Can the Resting State Peak Alpha Frequency Explain the Relationship Between Temporal Resolution Power and Psychometric Intelligence?

The temporal resolution power (TRP) hypothesis states that individuals with higher TRP, as reflected by a higher performance on several psychophysical timing tasks, perform better on intelligence tests due to their ability to process information faster and coordinate their mental operations more effectively. It is proposed that these differences in TRP are related to the rate of a master clock based on neural oscillations. The present study aimed to investigate whether the peak alpha frequency (PAF) measured via electroencephalography (EEG) reflects a psychophysiological measure of this rate and its potential role in explaining the relationship between TRP and psychometric intelligence. A sample of 129 young adults (M = 23.0, SD = 3.1) completed a short version of Raven's Advanced Progressives Matrices and three timing tasks. PAF was measured using EEG before each timing task during two resting states with eyes closed (EC) and eyes open (EO), respectively. From these PAF measurements, four latent PAF variables were extracted, differing in resting state (EC, EO) and electrode cluster (frontal/central, parietal/occipital). The results confirmed a strong association between TRP and psychometric intelligence (r = .56, p < .01), as previously reported in other studies. Additionally, we found a positive association between intelligence and a latent PAF variable extracted from frontal/central electrodes in the EO resting state conditions (r = .27, p < .05). However, there was no association between TRP and PAF. This indicates that PAF does not reflect the underlying psychophysiological mechanism that links TRP to intelligence.