Temple Grandin, the world's most famous person with autism, is a "savant" who is known for her exceptional nonverbal intelligence, spatial reasoning, sharp visual acuity, and an uncanny gift for spelling and reading. Now, looking to understand how she is able to perform such amazing cognitive feats, a group of neuroscientists have taken a deeper look into Grandin's mind. And not surprisingly, they've discovered a brain that doesn't function like most people's.
The details of the study were made public at the recently concluded 2012 Society for Neuroscience's annual meeting in New Orleans. To conduct their research, the neuroscientists gave Grandin a series of psychological tests and scanned her brain using several imaging technologies.
Writing in SFARI, Virginia Hughes goes over the details of their presentation:
Grandin's brain volume is significantly larger than that of three neurotypical controls matched on age, sex and handedness. Some children with autism have abnormally large brains, though researchers are still working out how head and brain size changes across development.
Grandin's lateral ventricles, the chambers that hold cerebrospinal fluid, are skewed in size so that the left one is much larger than the right. "It's quite striking," Cooperrider says.
On both sides of her brain, Grandin has an abnormally large amygdala, a deep brain region that processes emotion. Her brain also shows differences in white matter, the bundles of nerve fibers that connect one region to another. The volume of white matter on the left side of her brain is higher than that in controls, the study found.
Using diffusion tensor imaging, the researchers traced white-matter connections in Grandin's brain. They found what the researchers call "enhanced" connections - defined by several measures including the fractional anisotropy, or integrity, of the fibers - in the left precuneus, a region involved in episodic memory and visuospatial processing.
Grandin also has enhanced white matter in the left inferior fronto-occipital fasciculus, which connects the frontal and occipital lobes and might explain her keen visual abilities, the researchers say.
At the same time, however, the researchers also noticed some impairments, including "compromised" or weak connections. For example, she has a weak left inferior frontal gyrus, which includes Broca's area for language. And as Hughes notes, she also shows compromised connections in the right fusiform gyrus, a brain region involved in processing faces.
It would seem, therefore, that there's a tradeoff when it comes to being a savant, or someone with significant cognitive skills. But as Grandin would likely be the first person to admit, that doesn't necessarily imply a disadvantage or impairment — merely a neurological brain-type that's different.
Image via SFARI.