Ever since the case of Phineas Gage and Harlow’s landmark report on Gage, neuroscience has been aware of the fragility of personality and behaviour in light of traumatic injury.
The areas of the brain where Gage suffered injury led some of his closest friends to state that Gage ‘is no longer Gage’. Indeed the formerly responsible and hard-working Gage began to drift, and his social disinhibition led to a man who cursed and use profanity where before he never did so and to exhibit what Harlow called ‘obstinate’ behaviour’ whilst maintaining a childishness (O’Driscoll, 1998).
However, other events such as disease also have the capacity to drastically change one’s personality, and even to influence them towards criminal behaviour.
To illustrate this point, we can take a look at how brain tumours may affect behaviour depending on location and severity. Direkze et al (1971, cited in Lishman’s, 2009, pg. 288) found that out of 25 individuals, 11 presented with personality changes.
The nature of these changes could be classified broadly as changes regarding inhibition. For example, a 53-year old clergyman began to describe ‘smutty jokes’. Another, a pharmacist began to display forgetfulness as well as asking his wife to play cowboys and Indians with him. These patients were all found to have astrocytomas.
Perhaps some of the strangest manifestations of personality changes occur when the tumours bridge areas such as the frontal and temporal lobes. To illustrate the type of dramatic behaviour and change in personality one may experience can be seen with the case of a 53-year-old woman (Haberland, 1965 as cited in Lishman’s, 2009, pg. 291) In this case, a formerly sociable and amiable individual this woman began to suffer persecutory delusions and believed that her family wanted to harm her. The culmination of these events led to her attacking her husband with a knife. When she died, a glioblastoma was discovered in ‘the right temporal lobe’.
In a large review (Madhusoodanan et al, 2015) looked at research involving key terms like ‘brain tumour’ and ‘psychiatric symptoms’. The review found 172 cases and reviewed the types of psychiatric disturbances. They classified the changes into 7
categories:
Depressive symptoms
Apathy
Manic Symptoms
Psychosis
Personality changes
Eating Disorders
Miscellaneous
Results:
The results of this review found some interesting results regarding personality changes such as depression. Indeed, depression was more commonly found in frontal lobe tumours. As well as depressions, symptoms such as mania could also be present, and the review found that tumours affecting the right as opposed to the left frontal lobe tended to exhibit a greater incidence of manic episodes. This mania demonstrated itself as euphoria.
Perhaps unsurprisingly, is the involvement in frontal lobe tumours and dramatic displays of disinhibition. These changes as well as disinhibition, also included hypersexuality and aggressive behaviours. The review found other behavioural changes such as the onset of eating disorders and other miscellaneous changes.
Conclusion:
There is a large literature on the neuropsychiatric manifestations of various kinds of brain tumour. Specific key areas that are implicated in these changes are the frontal lobe and the temporal lobe. From a forensic point of view, it is clear that disease can influence a change of personality, but also, more drastically affect the behaviour leading to a potential for criminal behaviour to take place. Disease such as a brain tumour tend to be easier for people to forgive when a crime is committed, but other disorders such as Kluver-Bucy syndrome may be harder for people to forgive, especially since the crimes can be particularly repellent.
References:
David, A.S, Fleminger, S. Kopelman, M, Lovestone, S. Mellers, J. ‘Cerebral tumours’ in Lishman’s Organic Psychiatry (4th) (2009)
Madhusoodanan S, Ting MB, Farah T, Ugur U. Psychiatric aspects of brain tumors: A review. World J Psychiatry. 2015;5(3):273–285. doi:10.5498/wjp.v5.i3.273
O’Driscoll K, Leach JP. “No longer Gage”: an iron bar through the head. Early observations of personality change after injury to the prefrontal cortex. BMJ. 1998;317(7174):1673–1674. doi:10.1136/bmj.317.7174.1673a
@Daniel Sumner Wow, what a Beautifully written article with such precision.
Tumors are tend to change personality because they disturbed production of hormones and neurotransmitters in brain. For instance: if person has tumor in pituitary gland, that person may experience depression, panic attacks, uncontrollable emotions like rage and Aggression. It alters their personality. It feels like they become a new person and their old version is vanished.