Adolescent IQ Changes Tied to Alterations in Brain Structure

Verbal IQ is related to changes in motor speech area, non-verbal IQ with motor hand region

WEDNESDAY, Oct. 19 (HealthDay News) -- Verbal and non-verbal intelligence in adolescence changes with corresponding structural and functional alterations in speech and motor-related regions of the brain, according to a letter published online Oct. 19 in Nature.

Sue Ramsden, from the University College London, and colleagues investigated whether longitudinal fluctuations in IQ are related to brain development. A total of 33 healthy and neurologically normal adolescent participants were included. Each participant underwent brain scans using magnetic resonance imaging at age 12 to 16 (time 1) and at age 15 to 20 (time 2). Verbal and non-verbal IQ was measured using the Wechsler Intelligence Scale for Children at time 1 and the Wechsler Adult Intelligence Scale at time 2.

The investigators found that changes in verbal IQ correlated with alterations in gray matter in an area activated by speech. Non-verbal IQ changed with gray matter in an area activated by finger movements. Use of longitudinal assessments of the same individuals allowed for adjustment for confounding variations in brain structure.

"Our findings demonstrate considerable effects of brain plasticity in our sample during the teenage years, over and above normal development," the authors write.

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