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Showing posts with label vagus nerve. Show all posts
Showing posts with label vagus nerve. Show all posts

Thursday, August 18, 2016

Dopamine Stimulating Headphones and How They Can Change Our Definition of Being High


By Laura Morales





This post was written as part of a class assignment from students who took a neuroethics course with Dr. Rommelfanger in Paris in Summer 2016.






Laura Morales is 21 years old and originally from Panama. She is currently a senior pursuing a double major in Neuroscience and Behavioral Biology and Psychology in Emory University in Atlanta, GA.





If you have ever heard a song that sends chills down your spine, relaxes your entire body and gives you a general feeling of being close to ecstasy, you have experienced the “high-like sensation” the makers of Nervana wish to tap into. The company Nervana has designed a set of headphones that, while playing music, transcutaneously send electrical signals into the left ear to stimulate the vagus nerve to match the frequency of the beat of the music. The vagus nerve is involved with activation of the parasympathetic nervous system, which is normally activated when the body is at rest. This nerve stimulation results in the release of neurotransmitters like dopamine, serotonin and endorphins—these are transmitters thought to be related to that “feel-good” sensation (Ashby & Isen, 1999). Vagus nerve stimulation has been used to treat epilepsy (Schachter & Saper, 1998), although the mechanism through which it works is not well understood. While reducing seizures, there have also been reports that vagus nerve stimulation has improved the overall mood in people with epilepsy (Terry Jr, 2014). Transcutaneous vagus nerve stimulation has also been shown to have equivalent anticonvulsive effects as the more invasive method (Ellrich, 2011). Similar to this therapeutic approach, Nervana advertises their headphones as promoting wellness and recommends the headphones be used twice a day for 45 minutes to improve mood and increase general health.






According to the World Health Organization (WHO), a psychoactive drug is a substance that “when taken in or administered into one’s system, [affects] mental processes.” Many drugs of abuse like methamphetamine and cocaine work by modifying levels of neurotransmitters, especially dopamine (Di Chiara & Imperato, 1988). If Nervana use alters neurotransmitter levels, what makes the headphones different from consuming a drug that results in the equivalent kind and degree of neurotransmitter change?





What makes it socially acceptable (or socially insignificant) that these headphones stimulate the release of neurotransmitters, yet lack any additional regulations over the average pair of headphones? On their website, the company Nervana claims that they have found no evidence of dependence to the use of their headphones in the hundreds of humans in which they have tested the product. They also say that, because the stimulation can make the person feel more relaxed, it should not be used while operating heavy machinery—not dissimilar from warnings that come along with something like cough syrup. Even though the company has not found any signs of dependency, measuring the changes in neurotransmitter sensitivity caused by constant stimulation would require a more extensive, longitudinal study. After decades of research into the use of cannabis, only recently has it been shown that consistent use blunts the brain’s response to dopamine (Volkow et al, 2014). If constant exposure to neurotransmitter stimulation can blunt the brain’s response and increase the threshold for the neurotransmitter to have an effect, one wonders if a similar effect or desensitization would accompany long-term use of Nervana. More extensive research on the use of these headphones and how the headphones can alter brain function must be done, and if they have been done by the company, the data should be released for consumers to know that the product is safe.








Image Courtesy of Flikr user Naveen Jamal.

Neuroscientists still do not fully understand the brain’s plasticity—its way of making chemical and structural changes throughout life (Dagranski et al, 2004). Neurotransmitters seemingly are sensitive to whatever we expose ourselves to, but for some reason a pair of headphones that alter their activity seem more harmless than a chemical substance that is actively ingested but also alters neurotransmitter function.





The more we understand about neuroplasticity, the more ways we will find to push the limits, to change normal functioning and to alter the way we feel through external stimulation. Does this mean we would eventually have to revisit our meaning of what it is to be under the influence? Even though there are no imaging studies provided, there are likely to be some similarities between the dopaminergic pathways being activated by the vagus nerve stimulation of the headphones and other drugs that alter dopamine activity. Even though vagus nerve stimulation is used to treat epilepsy, there is a difference in what might be safe in a therapeutic approach versus a recreational approach and how we might weigh risks versus harms when one is sick versus healthy. While it may sound absurd to create a dependency to listening to music using a specific set of headphones, it is imperative to note that we do not understand the pathway through which they may be altering the brain.



