Intelligence and EEG current density using low-resolution electromagnetic tomography (LORETA)

• Published in: Human brain mapping Vol. 28; no. 2; pp. 118 - 133
• Main Authors: Thatcher, R.W., North, D., Biver, C.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.02.2007; Wiley-Liss
• Subjects: Adolescent; Adult; Age Factors; Biological and medical sciences; Brain - physiology; Brain Mapping; Child; Child, Preschool; Electrocardiography. Vectocardiography; Electrodiagnosis. Electric activity recording; Electroencephalography; Female; Functional Laterality; Humans; Intelligence; Investigative techniques, diagnostic techniques (general aspects); LORETA current density; Magnetic Resonance Imaging; Male; Medical sciences; Middle Aged; Multivariate Analysis; Nervous system; neuroimaging; neuropsychological tests; qEEG; Radiodiagnosis. Nmr imagery. Nmr spectrometry; Spectrum Analysis; Nervous system diseases; qEEG; Intelligence; Radiodiagnosis; Neuropsychological test; Electrophysiology; Electromagnetic; Electroencephalography; LORETA current density; neuroimaging; Tomography; neuropsychological tests; Current density
• ISSN: 1065-9471; 1097-0193
• DOI: 10.1002/hbm.20260

The purpose of this study was to compare EEG current source densities in high IQ subjects vs. low IQ subjects. Resting eyes closed EEG was recorded from 19 scalp locations with a linked ears reference from 442 subjects ages 5 to 52 years. The Wechsler Intelligence Test was administered and subjects were divided into low IQ (≤90), middle IQ (>90 to <120) and high IQ (≥120) groups. Low‐resolution electromagnetic tomographic current densities (LORETA) from 2,394 cortical gray matter voxels were computed from 1–30 Hz based on each subject's EEG. Differences in current densities using t tests, multivariate analyses of covariance, and regression analyses were used to evaluate the relationships between IQ and current density in Brodmann area groupings of cortical gray matter voxels. Frontal, temporal, parietal, and occipital regions of interest (ROIs) consistently exhibited a direct relationship between LORETA current density and IQ. Maximal t test differences were present at 4 Hz, 9 Hz, 13 Hz, 18 Hz, and 30 Hz with different anatomical regions showing different maxima. Linear regression fits from low to high IQ groups were statistically significant (P < 0.0001). Intelligence is directly related to a general level of arousal and to the synchrony of neural populations driven by thalamo‐cortical resonances. A traveling frame model of sequential microstates is hypothesized to explain the results. Hum Brain Mapp, 2007. © 2006 Wiley‐Liss, Inc.