Brain-to-brain interface (BBI)

A brain-to-brain interface reads a signal from one nervous system (the sender), converts it into information, and writes that information into a second nervous system (the receiver), so that a message passes brain-to-brain without going through the normal peripheral output and input — no speech, typing, gesture, or camera on the sending side and no eyes or ears on the receiving side. Architecturally a BBI is a brain-computer interface (the read side) chained to a computer-to-brain interface (the write side), the two halves joined by an ordinary digital link that may run over the internet.

The demonstrated systems are real but deliberately narrow. Non-invasive human BBIs (Rao and Stocco 2014; Grau et al. 2014) carry on the order of a single bit per trial and a bit or two per minute, and invasive animal BBIs (Pais-Vieira et al. 2013) let a decoder animal act above chance from an encoder's cortical activity. None of this is telepathy or mind-melding: the bandwidth is tiny, the content is a pre-agreed code rather than raw thought, and every link is computer-mediated.