Origin of Neural Frequency Responses: Intrinsic Sensory Coding vs. Structural Influences

Periodic changes in visual input can produce rhythmic patterns in EEG signals, which appear as narrowband frequency components. These components are commonly interpreted as reflecting the activity of neurons sensitive to the modulated stimulus features. Here, we present a scenario in which frequency components arise solely from retinotopic variations in signal strength, without reflecting any specific neural mechanism sensitive to the modulated feature. Using simulated and empirical data, we show that signal fluctuations based purely on retinotopic stimulus position can produce identifiable frequency components in response to position-modulated stimuli. These components likely reflect structural rather than functional cortical factors influencing signal strength across different retinotopic areas. Our results challenge the conventional assumption that frequency components necessarily indicate intrinsic neural signal processing, instead highlighting how interactions between stimuli and cortical architecture can give rise to such components.