Objectives: The objective of this study is to begin to elucidate the neuroanatomical and functional basis of Dr. Grandin’s cognitive strengths and weaknesses.
Methods: 3-Tesla anatomical, diffusion tensor, and functional MR imaging was performed on Dr. Grandin and compared to three female age-matched controls (Dr. Grandin age 61.3 years; controls mean age 62.3 years, range 59.1 to 67.9 years). MP-RAGE, T2-weighted anatomical, 12-direction DTI, and functional MRI (visual language, auditory language, resting state, and music) data were collected on all participants. Measures of total and regional brain volumes, cortical thickness, white matter microstructure, and functional (BOLD) differences were analyzed.
Results: Compared to the controls, Dr. Grandin had increased (greater than 2 standard deviations above control means) intracranial volume, and volumes of the left lateral ventricle, left hemisphere white matter, right amygdala, left cingulate, and entorhinal cortex. Her left lateral ventricle was 57% larger than her right. Cortical thickness was increased (greater than 2 standard deviations above the control mean) in entorhinal cortex. Fractional anisotropy was decreased in the white matter of her left posterior/superior temporal and inferior parietal regions. In contrast to controls, fMRI activation was significantly increased (q<0.05, FDR) in her bilateral parietal cortices during the visual language task. Activation was also significantly increased (q<0.05, FDR) in the medial prefrontal cortex, mPFC (especially in the pregenual right anterior cingulate), while she listened to her favorite song, Led Zeppelin’s Stairway to Heaven, compared to her resting state brain activity.
Conclusions: These fascinating findings suggest that differences found in white matter microstructure in her parietal lobe, especially at its junction with the temporal lobe, might account for the difficulties in working memory that Dr. Grandin reports. Increased activation in the mPFC suggests that she might be experiencing more self-reflection while listening to her favorite song than while resting. Past research has implicated the mPFC in self-reflective cognition. Her increased intracranial volume is consistent with the 20% rate of macrocephaly in autism. Dr. Grandin and the control participants will undergo neuropsychological testing that will provide further neuroscientific insights into her cognitive functioning and suggest new interventions to help improve the lives of more globally impaired children and adults with autism.
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