Bipolar Longitudinal — Double Banana
50 µV
1 s
Neg. up · standard EEG convention
Click or drag anywhere inside the head map to place a cortical source. The EEG traces update instantly. Use the scenario buttons for quick demos.
Amplitude — peak source voltage (µV).
Spread σ — spatial extent of the field; larger values affect more electrodes.
Polarity — negative (standard for most spikes) or positive.
Dipole — Radial: single-polarity field. Tangential: biphasic field with adjustable angle and pole separation.
Negative deflections go up (standard EEG convention). In a bipolar montage, a phase reversal — two adjacent channels deflecting in opposite directions — identifies the electrode closest to the source. Enable Highlights to mark these in amber.
Switch between bipolar (longitudinal, transverse, ring) and referential (linked mastoids, average, Cz) montages. Sensitivity controls the µV-per-mm gain — lower values make small signals visible, higher values prevent large spikes from clipping.
Add a sinusoidal background rhythm (delta → gamma) to simulate ongoing EEG activity. Press ▶ to animate a moving sweep across the trace window.