While observing top-sportsmen we noticed that they had similar
facial characteristics, namely eyes surrounded by masking
elements(1.1 The Facial Masking Alpha Channel).
At first we simulated this facial masking by laying a finger on the intersection between our eyes and looked at al types of (moving) subjects to see what influence was on our sight. The result for me as a dyslectic was quite significant: my view was more balanced, I could look at a subject without the extra concentration. This was something special so we started a quest into the world of sight and dyslexia.
To find out more about sight and balance, we studied the different parts of our visual system. Starting with the ocular dominance system and the interaction between our
eyes.
We evaluated A the exterior side and what the effects could be of different facial masking values, and B the interior side and the reflections of facial masking at the different steps of the visual pathways.
After our research we had to fit in this topic first, because a good understanding of how the interaction between our brain halfs work is crucial. The left eye collects visual information and sends it via the LGN to the primary visual cortex (V1) of the right brain and visa versa. (see: visual pathways)
But what's most interesting are the different way's these brainhalfs process their input: one side thinks and sees in wide-angle (S) while the other zooms in on the detail (F). Researchers have come to see the distinction between the two hemispheres as a subtle one of processing style, with every mental faculty shared across the brain, and each side contributing in a complementary, not exclusive, fashion. A smart brain became one that simultaneously grasped both the foreground and the background of the moment.
Ocular Dominance is the tendency to prefer visual input from one eye to the other, like right or left handedness. In binocular vision there is an effect of Parallax and therefore the dominant eye is the one that is primarily relied on for precise positional information.Dominanceswitches from the right eye (detail) to the left eye (global), just like walking.
When we aim with a weapon at a target, we close one eye to form a direct line with the target. When we read, the target isn't a solid object but a group of interacting letters (details) so we constantly have to make steps to understand it's meaning.
Result: Our visual reading system works as a bascule-like mechanism, balancing between detail an whole, this balance is influenced by physical proportions on the exterior side (positioning, size and facial masking) and on the interior side (the visual pathway and brain). (more)
The facial masking intersection between two eyes who follow a moving subject, is set at different levels. The captured images are combined and compared. (more)
Result: The intersection level is highly influential, the right intersection between the eyes in relation with the distance of the moving subject makes the transition from one eye to the other fluent. (see topic: 1.3 Different Intersections)
The facial masking intersection works as a hold-on, a base for our view and as a switch
to change from one view to the other. But if this was the case how come
asians who often haven't got a noticeable vertical intersection are
also verry sharp-sighted?
Asians have view reduction close to their eyes in a horizontal and oblique way, created by the eyelids, having similar effect as a the vertical intersection for occidentals, having a horizontal hold-on. There is an interesting article in National Geographic about this subject: "Chinese, Americans Truly See Differently".
Alignment is the adjustment of an object in relation with other
objects. Our view is aligned to the facial elements
that surrounds our eyes, for Asians this alignment is horizontal as they
haven't got the signature intersection like occidentals, who have a
vertical alignment.
Horizontal alignment represented by the stripes on the image is used by asians as a hold on to move over the picture. He/she will start at the tip of the boat on the left and will automatically go to the right to get immediately a full impression of the boat, he/she will move on to the boat in the back and on to the left of the visual field passing by the mountain in the far back, on to the wave that's going to crush the boat, creating a spiral movement that explains the story in one fluent motion. (more)
Semi-exterior physical (masking) facts that define how light falls into our eyes:
Big eyes are less curved creating a narrower view-field and a more sharper view because minimal diffraction of the incoming light (see topic: 1.7 Diffraction).
A lens with a large diameter converges more light and gives a brighter image.
There are 3 places of curvature in an eye: Cornea - Lens - Retina (more)
In Photography there is a conventional wisdom is that one can achieve a sharper image by stopping down to a smaller aperture, but this misses the mark in 2 fundamental ways:
1. An image will always be sharp at the point of focus, what a smaller aperture gives you is an apparent sense of greater sharpness by extending depth of field.
