fMRI can tell what noun you're thinking of (sometimes)

Posted by: Emily McManus

From Not Exactly Rocket Science, here’s a thoughtful report on a new fMRI technique that — 70 percent of the time, anyway — can tell what noun a person is thinking of:

Tom Mitchell and colleagues from Carnegie Mellon University [used] a technique called functional magnetic resonance imaging (fMRI) to visualise the brain activity of nine volunteers, as they concentrated on 60 different nouns. This ‘training set’ consisted of five words from each of 12 categories, such as animals, body parts, tools and vehicles.

The technique Mitchell’s team used is of interest to word nerds:

Mitchell analysed how these words are used with the help of a “text corpus”, a massive set of texts containing over a trillion words. A text corpus reflects how words are typically used in the English language. Linguists have used these tools to show that a word’s meaning is captured to some extent by other words and phrases that it frequently appears next to.

With the corpus, Mitchell worked out how often the 60 nouns occur next to 25 verbs, including “see”, “hear”, “taste”, “enter” and “drive”. All of them are related to sensation and movement because other studies have suggested that objects are encoded in the brain in terms of how you sense them and what you can do with them.

View the word analysis behind the study >>
Read the abstract of the paper “Predicting Human Brain Activity Associated with the Meanings of Nouns” >>
Read the full blog post from Not Exactly Rocket Science >>

Meanwhile, in the latest Wired, psychiatrist Daniel Carlat looks at other fMRI “mind-reading” applications that purport to find psychological states — like love, lying and OCD.