A research group’s claimed ability to communicate with completely paralyzed people has come under fire, prompting research misconduct investigations at a German university and at Germany’s main research agency, the German Research Foundation (DFG). Two years ago, researchers in Germany and Switzerland claimed that by analyzing blood flow in different parts of the brain with an electronic skullcap, they could elucidate answers to yes or no questions from completely paralyzed people. The find, published in PLOS Biology in 2017, raised hopes for patients with degenerative diseases like amyotrophic lateral sclerosis that ultimately leave them without any voluntary muscle control—not even the ability to blink or move their eyes—a condition called a “completely locked-in state.” Now, a simmering controversy about the paper has erupted into public view.
As first reported by the German newspaper Süddeutsche Zeitung, PLOS Biology yesterday published a critique of the paper that claims the authors’ statistical analysis is incorrect. Martin Spüler, an informatics specialist at the Eberhard Karls University of Tübingen in Germany, says his analysis of the data shows no support for the authors’ claim that their system could allow patients to answer questions correctly 70% of the time. His critique, first raised in late 2017, has prompted investigations of possible scientific misconduct at both DFG and the University of Tübingen, where the group studying locked-in patients is also based.
Spüler says he originally wanted to test whether a different algorithm could make the method even more accurate, but when he analyzed the data he found that the team had averaged its data in a way that ended up always producing a statistically significant result. “With the statistical tests they use, you will always get a positive answer.” He says his attempts to get explanations from the authors were unsuccessful. “It doesn’t add up,” he says.