Risto Kalervo Näätänen (14 June 1939 – 5 October 2023[1][2]) was a Finnish psychological scientist, pioneer in the field of cognitive neuroscience, and known worldwide as one of the discoverers of the electrophysiological mismatch negativity.

Under Lindsley's supervision, he defended his doctoral dissertation about brain mechanisms of selective attention [4] at the University of Helsinki in 1967.

[7] In 1975, at an age of 36, having published 13 academic articles, he was appointed a Professor of General Psychology at the University of Helsinki.

[16] MMN was established as a scalp-negative component of the event-related potential or ERPs, as derived from recordings made electroencephalographically via electrodes attached to the scalp.

MMN influenced theories of language perception, together with studies of cognitive development and musical intelligence.