Microsleep Research
April 2, 2008
NEWS RELEASE
A microsleep is more likely to happen when people are sleep-deprived due to having missed out on a good night’s sleep, according to neuro-engineer/scientist Associate Professor Richard Jones, from Christchurch Hospital, the Christchurch School of Medicine, and the University of Canterbury.
But what seems like an innocent daydream or momentary lapse can cause a fatal accident on the road or in a workplace where machinery is being used.
“When driving at 100 km per hour, a 3 second microsleep means travelling 80 metres when effectively unconscious,” Professor Jones said. “It is no trouble to drift into the side of a bridge or across the centre-line into an oncoming car in this time.”
“And although less critical, if you’re giving a talk at a seminar or lecturing a class of students, watch out for inattention – nodding off and microsleeps during talks is a common occurrence, especially when a bit sleep-deprived”.
Professor Jones said “studies have shown that a substantial proportion of the population is chronically sleep deprived.”
“It’s part of our sleep-deprived world. There are so many things that make people more likely to have microsleeps,” he said.
Recently, Professor Jones and his team have obtained the world’s first preliminary 3D image of what happens in the brain during a microsleep.
They have achieved this by recording functional-MRI and EEG at the same time in a MRI scanner – the first time this has been done in New Zealand. Furthermore, they also record video of eyes and visual-motor performance. All of this provides the behavioural and physiological information necessary to accurately detect microsleeps and capture the changes in neural activity in the brain.
“This has only been made possible by having the two machines available under the one roof and through a specially made system linking the two,” says Dr Richard Watt, CMRF MR research director at the Van der Veer Institute, where, together with Hagley Radiology, the images are recorded.
“Combining brain scanning with EEG scanning is technically very challenging and available in only a small number of research facilities world-wide,” he says. “It gives us a unique insight into both the timing and spatial distributions of brain activity associated with neural events such as epileptic seizures or microsleeps.”
An earlier study in the Lapse Research Programme revealed a much higher incidence of lapses in normal non-sleep-deprived subjects than anticipated.
“Cases of tired drivers falling asleep while driving are not uncommon and there is considerable anecdotal evidence of brief lapses of consciousness/ responsiveness, including microsleeps, during tasks such as driving and attending talks,” Professor Jones said.
“This indicates that lapses are a much more common phenomenon than generally recognised – but little is known about their characteristics and even less about their mechanisms in the brain,” Professor Jones says.
A longer-term aim of the research is to develop non-invasive technology which can use the EEG and other cues, such as video of the eyes, to detect – and even predict – lapses, provide warning/wake-up alarms, and hence prevent potentially serious accidents.
For further information, please contact Associate Professor Richard Jones on 378 6077.
