The Gowerlabs NTS system is being used in pioneering longitudinal studies at the University of Bristol, investigating how and when young children develop abilities that enable them to focus and learn.

It looks like a simple, repetitive game, but is actually a test of a fundamental skill that is developing in the toddler's growing brain. Henry is wearing a sensor-laden cap with wires emerging from it that are attached to a large piece of analytical machinery. While Henry plays the game, the cap is scanning his brain activity and building up a picture of how well he can control his decision making.

It is a test of inhibitory control, one of the skills scientists at the University of Bristol are measuring in babies and toddlers, as part of a mission to understand how and when very young children develop abilities that enable them to focus and learn.

Scientists already know these skills are critical - but they don't yet know at what point they are established in an infant brain.

The development of hundreds of children - from the age of six months to five years - is being tracked as they form the key skills that will shape their academic and social abilities.

But what is really special about this pioneering project is that it is a human experiment within another decades-long human experiment. The mothers of 300 of the children being studied are themselves part of a project that has monitored their health since they too were babies, in the 1990s.