It is difficult to see a pair of headphones as potentially presenting a risk, but if it is altering the brain’s chemical composition, even by stimulating endogenous change in the brain, it could potentially have the same effects as drug use. Of course, everything will stimulate an endogenous change in the brain (Draganski et al, 2004), whether it is via a drug or everyday learning, from the coffee you may have had this morning to reading this now. The more we learn about the brain, the more ways we will find to technologically alter it. The main issue is not that there might be a change in the brain that produces an alteration in mood, because we also rely on activities such as yoga and drinking tea to change our mood, but rather that these headphones have the potential to produce changes in ways that are unclear and therefore in ways that challenge one’s ability to mediate an endogenous change. Hence, such technologies require more cautious use and research on long-term effects and potential dependency. We must be wary about the potential risk of using neurotechnologies that might seem harmless, such as headphones, as well as the allure to experiment with novel technologies, especially when the impact of those technologies on our brains is not well understood.





References





Schachter, S. C., & Saper, C. B. (1998). Vagus nerve stimulation. Epilepsia,39(7), 677-686.





Terry Jr, R. S. (2014). Vagus nerve stimulation therapy for epilepsy. Epilepsy Topics. InTech, 139-160.





Volkow, N. D., Wang, G. J., Telang, F., Fowler, J. S., Alexoff, D., Logan, J., ... & Tomasi, D. (2014). Decreased dopamine brain reactivity in marijuana abusers is associated with negative emotionality and addiction severity. Proceedings of the National Academy of Sciences, 111(30), E3149-E3156.





Patel D., (2016), Nervana Dopamine-Stimulating Headphones Crowdfunds Nearly $600,000. The Huffington Post. Retrieved from http://www.huffingtonpost.com/deep-patel/nervana-dopamine-stimulat_b_9810332.html





Psychoactive substances (n.d.) In World Health Organization: Terminology & classification. Retrieved from http://www.who.int/substance_abuse/terminology/psychoactive_substances/en/





Di Chiara, G., & Imperato, A. (1988). Drugs abused by humans preferentially increase synaptic dopamine concentrations in the mesolimbic system of freely moving rats. Proceedings of the National Academy of Sciences,85(14), 5274-5278.





Ashby, F. G., & Isen, A. M. (1999). A neuropsychological theory of positive affect and its influence on cognition. Psychological review, 106(3), 529.





Draganski, B., Gaser, C., Busch, V., Schuierer, G., Bogdahn, U., & May, A. (2004). Neuroplasticity: changes in grey matter induced by training. Nature,427(6972), 311-312.





Ellrich, J. (2011). Transcutaneous vagus nerve stimulation. Eur Neurol Rev,6(4), 254-6.




Want to cite this post?



Morales, Laura. (2016). Dopamine Stimulating Headphones and How They Can Change Our Definition of Being High. The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2016/08/dopamine-stimulating-headphones-and-how.html

Tuesday, June 14, 2016

Consumer Neurotechnology: New Products, More Regulatory Complexity

By Anna Wexler






Anna Wexler is a PhD candidate in the HASTS (History, Anthropology, Science, Technology and Society) at MIT and a 2015-2016 visiting scholar at the Center for Neuroscience and Society at the University of Pennsylvania. Her dissertation focuses on the ethical, legal and social implications of emerging neuroscience technology, with a particular focus on the home use of noninvasive brain stimulation.




Just when it seemed like the consumer neurotechnology market couldn’t get any stranger—after all, who would’ve expected that a sleek white triangle could be placed on the forehead for “calm” or “energy” vibes—two new products recently hit the market that further complicate the challenges of regulating this emerging market. Halo Sport is a brain stimulator marketed for athletic enhancement that utilizes technology similar to transcranial direct current stimulation (tDCS), while Nervana, which began taking pre-orders in March, is the first noninvasive vagus nerve stimulation (VNS) device to be sold directly to the public in the United States.





Halo Neuroscience, the manufacturer of Halo Sport, advertises that its product “accelerates gains in strength, explosiveness, and dexterity.” In many ways, Halo Sport overcomes obstacles that have plagued other direct-to-consumer brain stimulation products. Because Halo Sport only claims to stimulate the motor cortex—which, conveniently for the company, lies beneath the area of the head where a pair of headphones might sit—the product does not utilize stray wires or a futuristic headset, but instead takes the recognizable shape of headphones. The beneficial effect of a familiar design should not be underestimated: many potentially useful technology tools have failed in no small part due to their unusual “look.”








