Sophisticated brain imaging technology is now making it possible to directly observe the brain at work and to detect subtle malfunctions that could never be seen before. Other techniques allow scientists to study the points of contact among brain cells and the ways signals are transmitted from cell to cell.
With this array of technology, NIMH is conducting research to identify which parts of the brain are used during certain activities, such as reading. For example, researchers are comparing the brain processes of people with and without dyslexia as they read. Research of this kind may eventually associate portions of the brain with different reading problems.
Clinical research also continues to amass data on the causes of learning disorders. NIMH grantees at Yale are examining the brain structures of children with different combinations of learning disabilities. Such research will help identify differences in the nervous system of children with these related disorders. Eventually, scientists will know, for example, whether children who have both dyslexia and an attention disorder will benefit from the same treatment as dyslexic children without an attention disorder.
Studies of identical and fraternal twins are also being conducted. Identical twins have the same genetic makeup, while fraternal twins do not. By studying if learning disabilities are more likely to be shared by identical twins than fraternal twins, researchers hope to determine whether these disorders are influenced more by genetic or by environmental factors. One such study is being conducted by scientists funded by the National Institute of Child Health and Human Development. So far, the research indicates that genes may, in fact, influence the ability to sound out words.
Animal studies also are adding to our knowledge of learning disabilities in humans. Animal subjects make it possible to study some of the possible causes of LD in ways that can’t be studied in humans. One NIMH grantee is researching the effects of barbiturates and other drugs that are sometimes prescribed during pregnancy. Another researcher discovered through animal studies that certain prenatal viruses can affect future learning. Research of this kind may someday pinpoint prenatal problems that can trigger specific disabilities and tell us how they can be prevented.
Animal research also allows the safety and effectiveness of experimental new drugs to be tested long before they can be tried on humans. One NIH-sponsored team is studying dogs to learn how new stimulant drugs that are similar to Ritalin act on the brain. Another is using mice to test a chemical that may counter memory loss.
This accumulation of data sets the stage for applied research. In the coming years, NIMH-sponsored research will focus on identifying the conditions that are required for learning and the best combination of instructional approaches for each child.
Piece by piece, using a myriad of research techniques and technologies, scientists are beginning to solve the puzzle. As research deepens our understanding, we approach a future where we can prevent certain brain and mental disorders, make valid diagnoses, and treat each effectively.