calcium imaging

A way of seeing neurons fire. When a neuron is active, calcium floods into it. Researchers add a fluorescent marker that glows when calcium is present, so a microscope can record which cells are active and when.

It shows activity cell by cell, which electrodes on the surface of the brain cannot. It needs an optical view of the tissue and, in most cases, genetically modified animals.

Documented real-world example: in the UC San Diego study behind transparent brain-computer interfaces, deep calcium activity recorded with two-photon microscopy served as the answer key. An AI model learned to predict it from electrical signals on the brain’s surface alone.

Related terms: two-photon microscopy, neural decoding, transparent brain-computer interfaces

Sources: Calcium imaging — Wikipedia; Transparent Brain-Computer Interface Uses AI and Nanotech — Psychology Today (Cami Rosso, 24 Jan 2024)