Scientists studying human behaviour and cognitive brain function are up in arms over a plan by the US National Institutes of Health (NIH) to classify most studies involving human participants as clinical trials.

An open letter posted to an online petition site on 31 August and addressed to NIH director Francis Collins on says that the policy could “unnecessarily increase the administrative burden on investigators”, slowing the pace of discovery in basic research. It asked the NIH to delay implementation of the policy until it has consulted with the behavioural-science and neuroscience communities. The letter has so far garnered more than 2,700 signatures.

“Every scientist I have talked to who is doing basic research on the human mind and brain has been shocked by this policy, which makes no sense,” says Nancy Kanwisher, a cognitive neuroscientist at the Massachusetts Institute of Technology in Cambridge, who co-wrote the letter with four other researchers.

The policy is part of an NIH reform effort started in 2014, which aims to ensure that all clinical results are publicly reported. The policy is scheduled to go into effect in January 2018; it defines a clinical trial as anything involving behavioural ‘interventions’, such as asking participants to perform a memory task or monitor their food intake. Under the policy, such studies would need special evaluation by NIH committees and institutional ethics-review boards. The experiments would also need to be registered in the database.

Waiting for clarification

But many researchers think that studies of normal human behaviour — intended to discover phenomena rather than alter them — should not be classified in this way. Among other concerns, small institutions that do not normally perform clinical trials may not have the resources or knowledge to comply fully with the policy.

These concerns are overblown, said Michael Lauer, NIH deputy director for extramural research, at a meeting of the agency’s advisory council on 1 September in Bethesda, Maryland. “The only regulation we’re talking about is reporting that the trial exists and telling the world about the results. It is as simple as this and as profound as this.” He said that his office would work with behavioural scientists to ensure that their studies were getting the proper review and that their research could be registered properly.

But council member Terry Jernigan, a cognitive scientist at the University of California, San Diego, told Lauer that it was “not as simple as that”. She said the policy has already caused problems for a study she is leading that tracks normal brain development in adolescents. When her group asked participants’ parents to sign the required clinical-trial consent form, some expressed concerns that the form’s language indicated that something was being done to their children, rather than that researchers were simply observing them.

In response to some of those concerns, the NIH will update a list of examples of studies that qualify as clinical trials under the policy this week. “The NIH definition of a clinical trial may be broader than other clinical-trial definitions because it reflects NIH’s mission, encompassing biomedical and behavioural outcomes as they pertain to human health,” said the agency in a statement to Nature’s news team. “This definition does not encompass all psychological and cognitive research that is funded by NIH.”

Jeremy Wolfe, a vision researcher at Brigham and Women’s Hospital in Boston, Massachusetts, says it is encouraging that the NIH plans to work with researchers in his field, but he adds that the details of the policy will be key. “We’re worried about whether those details can be worked out by the January deadline,” he says.