Q: What is your opinion of sensory integration dysfunction? My 3-year-old has been diagnosed with this condition and is in occupational therapy to address it. Is this a new fad or something real? Does occupational therapy help? — Via e-mail

A: Sensory integration dysfunction, now called sensory processing disorder, is not a fad.

The occupational therapist and developmental psychologist A. Jean Ayres first wrote about sensory integration almost 40 years ago.

I knew Ayres was onto something. My observations showed me that each newborn has a different tolerance for sensory stimulation. Such differences help make a unique individual — but they can be disabling.

For example, premature babies often are so hypersensitive to sight, sound or touch that when overstimulated they register changes in their vital signs. As children grow, differences in their experience of their senses can affect their behavior and learning.

During the past decade, science has affirmed the disorder. The Sensory Processing Disorder Foundation (www.sinetwork.org) features research as well as information for parents.

To make sense of our world, we must put together what we see, hear, smell, feel and touch, and we start learning to do this at the beginning of life.

Some children are more — or less — sensitive than others to sensation. The differences show up in how children react to, and understand, the information their senses detect.

We now think of sensory processing disorder as a large diagnostic category with three subtypes: sensory modulation disorder, sensory discrimination disorder and sensory-based motor disorder.

All involve some kind of disruption in learning. As a result, children may have trouble understanding about their world. They may react to it in ways that are hard to fathom until the specific challenges are identified.

For example, a child who is hypersensitive to loud noises may have tantrums in response to them. Nobody else may even hear the noises, but everybody notices the tantrum. Another child may not correctly process information that her joints and muscles send about her body’s location in space. As a result, she may be clumsy, bump into things and avoid sports.

For some children, a day with the usual barrage of stimulation from the environment can feel uncomfortable, even traumatizing. They and their parents may be immensely relieved just knowing the source of the problem.

Occupational therapists can help identify the differences in how children’s senses work and how their brains process information from their senses. The therapists can also help children learn how to avoid problem situations and how to cope with those that can’t be avoided.

For more information: “The Out-of-Sync Child,” by Carol Stock Kranowitz. Perigree 2005.

Questions or comments should be addressed to Dr. T. Berry Brazelton and Dr. Joshua Sparrow, care of The New York Times Syndicate, 620 Eighth Ave., 5th Floor, New York, N.Y. 10018. Questions may also be sent by e-mail to:

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