Gamma power in rural Pakistani children: Links to executive function and verbal ability

Abstract

Children in low- and middle-income countries are at high risk of cognitive deficits due to environmental deprivation that compromises brain development. Despite the high prevalence of unrealized cognitive potential, very little is known about neural correlates of cognition in this population. We assessed resting EEG power and cognitive ability in 105 highly disadvantaged 48-month-old children in rural Pakistan. An increase in EEG power in gamma frequency bands (21-30Hz and 31-45Hz) was associated with better executive function. For girls, EEG gamma power also related to higher verbal IQ. This study identifies EEG gamma power as a neural marker of cognitive function in disadvantaged children in low- and middle-income countries. Elevated gamma power may be a particularly important protective factor for girls, who may experience greater deprivation due to gender inequality.

Keywords: Cognitive development; EEG; Executive function; Low- and middle-income countries; Poverty; Sex differences.

Fig. 1

Estimated marginal means for log transformed gamma power by gender as a function of executive function (EF, 1a), Verbal IQ (VIQ, 1b) and Performance IQ (PIQ, 1c) scores 1 SD below and 1 SD above the mean. Gamma power values are negative due to log transformation of a value less than 1. In Fig. 1a, children with high EF have higher gamma, regardless of gender. In Fig. 1b, higher VIQ related to higher gamma for girls only. In Fig. 1c, gamma and PIQ are unrelated.