EEG for Beginners GitHub

Signal Lab

Open the course EDFs in your browser: scroll, filter, re-reference and read the spectrum.

Read locally; never uploaded.

0.0 s

Arrow keys page through the recording. Click a trace to highlight it everywhere.

Spectrum

Head map

Relative band power per channel

share of 1-45 Hz power · alpha peak searched 7-14 Hz

Things to try

  1. Find alpha. Open s01, click O1. Read the alpha peak from the table. Switch to s02 and compare the alpha column at O1 and O2.
  2. Kill the hum. Open s03 with every filter off and the gain at 1000 µV. Note the 60 Hz column. Add the 60 Hz notch, then a 1 Hz high-pass, then a 40 Hz low-pass, checking the trace and the spectrum each time.
  3. See the phase cost. On s06, find a blink at Fp1. Switch the filter type from zero-phase to causal: the blink shifts later and changes shape. Real-time neurofeedback has to live with the causal version.
  4. Watch a reference move a blink. On s06, switch the reference from "as recorded" to average and to Cz. Which channels gain a blink they did not have before?
  5. Mean vs median. On s09 with the whole recording, switch the spectrum average from median to mean. The mean is dragged up by the drift and movement bursts.
  6. Judge a cleaning pipeline. Step through s06, s07 and s08 with the same filters. What did rejection remove, and what did the full pipeline repair?

The browser filters are 4th-order Butterworth sections (notch Q = 30), not MNE's default FIR filters, so numbers will differ slightly from the Python labs. The ideas are the same.