- Located in the occipital regions bilaterally as positive waves.
- Triangular in shape (like the capital lambda: Λ) and generally symmetric.
- Amplitude: 50 microV
- Duration 200-300 msec
- Present with eyes opened and during visual fixation
- Same morphology as POSTS (Positive occipital sharp transients of sleep), both in form and in occipital distribution, however POSTS are during sleep.
Lambda waves bilaterally present and absent during eyes closed (double banana)