Personality and the brain; Can brain damage change personality?
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PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE PERSONALITY? 1 Personality and the Brain. Can Brain Damage Change Personality? Ivona S. Vukotic Herriot Watt University
Transcript
1. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 1 Personality and the Brain. Can Brain Damage Change
Personality? Ivona S. Vukotic Herriot Watt University
2. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 2 Introduction From early times, a relationship
between our mind and our brain, has been a great mystery and a
tempting enigma waiting to be explored and understood. Today,
neuroscience studies are giving us numerous evidence of a strong
relationship between brain and personality. Researches have shown
that when a brain changes, it usually doesn't leave the personality
intact. Personality, although considered inexplicable and vague, by
definition, is group of "more or less, stable, internal traits that
make one person's behaviour consistent from one time to another,
and different from the behaviour other people would manifest in
comparable situations (Child, 1968, p. 83). It is emphasized by its
definition that our core characteristics and traits should remain
stabile through time and context. Naturally, people do change,
mature and grow, but their basic personality remains the same.So,
what happens if personality change after a stroke, or a head
injury? Could it be that with the change in our brain, comes the
change in our mind? How important is a role of our brain in
decision making, emotions and judgment? Is it possible that we are
neurologically predisposed to have a certain personality, become
schizoids or psychopaths?If so, and if our brain is to blame and in
control, how much responsibility we have for what we are and do in
life? Neuroscientists have given us some evidence that could help
us answer some of these questions and understand the importance of
brain to our cognitive functions. Brain damage and Personality
disorders
3. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 3 "Brain damage" is a term used to describe
destruction or degeneration of brain cells, which can occur due to
a wide range of internal and external factors. There are three main
types of brain damage: congenital brain damage which is caused by
genetics or birth trauma, and traumatic or acquired brain injury,
which occur after birth. Neurological disorders can be categorized
according to damage localization, a primary type of dysfunction, or
primary type of cause. There are many well known diseases and
conditions caused by brain impairment such as Parkinson's disease,
epilepsy, Autism, , Huntington's disease and Alzheimer's disease,
but also a number of personality disorders, which will be a focus
of this essay. Along with the progress and improvement of
technology in medicine, a popularity of brain imaging usage in
studying personality disorders has increased.A strong link between
personality disturbances and criminals has urged researchers to
closer examine individuals with APD using brain imaging techniques.
These studies have revealed structural and functional damage in
antisocial and violent individuals. Moreover, researches dealt with
the issue of the brain scan results usage in the legal system.
There were three basic questions to answer for a start- Primarily,
do antisocial, and violent individuals have a brain abnormality?
Second, where are brain damages localized, widespread or focal? And
last, should these findings be used in legal purposes? Antisocial
Personality Disorder or Psychopathy Results of imaging studies
revealed that several brain regions have been commonly found to be
damaged in antisocial, psychopathic, and aggressive individuals,
whatever the type of imaging technique was used. Main areas of
disfunction include prefrontal cortex (particularly orbito- frontal
and dorsolateral prefrontal cortex), superior temporal gyrus,
4. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 4 amygdalahippocampal complex, and anterior cingulate
cortex. In frontal region, impairments in prefrontal and anterior
cingulate cortex resulted in impulsivity, irresponsibility, poor
decision-making, and difficulties in emotional processing. In
temporal regions, the amygdala hippocampal and superior temporal
damage contributed to antisocial issues such as inability to follow
social rules, deficiency in moral judgment, and failure to avoid
punishment. Researches have shown a weaker fear response in
antisocial personality disorder (antisocial PD) when presented a
negative stimuli, such as photographs of gun accidents (Levenston
et al., 2000; Vanman et al. , 2003, and Lindberg et al., 2005)
obtained a finding of low frequency EEG activity under similar
experimental conditions. In an interesting extension of this
theory, studies were taken to examine the activity
septo-hippocampal system and amygdala, the brain region responsible
for learning fear. After repeated classical conditioning, no
increase in amygdala activity was found (Birbaumer et al., 2005).
