Hearing Disability Linked To Poor Touch Sensitivity

Touch and hearing are very distinct, but German scientists have found a possible genetic link between the two sensory systems.

Superficially, the two senses might seem worlds apart, but both rely on the ability to translate motions - vibrations in the ear and movement and pressure on the skin - into signals to the brain. A common set of molecules or mechanisms might be at work.

To determine if touch sensitivity can be inherited genetically, Henning Frenzel of the Max-Delbruck Center for Molecular Medicine and his colleagues first examined 100 pairs of fraternal and identical twins in a study outlined in the journal PLoS Biology.

They tested the twins on two kinds of touch sensitivity traits: "vibration detection threshold," or how low a vibration the subject could detect with their pinky finger; and "tactile acuity," or the ability to distinguish between two pressure points on the skin that are very close together.

Since the identical twins are genetically identical and the fraternal twins share up to 50 percent of the same genes, any genetic effect on touch should be more pronounced in the former.

Next, Frenzel and his team calculated the heritability of the two traits, a figure that explains the degree to which genetic variation contributed to the variation in the traits seen in the subjects. On average, 28 percent of the differences in tactile acuity and 52 percent of the differences in vibration detection could be chalked up to genetic influence.

Second Experiment
In a second experiment, the scientists found that some - but not all - of a population of young people that were born deaf also had impaired tactile acuity. But since there are about 70 known genes that are involved in hearing impairment, the researchers wanted to focus on a smaller group of genes to test the link between hearing and touch impairment.

Third Experiment - Usher syndrome
The scientists next examined patients with Usher syndrome - a hereditary condition that causes both hearing and visual impairment. They zeroed in on USH2A, one of the nine known genes that, when mutated, cause Usher syndrome.

Of the Usher patients studied, the 19 individuals that had a mutation in USH2A had both impaired hearing and poor touch sensitivity. It's possible then, that this gene may play a role in both touch and sound.

"Our next task will be to investigate some of these other cases to see if they are also correlated with problems in touch," senior author Gary Lewin said in a statement Tuesday. "This will give us a better understanding of the genetic mechanisms that underlie both types of perception."

Dyslexia - Multi-sensory Learning

We are creatures of great sensitivity and have the ability to understand things from many perspectives. The most effective teaching method for children with learning differences is to engage a multisensory approach. Multisensory teaching strives to utilise all the child's senses, to relay information or convey meaning to the students.

The teacher accesses the auditory, visual, and kinesthetic pathways to enhance memory and learning because they know that by using as many sensory paths as possible the more likely that the message will be understood and be absorbed.

For example, when learning the vowel combination “oa” the student might first look at it and then have to trace the letters in the air while speaking out loud.

This combination of listening, looking, and moving around creates a more lasting impression for the student. Relationships and connections between items and events, will become more memorable and concepts can be built up.

Multisensory learning started back in the 1920s by Dr. Samuel Orton at the Mobile Mental Health Clinic in Iowa. Dr. Samuel Orton, one of the first to recognise, what we now call 'dyslexia' in students.

He suggested that teaching the “fundamentals of phonic association with letter forms, both visually and kinesthetically presented and reproduced in writing, until the correct associations were built up,” would be the best learning approach for students of all ages.

Dr. Orton had his patients trace, copy, and write letters whilst saying their corresponding sounds and associations. Today this method is known as multisensory learning.

Children experiencing dyslexia often struggle with auditory and/or visual processing. They have trouble recalling words and how they are pronounced. This means that they do not comprehend the roles that sounds play in words.

These children have difficulties rhyming words as well as blending sounds together to form words. Children who experience dyslexia, do not understand or acquire the alphabetic code. They are unable to grasp and retain the 'simple' repetative learning and memorising systems expected of them in the primary grades.

If a child with dyslexia is given a task that uses just hearing and vision, without drawing upon other senses, the student will be at a disadvantage. When taught with a multisensory approach, children will learn alphabetic patterns and words by utilising all pathways – hearing (auditory), seeing (visual), touching (tactile) and moving (kinesthetic).

Dyslexic students do not need more of the same instruction in class but a different type of instruction. They need to learn basic language sounds and the letters or letter combinations, that are used to make them. Becuase you are engaged in a building process, you need to starting from the very beginning and move forward in a gradual but logical, step by step process, which builds on the previous step.

For this to be retained, the children need to be taught to do this by using their eyes, ears, voices, and hands. We are a sensitive multi-talented creature that enjoys stimulation, challenge and achievement. Children experiencing Dyslexia are no different from the rest of us. They need to be stimulated, challenged and be able to feel that other great sense, the sense of achievement. Something we all crave and enjoy when we succeed in learning a new skill.

Conficious Proverb
Tell me, and I will forget.
Show me, and I may remember.
Involve me, and I will understand.

Dyslexia Untied: The Importance of Good Eyesight

Unfortunately, 20% (1 in 5) of all school age children have undetected vision problems. Don't panic! Not all of these are acute or permanent and not all are detrimental to the child's development but there are a number of issues that need to be addressed, as soon as possible (ASAP).

If your child has an undetected, undiagnosed or undefined vision problem, they can appear to demonstrate symptoms or behaviours that can be mistaken for dyslexia, but only superficially. Consultation with a qualified expert in the field will dispel or confirm this concern. Rapid intervention is important.

The worst case, and possibly your worst fear, is that your child does have dyslexia and their vision problems are making it more difficult.

Regular Eye Checkups
It is important for all young children that their eyesight is checked regularly and corrected accordingly. It is more important than for adults and older children, because the younger child may be growing and developing at a much quicker rate.

Unfortunately, even if you get your child's eyesight checked as part of a normal screening process, there is a possibility that the average optician will miss the telltale signs of dyslexia, unless it is brought to their attention. It falls back on the parent to be more aware and to be more insistant or assertive, on behalf of their child(ren).

Symptoms to look for
Symptoms that are often associated with Dyslexia can be as obscure as the slight tilt of the head when trying to read or follow words in a text or book. More complex issues are;

• Amblyopia (lazy eye) - When one of your child's eyes doesn't work as well as the other. 3% 0f children under the age of 6 are reported to have Amblyopia. Treatment: eye exercises, eye patch, etc. Long Term: If it's not treated early it can lead to poor vision into adulthood.


• Strabismus (deviating eyes) - When your child's eyes appear dis-coordinated and don't look towards the same object, together. It may be a fixed or permanent defect or it may only be temporary and brought on by stress and tiredness. Either way you should seek qualified expert advice.

These conditions are not rare and neither is the situation whereby your child has the 'normal' 20/20 vision but is having difficulties in sustaining their gaze, co-ordinating their eyes, holding and varying their focus, when objects move closer and away from them.

Scotopic Sensitivity Syndrome - Some children with Dyslexia have difficulty tracking words and letters along a line or sentence. This is known as Scotopic Sensitivity Syndrome, a known issue that can be addresed separately. The Irlen Method of treatment concentrates on this specific issue.

If you have concerns, take this up with your doctor or with a qualified optometrist or opthamologist. The qualifications of the local high street franchise opticians can vary quite dramatically. Check their credentials.

Early detection and diagnosis is important in all childhood issues and none moreso than in vision and hearing, as these can very much affect the child(dren)'s development, education and behaviour.

Summary

Don't Panic! The majority of Dyslexia consultants and experts will agree that vision problems 'alone' do not cause or lead to the onset of Dyslexia but it does complicate the situation for the child(ren), the family and the teachers.

Therefore, the message here is; be aware of the impact that vision has on the development of the child and their well being and importantly, early detection, diagnosis and correction or treatment by qualified experts, is essential.