The motor cortex, image courtesy

of Wikimedia Commons


One of the other barriers to wider uptake of consumer brain stimulation has been that the gains are, for the most part, relatively small. (In fact, it is debated whether tDCS provides any enhancement effect at all.) Even if a product provides a 5% or 10% improvement on cognitive or motor tasks, such a gain might be hardly noticeable to the average individual. But in the realm of professional athletes, small percentage increases are everything: the dividing line between a world champion sprinter and one who does not rank can be measured on the order of milliseconds. Thus, Halo’s decision to cater exclusively to athletes—a population for whom fractional gains in performance separate winners from losers—is a brilliant marketing move.




Though it is less clear who the intended market of “Nervana” is, the company has clearly struck a nerve (literally): their IndieGogo campaign netted a whopping $581,547 in pre-sales. The product, which is billed as the “The World's First Consumer Product to Stimulate the Body's Pleasure Center in Synchronicity to Music” also takes a familiar shape: earbuds are connected to a portable stimulation device that is vaguely reminiscent of a first-generation iPod. According to the company, in “Music Mode,” the device “generates a targeted vagus nerve stimulation output” via the earbuds that synchronizes with whatever music is being played. Since the vagus nerve is involved with the release of neurotransmitters, the company claims that its product promotes the release of dopamine and effectively gets you “high.”




Whether or not these products work as claimed is one issue—Halo, to its credit, has posted a considerable amount of data, though it has yet to be peer-reviewed—because by virtue of being on the market they present difficult problems for regulators. As I have written elsewhere, the question of whether consumer noninvasive brain stimulation devices should be regulated by the Food and Drug Administration (FDA) often comes down to the question of whether or not brain stimulation devices that make only “wellness” or “enhancement” claims can be classified as “medical devices.” So far, however, the discussion of the regulation of direct-to-consumer brain stimulation products has focused on cognitive and mood enhancement. But Halo Sport throws a wrench into the regulatory conversation: would brain stimulation products that claim to athletically enhance be treated differently than those that claim to cognitively enhance? In other words: is there a meaningful regulatory difference between different types of enhancement (mood, cognition, athletics)?






Diagram of the vagus nerve, image courtesy

of Wikipedia


In addition, while Halo Sport is based on tDCS—a technique that is not yet FDA-approved for any indication and therefore has no direct regulatory precedent—the situation with Nervana is slightly more complex. An implantable VNS device—that is, one that requires surgery and sits inside the body—has been FDA approved to treat epilepsy, and has shown efficacy in off-label use to treat depression. Nervana, however, claims to stimulate the vagus nerve from outside the body, through the skin. Though there are preliminary studies on using this kind of transcutaneous VNS (or, tVNS) to treat neuropsychiatric disorders, as of yet, the FDA has not yet approved a tVNS device for use in the United States. Thus, Nervana represents a noninvasive version of an invasive device that is FDA-regulated for treating medical conditions.




In addition to questions regarding state and federal regulatory pathways, it remains to be seen how direct-to-consumer electrical stimulation products will be regulated by professional organizations. Neuroethicists have long compared cognitive enhancement to athletic enhancement, but Halo Sport represents the first time that “electrical doping” for sports has been neatly packaged in a direct-to-consumer product. If the product (and copycat ones) gain a foothold, professional sports organizations will have to decide how to regulate their competitive use. Should agencies ban electrical doping, or perhaps restrict their use to training (and not competition)? Whatever position is taken, the rules will be challenging to enforce, as electrical stimulation may not leave detectable traces in blood or urine.




In the months to come, additional variations of direct-to-consumer electrical stimulation devices are likely to appear, and these products will raise questions that fall squarely at the intersection of law, ethics, and (neuro)science. While to date, the “neurolaw” field has centered on questions of neuroscience in the courtroom, the rise of direct-to-consumer neurotechnology suggests that scholars should pay more attention to how neuroscience enters other realms of law—particularly the regulatory arena.



Want to cite this post?



Wexler, A. (2016). Consumer Neurotechnology: New Products, More Regulatory Complexity. The Neuroethics Blog. Retrieved on , from http://www.theneuroethicsblog.com/2016/05/consumer-neurotechnology-new-products.html