In late 2011, Canadian researchers using a novel method of interpreting electroencephalograms asked 16 patients in an irreversible “vegetative” state to move their hands or toes. In three people, the scientists found brain activity similar to that of healthy people given the same instructions. The result suggested that the “vegetative” patients in fact might be hearing and understanding what was said.
The study, published in the prestigious medical journal The Lancet received widespread attention. But now a new analysis of the data, published online on Thursday in the same journal by other researchers, concludes that the results were almost surely due to chance.
The lead author of the new paper, Dr. Andrew M. Goldfine, an assistant professor of neuroscience at Weill Cornell Medical College, said the EEG data that the authors recorded do not necessarily indicate understanding.
Dr. Goldfine said the first study relied on a powerful tool that looks for patterns in EEG recordings. “The pattern could be coming from brain activity, or non-brain activity, or level of arousal,” he said. “You don’t know.”
“They went into this with the best intentions,” Dr. Goldfine added, “but they made assumptions that turn out not to be valid.”
In a response printed in the same issue of The Lancet, the authors of the 2011 study acknowledge that Dr. Goldfine and his colleagues “make some interesting points about the choice of statistical model,” but generally reject the new interpretation of their data.

Courtesy: NY Times

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