September 08, 2009
Brain scanning unborn babies:
I've just had pick my jaw up from the floor after reading an article on the brain scanning of unborn babies. I was idly wondering whether anyone had attempted to do an MRI scan of the fetal brain only to find that researchers are so advanced that they can do almost any sort of adult neuroimaging on the fetus - including psychological studies of brain activation.
One of the main difficulties with brain scanning unborn babies is that they move about a lot. You can asks adults and children to stay still, but fetuses are a little bit harder. One of the major advances in the field has been the development of algorithms to reconstruct high definition scans from blurred images.
Researchers have also completed diffusion scans that can create 3D maps of the white matter 'cabling' of the brain in the unborn baby, as with a recent study [pdf] on how brain connections develop during gestation. Recent studies have similarly been able to measure developing brain metabolism and examine how the size and shape of specific areas change during pregnancy.
But most amazingly, several studies have conducted functional MRI experiments on fetuses. In other words, they measured neural activity in specific brain areas in response to specific experiences.
The two scans on the right are from a 2008 study that looked at whether unborn babies at the 33rd week of development would show brain responses to sound in their auditory cortex, part of the temporal lobes. The researchers simply put headphones on the belly of the pregnant women and scanned while they played tones.
The top scan is from an adult, while the one from the bottom is from one of the fetuses, showing clear and selective activity the auditory cortex nearest the sound source.
I was completely blown away by that, and researchers are continuing to develop new and intriguing ways of presenting experiences to the fetus (such as shining lights through the belly to look for visual brain responses!).
Link to PubMed entry for paper on brain scanning fetuses.
