A World Without Meaning
As the fall settles in,
and the holiday season has officially kicked off with
Canadian Thanksgiving, opera
singers everywhere are performing superstitious
rituals with the aim of fending off illnesses.
Some rinse their sinuses with saline
daily, others add honey to their tea in generous
portions; everyone’s hands begin to dry up from
the liberal application of sanitizing gels and the
first sensation of an itchy throat sends us
burrowing under our covers to nap the germs away.
For a singer, losing one’s voice means losing work
and opportunities to generate future work. Because
our productivity and happiness depend on a healthy
voice, and getting sick is relatively
unpredictable and mysterious, we latch onto home
remedies and folk wisdom more readily than the
average Joe.
When we do get sick, however, we refrain from talking
as much as possible and, for a short while, we
glimpse a world in which speech is an inaccessible
form of communication. Being theatrical people by
nature, we rely more heavily on facial expressions
and gestures. Individuals with aphasia are also
encouraged to use other forms
of communication such as writing, or gesturing or
drawing to get their ideas and desires across.
But what if the very meaning of the words is what
begins to deteriorate rather than the ability to form
them? What does it feel like to lose concepts? If you
no longer know that an eagle is an eagle and a mouse
is a mouse, does the world seem full of wonder or
mystery? The patients that I’ve been studying at
UCSF are suffering from semantic dementia, a
progressive degenerative brain disease that slowly
erases their conceptual knowledge. A baby learns
first that a bird is a type of animal, and then
that an eagle is a type of bird: patients with
semantic dementia first forget that eagles and
hawks are different types of birds, and eventually
they can’t distinguish a bird from another
animal.Their loss follows the development of
language in reverse.
Often, these patients choose to engage in activities
that involve complex visual images as their disease
progresses: they love working on jigsaw puzzles, playing solitaire on the computer,
gardening, and some even begin to paint or sculpt works of
art. My goal has been to try to understand the
changes in the mind that lead to this paradoxical
emergence of visual creativity. I’ve approached
this question using the rigorous methods of
neuroscience: tracking where patients look when
they are viewing pictures or art work or searching
for a specific target in a large array, comparing
the brain volumes of patients with healthy
counterparts and patients with other diseases and
correlating these volumes with specific behavior,
timing how long it takes them to find a target and
how accurately they can perform a difficult visual
search task. It turns out that they are faster and more accurate than
healthy controls in tasks like ‘Where’s Waldo?’, and the brain
regions that correlate with performance on those
tasks are the same regions involved in
grapheme-color synaesthesia, a condition in
which people ‘see’ letters and numbers in color.
When a video like The Treasure Hunt puts the
experience of aphasia into a simple and elegant poem,
I can’t help but wonder what it must be like to
experience the world through the lens of semantic
dementia: when things lose their meaning, are they
less distracting? Does the world become more vivid
and alive? Many of their paintings seem to suggest
that it does. And the fact that these patients find
new ways of communicating underscores the central
role that relationships and social interactions play
in our lives. The holidays are designed to strengthen
the ties that bind us to friends and family, and as
the days get shorter and the nights grow colder, it’s
as good a time as any to return those personal
calls.