A new AI could finally spell the end for the IQ test - and work out how smart you really are just by looking at a scan of your brain.

Researchers from Caltech, Cedars-Sinai Medical Center, and the University of Salerno say their system can predict a person's intelligence from functional magnetic resonance imaging (fMRI) scans of their resting state brain activity.

They say an individual's intelligence can be gleaned from patterns of activity in their brain when they're not doing or thinking anything in particular, without the need for quizzes, math problems of vocabulary tests.

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Caltech researchers say their AI can predict a person's intelligence from functional magnetic resonance imaging (fMRI) scans of their resting state brain activity

HOW ACCURATE ARE IQ TESTS? After conducting the largest ever study of intelligence, researchers concluded that far from indicating how clever you are, IQ testing is actually rather 'meaningless'. In a bid to investigate the value of IQ, scientists asked more than 100,000 participants to complete 12 tests that required planning, reasoning, memory and attention. They also filled in a survey on their background. Scientists from Canada's Western University in Ontario discovered that far from being down to one single factor, what is commonly regarded as intelligence is influenced by three different elements - short-term memory, reasoning, and verbal ability. But being good at one of these factors does not mean you are going to be equally gifted at the other two. Advertisement

'We found if we just have people lie in the scanner and do nothing while we measure the pattern of activity in their brain, we can use the data to predict their intelligence,' says Ralph Adolphs, who led the study.

Functional MRI develops a map of brain activity by detecting changes in blood flow to specific brain regions.

To train their algorithm, researchers downloaded the brain scans and intelligence scores from almost 900 individuals who had participated in the the Human Connectome Project (HCP), a National Institutes of Health project that seeks to improve understanding of the many connections in the human brain

After processing the data, the team's algorithm was able to predict intelligence at 'statistically significant levels' across these 900 subjects, said Julien Dubois, a postdoctoral fellow at Cedars-Sinai Medical Center who worked on the study.

But there is a lot of room for improvement, he admitted.

'The information that we derive from the brain measurements can be used to account for about 20 percent of the variance in intelligence we observed in our subjects,' Dubois says.

'We are doing very well, but we are still quite far from being able to match the results of hour-long intelligence tests, like the Wechsler Adult Intelligence Scale,' he admits.

The team also created their own measure of intelligence for the study.

They extracted a more precise estimate of intelligence across 10 different cognitive tasks that the subjects had taken, not only from an IQ test.

In predicting intelligence from brain scans, the algorithm is doing something that humans cannot, because even an experienced neuroscientist cannot look at a brain scan and tell how intelligent a person is.

After conducting the largest ever study of intelligence, researchers concluded that far from indicating how clever you are, IQ testing is actually rather 'meaningless'. The new research could replace the test entirely.

The study was conducted as part of an ongoing quest to build a diagnostic tool that can tell a great deal about a person's mind from their brain scans.

Adolphs and his colleagues say that they would like to one day see MRIs work as well for diagnosing conditions like autism, schizophrenia, and anxiety as they currently do for finding tumors, aneurisms, or liver disease.

The researchers also conducted a parallel study, using the same test population and approach, that attempted to predict personality traits from fMRI brain scans.

An individual's personality, Adolphs says, is at least as stable as intelligence over a long period of time.

The personality test they used divides personality into five scales:

However, it has turned out to be much more difficult to predict personality using the method the team used for predicting intelligence.