Passive brain–computer interfaces (passive BCI; pBCI) have been introduced and formally
defined almost a decade ago and have gained considerable attention since then. In this
chapter, we clarify some points of confusion and provide a perspective on the past, present,
and future of the field of passive BCI. This perspective concerns a key aspect with regard to
which various pBCI-based systems differ from each other: interactivity. The more interactive
a system is, the more responsive it is, the more autonomous, and the better capable of
adaptation. Along these lines, we identify and describe four relevant categories of systems
with varying levels of interactivity: mental state assessment, open-loop adaptation, closed-
loop adaptation, and automated adaptation. We give examples of past and current research for
each of these categories. The latter three are collectively introduced as neuroadaptive
systems. This perspective and formal categorisation helps to highlight human–computer
interaction aspects that are relevant for the design of pBCI-based systems and points to
possibilities for future research and development into passive BCI, implicit interaction, and
neuroadaptive technology

Этот мини-обзор направлен на то, чтобы выделить последние важные аспекты, которые необходимо учитывать и оценить, когда системы пассивного интерфейса мозг-компьютер (pBCI) будут разрабатываться и использоваться в операционных средах, и отмечает будущие направления их приложений.