Some researchers believe that the capacity for empathy, is crucial
to the process of socialization. This perspective suggests that
some features of antisocial PD result of emotional deficits such as
lack of empathy. A study conducted by Blair et al. in 1997 confirms
this; the group of individuals diagnosed with antisocial PD have
shown less physiological responsiveness to photos of others'
suffering, as well as incapability of recognizing emotion of fear
in others (Marsh and Blair, 2008). Emotional deficits and reduced
capacity to learn fear are both associated with lower amygdala
activity ( Blair , 2006). These shortcomings are likely in the
background of altered moral reasoning and behavior of antisocial
individuals, because the moral issues include concerns about the
right and welfare of others. One group of researchers, however,
believes that the focus on immediate rewards is underlying cause of
this disorder. (Hiatt and Newman, 2006).
5. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 5 In order to explore emotions in personalities with
antisocial disorder , numerous neuroendocrinological parameters
have been used to measure emotional reactivity. O'Leary, Loney and
Eckel (2007) found a lower cortisol response to environmental
stress in antisocial PD. Also, the findings of both high level of
testosterone and low cortisol response (Glenn et al. , 2011 ) are
interpreted in The triple balance model of emotion (Terburg, Morgan
and van Honk, 2009). Such relationship between these hormones
reflects in motivational imbalance, which makes the individual
hyposensitive to a threator punishment and hypersensitive to
reward. Van Honk , Hormone-Jones , Morgan and Schutter (2010 ),
associate this imbalance with reactive and instrumental aggression,
as a result of serotonin levels. Specifically, low levels of
serotonin, associated with impulsivity and aggression (Siever,
2008), altogether with a high ratio of testosterone and cortisol,
lead to reactive aggression in psychopaths. Antisocial personality
disorder individuals who are characterized by deficits in emotions,
are more inclined to instrumental violent acts, while those with
some antisocial characteristics often show impulsive aggressive
reactions (Veit et al., 2010; Walsh , Swogger and Kosson, 2009).
There are some limitations in these studies. Even though these
researches showed strong evidence connecting brain damage and
antisocial aggressive behavior, there is still a question of
heterogeneity between antisocial individuals. Their personal
differences regarding various antisocial characteristics may result
in diverse degree of severity, or localization of brain
abnormalities. This theory could show inconsistency among these
studies, making it difficult to draw conclusions. Another issue
arises from the fact that the studies conducted to date are mainly
cross-sectional, which makes the cause of relationship between
brain damage and antisocial behavior left unclear. Neuroscience in
court
6. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 6 Is a killer-psychopath less responsible for a crime
if his conduct is a result of brain abnormality and genetic
factors, or should he get a more severe punishment, for that very
reason, bearing in mind that there is no control over his behavior,
which increases the risk of repeating the same or similar offense?
Having received information that the perpetrator of a murder is
diagnosed with an antisocial PD , judges have a tendency to impose
stricter penalties. If they are, however, presented with an expert
opinion - that the psychopathic behavior is a result of the
biological consequences - they tend to impose a more lenient
sentence. In both cases, the average length of the sentence, for an
offense of the same weight, is greater when the perpetrator is not
a psychopath. (Aspinwall et al.,2013). A study conducted by three
psychologists, John Monterosso, Edward B. Royzman and Barry
Schwartz, published in 2005 in the Ethics & Behavior journal,
found that people often find neuroscientific evidence as a relieve
of responsibility, an excuse, for criminal actions. Their research
showed that behavior of individuals with mild brain damage subjects
experienced as automatic, unmotivated and believed that it had
nothing to do with the "real" character of the protagonist. In
short, the behavior is caused, not intended.Cognitive psychologists
call this thought process a "naive dualism" - a belief that the
behavior arises either intentionally or as a result of natural laws
by which the brain works. In other words, if a behavior has
psychological causes, then the person is responsible for it, but if
it comes from biological causes, then he has no control over his
behavior and cannot be held responsible. Assuming further
development of neuroscience, it is not difficult to imagine a
future in which the complete, or almost complete, human psychology
is explained in terms of neurons, anatomy and biochemistry of the
brain. Does that mean that no one will be held accountable for
their actions? In other words, neurocognitive explanation of human
behavior denies free will?Neurocognitive explanation of human
behavior is in line with determinism. Behavior is a product of the
brain, whose structure and functions are defined by factors
