Brain implants and cognitive side-effect trading

This week’s Nature has an interesting article on the ethics of electronic brain enhancements. It does something quite unusual for an article on technological brain enhancements – it talks about the side effects.

Brain implants and ‘neuroprosthetics’ have been widely covered by the science media in recent years owing to a number of impressive advances but very little discussion has focused on the adverse effects.

In considering the ethics of using brain implants to enhance both the damaged and healthy brain, this article actually touches on some of the research on unwanted effects of deep brain stimulation.

Many patients with Parkinson’s disease who have motor complications that are no longer manageable through medication report significant benefits from DBS. Nevertheless, compared with the best drug therapy, DBS for Parkinson’s disease has shown a greater incidence of serious adverse effects such as nervous system and psychiatric disorders and a higher suicide rate. Case studies revealed hypomania and personality changes of which the patients were unaware, and which disrupted family relationships before the stimulation parameters were readjusted.

Such examples illustrate the possible dramatic side effects of DBS, but subtler effects are also possible. Even without stimulation, mere recording devices such as brain-controlled motor prostheses may alter the patient’s personality. Patients will need to be trained in generating the appropriate neural signals to direct the prosthetic limb. Doing so might have slight effects on mood or memory function or impair speech control.

The author of the piece argues that this does not raise any new ethical questions, as many psychiatric drugs also have side effects.

However, it’s probably true to say that ethical difficulties often arise with regard to specific side effects – talking about unwanted effects in general is a bit too vague to be useful.

Risk-benefit analyses are only useful when you know both the extent and quality of the risks and benefits and this is where it truly gets interesting.

The neuropsychology literature is full of surprising findings about what sort of functions the brain performs, suggesting that specific effects, wanted and unwanted, may have to be traded off against each other.

For example, is the loss of the ability to have an unconscious emotional reaction to a loved one worth a change in pathological gambling behaviour?

This is a hypothetical example based on the role of the ventromedial cortex in both situations, but who knows what sort of effects might need to be weighed up against each other.

Nature Network has an online discussion about the issues the piece raises which also links to the weekly podcast which has an interview with the author.

Link to Nature article ‘Man, machine and in between’.

2 Comments

  1. Posted February 26, 2009 at 10:05 pm | Permalink

    It’s a refreshing change to hear about considering the whole picture and balancing side effects against benefits.

  2. joseph lehmann
    Posted February 27, 2009 at 7:56 am | Permalink

    Vaughan,
    Thank you for this interesting post. The article concludes with optimistic statements:
    “Yes, the technologies pose ethical challenges, but these are conceptually similar to those that
    bioethicists have addressed for other realms
    of therapy. Ethics is well prepared to deal with
    the questions in parallel to and in cooperation
    with the neuroscientific research.”
    Well, these statements are not proven anywhere in the article and one can easily claim that their opposites are true.
    The article does not discuss the “whole picture” as Ms. Nattel wrote. In my mind, there is an always relevant question (as Kant wrote) “what is a man?” When technology changes our mind, who (or what) are we then?


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