Functional Imaging in Fragile X Syndrome Research.

In the Stanford Psychiatry Neuroimaging Laboratory we are trying to learn more about the involvement of different brain regions in cognitive and behavioral features commonly observed in individuals with fragile X syndrome. We are currently exploring brain function involved in:

• Attention and impulse control
• Cognitive interference
• Visual memory (encoding and retrieval)
• Visuo-spatial working memory
• Mathematical reasoning
• Language comprehension and production
• Social anxiety and gaze aversion

These studies will inform us about which brain regions show activation differences between subjects with fragile X and various comparison groups, how brain activation changes with a person's ability to perform the task, under what specific conditions performance begins to fail and what brain regions are involved in these changes.

These brain imaging studies will also address questions regarding the effect of the protein produced by the FMR1 gene in brain function. We hope to use this new information to design new and more effective treatments for persons with fragile X syndrome.

Results from some of our ongoing studies.

Working memory

During a memory task, where subjects must remember the location of objects, compared to normal control subjects, subjects with fragile X have significantly reduced activation in the frontal and parietal brain regions.

Response inhibition

During a response inhibition task, where subjects must with-hold response to particular stimuli, compared to normal control subjects, subjects with fragile X have significantly reduced activation in the prefrontal cortex.

Additonal studies are shown in selected fragile X publications.