New study: Brain stimulation alters response to primary, sexual rewards

LOS ANGELES - Dec. 1, 2016 - PRLog -- Even as humans strive to experience pleasurable rewards, we also must manage our experience of those rewards. Gambling in the casino we must keep an eye on our account balance; eating we must be mindful of how much chocolate we imbibe; being sexual we must manage the physical and emotional risks that can follow great pleasure. Managing rewards is an important part of our health, and a core problem in disorders like depression and mania. This publication is the first to demonstrate that brain stimulation alters evolutionarily important primary rewards in men and women. This opens up new methods of study and, possibly, treatments in many areas of life that rely on rewards.

In this study, 20 men and women who had several new sexual partners within the last years came to the laboratory at UCLA. They received two different forms of brain stimulation, both forms of theta burst transcranial magnetic stimulation (TBS). The two forms may excite or inhibit the area of the brain targeted, the left dorsolateral prefrontal cortex. Each time, they then completed two games in which they tried to win either money (a secondary reward) or seconds of vibrator stimulation on their genitals (a primary reward).

The bottom line: the brain stimulation altered how much people's brains responded to anticipation of the primary reward as they were anticipating it. This laboratory measure predicted real-world behaviors in the weekend after testing. Specifically, the brain response to primary sexual stimulation predicted how many orgasms the participants would have over the weekend after stimulation. This is important to show that the brain signal changed by the TBS could alter real feelings and behaviors in the real world beyond the laboratory.

"There were many novel aspects to this study that surge our knowledge in many areas of reward science", said Nicole Prause, PhD, lead author on the study. "For me, I am most excited that we have what looks like a good way to finally quantify sexual motivation in the lab, which has historically been very difficult in humans."

Marco Iacoboni, PhD MD, co-author and Director of the Neuromodulation Lab at the Abramnson-Lovelace Brain Mapping Center adds that "this study demonstrates how non-invasive brain stimulation techniques like TBS can be highly effective in modulating even rather complex behavior in health and disease." Greg Siegle, PhD, co-author, brought expertise in the unique hardware, processing, and reward theory. Team members Allan Wu, MD, and Choi Deblieck, PhD, also were co-authors.

         Dr. Prause described why it was so important to have genital vibrators, a new addition to protocols in the USA. "Sexual pictures are not rewarding in and of themselves, they just symbolize real sexual rewards. Direct genital stimulation is widely agreed to be a primary reward, but labs often shy away from developing these protocols assuming they will be difficult to implement or recruit. Our participants loved them, it was the easiest study we have ever recruited." Drs. Siegle and Prause co-developed the innovative hardware deployed in the study.

In addition to the strong protocol for studying primary rewards, they also used a Bluetooth electroencephalographic (EEG) device suitable for measurement during movement. In the future, a simple EEG measure may allow the identification of who is most likely to benefit from brain stimulation in the future.

The study authors: Nicole Prause, PhD, is a licensed psychologist and founder of Liberos LLC, a sexual biotechnology company. Marco Iacoboni, MD, PhD is professor in the Department of Psychiatry and Biobehavioral Sciences of the David Geffen School of Medicine at UCLA. Greg Siegle, PhD, is an Associate Professor at the University of Pittsburgh. Allan Wu, MD and Choi Deblieck, PhD were collaborators and co-authors on the project. Those interested in more information can visit http://liberoscenter.com/brain-stimulation-to-manage-sex-...