1.   A larger study is needed to make sure that this excess is a chance finding.

2.   But it can be tricky to infer brain functions from such chance findings because the destroyed areas may be only indirectly affecting a function like reading.

3.   Over the last half century, researchers have studied that and other chance findings, divining how the drugs interacted with the brain to produce their effects.

4.   The analysis, however, showed if anything a slightly higher risk of breast cancer in that group, though researchers said that was probably a chance finding.