Many scientists believe that the brain develops in definite
stages. Once the period of development has passed, they
maintain that the brain cannot change.
They call these periods `critical periods' in brain
development: if you haven't learned the skill by then, you
never will. They maintain that this is because as the brain
develops, certain circuits are set up which cannot be
changed.
In 1989, using prism glasses, a laboratory at Stanford
University School of Medicine in California identified a
critical period in barn owl development. During the first
months of an owl's life, the researchers showed that a brain
region called the tectum learns to coordinate what the owl
sees with what he hears. This enables an owl to identify a
mouse and its squeak as coming from the same place, even in
the dark.
Now two scientists are challenging the absoluteness of
critical periods. Brie Linkenhoker and Eric Knudsen have been
fitting prism glasses to adult owls. The prisms change the
path of light entering the owl's eyes so that the owl can now
no longer coordinate what he sees with what he hears. They
wanted to see whether the owl can relearn this skill. They
found that by fitting a series of prisms which only alter the
path of light progressively by small amounts, the owl can
relearn the ability to hunt for prey effectively.
Linkenhoker and Knudsen claim that this proves that there is
no fixed `critical period' for neural development but that
learning can continue even into the years of mature
adulthood, though learning might be slower and might need to
be done in smaller stages than in youth.
These findings confirm the practice of behavioral
optometrists who provide vision training to children and
adults at ages which many ophthalmologists claim is beyond
the age at which these skills can be learned.
As many as 80% of people with reading and learning
deficiencies also suffer from vision deficiencies -- even
though they might have 20-20 vision. If these vision
deficiencies are not treated, reading remediation can be
laborious and ineffective. However, if the vision
deficiencies are treated, remediation is usually rapid,
enabling the reader to quickly completely overcome his
problem.
This is particularly significant to readers of Hebrew since
reading Hebrew is much more visually challenging than reading
English [because of the voweling].
Recently, the vision skills of 26 `problem' cheder
children were screened using a Keystone Telebinocular. 25
were found to have serious vision deficiencies. Of these, 15
could be dealt with by a regular optometrist, but 10 required
more complicated vision training and were referred to a
behavioral optometrist.
[More information can be obtained directly from Rabbi Zobin
at 02-5373340.]