over
7. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 7 which we have no control - genes and environmental
conditions. Environmental component is partly a matter of choice,
but again, our choices are pre-determined by physical laws.Overall,
results from the research show that people are inclined to perceive
a person with mental disorder, if it has biological roots, as less
responsible for their behavior. However, in consideration of many
research findings, it is concluded that the neurocognitive
psychology, does not eliminate the concept of personal
responsibility. In conclusion, criminals with brain impairment,
whether they are capable to control and understand their actions or
not, pose a threat to society. If we bear in mind the statistic
which shows 80 percent of psychopaths repeating their offense after
release from prison (Hart et al., 1988), a conclusion would be to
impose greater penalties with medical care, or other correctional
treatment in the most effective manner. However, each person should
be respectively treated as unique, as well as every case ought to
be considered individually, thus the sentencing can not be
generalized. Positive effects of brain damage - When a brain injury
creates a genius Brain damage has led to discovery of extraordinary
talent in a small number of people with autism, or who, prior to
brain injury, were quite ordinary individuals. According to
American researcher Darold Treffert from the University of
Wisconsin , who has dedicated more than four decades of his life to
research this phenomenon called savant syndrome, that can be
genetic or acquired (caused by brain injury or disease).Savant
syndrome is extremely rare, currently in the world there are no
more than 50 people with it. It is usually manifested by a
phenomenal memory and calendar calculating, a unique mathematical
capability, mechanic skills, and talent in fine arts or music.An
example of a brain injury with such positive outcome is definitely
a case of forty-year-old Derek Amato,
8. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 8 whose life took a twist when he jumped headfirst
into a shallow pool and suffered a concussion. His head trauma
resulted in 35 percent hearing loss in one ear, headaches and
amnesia. But the most dramatic consequence appeared just four days
after his accident when he started playing the piano for the first
time, and discovered a musical genius he never knew existed. The
precise neuroanatomical mechanism for gaining this privileged
access is not yet resolved.An earlier study in 1970. found that
autistic savants with exceptional artistic, mathematical and memory
skills have damaged the left hemisphere of the brain. Researchers
Snyder and Mitchell (1999) argued that savant skills reside within
everyone, but that they are not normally accessible to conscious
awareness. They theorized that it may be associated with an
atypical hemispheric imbalance wherein concept networks are
bypassed or inhibited. Moreover, some interesting recent reports
from San Franciscan neurologist Dr. Bruce Miller indicate "savant
like" abilities in older people with front temporal dementia. The
reason why some autistic and disabled individuals have savant
abilities is not yet completely understood, however, the strong
link with autism offers a good starting point for all future
studies. Conclusion Neuroimageing has successfully painted the
picture of our brain, but has it also captured a glimpse of our
personality at the same time? By making a hidden visible, brain
imaging has made an enormous impact in science, and a large
contribution to the world.Human understanding mysterious brain ways
has traveled a great journey, and significantly evolved to this
point where we are today. And even though it seems that we now know
ourselves, there is still much to learn. In fact, it is highly
questionable whether a human
9. PERSONALITY AND THE BRAIN. CAN BRAIN DAMAGE CHANGE
PERSONALITY? 9 brain can adequately understand itself, because it
has to understand not only the enormous complexities and dynamics
of its biological, electrochemical and structural processes, but
also its temporal interactions with the surrounding environment,
the world, and the society at large. Science has helped us get a
sense of what is going on in our heads, through decades of
researches and studies. It has given us a much clearer picture of
the relationship between the brain and our personality, and made us
realize the magnitude of its role in our behaviour. The
neurobiological domain is one of brains and physical causes; the
psychological domain is one of people and their motives. Both are
essential to a full understanding of why we act as we do.
Neuroscience has found many missing pieces of the brain puzzle.
However, this puzzle is still incomplete, and new questions arise
every day. The brain and the mind are different frameworks for
explaining human experience. And the relationship between them
holds crucial information on how we think about human nature, the
ways to deal with ours and others' imperfections, as well as to
enhance the quality of life.It is our privilege and duty, to use
that information, and strive for our very own best. References:
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