2. Diffraction (spreading) can cause you to actually get progressively less sharp images beyond a certain aperture, even at your focus distance: at a sufficiently large aperture, light rays can pass through unobstructed on their way to the sensor, but as the aperture gets smaller, less light can get through. At really small apertures light rays can barely squeeze through at all and are actually bent slightly on their way to the sensor and begin to interfere with one another.
Result: Facial masking can block parts of the "in-falling" light, defining for a part the pupil-opening and the level of diffraction. (more)
Film speed is the measure of a photographic film's sensitivity to light. Film with lower sensitivity (lower ISO speed rating) requires a longer exposure and is thus called a slow film, while film with higher sensitivity (higher ISO speed rating) can shoot the same scene with a shorter exposure and is called a fast film.
A smaller aperture or higher shutterspeed is needed for a more sensitive film. As a result, increased facial masking (=smaller aperture) can be benificial for dyslexics with a more sensitive peripheral view caused by smaller M-pahtways of the LGN. (more)
When a person walks, each footstep sends a sizable jolt through the body. For the most part, we don't register these shocks visually, our brain automatically adjusts the information coming from the eyes. The film/video industry uses "internal "and "external" image stabilization techniques. A tripod with pivot and a "dolly on rails"workas an alignment system, just like the facial elements that lay within our visual field, beeing a hold-on to a have a steady view while filming motion, or moving along a subject (1.5 Alignment).
Result: The more relative facial elements (alplha) there are, the more aligned and steady our view and concentration is when we follow or move along a subject (reading). (more)
B. INTERIOR
Overview of the visual pathways:
Light fall's into our eyes and is projected through the lens' on rod- & cone cells in the retina (2.1 Rods & Cones). The information of these cells is collected by ganglion & bipolar cells (2.3 Ganglion & Bipolar) and is send on through a relay mechanism called the LGN (3. LGN: Magno & Parvo) and the SC (4. SC: Superior Colliculus) on to the first visual part of our brain called the Primary Visual Cortex (V1) (5. Primary Visual Cortex).
The facial masking structure that surrounds our eyes and the structure of the retina (rods & cones) has intresting correlations. Key points of where the eyes get in contact or lose contact with the nasal intersection, correspond to bumps in the diagram where the percentage of rods take a drop.
These key points work as thresholds aligning and locking our view. The bumps are situated in the peripheral rods-fields of the retina, that defines contrast and movement, important for reading. (more)
Binocular view is represented in the primary visual cortex of the brain as a striped pattern, the blank triangular area represents monocular view (MC). The MC region is defined by facial masking elements that surround our eyes, the more masking there is, the lesser peripheral-binocular input our brain has to process. There is an interesting theory by Professor Dmitri B. Chklovskii and Alexei A. Koulakov explaining the function of the striped patterns. (more)
The Striped pattern is an evolution of making the shortest and as a result, the fastest connections between visual input of both eyes. It represents fluent transition/fluctuation/oscillation between the two brain-half's. (more)
Two eyes focusing at a point, nasal masking is increased, on the diagram we can see what the influence is of the different masking levels on the primary visual cortices.
Result: Larger masking elements significantly reduce visual noise and our brain has to make less connections, making it easier
to focus. The diagram shows the results of how facial masking elements restrict our view-field, reducing peripheral distraction and improving concentration. (more)
C. DYSLEXIA
Professor Albert Galaburda and his research team at the Harvard Medical School discovered in dyslexic brains:
a. Differences in the LGN.
b. Language centers that showed microscopic flaws known as Ectopias and Microgyria.
A study published in 1991 by Harvard Medical School researchers reports of a post-mortem study of people with dyslexia and found differences in their Lateral Geniculate Nucleus (LGN). They looked at the subdivision of the LGN and found that the cells in the M-pathway are smaller in people with dyslexia.
This smaller M-pathway leads to a different processing of information from the eye's retina to the primary visual cortex (V1) in the back of our brain.
Result: A less filtered input-stream of Motion and Orientation makes it harder for Dyslexics to have a steady / balanced view or in contrast a muted input can give less visual grip. (more)
"The Magnocellular Theory of Developmental
Dyslexia" (link pdf) publication of Professor John Stein of Oxford
University, covers many topics including monocular occlusion where-in he writes:
"…abnormal magnocellular function may cause such binocular instability."
