QUESTION: ... if I can give you a set a circumstances; if someone is said to have received a head injury and shortly afterwards is said to have done a U-turn in a car and then driven off the road on to a nature strip and hit someone, and then hit some objects, is there - can there be a link between the head injury and the subsequent driving of that person in that manner as a result of the injury sustained?
ANSWER: One of the effects of head injury is that a person can have a confusional state, they can become disorientated; that is, not be aware of themselves in relation to their surroundings. In instances of head injury, you can have behaviour where a person might wander, they might be able to walk and talk but they may not be engaged in fully sort of sequenced and co-ordinated activities.
QUESTION: Are there psychological classifications for this kind of behaviour?
ANSWER: If a person has a head injury they would be assessed by the ambulance via the Glasgow Coma style and that has categories related to verbal response which look at aspects of orientation, confusion and the like. There are categories within the broader guidelines of society such as the American Academy of Neurology where they have categories for head injury where this may or may not occur without loss of consciousness; that is, with categories related to mild traumatic brain injury or concussion.
QUESTION: With respect to the potential for psychological disturbance, where someone is exposed to a fearful situation in addition to a head injury, what are those potential psychological disturbances?
ANSWER: Well, when we look at fear, fear is an emotion and it has a number of components. It has the psychological component of arousal and that can be guided as an automatic response through things such as adrenalin. So you have the physical component to the emotion. You also have the psychological component to emotion in terms of how we interpret that physical feeling.
QUESTION: What is that psychological component?
ANSWER: It's whether we actually perceive a threat, what response one makes in relation to that threat. There can be sort of responses in terms of perceiving what the threat is.
QUESTION: These responses in relation to perception, are there changes in those responses as a result of the head injury and a result of the fear?
ANSWER: In relation to the first, the head injury, there are changes with respect to attention, the ability to focus your attention and to integrate what's occurring in a sequential manner. Part of that also, a significant feature of head injury or a concussion is confusion, plus disturbance of memory. So in cases of head injury, what you can get is what you can get, say, a reduced Coma score where that provides an indication of the injury but you also get changes in memory or what we call post traumatic amnesia around the time of the blow.
QUESTION: There's no evidence in this case of concussion or amnesia but with respect to confusion, what kind of confusion would you expect after a head injury? Are you able to say?
ANSWER: Well a person can appear stunned or dazed. Their ability to take in information and attend to that information and to organise it in a coherent sequential manner can be impaired.
QUESTION: What about their motor skills?
ANSWER: Well, with respect to motor skills, you can have people engaged in acts with which they're quite familiar. So if you've had a routine sort of act and you're quite knowledgeable of that, you might be able to continue to engage in that act. You can become inco-ordinated in terms of your motor responses. The person also can engage in wandering behaviour as part of that response. If they're walking, their gate or their walking can be affected as well.
QUESTION: You spoke about behaviour which they have practised before, are they capable of engaging in that behaviour notwithstanding motor co-ordination difficulties?
ANSWER: You could engage in those gross acts because there's aspects of memory to do with motor function which we call procedural memory.
QUESTION: What's that?
ANSWER: Procedural memory has got to do with your memory for motor acts. We have certain routines within our head, our brain, as to how we do things because we have done them so often. That doesn't necessarily mean that the precision with which we do them or the co-ordination with which we do them might differ but we can still engage in those sort of gross acts - motor - so it's not as if you're sitting still doing nothing.
QUESTION: When you say "gross acts" what kind of acts?
ANSWER: You can have people walking and talking and yet still be confused and they can appear to the casual observer as sort of being relatively intact when in fact they're not.
QUESTION: With respect to I think you said "relatively intact when in fact they're not" what do you mean by they're not, relatively?
