Brain responses to passive sensory stimulation correlate with intelligence

Abstract

This study investigates the association between intelligence and brain power responses to a passive audiovisual stimulation. We measure the power of gamma-range steady-state responses (SSRs) as well as intelligence and other aspects of neurocognitive function in 40 healthy males born in 1953. The participants are a part of a Danish birth cohort study and the data therefore include additional information measured earlier in life. Our main power measure is the difference in power between a visual stimulation and a combined audiovisual stimulation. We hypothesize and establish empirically that the power measure is associated with intelligence. In particular, we find a highly significant correlation between the power measure and present intelligence scores. The association is robust to controlling for size-at-birth measures, length of education, speed of processing as well as a range of other potentially confounding factors. Interestingly, we find that intelligence scores measured earlier in life (childhood, youth, late midlife), are also correlated with the present-day power measure, suggesting a deep connection between intelligence and the power measure. Finally, we find that the power measure has a high sensitivity for detection of an intelligence score below the average. HIGHLIGHTS - Intelligence scores are correlated with the change in steady-state evoked power responses from single to double-sensory stimulation (1P). - Intelligence scores measured earlier in life (childhood, youth, and late midlife), in addition to scores measured presently in old age, are also associated with present-day 1P. - The correlations are not driven by observed covariates, including birth size, education, processing speed, or a range of other potentially confounding factors determined after youth, nor other day-specific factors or factors that operate in an additive and constant fashion on the level of steady-state power responses.