Think positively or you could end up with a brain the size of a pea - that's the stark warning from scientists at Montreal's McGill University.

Dr Sonia Lupien has spent 15 years scanning the brains of OAPs and discovered that old timers with low self esteem were more likely to suffer from brain shrink and memory loss, the BBC reports.

Incredibly, those who didn't love themselves as much as they should have lost up to one fifth of their grey matter as a result. Unsurprisingly, they were also a few sandwiches short in the memory and learning departments.

Thankfully, Dr Lupien reckons there is hope, noting: "This atrophy of the brain that we thought was irreversible is reversible - some data on animals and some data on humans shows that that if you enrich the environment if you change some factors this brain structure can come back to normal levels."

Which is where Korean outfit DreamFree comes in. The company has developed the "Personal electroencephalogram", or Peeg - a PDA peripheral which is said to tickle your brain and stimulate positive brain waves.

It's basically a pair of specs with flashing lights plus headphones driven by a Microsoft Pocket PC application. Fire it up and you're subjected to a electronic son-et-lumière show which can alter brain wave frequency with beneficial results.

One ZDnet reporter found it "a bit like taking a nap while listening to a Kraftwerk album", although El Reg can't say its overly familiar with this concept.

Mind you, since the Peeg sells for $300, perhaps those seeking to reverse brain atrophy caused by years of negative thinking would be better off simply crashing into their chair to the strains of electronic Europop, rather than shelling out hard cash. It probably won't work, but then you'll still have $300 to go and get drunk - the only tried and trusted method which instantly increases self-confidence and mental agility. ®