Look at the first picture and read down the column. Read down the second picture and this time say out loud the colour you see, not what is written.
This is a Stroop test. It is a measure of attention inhibition, which is one part of executive functioning.

Executive functioning has been a pervasive concept at this conference. It might be thought of a the new IQ. It captures our ability to control our skills. One might be very brainy, but if one cannot use that brain effectively it will be of little value.

Tom Dishion, Director of Research at the Child and Family Center at the University of Oregon is one of a handful of scientists using brain imaging to have a look at what is going on in the minds of children whose executive functioning is impaired. The procedures is known as fMRI; and MRI that looks at how the brain functions.

Dishion's interest stemmed from drug and alcohol misuse. He starts from the premise that early use of drugs is the best predictor of later use. The strongest correlate of early use is friends doing the same. Kids with good self-regulation mixing with friends who use drugs appear less likely to take up the habit.

In his latest studies Dishion has compared fMRIs of drug and non-drug using adolescents. He finds their brains have to work much harder to do tests like stroop. In fact, he speculates that the functioning of the brain in these drug users is more like a child than an adolescent.

The work of Dishion and others in the same field is at the cutting edge. Much more needs to be known. The goal is to find better interventions and prevention. Reducing disinhibition is one obvious target.

But there is another side to the coin. There have been numerous examples at this conference of programmes that succeed with children with some impairment but that fail those with a lot of impairment.

One possibility is that there exists a group of children who struggle to cope with the various curricula and other programmes designed to reduce disinhibition. In other words, the problem being treated might be getting in the way of the treatment.