Sampling Rate

Sampling rate is the frequency at which your recording system digitizes analog voltage signals, measured in samples per second (Hz or kHz). It determines the temporal resolution of your recordings and what frequencies you can accurately capture.

Why it matters: Sampling rate must be high enough to capture all frequency components in your signals of interest. Too low, and you'll miss fast events or introduce aliasing artifacts. Too high, and you generate unnecessarily large data files.

Nyquist theorem: To accurately capture a frequency, sampling rate must be at least 2× that frequency. In practice, use 2.5-3× to provide margin for analog filters.

Common sampling rates:

• 1-2 kHz: LFP-only recordings, slow signals
• 20 kHz: Economy wide-band (captures up to ~8 kHz)
• 30 kHz: Standard for spike recordings (captures up to ~12 kHz)
• 40 kHz: High-fidelity spike waveforms

Data volume impact: Doubling sampling rate doubles data size. A 128-channel probe at 30 kHz generates ~7.7 MB/second. At 40 kHz this increases to ~10.2 MB/second. Consider storage capacity when choosing sampling rate.

Practical recommendation: 30 kHz is the industry standard for multi-site spike recordings, providing good spike waveform fidelity without excessive data volume.