Stand up and look straight ahead. Without moving your eyes, use your peripheral vision to become aware what furniture or people are on your left and your right. Now imagine that you are unaware of what is on your left. Not that you can’t see or hear them but that you have no concept of their existence. It can’t be done consciously but this is one of the harder to comprehend effects of a stroke or brain damage and is known as hemispatial neglect. (You can sit down now). This strange phenomena leaves the patient unaware of anything on their left and can result in patients only eating food on the right-hand side of the plate. This isn’t blindness, the visual signals reach the brain, it is just that different parts of the brain are not functioning together. It is a problem that is hard to understand, almost impossible to treat and raises questions about what is consciousness.
Now a cluster of new studies led by Dr Tom Manly of the Cognition and Brain Sciences Unit at Cambridge has looked at hemispatial neglect in people with ADHD. The found that is was more widespread than had ever been considered. During boring or repetitive task the right brain, which deals with vision from the left eye, simply switches off. Even in normal children this happens after about 40 minutes but in ADHD it happens more often. This can cause reading problems as the child misses the first letter or two of the word. It would also cause clumsiness and inattention / misbehavior. A child isn’t going to obey an instruction if they are not aware of the parent even being there.
I wonder how this relates to your general field of vision as from my own experience a dyslexic can have a very narrow field of vision.
See also: New Clues to Understanding Attention Deficit Hyperactivity Disorder in Children, Left blind-spot ‘gives ADHD clue’
Examining the relationship between rightward visuo-spatial bias and poor attention within the normal child population using a brief screening task
Asymmetric deterioration of spatial awareness with diminishing levels of alertness in normal children and children with ADHD
Spatial awareness, alertness, and ADHD: the re-emergence of unilateral neglect with time-on-task.
We know that visual noise is harder for dyslexics to cope with than non-dyslexics. Now a new study looks at learning and visual noise. Participants were trained on a visual orientaton task with either a clear display or a noisy display.
Clear and Noisy Displays
They then were swapped so those trained on the clear display used the noisy one and vice versa. The clear-to-noisy participants continued to improve despite the visual noise but those going from noisy-to-clear improved less. The researchers speculate that by learning in a clear environment the brain directly improves the underlying skills required. Where as in a noisy environment the noise acts as a handicap, limiting the brains potential for improvement. When placed in the clear environment the handicap is carried over because the underlying skills haven’t been improved as much. This suggests that learning should take place in a simple environment even if this doesn’t reflect how the skills will be learnt in real life.
For example, learning to drive. Even if you start learning on a quiet road there are still curbs, signs, trees and parked cars to deal with whilst you learn to master the accelerator, brake and steering. If instead you learnt the basics in a huge, completely empty car-park, then when you go on the road, you will be better at handling the controls than if you had spent the same amount of time learning on the road.
This suggests that even though we expect children to be able to read and work in a noisy classroom environments, the learning of key reading skills should take place in the quietest, simplest environment possible,
Full Text: Perceptual learning in clear displays optimizes perceptual expertise: Learning the limiting process
Coverage on the University of Southern California web site
That what we see effects what we hear is clearly demonstrated in the McGurk effect (Hear My Voice, Read My Lips) and other experiments (see Integrated Senses). Dr. Deborah Zelinsky’s Mind-Eye Connection is a doctor of optometry and runs a treatment centre in Northfield, Illinois, USA that goes ‘beyond traditional vision care‘. There are no details of how the treatment works though Dr Zelinsky has two books available from the website but I can’t find them listed on Amazon. There is also a good list of links to vision related resources.
We all treat our senses as being distinct from each other, vision is different from hearing, smell is different from touch and so on. Only when talking about smell and taste do we expect some overlap in our senses. However this view of our senses appears not to be the case.
In a 2001 paper, Sensory modalities are not separate modalities: plasticity and interactions [PDF], the researchers review research in to this area. They highlight the effects sound can have on vision in the form of the McGurk effect (see Hear My Voice, Read My Lips) and other experiments. This includes a study that found that when trying to judge which of two lights came on first, sounds before or during the process made an impact on accuracy.
This work emphasizes the role sensory integration plays in our brain functions and reinforces treatment programmes that utilise a multi-sensory approach.
See Rhythm and Dyslexia and Sense Round-Up.
Its obvious that if a child has poor eyesight they will struggle in school. This is why many concerned parents’ first steps is to have their child’s eyes examined. Unfortunately visual acuity (what is tested using the standard ‘can you read the bottom line’ eye-test) is not the only visual problem that can effect learning. In the 1996 study The Vision Screening of Academically & Behaviorally At-Risk Pupils, published in the Journal of Behavioral Optometry, the researchers put eighty one ‘at risk’ students through a battery of tests. The students ranged from elementary school pupils to high school pupils. Thirty three of the students were in special or alternative schools due to their behavioral problems. The remaining students were in mainstream education. All students were considered ‘at risk’ of unsatisfactory academic achievement. The test involved:
Tracking: the ability to move the eyes across a sheet of paper
Fusion: the ability to use both eyes together at the same time
Acuity-Distance: visual acuity (sharpness, clearness) at 20 feet distance
Stereopis: binocular depth perception
Acuity-Near: near visual acuity for a short distance (specifically, the reading distance)
Convergence: the ability of the eyes to move and work as a team
Hyperopia: a refractive condition that makes it difficult to focus, especially at near viewing distances
Color Vision: the ability to differentiate colors
Visual Motor Integration: the ability to transform images from a vertical to a horizontal plane
Out of all the students, 85% failed at least one test and of the thirty three alternatively schooled students, 97% failed one or more tests. Over a third failed the tracking test, a vital skill in reading. With these results it is obvious that visual problems are prevalent in under-achieving children. So if you are having your child’s eye-sight checked, talk to the optometrist or optician about what is actually being tested and insist that tracking, stereopis and visual motor integration are covered.
