The tracking umbrella: Diverse interpretations under a common neural term.

Neural tracking, the alignment of brain activity with the temporal dynamics of sensory input, is a crucial mechanism underlying perception, attention, and cognition. While this concept has gained prominence in research on speech, music, and visual processing, its definition and methodological approaches remain heterogeneous. This paper critically examines neural tracking from both theoretical and methodological perspectives, highlighting how its interpretation varies across studies. A central debate concerns whether neural tracking primarily is a byproduct of stimulus rhythmicity (train of evoked responses) or it is driven by intrinsic oscillatory synchronization (neural oscillations), particularly in speech processing-two perspectives often associated with distinct analytical methods. I review key approaches to measuring tracking, including evoked responses, multivariate temporal response functions, coherence, and phase-locking, discussing their theoretical implications and limitations. Based on available evidence, I propose that the evoked and the oscillatory perspectives should be viewed as complementary and emphasize the importance of methodological choices in accurately capturing neural tracking. Finally, I discuss the role of neural tracking in speech comprehension, advocating for future research to integrate causal methodologies, such as brain stimulation and closed-loop paradigms, to refine our understanding of its functional role.