Spinning Icons: Introducing a Novel SSVEP-BCI Paradigm Based on Rotation

Abstract

Steady-State-Visually-Evoked-Potential (SSVEP) Brain-Computer Interfaces (BCIs) make use of flickering stimuli to determine the target a user is looking at and select commands accordingly. Those types of BCI can be operated with little to no training, achieve high classification accuracies and are robust in application. A drawback of this approach is the reduced user comfort due to the constant flickering of the stimuli which can be annoying and tiring to look at. Existing studies addressing this issue try to make use of motion to disguise the oscillating patterns. However, this makes them look abstract and restricts the design of those applications as those patterns do not blend in to conventional user interfaces. In this work we introduce the concept of spinning icons to evoke SSVEPs. The icons are rotating in a certain frequency around their vertical axis and are supposed to appear more natural and be less stressing for the human eye. Furthermore this concept is not bound to any kind of abstract motion based pattern but rather supposed to work with any type of icon or image. The newly designed stimuli were evaluated in an application-oriented scenario and compared to standard and state-of-the-art movement-based SSVEP stimuli regarding the classification accuracy and experienced visual fatigue. The results show that the newly created stimuli performed equally well and partially even better in terms of classification accuracy and were rated throughout better concerning visual fatigue by the study participants. This work therefore lays the foundation for more comfortable SSVEP-BCIs which can be used with basically every icon or UI element spinning around their vertical axis. CCS CONCEPTS• Human-centered computing → Graphical user interfaces.

Optimal Stimulus Properties for Steady-State Visually Evoked Potential Brain–Computer Interfaces: A Scoping Review

“…Apart from the classic flickering or pattern-reversal checkerboard stimuli, several motion stimulus types have been used and proven to work. These include a sliding shape that moves every iteration [51,55], a grow-shrink stimulus [15,16,54,66], a Newton ring stimulus [66], a spinning icon/flipping coin [55,77], a rotation stimulus [44,73], a ringshaped arc inverse pulsation [55], a ring-shaped arc inverse rotational oscillation [55], a ring-shaped checkerboard that contracts concentric [20], and a gaiting action video [53]. A visual overview of the different stimulus types can be found in Figure 4.…”

A Review of EEG-Based User Authentication: Trends and Future Research Directions

“…SSVEPs are brain signals in response to visual stimulation presented as flickering at a specific frequency [39]. Those potentials can be evoked by different means, such as LEDs flashing on and off or an alternating pattern presented on a screen oscillating at a particular frequency [58]. SSVEPs are typically preferred in the research because of their excellent signal-tonoise ratio and relative immunity to artifacts [55].…”

“…A viable solution to this problem is to hide the flickering and the related repeating patterns within different kinds of motions. Those approaches are called Steady-State-Motion-Visually-Evoked-Potentials (SSMVEP) [58]. Rapid serial visual presentation (RSVP) is a special protocol that triggers targeted stimuli (e.g., letters or images) that are presented sequentially in a stream and helps in the detection of brainiac response to the serial stimuli.…”

Steady-State Visual Evoked Potential-Based Brain–Computer Interface Using a Novel Visual Stimulus with Quick Response (QR) Code Pattern

“…Furthermore, some researchers demonstrated different flicker patterns through employing rapid object motion and lower light intensity than the flashing pattern [30]. For example, the use of object motion or spin patterns [31] was used to activate some phenomena in the visual cortex. This technique can reduce visual fatigue problems but has a low ITR.…”