See also: Visual Field Testing, Vision & Reading, ADD/ADHD, VISION & LEARNING
There is a strong link between sensitivity and educational problems. This is most apparent for children in the autistic spectrum where certain noises or being touched in particular places can generate extreme effects. (See The Senses of Autism, Background Noise, Dysleixa and Earobics, Cocktail Party Deafness, Visual Noise Hard for Dyslexics to Cope With).
This study, Dynamic sensory sensitivity and children’s word decoding skills, looked at ten year old children who had not been diagnosed as having any learning difficulties. They were trying to establish if better hearing and better visual skills were correlational to better spelling and reading. The found that “The results suggest that children’s sensitivity to both dynamic auditory and visual stimuli are related to their literacy skills. Importantly, after controlling for intelligence and overall reading ability, visual motion sensitivity explained independent variance in orthographic skill but not phonological ability, and auditory FM sensitivity covaried with phonological skill but not orthographic skill. These results support the hypothesis that sensitivity at detecting dynamic stimuli influences normal children’s reading skills. Vision and audition separately may affect the ability to extract orthographic and phonological information during reading.”
So how effective your sight and hearing are affects your ability to learn to read and spell. In people with learning difficulties it may be that they are oversensitive to some things and under-sensitive to others. This might prevent them hearing the difference between a ‘f’ sound and a ‘th’ sound or it may mean they cannot ignore the sound of other children talking. Either way, they are not getting the proper signals that normal child use when learning.
One of the researcher on this paper was Joel B. Talcott who also worked on the paper covered in Walk Like A Dyslexic. He also done work on visual skills of dyslexics: Visual motion sensitivity in dyslexia: evidence for temporal and energy integration.
Following on from The Senses of Autism, here is a round up useful links.
Sense-Think-Act has a range of articles about your senses and how to improve them.
As a medical or educational problem, there are a range of approaches and names to sensory problems in autism and as a problem in its own right. To quote from the web siteSensory Processing Disorder “Sensory Processing Disorder (SPD) is a complex disorder of the brain that affects developing children and adults. People with SPD misinterpret everyday sensory information, such as touch, sound, and movement. They may feel bombarded by information, they may seek out intense sensory experiences, or they may have other symptoms.”
The problem is also called Sensory Integration Dysfunction which Wikipedia defines as: “Sensory Integration Dysfunction is a neurological disorder causing some people to have difficulties in integrating information coming in from each of their five senses. Sensory integration disorders span a wide range of neurological conditions, including autism spectrum disorders, dyslexia, pervasive developmental disorder, multiple sclerosis and speech delays, among many others“. A collection of articles on the subject.
On Amazon, The Out of Sync Child by Carol Stock Kranowitz is highly regarded. The book also has a web site.
Sensory Resources offer a range of book and videos about sensory integration.
One of the defining aspects of autism is how autistic children react to different stimuli. Some children find being touched highly disturbing or particular noises may set off screaming fits. This article: Ideas on Autism: Building sensory communication with your child from PregnancyAndBaby.com explores how autistic child develop their own sensory preferences and how a parent can observe and use this information.
This hypersensitivity can evident in people with aspergers, dyslexics, ADHD and indeed normal people (see Hearing Things). It is sometimes known as Sensory Integration Dysfunction and sensory integration training has been an effective form of treatment. Such hypersensitivity might not be just limited to the five senses: sight, hearing, taste, touch and smell. In addition to proprioception, the awareness of where your limbs are) there are internal senses known as Interoceptors. These tell you how full your bladder is, if you are thirsty or how hot you are. Rather than five senses we may have twenty one or more. This is a relatively new area of research but when trying to understand an autistic child’s behavior its worth remembering that the way they sense the world around them and what inside them is unlikely to be the way you do.
Back in August we reported on a new font called Read Regular that was designed specifically for dyslexics. In the font, the letters a subtly different so, for example, b and d are not mirror images of each other. The idea being that it makes each letter more distinct and easier to read.
Now the Chrysalis Book Group are publishing books using this font. The Read Regular web site has very little on it so there is no evidence that this font actually helps. It would be nice to see controlled trials of reading speeds using this font. Regardless of this, it is good to see publishers considering the problems of dyslexics when creating books.
Sensory Integration refers to the hyper or hypo sensitivity to light, sound, touch etc that is especially common in autistic children (Sensory Integration Dysfunction). As a treatment method, sufferers are exposed to gentle stimulation of the senses in a process of systematic desensitization.
Medical News Today is carrying a story about a study that used sensory integration methods with ADHD suffers.
“‘Many children with ADHD also suffer from sensory processing disorder, a neurological underpinning that contributes to their ability to pay attention or focus,’ explained Koenig. ‘They either withdraw from or seek out sensory stimulation like movement, sound, light and touch. This translates into troublesome behaviors at school and home… …Therapy techniques appeal to the three basic sensory systems: The tactile system controls the sense of touch, the vestibular system controls sensations of gravity and movement, and the proprioceptive system regulates the awareness of the body in space. Therapy is tailored to each child’s needs and can involve such techniques as lightly or deeply brushing the skin, moving on swings or working with an exercise ball.
‘We found significant improvement in sensory avoiding behaviors, tactile sensitivity, and visual auditory sensitivity in the group that received treatment,’ said Koenig. ‘The children were more at ease. They could better attend to a lesson in a noisy classroom, or more comfortably participate in family activities,’ said Kinnealey. ‘The behavior associated with ADHD was significantly reduced following the intervention.’”
The text of the study, Comparative Outcomes of Children with ADHD: Treatment Versus Delayed Treatment Control Condition, is not yet available.