Brain training study could help explain the placebo effect

A Nature Medicine study reports that neurofeedback training helped some people increase activity in deep reward regions of the brain, and those with higher ventral tegmental area activity showed higher antibody levels after a hepatitis B vaccine; researchers say the finding may relate to mechanisms behind the placebo effect.

Researchers published a study in Nature Medicine reporting that neurofeedback training helped participants raise activity in deep-brain reward regions. Thirty-four people learned to use real-time brain-scan feedback and mental strategies to try to activate the ventral tegmental area (VTA) and the nucleus accumbens. After training, all participants received a hepatitis B vaccine and researchers measured antibody levels two and four weeks later. The work is discussed as a possible biological link to the placebo effect. Key findings: - Thirty-four participants received neurofeedback training to increase activity in deep reward regions, and two other groups received different training or no training. - Participants used strategies such as recalling a positive memory or focusing on their body while watching real-time brain activity to try to raise activity in the VTA and nucleus accumbens. - Higher activity in the VTA was associated with higher hepatitis B antibody levels measured after vaccination. - There were no significant differences in antibody levels between the reward-region training group as a whole and the other groups. - Participants who focused on positive expectations were more able to increase VTA activity than those who aimed at broader feelings of happiness. Summary: The study links activity in a specific deep-brain reward region with downstream antibody responses, and authors and outside experts say the result could help explain how expectations affect the body. The overall comparison between trained and untrained groups was not clearly different, and researchers are still working to understand the biological pathways involved. Ongoing questions include whether brain signals reach immune cells via nerves or other mechanisms and whether the connection has evolutionary roots. Further research is needed to clarify these mechanisms and their implications.