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· Arousal · Hearing · Posture · Sleep · Vision
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Laterality
Note · The title of this page was originally titled cross dominance. In addition to cross dominance, it also contains information about mixed laterality · Cross dominance is also referred to as mixed dominance and cross laterality. · The words dominance and laterality are used on this page interchangeably.
· Problems with Lateralisation · Mixed Laterality or Lateral Confusion · Hemispheric Language Dominance · Correcting Hemispheric Dominance · Unilateral Nostril Breathing · Discomfort caused by Covering One Eye · Services · Hemispheric Communication, Cross Dominance, and Binocular Function · Binocular Convergence and Photophobia
There are several topics on this page which are not merely applicable to laterality, but are applicable to other conditions as well. An example is the section entitled Hyperacusis, Recruitment, and Hyperacute Hearing. Although this section was included on this page, people without laterality issues may have a condition like hyperacusis. Even if you don't have laterality issues, or if you don't believe that mixed or cross laterality is causing problems, there may be useful information on the this page.
Lateralisation What is Lateralisation? "Lateralisation refers to development of lateral dominance (right or left eye, ear, hand, leg) and development of specialised centres and functions in the left and right brain hemispheres. The right side of the body sends messages to and is controlled by the left side of the brain, and the left side of the body by the right side of the brain. Differentiation is a precursor to the development of lateralisation. The ability to cross one’s midline is also a necessary component for mature lateralisation."
Unilateral Cerebral Dominance "Most people develop unilateral cerebral dominance - that is their dominant eye, ear, hand and leg are on the same side of the body."
Mixed or Cross Dominance/Laterality "Approximately 20% of the population has mixed dominance or other irregularities in the development of dominance. Those irregularities of dominance that are the most difficult to resolve without therapeutic help involve alternating reliance on one side or the other without conscious decision to do so [mixed dominance/laterality]. Such children will use first one hand when writing and then the other, for example. This causes instability in perception and performance. Immaturities and irregularities in lateralisation can cause perceptual, organisational and performance problems in all areas of life."
"The following are issues that may occur in a person experiencing difficulties with lateralisation:
∙ Delayed decision of lateral dominance
∙ Tendency to scatter and misplace objects in personal space
∙ Extreme rotation of writing or reading surface
∙ Unusual tip of the head while writing (30-40 degree tip usually indicates crossed dominance between eye and hand)
∙ Difficulty perceiving left and right sides of objects and letters
∙ Uncertainty about personal left and right body sides
∙ Tendency to move toward the non-dominant hand in motor activities
∙ Need to rotate surfaces to complete motor activities that cross the midline
∙ Difficulty making decisions
∙ Difficulty accepting a change in a rule or decision once it is made.
∙ Excellent batting in cricket or baseball but difficulty with many other sports."
"Your foot, eye, and ear should be dominant on the same side as your dominant hand. If one or more is not, you have mixed dominance issues." Katherine's Page: Mixed Dominance
"If an individual has no dominance or is mix-dominant after the age of 7, dominance will not be established without specific intervention. Some individuals may be able to compensate for lack of dominance, but the fact is that to be neurologically efficient, establishing dominance will make organizing information learned visually and auditorily much easier. An analogy would be a filing system. An individual with dominance established has an orderly filing system and can retrieve information easily and efficiently. An individual without dominance has trouble retrieving information, especially when he gets emotional."
Mixed
Laterality or Lateral Confusion There seems to be some confusion (no pun intended) about the definition of mixed dominance. According to some sites, mixed dominance is synonymous with cross dominance. Others use it synonymously with mixed laterality. Mixed laterality is defined as:
"Tendency to perform some acts with a right side preference and others with a left, or the shifting from right to left for certain activities.(10)" Glossary of Learning Disabilities Terms
At the moment, I'm not absolutely sure which definition of mixed dominance is being used by the sites which I have referenced on this page. I had assumed that they were using the term mixed dominance synonymously with cross dominance.
As far as mixed laterality is concerned, I have read that it is perfectly normal to use your other hand under some circumstances. For instance, I believe it's common for right-handed mothers to hold their babies with their left arm.
