World-first machine bypasses cochlear 'distortions' A WORLD-FIRST brain scanning machine, unveiled yesterday at Macquarie University, will allow therapists to do something they havent been able to do before - analyse neurological activity in people with cochlear implants. The new magnetoencephalography or MEG machine, which can measure brain function despite electronic interference from the implants, means therapists will no longer be operating "in the dark" when they fine-tune the devices. Blake Johnson, chief investigator with the Centre for Cognition and its Disorders, said the machine could also give rise to a new generation of implants capable of dealing with people's idiosyncratic responses to the devices. " (And) there are vast opportunities for research," Dr Johnson said. If you take away sensory information from the brain, what organisational changes does that cause? That's resulted in Nobel prizes in some very important lines of research. MEG machines are powerful analysis tools, but the expense - around $2 million to buy, with $250,000 annual operating costs - means there are only about 150 in the world. Macquarie laid claim to the southern hemisphere's first MEG in 2006, and followed up the next year with a machine adapted for children's small heads. The latest addition is the first in the world that can cope with the distorting effects of electronics and magnets in cochlear implants. " (It's) especially engineered to deal with those artefacts," Dr Johnson said. He said the machine would yield information currently unavailable. It provides direct neurological measurements that cochlear implant manufacturers can use to determine and fine-tune their instruments. At present, the only check is behaviour. We know that people understand by their behaviour, but the brain is a black box. It's of fundamental importance to look at what's happening in that box. Macquarie worked with engineers from Cochlear, CSIRO and Japan's Kanazawa Institute of Technology to develop the machine. It has undergone two years of testing in Japan, and two months of simulations since it was installed at the university. It is expected to become fully operational from late next month. Dr Johnson said it would have particular therapeutic benefits for the very young. With children who are born deaf it's becoming increasingly clear that you have to implant as soon as possible - at a year or younger - (because) there's a critical period for acquiring spoken language. If you don't get spoken language very early, the brain changes. It adapts to the lack of sensory input, in ways it can never recover from. Dr Johnson said the new MEG would also have applications for adults who became deaf after acquiring language. Their brains also undergo reorganisation after the loss of auditory input - the other sensory systems take over the inactive auditory regions of the brain. That creates a problem because essentially the visual system has invaded the auditory brain and taken over the functions. It leaves less of the brain for the auditory system to make computations and so on when you restore input. He said the extent of these "plastic changes" was unknown. One of the reasons we're very excited about having access to the brains of cochlear implant recipients is that we can look at (them) after varying durations of deafness, and see what effects the deafness has had on the brain.