By Stephen
Goodspeed, ’12
In The Importance of Being Earnest, Oscar
Wilde called memory “the diary that we all carry about with us,” a symbol and
bearer of our past. Without it, how does
one retain his identity? Sadly, many
patients with dementia suffer severe memory loss, along with various other
cognitive impairments.
The
biological effects of dementia lead to serious identity questions posed to us
by neuropsychologist Dr. Stephanie
Cosentino of Columbia University: How does self-awareness change in
dementia-stricken patients, and to what extent to they remain the same
individual? The case
of Phineas Gage prompted Gage’s friends to claim that, post-accident, he
“simply was not Gage”; can a neurodegenerative disease cause similar loss of
self-awareness and character?
In an effort
to help patients avoid the terrible fate of a loss of identity and
self-awareness, Dr. Cosentino assesses awareness in people with dementia. These assessments have formed the basis for
her published research on the causes and effects of anosognosia, the disordered
awareness of cognitive and behavioral deficits.
During
her visit to the Brain/Mind/Soul Seminar, Dr. Cosentino prefaced the awareness
discussion with background information on neuropsychology and how neuropsychologists
evaluate patient awareness. She
suggested as a point of contrast the field of Neurology, which is founded upon
biological analysis. Neurologists use medical
procedures to determine physical causes of degeneration such as tumors or
infections. Neuropsychology, on the
other hand, addresses problems that cannot be solved through purely medical interventions. It involves an interdisciplinary approach
appropriate to mysteries that often have subjective or ambiguous symptoms or
apparent causes.
Still,
it is difficult to anticipate and explain cognitive decline. Most coding and storing of recent information
in the brain occurs in the hippocampus , yet a model of a brain in the early
stages of dementia shown by Dr. Cosentino depicted general frontal lobe decay
that, for the most part, left the hippocampus unscathed. The parts of the prefrontal cortex that are
affected impact abilities to strategize and organize, but performance on strategy
and organization tests does not necessarily indicate the progression of
dementia. This makes preventing the
process extremely difficult and puts even more stress on the halting of the
disease’s progression once diagnosed.
When
dementia sets in, self-awareness begins to fade. At least it appears that way; self-awareness
is a very blurry concept (does it refer to memory capabilities? spacial
awareness? something else?). Because assessment
is problematic, Dr. Cosentino focuses on evaluating patients’ current problems
rather than attempting to trace etiologies.
To get as objective an analysis as possible, she seeks opinions from
those around an afflicted individual instead of relying on the opinions of the
patient himself. For example, when she asks
patients if they think they have dementia, she gets answers ranging from
“Definitely not; I don’t know why I was even sent here,” to “Yes, it’s
terrible. I forget everything”—even if
the degrees of severity are the same in those patients.
Dr.
Cosentino’s work in addressing anosognosia has led her to create metacognitive
tests that accurately determine a patient’s self-awareness through a
gamma score, a number ranging from -1 to 1 conveying the correlation between
the test-taker’s correctness in responses and his confidence about his
correctness. These kinds of tests differ
from average motor and higher-order thinking tests, such as connecting numbered
dots, in the sense that they require both memory capabilities and
organizational/strategic skills.
Although
no theory has been proven to identify an area of the brain devoted to
awareness, research has shown that right-hemisphere stroke patients suffer much
greater damage to their self-awareness than left-hemisphere victims. Another popular topic of discussion is the
relationship between dementia and depression, as each has been found to play a
role in causing the other. Even dealing
with such a dauntingly ambiguous concept as self-awareness, devoted
neuropsychologists like Dr. Cosentino give hope for a better future for those
afflicted with neurodegenerative diseases.
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