ANSWER: It means that they can have quite subtle changes in their thinking where without sort of detailed or specialist examination of them they might give the appearance of having their full capacities but if you actually tested them you might find actual difficulties. So for example if we're testing someone for their level of orientation, it's not just a case of just ticking a box "Orientated". You ask questions of the person. You might say "Well, what's your name? Are you orientated to person? Where are you? Are you orientated to place? Do you know where you are in relation to other things, other objects?" You might ask "Do you know the time? Are orientated to time and day, so are you able to position yourself in time, place and person?" So you will ask specific questions. It's the same with things to do with confusion and with memory. With memory, it's not just the question of - if you actually [ask] someone with a memory disorder you can actually ask them a question about something with which they are quite familiar and they will actually respond quite well. It's their ability to deal with events here and now that are ongoing where the memory compromise or the difficulty occurs. Often we talk about memory disorders and people think "I can't remember things in my past". In fact it's actually [an] ability to lay down memories over time and you can test that as well by getting a person to remember three objects for example and then come back a couple of minutes later and asking what they remembered, so you can see whether they have got any ongoing memory function.
QUESTION: What is meant by "disassociation"?
ANSWER: Disassociation is a psychological response or process. It's where a person is not able to integrate different aspects of their perceptions, such as what they see, they hear, they feel. They can't sometimes integrate memories and they can't integrate themselves in relation to who they are in relation to the environment. So you can get a phenomenon known as "depersonalisation". That is that the person sees themselves as somewhat detached from himself, and I can sometimes describe this as looking down on this thing just sort of happening; the event is happening, "but I was removed from them from where I am in my body". They can also get a sense of "derealisation" where the physical world around them may not feel as though it is tangible or real: it has a sort of dreamlike quality.
QUESTION: Are these disassociate states, do they have any relevance with respect to a head injury at all?
ANSWER: In some respects the processes are similar but I see the psychological responses due to, say, a trauma or fear, such as a disassociative response or a physiological response as being slightly mechanical effects of a head injury. But they are quite similar but they are two separate things.
QUESTION: This disassociative state, what affect does this have on a person's capacity to control what it is that they do?
ANSWER: The classic case of this is where the person sort of experiences sort of extreme trauma. Often there's a threat, and the perceived threat is actually the perception that their life is at threat. So there's often in response to extreme threats to life and fear. The individual can become disconnected from their environment and not integrate everything that's happening around them, and they might engage in activities to which they don't have full capacity to be able to do and say "Am I in voluntary control? Can I choose to do this or not to do this?" because they do not have access to any perceptions in an integrated manner.
QUESTION: If that can come from fear, can it come from a head injury as well?
ANSWER: Yes, the ability to have full capacity to make a reasoned decision is means you will say "I will do the act" or "I will not do the act". It can be impaired in the sense that it is not fully integrated or informed by one's attention, perceptions, memory, motor, and those sort of responses.
QUESTION: During that state, can there be any effect on motor co-ordination?
ANSWER: Yes there can be motor responses. The person can be inco-ordinated - that is, that they don't have the same fine motor control. One of the ways in which that type of thing is examined if someone was to examine it through - and it wouldn't be through a neuropsychologist, ideally through a medical doctor - is to actually assess co-ordination. One of the ways they do is to say "I want you to touch my finder and then touch the top of your nose" and do that in alternating ways. A person who is inco-ordinated with actually do that, but then not strike their nose because their judgment in terms of the distance is impaired. The other thing is, you can get similar things where the perception in terms of space - the test for that might be that they will get a person to close their eyes and then get them to touch the tip of their nose. So you close your eyes, touch the tip of your nose, and thankfully you hit the middle of it. In other instances you will close your eyes and the thing will pass point - that is, it will not be accurate.
QUESTION: Would this state have any affects on the procedural memory that is for doing previously familiar motor acts?
ANSWER: You would be able to do gross motor acts: the precision with which you do them might be impaired.
QUESTION: Would driving a motor car fall into the category of those gross motor acts?
ANSWER: Yes.
QUESTION: But the capacity to drove properly - would that be affected?
ANSWER: If one has had these sort of responses, then the capacity would be diminished.