In a second study, researchers repeated the same experiment with 38 college students who consumed higher levels of caffeine each day. The java junkies typically had at least 300 milligrams of caffeine daily.
在第二个试验中，研究人员还是以同样的方法对38名每天会摄入高剂量咖啡因的学生做了测试。这些咖啡控们每天至少摄入300毫克咖啡因。

The low-caffeine crowd was best at finding and correcting these grammatical goofs at 200 milligrams of caffeine. But it took more in the highly caffeinated -- 400 milligrams -- to achieve the highest detection rates.
不太喝咖啡的那一组学生在喝入200毫克咖啡因后找到和更正语法错误的能力最佳，而摄入400毫克咖啡因时，他们找出文中错误的检测能力是最强的。

Interestingly, caffeine didn't affect the students' skill at finding and correcting misspelled words. And it had no effect on noticing mistakes in words that sound alike, such as weather and whether or seams and seems.
有趣的是，咖啡因并没有对学生们找到和更正拼错单词的能力造成影响。对于发现weather和whether、seams和seems这样发音类似的词也无影响。

"Individuals who habitually consume caffeine on a daily basis are less likely to benefit from caffeine's performance advantages without upping the dose," Brunye says.
“而平时习惯每天喝咖啡的人除非加大剂量，否则获益无多。”Brunye说。