Impairment Of Social And Moral Behaviour Related To Early Damage In Human Prefrontal Cortex*by Steven W. Anderson, Antoine Bechara, Hanna Damasio, Daniel Tranel and Antonio R. Damasio,*Nature Neuroscience,*2(11):1032-1037 (November 1999)
Here's what this paper says:
Anderson*et al, 1999 wrote:The long-term consequences of early prefrontal cortex lesions occurring before 16 months were investigated in two adults. As is the case when such damage occurs in adulthood, the two early-onset patients had severely impaired social behavior despite normal basic cognitive abilities, and
showed insensitivity to future consequences of decisions, defective autonomic responses to punishment contingencies and failure to respond to behavioral interventions. Unlike adult-onset patients, however, the two patients had defective social and moral reasoning, suggesting that the acquisition of complex social conventions and moral rules had been impaired. Thus early-onset prefrontal damage resulted in a syndrome resembling psychopathy.
Indeed, further research in this area has established an interesting fact: if the pre-frontal cortex is damaged in childhood, before a child has begun to learn basic ethical precepts, that child becomes a sociopathic adult, incapable of responding to any impulse other than instant gratification of wants and desires, regardless of the cost to that person or others affected by said behaviour. If the damage occurs in adulthood, the behaviour is still antisocial, but is accompanied by feelings of guilt because ethical precepts have already been learned, and knowledge of this affects the individual adversely in terms of guilt feelings after the fact. Plus, when subjected to testing in a clinical environment, adults with pre-frontal cortex damage can give appropriate responses to questions about appropriate behaviour in social settings, but are unable to*act*upon this knowledge, and continue to be driven by immediate gratification, even when they know that this behaviour is self-defeating. The pre-frontal cortex has also been implicated as the origin of fear memories in normal individuals, as of 2006 (courtesy of researchers at the University of Toronto). Modern data with respect to this relies upon functional MRI scanning, which can track brain activity in real time, and those brain imaging systems have found a startling correlation between reduced activity, reduced volume and reduced interconnections with other brain subsystems, and individuals falling into the following categories:
[1] Sufferers of unipolar depression;
[2] Persons subjected to repeated high-intensity stress (e.g., battlefield shock cases);
[3] Incarcerated criminals;
[4] Diagnosed sociopaths;
[5] Drug addicts;
[6] Suicide victims (survivors of suicide attempts have been imaged via fMRI: successful suicide victims have had the pre-frontal cortex directly measured by dissection).
Therefore there is a*biological basis*for ethical behaviour in humans, and work on the great apes is being performed in anticipation of finding corollary brain activity related to socialisation and the establishment of behavioural 'norms' within great ape social groupings.
The pre-frontal cortex is regarded as being implicated in the presence of empathy not just in humans, but on other mammals too, though this work is in its infancy and detailed, robust findings have yet to be published. However, given what has been*verified empirically*in cases of pre-frontal cortex injury, scientists anticipate that empathy will also be found to be correlated with healthy functioning of the pre-frontal cortex.
Additionally, I have since found that pre-frontal cortex damage is implicated in schizophrenia, courtesy of*this page*from the Society for Neuroscience. Again, it refers to brain imaging studies, this time in*humans and other primates.
A letter to*Nature*is also apposite here (link), viz:
The psychological and neurobiological processes underlying moral judgement have been the focus of many recent empirical studies 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11.*Of central interest is whether emotions play a causal role in moral judgement, and, in parallel, how emotion-related areas of the brain contribute to moral judgement. Here we show that six patients with focal bilateral damage to the ventromedial prefrontal cortex (VMPC), a brain region necessary for the normal generation of emotions and, in particular, social emotions12, 13, 14, produce an abnormally 'utilitarian' pattern of judgements on moral dilemmas that pit compelling considerations of aggregate welfare against highly emotionally aversive behaviours (for example, having to sacrifice one person's life to save a number of other lives)7, 8. In contrast, the VMPC patients' judgements were normal in other classes of moral dilemmas. These findings indicate that, for a selective set of moral dilemmas, the VMPC is critical for normal judgements of right and wrong. The findings support a necessary role for emotion in the generation of those judgements.
