Free online Dual N-Back training with N=1/2/3 difficulty: every 2.5 seconds, one of 9 grid positions lights up and a letter (C/H/K/L/Q/R/S/T) appears. You must simultaneously judge whether the current position and letter match those from N steps ago. Tracking two streams at once continuously activates the dorsolateral prefrontal cortex (dlPFC), one of the best-evidenced working memory training methods. Tracks hit rate, miss rate, and false alarm rate for both position and letter. Keyboard shortcuts (A/L) supported. Best scores saved per N level.
Select N level then click Start — track both position and letter
Keyboard: A = Position, L = Letter
❓ FAQ
What is the difference between single and dual N-Back?
Single N-Back tracks one stream (position or letter); Dual N-Back tracks both simultaneously. The dual-task format places greater demands on working memory, and research shows it produces better transfer to fluid intelligence than the single-task version.
Which N level should I choose?
Start with N=2. N=1 is too easy to be effective; N=2 is the most-studied standard version; N=3 is challenging and suitable once you have a solid foundation. Aim for 70–80% accuracy — too high means N is too low, too low means N is too high.
What are hits, misses, and false alarms?
When the current stimulus matches N steps ago and you press the button = Hit. When it matches but you don't press = Miss. When it doesn't match but you press anyway = False Alarm. The goal is high hit rate with low false alarm rate.
How many stimuli per session is recommended?
Standard research protocols use 20+N stimuli per block (~50–60 seconds), with 15–20 blocks per session, 4–5 times per week for 4–8 weeks. This tool uses 20 effective stimuli per round, suitable for daily practice.