Scientists in Canada have launched what is set to become the world's largest study of the effects of lack of sleep on the brain.
A team, at
Ontario, want people from all over the world to sign up
to do cognitive tests.
The specially devised computer games test skills such as reasoning, language comprehension and decision-making.
I joined a group of volunteers trying out the tests and had my brain scanned while doing them.
He told me: "We all know what it feels like to not get enough sleep but we know very little about the effects on the brain; we want to see how it affects cognition, memory and your ability to concentrate."
The team will collate the cognitive scores and see the variations depending on how much sleep people have had.
Everyone's sleep requirements are different, but if enough people join the study, it may allow scientists to determine the average number of hours needed for optimum brain function.
I joined four volunteers spending the night at Western University, where we road-tested the brain games and were able to demonstrate how lack of sleep affects cognitive performance.
The tests can be played on any computer, tablet or smart phone.
Double Trouble: This looks simple but really stretches the grey matter. You have to click on the word below that corresponds to the colour in which the word above is written. So, if the word at the top is "blue", but is coloured in red, you must click on the word below that is coloured red, even if it is written as "blue". Fiendish.
Odd One Out: This starts simple but gets increasingly complex as you try to find the one shape that is different from the others.