Monday, March 26, 2012

Just One Zap: Neuroenhancement with TDCS


When we discuss cognitive enhancement, we almost always focus on drugs. What can we develop to make our thinking more efficient, to make us learn faster and do more? Drugs that we classify as cognitive enhancers—Ritalin, adderall, modafinil, and even caffeine—however, are only one method of enhancing our thinking. Recent research into non-invasive brain stimulation techniques have shown promise in enhancing cognition. TDCS, or Transcranial direct current stimulation, has shown particular promise because of its efficacy and relative simplicity.

In TDCS, weak electrical currents (on the scale of 1-2 mA) are applied to the head through electrodes on the scalp. The currents pass through the skull and alters neural activity. The treatment has been used successfully in treating various condition such as depression, but the main interest of research into its effects lies in how it effects learning. Research into the treatment in both humans and animals have shown effects of the treatment, many of which improve the performance of mechanisms associated with learning, can last up to 12 months. Other TDCS studies have shown lasting improvements in fundamental areas such as motor skills, vision, problem solving and decision making, mathematical abilities, language, memory, and attention. These improvements appear with no obvious side effects. It is this seemingly free efficacy that makes TDCS so promising. It is well along the path to satisfying criteria for the holy grail of human neuroenhancement: painless, safe, cheap, and effective.

Given these qualities, TDCS presents few ethical issues. The ease of manufacturing and reusing TDCS machines means that unlike enhancement drugs which ethical problems with access to treatment, TDCS machines could become widespread and cheaply available enhancement. In addition, the apparent safety of TDCS separates it from the addiction potential and numerous side effects of drugs such as Ritalin. Removing the concerns about safety and fairness leaves TDCS in the same vein as nutrition: another aid for learning that does not replace hard work and effort.

Even with this in mind, TDCS should not be used until more research to confirm its safety is carried out. This is a particular concern in the child brain. We understand many of the effects of the treatment in adults, but not much research has been carried out in children. We do not know how it affects the developing brain. Until we know more, ethical issues remain for scenarios such as parents using such treatments on their children without understanding the long term effects. Because of its efficacy, relative cheapness, and known safety in the developed brain, however, TDCS does not present any clear ethical issues when used in adults.

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