Correlation Between the Wechsler Adult Intelligence Scale- 3rd Edition Metrics and Brain Structure in Healthy Individuals: A Whole-Brain Magnetic Resonance Imaging Study

• Main Authors: Shinsuke Hidese, Miho Ota, Junko Matsuo, Ikki Ishida, Moeko Hiraishi, Yuuki Yokota, Kotaro Hattori, Yukihito Yomogida, Hiroshi Kunugi
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2020-06-01
• Series: Frontiers in Human Neuroscience
• Subjects: gray matter; healthy individuals; Japanese Adult Reading Test; Wechsler Adult Intelligence Scale; white matter; whole-brain magnetic resonance imaging
• Online Access: https://www.frontiersin.org/article/10.3389/fnhum.2020.00211/full

BackgroundThe Wechsler Adult Intelligence Scale, 3rd edition (WAIS-III) is widely used to evaluate the intelligence quotient (IQ). We aimed to investigate the correlation between the WAIS-III metrics and whole-brain structures using magnetic resonance imaging.MethodsThe participants were 266 healthy, right-handed individuals (age: 45.6 ± 12.9 years, 98 males and 168 females). IQs were evaluated using the WAIS-III and Japanese Adult Reading Test (JART). Voxel-based morphometry and diffusion tensor imaging were performed to analyze the correlation of the WAIS-III metrics and JART score with the gray matter volume and white matter integrity, respectively.ResultsThe verbal IQ significantly and positively correlated with the left gyrus rectus and anterior cingulate gyrus, left posterior insula and planum polare, and left superior and middle frontal gyri volumes (p < 0.05, corrected). The verbal comprehension group index significantly and positively correlated with the left superior and middle frontal gyri, left gyrus rectus and anterior cingulate gyrus, and left middle frontal gyrus volumes, while the processing speed group index significantly and positively correlated with the bilateral various regional white matter fractional anisotropy values (p < 0.05, corrected). In contrast, the JART score showed no correlation with any brain structure.ConclusionThese results suggested the neurostructural bases of the WAIS-III IQs and group indices in the brain of healthy individuals.