I've also read that no one is truly ambidextrous. I believe there is a test for determining if you are left or right hand dominant.
People with mixed laterality might have an aversion to exercises such as walking and running because these exercises tend to strengthen both sides of the body equally. Compensating for these exercises, by spending additional time strengthening your dominant hand and the foot that is on the same side as the dominant hand, may be helpful. It also may be helpful to squeeze your dominant hand while exercising.
"The hand is the best way to determine which is your dominant side. It almost never gets confused unless you lose your dominant hand, or lose the use of your dominant hand. (That is why it is so detrimental to force a left-handed person to use his/her right hand. It really messes with the brain.) NACD tells me that they have never once run across a truly ambidextrous person – every single case they have seen, without exception, was actually a case of mixed dominance." Katherine's Page: Mixed Dominance
http://www.golfalot.com/lucylocket/cross.shtml
"Note which ear the individual uses for the telephone, which ear does that individual turn towards you to hear more clearly, to which ear does that individual bring an object to hear slight sounds like a watch."
Note: Foot dominance is sometimes referred to as 'footedness'. "The foot. When you go to kick a soccer ball, you generally lead with your dominant foot. You might have to observe yourself or your child over a period of time to be certain which foot is actually dominant." Katherine's Page: Mixed Dominance
Description "Picasso also provides a good example of another laterality, leg-crossing. Most people sit in a chair with one leg crossed over the other, and for most people this tends to be with right leg over the left, at least at first until the legs begin to ache when people will cross the other way. Leg-crossing seems to be constant through life, and there are pictures of Picasso taken in 1939, 1948, 1952, 1954 and 1957, in each of which he sits with the left leg crossed over the right. Leg-crossing is statistically related to handedness (Reiss, 1994) and should not be confused with the 'palthi' style in India of sitting cross-legged on the ground, where the palms of the feet point upwards (Chaurasia, 1976)." RightHandLeftHand.com: Chapter 7: Hypernotes
Related Topics Mixed Laterality and Muscle Tension
Hemispheric Language Dominance Left Hemisphere "In most people the left hemisphere [and the right ear] of the brain is dominant for language." Handedness and hemispheric language dominance in healthy humans.
Right Hemisphere Because of the increased incidence of atypical right-hemispheric language in left-handed neurological patients, a systematic association between handedness and dominance has long been suspected…The incidence of right-hemisphere [and left ear] language dominance was found to increase linearly with the degree of left-handedness, from · 4% in strong right-handers…to · 15% in ambidextrous individuals and · 27% in strong left-handers" Handedness and hemispheric language dominance in healthy humans.
Listening to dialog with the ear which _should_ be dominant may be helpful in correcting ear dominance if the language center of the brain is located in the more mature or dominant hemisphere of the brain.
Change in Chewing-Side Preference May Cause TMD "Here we can see a patient whose usual chewing side is the left side, but he has changed it to the right side due to a pain in the molars (see orthopantomography). This change has caused occlusal interferences (CP), which at the same time force the malpositioning of the jaw producing TMD symptoms" Change in side of chewing due to pain in the molars to come out
Hemispheric Dominance of Tongue Control "The results suggest that there is a relationship between hemispheric dominance and chewing-side preference in primary sensorimotor cortices responsible for tongue movements." Hemispheric dominance of tongue control depends on the chewing-side preference.
If you don't participate in activities that require the use of your dominant hand, it's a good idea to exercise your dominant hand regularly. I have found that squeezing 'stress' balls is helpful. More information about hand dominance can be found in the section Handedness
Correcting Hemispheric Dominance Note: Blocking the vision in one of your eyes for a long period of time (i.e. more than 6 hours per day) may cause vision problems.
According to Dr. Fredric Schiffer, the creator of Dual-Brain psychology, for some individuals one hemisphere of the brain is more mature than the other. Under these circumstances he refers to the hemispheres as being mature and immature.
Anxiety can cause the immature hemisphere of the brain to become dominant.
