Can I be so blunt to make this statement about social contacts? Yes, I certainly can. Not based on the literature, because when reading that you get the impression all is quite well (where did I read that earlier?). There is some mention of personality changes after brain injury, and usually such news is accompanied by juicy anecdotes about people changing completely after a brain injury. Preferably into monsters, I might add.
Throughout his whole website my message is that brain injury can and usually will change your life and your social contacts, much more than most people and even professionals think. Of course, I am talking here about the more severe forms of brain injury such as large strokes, anoxic brain injuries (due to lack of oxygen), or forms of dementia (wide-spread brain injury). However, even in mild head injuries I have seen rather subtle but significant changes in someone's personality. And to understand that please read my pages on Personality deficits after brain injury.
When you start to realize that our personality and character is completely regulated by our brain, then you can understand more easily the stories of family members of brain injured patients. Changes in personality go in either one of two ways: positive or negative. Either a strengthening or a weakening of already existing personality characteristics is mentioned. When someone was nice and friendly, brain injury could have changed that into being either more or less friendly. Come to reflect on this, I have to admit that I seldom see or hear more positive changes in personality. Usually, already less positive characteristics of someone are increased.
This can be explained quite simply, although speculative because science has no answers here. I think that brain injury decreases our ability to emotionally regulate ourselves. This regulation seems to be taking place in the frontal lobes, according to science nowadays. Usually, these frontal lobes do function less optimally after any form of brain injury. Perhaps, their ability to control everything in the rest of the brain, including the deeper emotional brain systems, is therefore weakened. You may compare it with taking drugs such as alcohol or speed. The control over your emotional 'impulses'(in my opinion a totally wrong description for emotions) is lessened when under influence.
This does not mean that someone will become nicer after a brain injury. Being nice has not much to do with an emotion 'niceness'. Being nice is usually the absence of frustration or other negative emotions like sadness or anxiety. Furthermore, it has a lot to do with the ability to feel compassion. We do know from science that frontal lobe injuries can heighten fear but also reduce fear to the extent that it becomes inadequate. Not feeling much shame anymore can lead to socially awkward behavior, not realizing behavior is becoming shocking or confronting to others.
Sometimes I hear the story of a mother who tells me that her son of 20 has become more 'sweet and caring' after his traumatic brain injury. That's a nice side-effect you might say. There is no real explanation for this kind of change, science still knows little in this respect. Sometimes I also hear other family members say that their partner after his stroke has become less outspoken, more gentle in his wordings. Well, that can happen.
However, usually the changes are less positive. Often someone becomes more ego-centric, more concerned about himself, less about his partner or children. Normally, I explain this as the evolutionary normal reaction that a wounded animal takes care more of himself than of others. But another explanation is that brain injury reduces the ability to cope with every stressor. To protect yourself from too much stress, you only deal with your own stress. I can not find real evidence that people do indeed become more ego-centric on purpose. When you talk to them alone, in some rare very intimate moments, they usually start to cry and open their hearts and say that they do see that they have become less gentle, less attentive, but they do NOT want that as they tell me vehemently. That gives me the hope that something can be done about this so-called ego-centric change in personality. And indeed, that is also my experience of which I will tell you more on the pages about Personality training.
Often heard examples of strange and changed behavior in social contacts after brain injury is a withdrawal from contact. Usually, in a group someone suddenly becomes more quiet and steps out of contact. Doesn't say much anymore, in sharp contrast to one hour earlier. Related to this behavior is a sudden explosion of irritation and anger, when having been in a group for an hour or so.
I think this has not much to do with being less friendly or less attentive. The behavior one hour before this change was indeed normal, proving that someone cán be nice and attentive in social contacts. The best explanation of which I am now convinced in such anecdotes, is that someone is getting fatigued and overwhelmed by a sort of information overload. Brain injury usually reduces the capacity to process information, in my words: the attentional capacities are reduced (this can be measured!). Being in a group and participating attentively (the essence of social contacts) does cost much more attention and energy from a brain injured person than is the case with a healthy person. The result is that the 'battery' of the patient is much earlier empty than he is used to. As with real batteries, the last phase of energy drain goes exponentially fast and within minutes it can happen that no energy is left. When information exchange keeps going on, while being in a group, a brain injured patient can not handle that anymore and shuts down. The end of social contact. Either literally by withdrawing, or indirectly by reacting aggressively to protect himself against overload. No wonder that social contacts diminish after several of such experiences.
We (social work and I) have often worked with this idea and usually with success. That as well is some evidence for this hypothesis (idea that has to be proven).
The above mentioned anecdote is of course a happy ending. However, there are also other anecdotes. Especially after a traumatic brain injury where the damage is more diffusely spread in the brain ánd the frontal lobes are much more damaged, I have seen pseudo-psychopathic behavior. Meaning, less attentive behavior, being aggressive just to hurt someone, not having any regrets, purposely provoking and shocking people, even subtly.
This kind of change is known in scientific literature and has a bad prognosis. Eventually, the patient becomes not only brutal or rude towards his spouse or partner, but also towards his boss at work. As if there is no fear anymore of being fired or losing his job. And that's indeed how it ends in those cases: getting fired and losing almost every friend there was. As a neuropsychologist the least I can do is testify in court in favor of this patient who has suffered a serious brain injury because of which his behavior is so dramatically changed.
The loss of fear in social contacts has devastating consequences. No longer can someone feel when he's crossing the line, no longer can he interpret subtle social cues that his behavior is intolerable. Using harsh words, cursing in public, saying just too directly what one thinks, all signs of a lesser functioning frontal brain. Especially, when it becomes clear that someone can not adapt or change this kind of inadequate behavior.