A Comparison of Three Different NeuroTag Visualization Media: Brain Visual Stimuli by Monitor, Augmented and Virtual Reality Devices

Abstract

Brain Computer Interfaces (BCIs) proved to overcome some limitations of other input modes (e.g., gestures, voice, haptic, etc.). BCIs are able to detect the brain activity, thus identifying searched patterns. When a specific brain activity is detected, a well-defined action can be triggered, thus implementing a human-machine interaction paradigm. BCIs can be used in different domains ranging from industry to services for impaired people.Small and ergonomics devices, such as the NextMind (https://www.next-mind.com/) are the result of recent technological advances; these new devices allow to support users in everyday life, thus bringing the design of BCIs into a new dimension well beyond the scope of laboratory tests.In particular, The NextMind is a device able to detect and classify signals coming from the visual cortex. Visual stimuli are blinking/flickering textures that are associated with objects called NeuroTags (see Figure 1). An event is triggered when the user focuses on the same NeuroTag for a given amount of time. This paradigm can replace selection methods based on keyboard, mouse, gesture, touch, voice, and gaze.This paper compares and assesses three different interfaces that share the same input device (the NextMind) to detect the brain activity and differ in the medium to convey to the user the visual stimuli. A monitor, an Augmented Reality (AR) device (the Microsoft HoloLens), and a Virtual Reality (VR) device (the Oculus Rift) are considered. The aim of this work is to assess any difference in the three visualization media when displaying NeuroTags. User tests have been performed in order to evaluate the usability of the three different solutions. After each test, users were asked for filling out the System Usability Scale (SUS) questionnaire and the SUS scores have been used for statistical analysis.