Reestablishing the more mature hemisphere's dominance may be accomplished using a pair of right visual field goggles periodically if your mature hemisphere is your left hemisphere, and the opposite if your more mature hemisphere is your right hemisphere.
Dr. Schiffer's goggles are described in his book The Revolutionary Science of Dual Brain Psychology.
His design blocks one eye completely, and also blocks the inner half of the other eye. It is very effective for stimulating activity in the opposite hemisphere. However, it is also difficult to see while wearing his goggles.
An alternative would be to only block one eye [monocular vision]. This design would be less of an obstruction, but it would not be as effective as Dr. Schiffer's design.
For more information about Dual-Brain psychology please visit the Dual-Brain Psychology page.
"Relative nostril efficiency (nasal cycle) is related to hemispheric EEG differences and performance on cognitive tasks. We investigated how unilateral forced nostril breathing influences spatial and verbal performance. Right-handed males and females performed both tasks under either left-nostril, right-nostril, or free-breathing conditions. Unilateral breathing affects performance differently in males and females. It influences male performance ipsilaterally on both tasks: Their spatial performance is better during right-nostril breathing, and their verbal performance is better during left-nostril breathing. Unilateral breathing influences female performance contralaterally, but only on the spatial task: Their spatial performance is better during left-nostril breathing. These differences within and between sexes may exist because unilateral nostril breathing differentially activates the two hemispheres and thereby facilitates performance, or because attempts of the brain to control the nasal cycle unilaterally interfere with performance." Brain Cogn.: Unilateral nostril breathing influences lateralized cognitive performance
"In an interesting twist, Josh Backon, a member of the Department of Cardiology, The Hebrew University of Jerusalem, writes in an Internet posting…that in order to increase left-hemisphere activity (linear, language, logical), one can block the left nostril and engage in 'forced unilateral nostril breathing.' Likewise, to increase right-hemisphere activity (creative, holistic, emotional), the right nostril should be blocked. This practice increases the supply of negative ions to a specific hemisphere." Comtech Research: Some Scientific Research
Vision Suggestions: Binocular Functions: Amblyopia
Discomfort caused by Covering One Eye The author of the article 'Mixed Dominance' (which was referred to in the Warning, Other Suggestions section) suggests covering one eye with an eye patch to correct cross eye dominance. Today there are alternatives to eye patches, such as glasses with frosted lenses. The restricted field of view caused by blocking one eye can cause anxiety. This anxiety can cause a decrease in hemispheric communication, which may exacerbate binocular dysfunction. To compensate for this, I would suggest some form of vision therapy, such as the Bates Method. I believe that the Bates Method exercises increase hemispheric communication. Improved hemispheric communication may help to alleviate binocular dysfunction.
Hopping Exercise Note:The hopping exercise mentioned in this section can place a lot of stress on your knee. Perhaps another form of exercise may be better. If you do choose to do the hopping exercise, keep your knees bent and try to avoid locking your knees. "NACD had me do “hopping” exercises with my kids when they were little to firmly establish the right foot as their dominant foot – they’d hop on the right foot for 2 minutes, twice a day." Katherine's Page: Mixed Dominance
Things to Avoid The dominant foot is the foot you typically use to balance your weight and should be on the same side of your body as your dominant hand. Avoid supporting the bulk of your weight on the non-dominant foot, for example while sitting. Instead, resting the bulk of the weight on the dominant foot may be beneficial.
Diet "Avoid food additives, chemicals, sweeteners and sugar, Whole grains should be used. Milk should be avoided [ear infections]."
High Frequency Sounds Note: Some people with sound sensitivity may be hypersensitive to high frequency noise. "Lack of good qualty input, that is, excellent language, music, etc, can result in lack of ability in auditory function. There are indications that high frequency sounds stimulate and energize the brain. Low frequency and distorted sounds (like rock and rap music) disorganize and shut the brain down."
