• Question: is it possible for a virus or parasitic infection to control your brain and what you do? Ex- A zombie apocolypse- The virus to cause them to crave meat or other people?

    Asked by booklover to Artem, Caroline, John, Gunther on 20 Jun 2012.
    • Photo: Artem Evdokimov

      Artem Evdokimov answered on 20 Jun 2012:

      Zombies are just so popular these days 🙂

      So let’s dissect the facts: are there viruses and other parasites that can change behavior of the host? The answer is a clear yes – you can consider the cases of ‘zombie ants’, ‘zombie snails’, and ‘puppet crabs’ for example:

      http://www.npr.org/blogs/thetwo-way/2012/05/02/151890185/zombie-ants-and-the-fungus-that-saves-them

      http://en.wikipedia.org/wiki/Leucochloridium_paradoxum

      http://en.wikipedia.org/wiki/Sacculina

      and other lovely creatures discussed in this book:
      http://www.amazon.com/gp/search?index=books&linkCode=qs&keywords=0684856387

      However, it is a very different situation where a virus would turn people specifically into zombie-like ravenous creatures. Even the dreaded Rabies virus does not really come close to the behavior changes on this scale.

      So I would say that it is theoretically possible but is extremely unlikely. Simply speaking, there are better and ‘cheaper’ (simpler and more effective) ways for viruses to propagate themselves. Common cold is one of the absolute best in its class – just look how successful its infection strategy is and how it evades our immune systems’ response every year…

    • Photo: John Short

      John Short answered on 20 Jun 2012:

      Direct control, in terms of telling you what to do or think would not be possible. However, a virus or parasite (collectively known as pathogens) could destroy or damage parts of the brain to do with consciousness, i.e. the personality of someone. If that happened, in that scenario and left the other functions of the brain intact, you would therefore be an organism that survived completely on instinct as most animals do. Then you would act as a zombie that ran at people trying to eat them transmitting the virus to them, or you could turn into a sex fiend or sleep lots, as the basic functions would be to eat, to reproduce and to sleep.

      However, here is a thought for you, scientists are trying to use viruses to deliver drugs into cells to treat cancer, or deliver new genetic sequences to cure genetic conditions of people. If, however you engineered a virus to deliver a drug to the brain, you could render them zombified, or deliver truth serum type drugs or paralyse them.. scary thought..

Comments

  • Photo: Artem

    Artem commented on :

    “An instinct is an inborn complex pattern of behavior that must exist in every member of the species and, because it is embedded in the genetic code, cannot be overcome by force of will”

    Most of our behavior is learned. We cannot even eat without learning (yes, babies instinctively suck milk but that’s about it), not to mention walk. Animals also learn – and most of the patterned behaviors in mammals are not instincts (consider how predators teach their young to hunt, sometimes for a year or more).

    So it is really not likely at all that a virus would be able to destroy higher mental faculties on the one hand and on the other hand allow the affected person to exhibit purposeful complex actions such as walking to someone and biting their nose off. In order to produce a ‘passable zombie-like behavior’ a virus would have to cause intense aggression and rage, while at the same time suppressing empathy, sense of pain, desire for self preservation, and so on. This would involve massive alteration of the regulatory systems in the brain similar to that produced by abuse of certain drugs.

    Notably, there’s an interesting side topic here: can a virus reprogram a person to become someone else? Or revert a person to a baby-like state? There is some evidence regarding epigenetic basis of memory – does it mean that viruses might impart memories or learnings?