Foundations
This chapter provides the top-level classification, brief history, and core terminology of the BCI field. It is the entry point of the whole chapter and the vocabulary sheet for all subsequent chapters.
Why start here? BCI systems differ enormously in performance, risk, and target population, and lumping them together quickly leads to confusion. Invasiveness (invasive / minimally invasive / non-invasive), signal direction (decoding / encoding / bidirectional), and application scenario (clinical / consumer / research) are the three keys that locate any given BCI work in the field — Neuralink, Stentrode, Muse, and MindEye in later chapters can all be read against this three-axis grid.
Recommended reading order. Readers with no prior background should read the three sections in order: first use BCI Overview and Classification to build a mental map; then use Brief History to trace the century-long timeline from Berger (1924, EEG) → Kennedy (1998, first invasive case) → BrainGate (2006) → Neuralink (2024, PRIME) → Neuracle (2026, first NMPA approval); and finally use Core Terminology and Metrics to master ITR, bitrate, closed loop, decoder vs encoder, and other concepts that recur throughout the chapter — before moving on to Chapter 02 on neurophysiology.
Contents:
- BCI Overview and Classification — Three-dimensional taxonomy by invasiveness, signal direction, and application scenario
- Brief History — A century-long timeline from Berger 1924 to Neuracle 2026
- Core Terminology and Metrics — Closed loop, ITR, bitrate, latency, decoder vs encoder