Our brain has distinct areas for all manner of ideas, research suggests.

Researchers have deciphered the abstract concepts people are thinking about – for example justicetruth and forgiveness – merely by analysing their brain scans.

Until now, this type of “thought decoding” has been largely confined to concrete concepts such as apple and hammer. The new findings, however, suggest slippery ideas that are not of the physical world also inhabit distinct parts of the brain.

The study is the work of psychologist Marcel Just and graduate student Robert Vargas from Carnegie Mellon University in the US.

It makes intuitive sense, they say, that physical or “concrete” objects, such as hammers and apples, will be represented in the brain similarly between people. Trade tools and fruit are, by nature, unambiguous.

It’s a contention born out in the science of neural decoding, where patterns of activity on brain scans are used to work out what someone is thinking.

Just, for example, has used brain scans to predict when a person is reading sentences that refer to concrete things, such as “the flood damaged the hospital”.

But given the fuzziness of abstract ideas like justice and ethics, intuitions cut the other way – could we really share common brain space for them too?

To find out, Vargas and Just put nine people in an MRI scanner and flashed an array of 28 abstract concepts at them, shown as words.

Read the full story in Cosmos magazine here