Developing tests requires a large number of subjects. Several dozen have been tested in Tucson, Baltimore and Atlanta. Nadel is creating a fixed battery of nine or 10 tests that can be useful worldwide.
The test battery has to be precise in its ability to tell researchers about a particular brain structure. Three of these tests are targeted as assays, like blood tests that detect the presence of blood sugar. Performance on a cognitive test indicates how well the subject's hippocampus or the prefrontal cortex, another structure thought to be compromised in Down syndrome, are functioning.
"The battery has to be designed to be quite specific to only assay one particular structure and not be affected by the function of other structures," Nadel said.
"They have to be targeted and precise. They also have to be fairly short. All kids have a short attention span, so we want tests that are precise and targeted and short. They typically are computer based, but not always.
"They also are portable. We want to be able to test not only on kids or individuals who can make it into a university or hospital laboratory, but in schools and homes," he said.
Nadel said a number of criteria constrain the development of this battery but the goal is to have something that is repeatable, to test subjects initially and then bring it back a month later and still get reliable results.
Down syndrome also cuts across languages and cultures, so tests have to work the same way anywhere in the wor
|Contact: Lynn Nadel|
University of Arizona