The Tomatis Method (I do not recommend this for left handed people) Note: The Tomatis method always encourages right ear dominance. I believe that this is wrong. A left-handed person who is right ear dominant would be cross dominant. I wonder if this method may be causing psychological problems for left handed people, by encouraging their right ear to be dominant. The creator of this method also assumes that it can benefit people with conditions such as ADD and autism. If this method did correct cross dominance, instead of always encouraging right ear dominance, I believe it might benefit people with autismor ADD or some similar condition. However, conditions such as autism can have other causes - some of them physiological in nature, which may not be affected by the Tomatis method. I do not recommend the Tomatis method for left-handed people. However, you may find that the following article contains some useful information.
If you have mixed ear dominance you should avoid loud or disturbing noises. If you play computer games I would suggest turning off the volume.
Since white or pink noise can be used to mask sound, it may be helpful to listen to it with the ear which _shouldn't_ be dominant. The volume of this noise shouldn't be louder than the noises in your surrounding environment. Most people seem to prefer ear plugs instead of listening to white or pink noise. More information about ear plugs can be found in the section Hearing Suggestions: Ear Plugs
If you are experiencing high arousal or hyperactivity, stimulating the ear which _should be_ dominant will only make you more tired. More information about hyperactivity can be found in the section Hyperactivity/High Arousal
Note: · The author of the article 'Mixed Dominance', Katherine Bell is not an expert on the treatment of mixed dominance. · One of the author's suggestions is that mixed ear dominance may be corrected by plugging the offending ear. She specifies that this should only be done for several hours a day, over a period of weeks or months. She also mentions that she is not an expert on this subject. · Chronically plugging one ear permanently impairs some auditory functions. More information about this topic can be found in the section Ear Plugs: Chronically Plugging One Ear "NACD rarely tries to correct dominance issues in normal, high-functioning adults. First, it will drive you crazy to mess with it, so unless it’s causing you a lot of difficulty, you may be better off leaving it alone. Also, the older you are, and the longer you’ve had the problem, the longer it takes to switch it back. But it can be nice to know what the problem is, and if you’re really determined, you can do it." Katherine's Page: Mixed Dominance
Neuropsychological Stimulation, Psychomotor Patterning, New Visions school (Bob DeBoer), Art Sandler (therapist), Neurofeedback The following excerpts are from the book 'A Symphony in the Brain' by Jim Robbins
"As an infant is exposed to sound, for example, neuronal pathways in the brain develop that govern different aspects of hearing, a little at a time. When there is brain damage, those pathways do not form or form improperly. Because function, says DeBoer, builds this structure in the brain, Sandler's program puts a patient through a long and intensive period of therapy that uses repeated movement and sounds and visual exercises to slowly create new pathways in the brain where there were none and to take over for damaged or undeveloped areas."
"Sandler's work [neuropsychological stimulation] borrowed some from a controversial technique called "psychomotor patterning," developed in the 1960s by Glenn Doman and Carl Delacato."
· Correcting Hemispheric Dominance: Lateralized Goggles
Developmental Causes "We are finding that the too early and too complicated activities which are demanded from the senses today cause many children who are right-handed to use their left eye when looking at objects rather than their right eye. This is termed a cross dominance between the eye and hand, displacing the normal laterality of the body.Then, too, there are the growing numbers of children who use the left hand while retaining the dominance of the right eye." Dominance: Its Relationship to Behavior and Learning Difficulties
Slowness in Developing Skills, Concentration "…Activities with normal right-handed orientation are disappearing in our daily living: sweeping, polishing, beating eggs, stirring cakes, repairing, etc. The modern substitutes have become passive rather than active activities. Activities such as sitting and watching TV do nothing to educate the child in using his/her bodily construction in accordance with nature’s plan. The result is slowness in developing skills and weakened powers of concentration. The freedom that technology brings lays on us the responsibility of more consciousness toward the needs of the next generation." Dominance: Its Relationship to Behavior and Learning Difficulties
When we're tired we tend to depend more on the other side of the body. Over time, we may become more dependent on our other eye, hand, foot and ear.
Mixed Laterality and Muscle Tension Mixed Laterality and Muscle Tension: Description The right hemisphere of the brain controls the left side of the body, and the left hemisphere of the brain controls the right side of the body.
