Can damage to the brain make you violent?


Back into normal postings now with a study published by PLoS regarding the possible effects of brain damage on behaviour, specifically violent behaviour. In the Raine (1997) study that we cover as part of the physiological psychology module in the AS it is put forward that slight differences in levels of processing in specific parts of the two hemispheres and a lowering of communication over the corpus callosum were found in murders who had pleaded NGRI.

I have written about other studies which have hypostesised that they may be a link between the functions of the brain and violence before but as you can read it highlights one distinct issue. If take the argument that poorly functioning parts of the brain are to blame for violent behaviour does this take away the ‘freewill’ from any acts; therefore mitigating that person from blame and prosecution?

… the exciting discoveries of neuroscience resonate far beyond mere philosophical banter and may have important implications for the way government institutions, including education and legal systems, operate. For example, to the extent that legal systems attempt both to move behaviour in socially desirable directions and also to adjudicate transgressions fairly, the legal system’s effectiveness can be improved by deepening our understandings about why people behave as they do and both how and why people respond to various changes in legal incentives. Specifically, neuroscience may have important implications for both how we understand the multiple influences on violent behaviour and how the legal system may better engage with violent criminals. [quote]

In the article Mobbs et al. highlight some cases where brain abnormalities have lead to behavioural changes (not all violent changes though):

(A) Brain scan of patient J. S., who exhibited sociopathic behaviour [5].

(B) fMRI sagittal slice of the brain of patient J. Z., showing a lesion that was caused by the resection of pituitary tumour [4]. This lesion led to anti-social conduct, which was not exhibited before the surgery.

(C) Orbitofrontal damage associated with symptoms of paedophilia and sexual misconduct in the case of a 40-year-old male patient.

(D) Photograph of a patient after head injury (right) and fMRI scan 60 years later showing PFC damage (left) [53]. This patient showed personality changes, but no signs of anti-social conduct.

(E) Cranial X-ray of a man who attempted suicide with a crossbow. Although the individual exhibited premorbid APD, the PFC damage caused by the crossbow arrow resulted in reversal of anti-social conduct [54].

Further to this Mobbs et al goes on to identify that there are also methodological problems with using imaging software to attempt to understand the functioning of the brain.

There are many exciting possibilities for how law and neuroscience may eventually partner—with neuroscientists discovering new things about the brain potentially relevant to law, and law asking questions that new neuroscientific research may help address. However, it is important to keep in mind a variety of limitations of brain-imaging technology. We highlight six.

In their concluding remarks the issue of causality is raised. Although there are examples where it has been shown that brain abnormalities have, at least in part, contributed to violent or psychopathic behaviour it is by no means a predictor of such behaviour. Even if it was a predictor could we actually do anything about it? On ethical and moral grounds could we [as a society / community etc] actually condone intervention on the basis that a person posibally has a preduisposition to violent behaviour before any violent acts have been comitted. Maybe that’s not too far away from what we see in Minority Report.

An excellent article that is well written an accessable. It’s critique of the techniques used by researchers in this area is superb and, as mentioned above, links in well with Raine and the other physiological (or even A2 crime) related discussions. Your thoughts in the comments as always.

Law, Responsibility, and the Brain Mobbs D, Lau HC, Jones OD, Frith CD PLoS Biology Vol. 5, No. 4, e103 doi:10.1371/journal.pbio.0050103ho

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One Response to “Can damage to the brain make you violent?”

  1. London Counselling September 6, 2011 at 6:32 pm #

    As to my partner’s experience, I believe it does make you a violent person when your brain is damaged. When parts of the brain are disconnected or is given an impact to a certain extent, it can really cause a number of problems to the being of a person, so might as well observe and prevent it from going worse.

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