Australasian Science: Australia's authority on science since 1938

Brain Stimulation Solves Puzzle

By Stephen Luntz

Transcranial brain stimulation has enabled people to solve a puzzle they could not previously crack, offering the promise of a smarter future.

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Prof Allan Snyder and Mr Richard Chi of the University of Sydney’s Centre for the Mind used an old puzzle known as the nine dots problem, in which participants are presented with three rows of three dots and, in Snyder’s words, are “asked to join all the dots with four straight lines without taking the pen off the page”.

“Under lab conditions nobody gets it,” Snyder says, although when students at Princeton University were presented with the problem in a more relaxed environment about 5% succeeded.

In work published in Neuroscience Letters Snyder and Chi gave 11 people the problem for 3 minutes before they underwent 10 minutes of transcranial brain stimulation in which the left anterior temporal lobe was inhibited while the right anterior lobe was excited using direct current stimulation. Participants were given the final 3 minutes of stimulation and a further 3 minutes after it ceased to confront the problem.

None got the solution before the stimulation started, but once it began answers started to appear. Four solved it during the stimulation and one almost immediately afterwards, but not all of them could remember how it was done some time later. Meanwhile, no members of a control group given a sham stimulation were successful.

Snyder says that the combination of right stimulation and left inhibition was based on observations. “Savant-like...

The full text of this article can be purchased from Informit.