Brain-Computer Interfaces and Visual Activity

Introduction

Brain states can be detected and translated into actions such as selecting a letter from a virtual keyboard, playing a video game, or moving a robot arm. Such devices, which do not require the user to perform any physical action, are called brain–computer interfaces (BCIs) or brain–machine interfaces (BMIs). Although brain–computer interfaces and brain–machine interfaces involve the same kind of interface technology, it is agreed for purposes of precision in nomenclature that the latter are based upon invasive signals whereas the former rely upon non-invasive signals. For this reason, the term ‘BCI’ will be used in this chapter.

It is important to remark that, although the main application of BCI technology has been centred in providing a new communication channel for patients with severe neuromuscular disabilities (Kübler et al., 2011), it is also a powerful tool for contribution to a better understanding of the brain and it provides a novel communication channel for human–machine interaction. Also, BCI prototypes have only been developed recently, but the basic ideas were already put forward in the 1970s. Initial successful experiments were based on analysis of the brain’s electrical activity, namely, the visual evoked potential, generated in response to changes in gaze direction (Vidal, 1977).

We also wish to remark that some of the text included in this introduction has been extracted from the introductory chapter of the book Towards Brain–Computer Interfacing (Kübler & Müller, 2007). The curious reader is enthusiastically referred to this book, as it provides a still-timely overview of the BCI field (Dornhege et al., 2007).