Since 2003, I have been developing and refining a new
tool for cognitive assessment of ‘higher mental functions’ and June 2012 has
been a particularly good month for this research.
The human brain is a very complex organ, easily more
complicated than the most sophisticated computers ever created. While the brain
generally works as one unit, there are specialisations within it such that, for
example, visual recognition occurs at the back of the brain roughly behind the
ears. Relative to other mammals, the human frontal lobes (also known as the
‘pre-frontal cortex’ or PFC), occupy the largest proportion of the cortex,
constitute one third of the brain, and have shown the greatest enlargement
through evolution. Whilst more posterior areas of the brain are involved in
primary aspects of mental abilities such as language, memory and vision, the
PFC seems to play a more complex role in behaviour. The PFC acts as a kind of
manager co-ordinating what the rest of the brain does and therefore is known as
the ‘executive’ system; when the executive system is damaged, then a person can
end up with a variety of problems in areas such as decision-making, planning,
multi-tasking and adapting to new situations. This suggests that the PFC
co-ordinates functioning at higher-levels of human behaviour.
The executive system can be affected in many different
ways; for example strokes, brain surgery or virtually any form of closed head
injury (as in a car crash or fall) can all damage the system. Additionally, due
to the integrated manner in which the brain works and the fact that the PFC
gathers information from other parts of the brain, any change in the system
‘downstream’ can have an impact on higher level functions. Therefore, for
example, cognitive problems associated with conditions such as multiple
sclerosis or a wide range of different forms of dementia will also have an
executive component. Further, since it is believed that the frontal lobes are
not fully formed until the early 20s, the executive system will correspondingly
not be fully functional until this point in life. Indeed, most forms of
behavioural disorders linked to development during childhood such as Autistic
Spectrum Disorder (ASD) and Attention Deficit Hyperactivity Disorder (ADHD) are
linked with poor executive functioning. Finally, due to the hormonal and blood
circulation system within the brain, the PFCs are susceptible to the impact of
a large range of chemicals.
Given the centrality of the PFC and executive system to
so many aspects of behaviour, accurately being able to assess the impact on
someone’s life of dysfunction to it is a primary aim of clinical
neuropsychologists; once this impact is known then it can possibly determine the
course of rehabilitation therapy &/or decisions about going back to work.
Unfortunately, the currently available tools for assessing damage to the
executive system are notoriously unreliable and this has can greatly affect
adjustment to life post-injury. While a number of experimental paradigms have
been created to develop theoretical models of the PFCs, they have been poor at
assessing dysfunction. Even where tests have been developed specifically to
assess clinical populations, their success has been mediocre at best and often
the findings are not of great use for health professionals working with the
affected individuals. So for example, most assessments will fail to detect
deficits in a significant proportion of patients. In a classic example, Eslinger
& Damasio (1985) studied a patient known as EVR who had undergone surgery
to remove a tumour located in his frontal lobes. Following recovery from the
surgery, the patient’s general intellect was unaffected but his ability to
manage everyday behaviour was severely changed. Having been a successful
accountant pre-operatively, he ruined himself financially within two years. In
the same time, he managed to get divorced, married again and divorced again! At
a daily level, he would become immersed in the most mundane tasks sometimes
taking hours to make the simplest of decisions; eventually the patient had to
live in a care home since he could not be trusted to manage his own affairs.
Despite this catastrophic change in behaviour, EVR passed all the tests of executive
functions that were available at the time. Even when failure on the tasks does
occur, the results do not necessarily translate into real-world behaviour; in
other words, the tests lack ‘ecological validity’ in that they seldom map onto
the problems in everyday living that are common subsequent to PFC damage.