"…blanking the vision of one eye can simplify the visual
confusion…" (more)
Thesetopics correspondent to my experience of increasing facial masking by laying a
finger between my eyes, giving me visual balance. But
there's something extra: by increasing the facial-masking between the eyes, the
peripheral view of both eyes is decreased, reducing the input
for the M-pathway of the LGN.
(3.2 Dyslexia and LGN )
Parallelwith the LGN are the Superior (SC) and Inferior Colliculi (IC), they are 2 pairs known collectively as the Corpora Quadrigemina (Latin: quadruplet bodies). The CQ receives visual as well as auditory inputs in its layers, who are connected to many sensorimotor areas of the brain. The CQ as a whole is there to orient our head and eyes to what we see and hear.
The superior colliculus: Visual processing, control of eye movements.
The inferior colliculus: Auditory processing.
The SC is an important link in the visual brain streams transmitted from V1 (6. Dorsal en Ventral Stream) and controls the extra-ocular muscles that direct gaze (8. Oculomotor System) needed for al the different types of eye movements as saccades (7.2 The saccadic system). The SC works with the sensory system that provides the input for movement and orientation in space and is linked with the Auditory-system to keep our balance (9. Balance System).
This system is like a chain, where a deficit in one part has an effect on the other elements. For dyslexics, a differentiating LGN linked to SC and IC can cause enough deviation (noise) withdrawing the eyes from staying focused to read a text-line. It also effect the hearing system where many dyslexics fail to develop adequate phonological skills(more)
An other element that Albert Galaburda and Thomas Kemper found from examining dyslexics brain, were clusters of ectopic neurons in the outside layer of the cerebral neocortex. This layer usually is devoid of nerve cell bodies, most ectopias were found in the Frontal and Perisylvian language regions, they are produced before six months of gestation when there is a breach in the Pial-Glial border which normally prevents neurons from migrating too far. (more )
Scientists recently identified a risk haplotype (a genetic constitution of an individual chromosome) associated with dyslexia. Their data suggest a direct link between a specific genetic background and a biological mechanism leading to the development of dyslexia. (11.1 Genetic Etiology)
It is known that in fetal-development by the end of the 6th month,
the eyelids begin to part and the eyes open, and the baby may respond
to sounds by moving or increasing the pulse, this corresponds to the areas where dyslexics are disadvantaged.
Could Pressure Phosphenes be one of the "biological mechanism" that causes these Ectopias? Pressure phosphenes appear at the peripheral areas of our sight, analog to the M-pathway of the LGN.
Ectopias are produced before 6 months of gestation when there is a breach in the Pial-Glial border which normally prevents neurons from migrating too far. Eyes that are shallow may be more sensitive to pressures in the womb and in combination with rapid eye movements, could lead to Pressure Phosphenes giving strong pulses to the LGN and on to creating Ectopias. (more)
D. READING
Aside of how our interior and exterior visual system work, we took a look at how the reading and language process evolves and where there are disruptions for dyslexics.
When it comes to reading our right eye sees a point and the left eye sees the relation to a line; next: the right eye sees this line and the left eye sees it's relation to a letter; next: the right eye sees the letter and the left eye sees the relation to a word, and finaly we read a whole sentence. Our eyes are always taking steps, from detail (part) to global (pattern).(more)
12.2 Dyslexics and Image Processing / Reading Dyslexics have trouble to gaze around and focus at a point due the LGN-deficit causing a more sensitive peripheral-view. This non foveal input is used for processing motion and orientation, and necessary for a steady and balanced view. In combination with the facial-masking-alpa-region, a reduced LGN has possible 2 different implications:
Large alpha region: makes it hard to switch view from one eye to an other, there is a tendency to keep a one-sided dominant view and not change fluently between the two eyes because of the Gap (1.3.3 Long Intersection).
Small alpha region: makes the eye dominance change more then normal: Unsteady -> Blur (1.3.1 Short Intersection). (more)
The Latin Alphabet is build in a vertical line pattern: I I I I I I I I, ideal for a balanced sight with a vertical facial-masking-alpha-intersection (1.5 Alignment).
