Individual resonant frequencies at low-gamma range and cognitive processing speed

Brain electrophysiological activity within the low gamma frequencies (30–80 Hz) hasbeen proposed to reflect information encoding and transfer processes. The 40-Hz auditory steady-state response (40-Hz ASSR) is frequently discussed in relation to changed cognitive processing inneuropsychiatric disorders. However, the relationship between ASSRs and cognitive functioningstill remains unclear. Most of the studies assessed the single frequency ASSR, while the individualresonance frequency in the gamma range (30–60 Hz), also called individual gamma frequency(IGF), has received limited attention thus far. Nevertheless, IGF potentially might better reflectindividual network characteristics than standardly utilized 40-Hz ASSRs. Here, we focused onthe processing speed across different types of cognitive tasks and explored its relationship withresponses at 40 Hz and at IGFs in an attempt to uncover how IGFs relate to certain aspects ofcognitive functioning. We show that gamma activity is related to the performance speed on complexcognitive task tapping planning and problem solving, both when responses at 40 Hz and at IGFswere evaluated. With the individualized approach, the observed associations were found to besomewhat stronger, and the association seemed to primarily reflect individual differences in higher-order cognitive processing. These findings have important implications for the interpretation ofgamma activity in neuropsychiatric disorders