N-Back
A position will flash on the 3×3 grid. Judge whether the current position matches the one shown N steps ago. Click "Match" if it matches, or "No Match" if it doesn't.
2-Back
A position will flash on the 3×3 grid. Judge whether the current position matches the one shown N steps ago. Click "Match" if it matches, or "No Match" if it doesn't.
2-Back