Arab script is a combination of flat and vertical and it's symbols are very detailed, —.—I—.—I—.— (ويكومي العالميه ), ideal for their sharper reading ability; arabs tend to have big eyes with a large masking-alpha-channel in-between.
Chinese script: asians have no significant intersection in the Y-direction, their writing-language therefor has developed in a vertical manner as their eyes are narrow by horizontal facial masking areas (1.4 Asians have a Horizontal Alpha-Area ), their alphabet is also based on a more image explanatory way, rather then a composition of letters forming words, making it a different comprehension process. (more)
E. ANIMALS
A last topic is about how the facial masking alpha areas are represented in the animal world.
Evolution adapted the eyes of different species to different types of environments. There are Nocturnal, Diurnal and arrhythmic types and each type has their predators and prey animals. Nocturnal animals have big lenses and a small Vitreous Humor. Their eyes work as a sensor for movement in the dark and mainly use rod-type cells for night vision. A large lens also converges more light and gives a brighter image.
Pupils work as the primary view masking-alpha-areas of the eyes, contracting when more focus is needed, in contrast to the passive view blocking areas that surround the eyes, although the eyebrows can be frowned and eyelids can be narrowed to increase masking. Like painters do when the put their brush in front of them to measure the proportions of their composition.
Cats who live close to the ground have to keep track of horizontal, back and forth moving objects like mice. Vertical alignment improves this ability, therefor they narrow their pupils into a vertical-line shape. (more)
Deer have pupils in the shape of a horizontal ellipse to have a horizontal alignment with their environment. When they graze, they turn their eyes 90° clockwise, to keep their view horizontally aligned. They also lift their eyebrows to keep their eyelashes horizontally aligned using them as an alignment tool in conjunction with their pupils. (more)
The pupils of Frogs & Toads come in all kinds of shapes, there is even a group with Heart-Shaped pupils, this group is interesting when it come to alignment, when we closely look at the skin-pattern of Oriental fire-bellied Toads we can see that they have direction lines on the front of their beak/belly. This fire pattern works as a watch-like alignment system that helps as a hold-on for the toad's to track and catch quick moving insects. (more)
The facial masking alpha-area can be considered as an important influence on our viewing
process, it is the exterior gateway of our sight, styling the way light
falls into our eyes and how this information is send to our brain and defining the way our eyes interact.
A weak alignment system typical for some types of dyslexicswith sensitive peripheral-view, can be helped by extra Alignment, in my case and starting point of this whole quest by using my finger to increase the
intersection between my eyes. It worked for me like balancing a car by putting
little bits of lead on the wheels to keep the car from trembling.
Result: The right amount of intersection leads to a steady hold-on and alignment for a balanced view, the basis for a sharp-sight. At first I used as a practical solution, for me as a dyslectic, some tape on a pair of glasses to increase the facial masking alpha between my eyes. A second option is to use a transparent sheet with yellow alignment lines on, to lay over a text see topic1.5.b Alignment & Dyslexia. (Left-click to download pdf's with pattern to print on film: 1 , 2 , 3).
Comments are welcome at:
If you are new to the subject of Eye-movement, Retina, LGN, Primary Visual Cortex (V1), etc., there is a very informative site: "The Physiology of the Senses Transformations for Perception and Action" from Professor Tutis Vilis from the University of Western Ontario, that has nice flash presentations about these subjects, they can also be downloaded in the pdf-format. link: http://www.physpharm.fmd.uwo.ca/undergrad/sensesweb/
But what's most interesting are the different way's these brainhalfs process their input: one side thinks and sees in wide-angle (S) while the other zooms in on the detail (F). Researchers have come to see the distinction between the two hemispheres as a subtle one of processing style, with every mental faculty shared across the brain, and each side contributing in a complementary, not exclusive, fashion. A smart brain became one that simultaneously grasped both the foreground and the background of the moment. 
Could Pressure Phosphenes be one of the "biological mechanism" that causes these Ectopias? Pressure phosphenes appear at the peripheral areas of our sight, analog to the M-pathway of the LGN. 
The
purpose of this site is to present questions and new ideas about
the above subjects.