abstract

An oncoming interactive platform integrated with LCD provides another option not only for handicapped but public to make our daily lives more convenient. Steady‐state visual evoked potentials (SSVEPs) are human brain responses to visual stimulation at specific light flashing frequencies. With the improvement of brain‐computer interface (BCI) applications in mind, this paper proposed effective and comfortable SSVEP stimuli of high‐frequency and polychromatic encoded lights with tunable duty cycles and phases.

A High-Speed Brain Speller Using Steady-State Visual Evoked Potentials

“…The methodologies developed in this study also provide a practical solution to the newly proposed concept of the brain-display interface technology. 46 The proposed target identification approach can be adopted to implement SSVEP-based BCIs for other applications that require fewer targets. 47 For example, a 4-target system can be realized using two frequencies (e.g., 10Hz and 15Hz) and two phases (e.g., 0 and 180 degrees).…”

Polychromatic SSVEP stimuli with subtle flickering adapted to brain-display interactions

“…In the future, if embedded displayed images of less distractive high-frequency stimuli prove feasible, it will allow SSVEPs to be employed more freely among interactive display systems. We have engaged in the design of high-frequency polychromatic SSVEP stimuli since 2011 [36][37][38]. This paper is a report of our preliminary results.…”

High-frequency polychromatic visual stimuli for new interactive display systems

“…As part of this work, we have proposed using a combination of flickering red-green lights to create an imperceptible flickering visual stimulus that can elicit an SSVEP at a basic flickering frequency. 4 We have thus conducted a series of experiments to investigate whether the acuity of foveal vision (i.e., sharp central vision) can be used to overcome the limits of high-frequency-SSVEP (HF-SSVEP). 5 For our experiments, we hypothesize that the fovea centralis-because of its high photopic visual acuity (i.e., in welllit conditions)-should be capable of producing a detectable SSVEP in response to stimuli flashes above flicker fusion thresholds.…”

“…We therefore chose polychromatic flickering lights with frequencies as our experimental visual stimuli. 4 In particular, we propose using high-frequency (32 and 40Hz) flickering red/green mixed stimuli, with modulated amplitude and relative-phase offsets, to understand more about color perception within the red-green channel of human eyes. In our experiments, we used high-frequency polychromatic lightswith higher flickering frequency (40Hz) and larger phase offsets (180 • )-to induce distinct SSVEP responses, but with small levels of associated flickering sensation (see Figure 3).…”

“…In our experiments, we used high-frequency polychromatic lightswith higher flickering frequency (40Hz) and larger phase offsets (180 • )-to induce distinct SSVEP responses, but with small levels of associated flickering sensation (see Figure 3). 4 Although 3D displays offer realistic sensations and various stimuli with depth information, few studies of SSVEP-based BCI systems have been conducted in 3D environments. 7,8 We have therefore investigated the potential improvements to SSVEPbased BCI systems that can be enabled by 3D displays.…”