I have been
thinking a great deal about the ‘research’ that has come out of Harvard
recently.
The abstract
I reprint below. This research has been
published on PLOS ONE, a peer reviewed, open access journal. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0075634.
The
original, article makes very interesting reading especially in the context of
the USA where to even imply the
possibility of a visual component in dyslexia can bring down the ‘wrath of the
IDA’ !
After
re-reading the original article, which I commend everyone to read, the
conclusions seem a bit guarded. I have highlighted components of the abstract
which I feel need much more consideration.
E-readers are fast rivalling
print as a dominant method for reading.
Because they offer accessibility options that are impossible in print, they
are potentially beneficial for those with impairments, such as dyslexia. Yet,
little is known about how the use of these devices influences reading in those
who struggle. Here, we observe reading comprehension and speed in 103 high
school students with dyslexia. Reading on paper was compared with reading on a
small handheld e-reader device, formatted to display few words per line. We found that use of the device
significantly improved speed and comprehension, when compared with
traditional presentations on paper for specific subsets of these individuals: Those who struggled most with phoneme
decoding or efficient sight word reading read more rapidly using the
device, and those with limited VA Spans
gained in comprehension. Prior eye tracking studies demonstrated that short
lines facilitate reading in dyslexia, suggesting that it is the use of short
lines (and not the device per se) that leads to the observed benefits. We
propose that these findings may be understood as a consequence of visual
attention deficits, in some with dyslexia, that make it difficult to allocate
attention to uncrowded text near fixation, as the gaze advances during reading.
Short lines ameliorate this by guiding attention to the uncrowded span.
In the actual paper, they state that
they were comparing reading performance on a font 14 in the print with font 42
on the e reader.
In the actual paper, they state that
they were comparing reading performance on a font 14 in the print with font 42 on the e reader.
Now don’t get
me wrong, but perhaps they should have looked at other font sizes on
paper? They did say that the e reader
allows accessibility options so really they were not really looking at e
readers, but at font size. If you read other postings in this blog, this would
not surprise you at all. The graph on optimal
font size for an individual shows the critical importance of font size.
Each
individual appears to have an optimal font size. For most students in the UK which
myself or my colleagues have seen it is far greater than font 14, the default
used on the printed task.
The ‘pretty ‘graph
above shows how the optimal font size varies in a population of dyslexic
students. The modal size is font 17.
About half the students need a font greater than this. Very few though benefit
from a size greater than 24. This data
is collected from students who have full optometric correction. The range of
font optimal font sizes will reflect issues such as...
- Crowding effects associated with cone cell size.
- Diffraction issues associated with corneal problems
- Other low vision issues not correctible by optometrists.
In other postings there are graphs showing the effects on reading
performance of
- Changing the background brightness to the text for individuals
- Changing the relative brightness of the red, green and blue pixels.
These
effects will be affected by the individual’s working cone pigment densities,
how quickly the epithelial cells they are plugged into can re-activate the
pigment molecules after they are bleached, as they read as well as the ability
of the individual’s iris to dilate and constrict to optimise the rate at which
the pigments in general are being bleached.
I could even ‘hypothesize’ that changing the relative stimulation of the
red and green cells, which is the basis of foveal edge detection, will change
the rate of data transfer about those edges to the visual cortex. I challenge anyone to explain it differently!
As such for
each individual there would be a specific ratio which sends the most data per
millisecond and this would provide the best provision of data for phonological
processing, and ‘gaze’ management.
But I am not
a Harvard researcher. So I will have to wait until they catch up.
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