Earlier this year, our colleague Ben Herold reported on Secretary of Education Betsy DeVos’ investments in a firm that says its use of “neurofeedback” can help children with issues such as autism and attention deficit hyperactivity disorder. Since DeVos took office, it turns out, she’s put more money into that company.

On Monday, Ben reported that the DeVos has made an additional investment, up to $5.5 million, in Neurocore, which is based in Grand Rapids, Mich. The company analyzes a person’s brainwaves and then provides “neurofeedback sessions” to (purportedly) help the brain function better. The firm uses the treatment on both children and adults, and can charge up to $2,200 for a cycle of up to 30 sessions. The investment was made in a financial disclosure form filed by the secretary with the Office of Government Ethics.

However, there are plenty of skeptics that such treatments are effective, including the American Academy of Pediatrics, which along with other researchers has said there’s little evidence to back up neurofeedback. Neuorcore highlighted a new study in March and said it validated the company’s claims, but that study has also met with pushback.

There are also concerns that DeVos’ investment in the company signals that the secretary isn’t firmly committed to high standards of scientific research.

Click here to read Ben’s full report on DeVos’ new stake in Neurocore.