The connectivity between pairs of brain regions is commonly assessed through the measurement of phase coherence or the correlation of their amplitudes. Despite large evidence linking these measures to brain functions and cognitive processes, a consensus on the mechanistic relationship between both types of coupling modes is lacking. We investigated the hypothesis that a causal relation exists between both types of functional coupling across multiple cortical areas. To this end, we utilized a multisite approach to obtain a time-resolved definition of phase and amplitude coupling parameters. Analyzing data recorded with a multichannel µECoG array from the ferret brain, we observed that the transfer entropy, a measure of the transmission of information, between both modes was predominantly unidirectional, with the amplitude coupling playing a leading role, dependent on the frequency band of the underlying signal. This finding was reproduced in magnetoencephalography (MEG) data recorded during rest from the human brain. Additionally, we determined that the transfer of information occurred within a time window ranging from 160 to 220 ms. Finally, we demonstrated that this transmission of information also occurs in a model of coupled oscillators and may represent a generic feature of a dynamical system.Disclosure of potential conflict of interest: No potential competing interest was reported by the authors.Funding: We acknowledge support of this study by the DFG (SFB936-178316478-A2) and the EU (ERC-2022-AdG-101097402).