专注力与灵活性

以最小成本在心理规则之间切换。

每个练习针对一个狭窄的构念：工作记忆、选择性注意、速度。

训练模式提供即时反馈。测试模式有计时和评分。

Each exercise here is scored so you see your real progress, not vague points. Train mode gives immediate feedback. Test mode is timed and comparable to your past sessions.

Each test is constructed using Item Response Theory (IRT) and Classical Test Theory (CTT) to ensure reliable measurement of knowledge and ability across different difficulty levels.

Questions undergo rigorous review including difficulty calibration, discrimination analysis, and distractor effectiveness evaluation to maintain high assessment quality.

Training reduces switch costs, and the reduction transfers to untrained tasks more than most "brain training" claims do. This is the cleanest evidence-backed lever for improving real multitasking.

1. Verbalize the current rule: Before each trial, silently say the rule. This shrinks switch costs by half.
2. Accept slower early: Switch trials are supposed to be slower. Fighting that just produces errors.
3. Track switch cost, not average RT: The interesting metric is the gap between stay and switch trials.
4. Train in short sessions: 10 minutes of switching is harder than 30 minutes of a single task. Don't overdo it.