  Frequency tagging is a powerful approach to investigate the neural processing
of sensory features, and is recently adapted to study the neural correlates of
superordinate structures, i.e., chunks, in complex sequences such as speech and
music. The nesting of sequence structures, the necessity to control the
periodicity in sensory features, and the low-frequency nature of sequence
structures pose new challenges for data analysis and interpretation. Here, I
discuss how to interpret the frequency of a sequential structure, and factors
that need to be considered when analyzing the periodicity in a signal. Finally,
a safe procedure is recommended for the analysis of frequency-tagged responses.