As a result: · Tension on one side of the body is associated with an increase in activity in the opposite hemisphere of the brain. · Tension on both sides of the body is associated with an increase in activity in both sides of the brain.
Because of these relationships: · It is important to try to avoid muscle tension on both sides of the body because it may exacerbate mixed laterality. · It is especially important to avoid muscle tension in your subdominant hand, foot, eye, and ear because it may cause or exacerbate cross laterality. Try to avoid habits such as:
· It seems that you could increase acitivity in the hemisphere of the brain which should be dominant by allowing tension in the opposite side of the body. But, obviously, any tension will ultimately lead to fatigue, and more tension. · Instead of allowing the dominant side of your body to be tense, you might want to consider spending some time in a meditative pose, or simply crossing your legs while sitting, with the leg which shouldn't be dominant crossed over the leg which should be dominant.
Mixed Laterality and Muscle Tension: Related Topics
Telephones "A big cause of mixed ear dominance in our day and age is the telephone. Right-handed people tend to always put the telephone to the left ear in order to keep the dominant hand free for writing (and vice versa for left-hander). This is fine for writing; but over time, especially if you have a job that requires you to be on the phone for extended periods, you can inadvertently shift your dominance to the wrong ear. If you find you have a lot of trouble remembering facts you receive by phone, it may be because you’re inputting the information sub-dominantly. Try switching to the ear on the same side as your 'handedness.' You may be able to remember better." Katherine's Page: Mixed Dominance
Vaccinations "There are many parents with whom I have worked that identify vaccinations, especially the MMR, and DPT as the start of their child's troubles. There is much information out there for parents to research on this subject and should be seriously considered."
Distortions, Hypo/Hyper-Auditory Hearing "Listening is an active process and must have good tonal processing. Research has shown that the ability to distinguish sounds and process those sounds can be bad even though the audiogram looks good. Working with many, many individuals that manifest auditory problems, we can see that there are certain frequencies in which a person processes very little information, certain frequencies in which the individual is too sensitive and hence shuts down, and frequencies in which the hearing is distorted and sounds can't be distinguished in a noisy background...everything is a buzz. The autistic child, who has major auditory problems, usually manifest normal or superior hearing across the frequencies, but with extreme distortions. Many of the ADD or ADHD children manifest extreme hypo/hyper-auditory hearing profiles, manifesting both problems in the same individuals"
Hyperacusis, Recruitment, and Hyperacute Hearing
Hemispheric Communication, Cross Dominance, and Binocular Function "Interhemispheric integration refers to the communication between the left and right cerebral hemispheres. To function efficiently, we need to integrate information from various specialised centres and to coordinate a planned response. Efficient binocular functions require interhemispheric integration of the two hemispheres. Children who are cross dominant (e.g. right handed but left eyed) require very efficient interhemispheric integration to compensate for additional demands to integrate information from two competing or differing perceptual and operational modes. Sucking and crawling are two activities of infancy that assist in developing interhemispheric integration. Furthermore, interhemispheric integration is interdependent on differentiation and lateralisation." ILT: “What’s wrong with my child”: Getting to the root causes of learning difficulties
"A person with mixed dominance may have trouble learning things sometimes, this is because their brains have to work a bit differently from others. To interpret information in a brain with a mixed dominance it must travel back and forth between the hemispheres. But it doesn't always cause problems, Einstien and Leonardo Da Vinci both probably had a mixed dominance"
Binocular Convergence and Photophobia "At
issue in this study is functional photophobia, first described by
Lane (1963) as associated with what Kaufman (1963) has called 'variability
[or variation] of binocular convergence.' Functional photophobia is
the most commonly encountered form of glare hypersensitivity in the United
States, and it is an important clinical problem in ophthalmic practice. It
produces discomfort more usually than pain, and much (but not all) of what
is considered "discomfort glare" may be attributed to functional
photophobia" The Functional Photophobia Syndrome and Binocular Fusion in Neuro-Rehabilitation PDF, 116KB
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