Improve Sensory Memory & Working Memory using N'Back. ◆Flash Mode / Slow Mode / Step Mode Tap the number key matches the one from N steps earlier in the sequence. In 1'Back 1 task1: count & memorize 2 task2: count & memorize 3 __keyboard__: answer for task1 4 task3: count & memorize 5 __keyboard__: answer for task2 6 task4: count & memorize : In 2'Back 1 task1: count & memorize 2 task2: count & memorize 3 task3: count & memorize 4 __keyboard__: answer for task1 5 task4: count & memorize 6 __keyboard__: answer for task2 7 task5: count & memorize :