To address the limitations of currently available tests
of executive function, I have developed a test known as JEF© (the
Jansari assessment of Executive Functions) has been developed using non-immersive
virtual reality (Jansari, Agnew, Akesson & Murphy, 2004). JEF©
uses a standard laptop and is presented as a computer-game with the participant
navigating around the virtual environment of an office performing a number of
tasks known to rely on intact executive functions. JEF© is able to
successfully detect the executive impairments of patients with brain injury
that standard clinical tests fail to do (Jansari et al, 2004). Further, since
an individualised profile is produced for each person showing their strengths
and weaknesses, this has proven beneficial for the patients to understand their
cognitive problems post-injury which itself can have significant positive
impacts on psychosocial adjustment; additionally, these profiles can be used by
rehabilitation therapists who are attempting to ameliorate the difficulties
faced by the patient as well as aiding them to re-enter the workforce (or find
gainful employment which can often be severely affected by brain injury).
Following the initial success of JEF© with
patients with brain damage, further studies have shown that it can be used in
healthy brain-intact individuals to investigate the impact of chemical
substances on higher mental functions. Montgomery, Hatton, Fisk, Ogden &
Jansari (2010) have shown the negative impact of the recreational drug ecstasy
while Montgomery, Ashmore & Jansari (2011) showed similar with cannabis.
Montgomery, Seddon, Fisk, Murphy & Jansari (2012) have also shown that even
an amount of alcohol that is within the legal limits for driving in the UK can
significantly lower executive performance. Collaborating with one of our
colleagues Lynne Dawkins and a colleague Trudi Edginton at Westminster
University along with an MSc student, we have demonstrated that while heavy smoking
impairs executive performance, nicotine itself can have facilitatory effects
even in non-smokers (Jansari, Froggatt, Edginton & Dawkins, 2011). Since it
is found that fewer smokers develop Senile Dementia of the Alzheimer’s Type
(SDAT) and that nicotine can reduce agitation in dementia, these potentially
positive effects of nicotine could have significant impacts on development of
drug therapies to deal with dementia. JEF© has also been used to
demonstrate that Androgen-Deprivation Therapy (ADT) which is used for treating
prostate cancer that has spread beyond the prostate gland significantly lowers
executive performance; patients anecdotally report these problems but this is
one of the first times that it has been demonstrated objectively possibly because
of the insensitivity of the assessments used previously (Jansari, Mills,
Edginton & Green (under review)). Since prostate cancer is the most common
form of cancer in the UK and in many Western countries , large-scale drug
trials are planned to evaluate this further. Finally, in a recent study in
collaboration with Caroline Edmonds and an MSc student aided by the excellent
programming skills of Tony Leadbetter we have developed a children’s version of
the assessment, JEF-C© to assess the development of executive
functions during adolescence (Jansari, Gordon, Edmonds & Leadbetter, 2012).
This is currently being used to investigate higher mental functions in children
with ASD, ADHD and Traumatic Brain Injury (TBI).
Following the success of JEF© a Swedish BSc
student translated it into her native language and ran a study with a
collaborator in Stockholm to look at how culturally appropriate it was in
countries where English is not the first language; using this translated
version, we compared Swedish TBI patients with matched controls. We found a
significant difference between the two groups showing the utility of JEF©
in other cultures (Jansari, Debreceni, Bartfai & Eriksson, 2008). As a
result, JEF© has now been translated into French, Finnish, Dutch and
Portuguese with trials underway to collect normative data in Belgium (French
& Dutch), Finland (Finnish) and Brazil (Portuguese).
In June, I visited my collaborators in Belgium where data
collection is going well for the French version and there are plans to see if
the assessment can be used to look at cognitive impairments related to
depression; similarly, research with the Dutch version is going well with plans
to see if the assessment can be used with other neuropsychological disorders.
Finally, I have been invited by a network of neuropsychologists in India in
Mumbai, Delhi, Kolkota and Bangalore to be a co-applicant on a government grant
to explore how JEF© and JEF-C© can be adapted for use in
an Indian population.
So these are exciting times for UEL’s virtual reality
research......
Ash
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