Neurons can act as signal mixers, combining exogenous and endogenous subthreshold membrane potential oscillations to produce new frequencies. This frequency mixing, driven by voltage-gated ion channels, was observed in both in vitro and in vivo experiments. The study demonstrates that individual neurons can generate new oscillatory frequencies through nonlinear interactions, a process that is also evident in human brain activity. The human electroencephalogram (EEG) shows local and inter-region frequency mixing interactions, with the conversion of posterior alpha-beta oscillations into gamma-band oscillations regulating visual attention. The findings suggest that signal mixing enables individual neurons to shape the spectrum of neural circuit oscillations and utilize them for computational operations. The study also highlights the functional relevance of frequency mixing in the human brain, showing that it is associated with cognitive functions such as visual attention. The results indicate that the mixing of frequencies occurs in both exogenous and endogenous membrane potentials, and that the strength of this mixing is influenced by the input frequencies and the properties of the neurons. The study provides evidence that frequency mixing is a fundamental mechanism for integrating high-order information across spatiotemporal scales in the brain. The findings have implications for understanding the computational functions of the brain and the role of neural oscillations in cognitive processes.Neurons can act as signal mixers, combining exogenous and endogenous subthreshold membrane potential oscillations to produce new frequencies. This frequency mixing, driven by voltage-gated ion channels, was observed in both in vitro and in vivo experiments. The study demonstrates that individual neurons can generate new oscillatory frequencies through nonlinear interactions, a process that is also evident in human brain activity. The human electroencephalogram (EEG) shows local and inter-region frequency mixing interactions, with the conversion of posterior alpha-beta oscillations into gamma-band oscillations regulating visual attention. The findings suggest that signal mixing enables individual neurons to shape the spectrum of neural circuit oscillations and utilize them for computational operations. The study also highlights the functional relevance of frequency mixing in the human brain, showing that it is associated with cognitive functions such as visual attention. The results indicate that the mixing of frequencies occurs in both exogenous and endogenous membrane potentials, and that the strength of this mixing is influenced by the input frequencies and the properties of the neurons. The study provides evidence that frequency mixing is a fundamental mechanism for integrating high-order information across spatiotemporal scales in the brain. The findings have implications for understanding the computational functions of the brain and the role of neural oscillations in cognitive processes.