When directing the writing by hand, the brain has to visually
track rapidly changing positions of the pencil and control hand and finger
movements. To learn such skills, the brain must improve its control over
eye-movement saccades and the processing of visual feedback to provide
corrective feedback. Both tracking and movement control require much more engagement
of neural resources in producing cursive or related handwriting methods than in
hand printing, because the movements are more complex and nuanced. Thus,
learning cursive is a much greater neural activator, which in turn must engage
much more neural circuitry than the less demanding printing.
The key to learning successful handwriting, whether cursive,
italics, or calligraphy, is well-controlled visual tracking and high-speed neural
responses to the corrective feedback. Scientists are now starting to study the mechanisms,
but not yet in the context of education. Two recent reports, seemingly
unrelated to each other or to cursive, examined visual tracking and found
results that could have profound educational implications for both reading and
hand-eye coordination training, as in learning to touch type.
Visual targets are fixed by saccades. One theory is that the
eyes scan the target with a linked series of saccades, in this case the changes
in cursive letter structure as the letters are being rapidly formed. We already
know that the brain predicts eye movements based on what they see at each saccade
fixation. This is how our visual world is made stable, even though the eyes are
flicking around; otherwise, the image would jitter back and forth constantly.
This suggests that visual image representation is integrated rapidly over many successive
saccades. The degree of tracking speed, accuracy, and prediction error must
surely influence how well the letters are transcribed during handwriting. The
corollary is that the better one learns to write by hand, the better the brain
is learning how to track visually.
Scientists used to think that these predictions were the
source of error in estimating the position of seen objects. In handwriting, for
example, the brain would assess the shape of part of a letter as you draw it
and predict how and where the next portion of the letter should be added.
Learning how to optimize the drawing then would be a matter of learning how to
reduce prediction errors.
However, a new study tested the hypothesis that if localization
errors really are caused by faulty predictions, you would also expect those
errors to occur if an eye movement, which has already been predicted in your
brain, fails to take place at the very last moment in response to a signal to
abort the eye movement. The investigators (Atsma et al. 2014) asked test
subjects to look at a computer screen and tracked eye movement fixation on a
very small ball that appeared at various random positions. During this task,
the brain must correctly predict where the eyes have to move to keep the eye on
the ball.
The experiment ended with one last ball on the screen,
followed by a short flash of light near that ball. The person had to look at
the last stationary ball while using the computer mouse to indicate the
position of the flash of light. However, in some cases, a signal was sent
around the time the last ball appeared, indicating that the subject was NOT
allowed to look at the ball. In other words, the eye movement was cancelled at
the last moment. The person being tested still had to indicate where the flash
was visible.
Subjects did not make any mistakes in fixation on the light
location during the abortion test, even though the brain had already predicted
that it needed to fixate on the ball. Most mislocations occurred when the flash
appeared at the moment the eye movement began. Thus, the errors seemed to be
associated with neural commands for eye fixation, not with saccade predictions.
The application for handwriting learning is that the neural circuits that
control target fixation may be a major factor in learning how to write cursive
well. Surely, these circuits would be responsive to training, though that was
not done in this experiment. It would seem possible that these circuits might
be trained via learning cursive to provide faster and more accurate visual
tracking, which should have other benefits—as in reading.
A related study of visual tracking in monkeys reveals
parallel processing during visual search (Shen and Paré. 2014). Recordings from
neurons in the visual pathway during visual tracking of targets in a
distracting field showed that in the untrained state, these neurons had
indiscriminate responses to stimuli. However, with training the neuronal
function evolved to predict where the moving target should be in advance of the
actual saccade. Results also showed that more than half the neurons learned to
predict where the next two eye movements (saccades) needed to be, which
obviously suggests that accurate tracking can be accelerated without loss of
information.
In short, learning cursive should train the brain to
function more effectively in visual scanning. Theoretically, reading efficiency
could benefit. I predict that new research would show that learning cursive will
improve reading speed and will train the brain to have better hand-eye
coordination. In other words, schools that drop cursive from the curriculum may
lose an important learning-skills development tool. The more that students
acquire learning skills, the less will be the need for "teaching to the
test."
"Memory Medic's" latest books are
Mental Biology (Prometheus) and Memory Power 101 (Skyhorse).
Sources:
Atsma, J. et al. (2014). No peri-saccadic mislocalization
with abruptly cancelled saccades.
Journal of Neuroscience, 15 April 2014. ttp://www.jneurosci.org/content/34/16/5497.full.html
Journal of Neuroscience, 15 April 2014. ttp://www.jneurosci.org/content/34/16/5497.full.html
Shen, Kelly and Paré, Martin. 2014. Predictive saccade target selection in
superior colliculus during visual search. The Journal of Neuroscience, 16 April
2014, 34(16): 5640-5648; doi: 10.1523/JNEUROSCI.3880-13.2014
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