The human mind,
a labyrinth of curvatures and intricacies conducting an orchestra with every
impulse sent and received. As the crescendo fades and neurodegenerative disease
progresses, the synchronous melodies grow fainter, yet vague resonances persist. The arrangement of memories, perceptions and
thoughts are composed from a lifetime of visual stimuli and for patients who
suffer from different types of dementia, art helps to manifest remnants of
their experiences.
According to
behavioral neurologist, Dr. Bruce Miller, art draws on different cognitive
areas and processes within the brain and while behavioral and emotional
deficits occur there is a component of visual creativity which can emerge, be enhanced
or decline. He asserts the importance of
understanding visual creativity in dementia as a tool for unlocking the brain
areas activated by artistic processes and can aid in rehabilitation of such
patients. Dr. Miller’s research has led
to the realization that artistic creativity varies among the different types of
dementia patients. For example, a patient suffering from frontotemporal
dementia can copy images without problems, but someone with Alzheimer disease
struggles with a copying task.
Dr. Miller
explains that artistic creativity in dementia patients comes from a “ventral
stream involved with the recognition of ‘what’ is seen, and a dorsal stream
that localizes ‘where’ an item has been perceived and these visual scenes are
absorbed throughout a lifetime.” People
with dementia begin to unravel their woven tapestries of objects, landscapes,
and people through paintings and drawings. Clearly, Dr. Miller’s focus was on patients who
had vision, but what about blind and visually impaired people who suffer from
dementia. For some dementia patients
vision declines as the disease progresses, and others may have been blind and
developed dementia later in life. Some
studies suggest links between Alzheimer disease and nerve damage in glaucoma. There
are associations between reduced vision and hallucinations in dementia patients
and studies have pointed to the therapeutic value of helping to improve their
vision.
Grid of electrodes implanted on retina
A breakthrough
in neuroprosthetics may prove helpful for blind dementia patients. Researchers at Second Sight Medical Products
have devised a new retinal implant where words are stimulated directly onto the
retina. The device uses a small camera
attached to eyeglasses which sends input to a portable processor. The processor translates the signal from the
camera to a microchip with electrodes that is implanted on the retina. The remaining retina cells are stimulated and
electrical impulses are transmitted down the optic nerve conveying visual
information to the brain. The brain perceives the pattern of light and the
patient learns how to interrupt the visual patterns.
So far, the
device has been implanted in 50 patients and reports indicate that some see
color, movement and objects. However, the device does not give a full sense of
what is around the person; rather it grants a rough idea of their surroundings. Reading Braille is also possible and achieved
without any sensory input like touch. Researcher,
Thomas Lauritzen explains that, “patients could see the patterns projected and
then read individual letters in less than a second with up to 89% accuracy.” Patients with the device have the ability to
read up to four letter words, which proves that patients had good spatial
resolution because they could easily distinguish signals on individual electrodes.
http://www.sciencedaily.com/releases/2012/11/121122095433.htm
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