A
scientist at the Massachusetts Eye and Ear institute's Schepens Eye Research
Institute, Dr. Corinna M. Bauer, who is also the lead author of the study, said
that their results show that the
changes that
occur in the brains of people post ocular blindness are more rampant that
previously believed. The author, who is also an instructor of ophthalmology at
Harvard Medical School said that significant changes were not only identified
in the occipital cortex but were also identified in the regions of the
associated with
language processing, memory and sensory motor functions.
‘Brains of blind people program themselves to use other senses and cognitive abilities in order to compensate for vision loss.’
Imaging the Brain
The
research team utilized both the diffusion based and resting state MRI
multimodal brain imaging techniques to identify changes that occur in the
brains of 12 subjects, who were born blind or who became blind before the age
of 3 years. These scans were then compared with the brains of 16 normal sighted
age matched subjects.
The
study found that among those who showed signs of early blindness
- There were changes in the structural and functional
connectivity
- There were signs of enhancement in connectivity
- There was transmission of signals, back and forth, in
the regions of the brain that were not observed in people with normal
sight
- Certain connections that were
identified in the brain imaging studies were unique among people with
blindness
These
findings suggest that the brain rewires itself, to improve the other senses
when there is an absence in visual information. The brain is believed to
'rewire' itself, made possible through
neuroplasticity,
a process by which the brain is able to adapt to the experiences.
The
research team believes that this study could be used to
enhance the experience of visually challenged individuals,
providing them with the right kind of support, by understanding their
strengths. The study findings can be
used for effective rehabilitation, which will help improve other associated
faculties, compensating for the loss of visual information.
Dr.
Lotfi Merabet, who is the senior author of the study and the Director of
Schepens Eye Research Institute of Mass. Eye and Ear's Laboratory for Visual
Neuroplasticity, said that according to the study, there are changes in the
brain which aid in utilizing the information gathered in a more effective
manner even when the subjects were profoundly blind. Dr. Merabet, who is also
an associate professor of ophthalmology at
Harvard
Medical School, said that the study brings to the fore the ability of the
brain to rewire itself. When the brain can rewire itself, then improved
training could enhance
hearing, language
skills and the ability to feel and improve aspects like braille reading.
The
study provides evidence that the brain has the ability to adapt to the
environmental changes and that, through proper training other faculties can be
enhanced in every individual.
Re-organization after
Sensory Loss
The
senior author of the study, Dr. Lotfi Merabet, and his colleague Dr. Alvaro
Pascual-Leone, have been studying the remarkable ability of the brain to
re-organize itself after sensory loss for many years, and have published a
study in 2010 titled "Neural Reorganization Following Sensory Loss: The
Opportunity Of Change".
The research delves into the changes that
occur when the individual is blind or deaf. Just like in people who are blind,
the study showed that there were other senses, among the deaf, which were
intact and aided in interaction with the environment. The study provided
examples of enhanced sensory stimulation among the deaf, which include
- The ability to
use visual or tactile stimuli
to alert attention
- Interactions
using visual-spatial methods of
linguistic communication like the use of sign language
- Superior ability
in certain tasks compared to control subjects who can hear
- Improved visual
ability compared to controls, especially in identifying emotional
expression
- Being better at
carrying out tasks that involve peripheral vision; this could be an
adaptive phenomenon
- Superior ability
in detection of visual motion
The
loss of a faculty has been shown to be associated with a compensatory
enhancement in other faculties, which will improve the interaction of the
individual in the social scenario. The findings of the study can be used to
devise training methodologies which will better guide people with improper
vision or hearing, into becoming independent with the other faculties. Such
constructive training will prepare them for a better quality of life, and
further
enhance their natural
adaptability.
References :- Neural Reorganization Following Sensory Loss: The Opportunity Of Change - (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3898172/)
Source: Medindia
