How to test for oscillatory modulation of neural function and behaviour

The question whether perception or other processes depend on the phase of neural oscillations is a research topic that is rapidly gaining popularity. Importantly however, it is unknown which methods are optimally suited to evaluate the hypothesized phase effect. Using a simulation approach, we here test the ability of different methods to detect such an effect and reject an absent one. We reveal optimal methods for different parameters that characterise the phase effect or depend on the experimental design to test for it. We demonstrate that permutation-based methods perform better than parametric ones for all of the simulated parameters. The identity of the optimal parametric method varies with several parameters, in particular with the number of phase bins chosen for the analysis and the width of the phase effect. In contrast, the identity of the best permutation-based method is unaffected by changes in the simulated parameters. In sum, our study lays a foundation for optimized experimental designs and analyses in future studies investigating the role of neural phase for behaviour and neural function. We supply MATLAB code that can be used to identify the ideal method (among all of the methods tested) for a specific scientific hypothesis and set of experimental parameters.