Spectrogram

A spectrogram is a time–frequency representation showing how the power spectrum of a signal changes over time, computed using short-time Fourier transforms or wavelet analysis.

Why it matters: Spectrograms reveal the dynamics of neural oscillations — when and at what frequencies the brain is active. They are essential for studying event-related changes in theta (4–8 Hz), alpha (8–13 Hz), beta (13–30 Hz), and gamma (>30 Hz) activity.

Parameters: Window length (50–500 ms), overlap (50–90%), and frequency resolution trade off temporal and spectral precision. Shorter windows give better time resolution but worse frequency resolution.

Software: Radiens Videre provides interactive spectrogram visualization for recorded neural data.