Breaching Subjects’ Thoughts Privacy: A Study with Visual Stimuli and Brain-Computer Interfaces

Abstract

Brain-computer interfaces (BCIs) started being used in clinical scenarios, reaching nowadays new fields such as entertainment or learning. Using BCIs, neuronal activity can be monitored for various purposes, with the study of the central nervous system response to certain stimuli being one of them, being the case of evoked potentials. However, due to the sensitivity of these data, the transmissions must be protected, with blockchain being an interesting approach to ensure the integrity of the data. This work focuses on the visual sense, and its relationship with the P300 evoked potential, where several open challenges related to the privacy of subjects’ information and thoughts appear when using BCI. The first and most important challenge is whether it would be possible to extract sensitive information from evoked potentials. This aspect becomes even more challenging and dangerous if the stimuli are generated when the subject is not aware or conscious that they have occurred. There is an important gap in this regard in the literature, with only one work existing dealing with subliminal stimuli and BCI and having an unclear methodology and experiment setup. As a contribution of this paper, a series of experiments, five in total, have been created to study the impact of visual stimuli on the brain tangibly. These experiments have been applied to a heterogeneous group of ten subjects. The experiments show familiar visual stimuli and gradually reduce the sampling time of known images, from supraliminal to subliminal. The study showed that supraliminal visual stimuli produced P300 potentials about 50% of the time on average across all subjects. Reducing the sample time between images degraded the attack, while the impact of subliminal stimuli was not confirmed. Additionally, younger subjects generally presented a shorter response latency. This work corroborates that subjects’ sensitive data can be extracted using visual stimuli and P300.

Understanding the Ethical Issues of Brain-Computer Interfaces (BCIs): A Blessing or the Beginning of a Dystopian Future?

“…The use of BCIs raises important issues regarding the privacy and security of their users. In the scientific literature, there are several papers, with an increasing trend over the last years, showing that brain data could be extracted through malicious external action or there could be a case of unauthorized access to the functions of BCIs with further impact on the issues of autonomous action and liability [29][30][31][32]. Indeed, the issue of malicious external attacks on the brains of BCI users could be described as a kind of 'neurocrime' [33].…”

Analyzing the impact of Driving tasks when detecting emotions through brain–computer interfaces

“…For example, some of the existing solutions aim to mark the direction to be followed by an autonomous car [3] or control a vehicle's multimedia system [4]. Nevertheless, these systems must consider existing cybersecurity challenges, such as the impact of adverse external stimuli [5], or data disruption based on malicious signals [6]. Other works, for instance, try to detect when the driver is distracted by using electroencephalography (EEG) [7].…”