Hess E H, Polt J M
Science. 1964 Mar 13;143(3611):1190-2. doi: 10.1126/science.143.3611.1190.
Changes in pupil size during the solving of simple multiplication problems can be used as a direct measure of mental activity. The pupil response not only indicates mental activity in itself but shows that mental activity is closely correlated with problem difficulty, and that the size of the pupil increases with the difficulty of the problem. These findings relate to recent Russian research on the pupillary reflex in connection with orienting and brain stimulation.
在解决简单乘法问题过程中瞳孔大小的变化可被用作心理活动的直接测量指标。瞳孔反应不仅本身表明心理活动，还显示出心理活动与问题难度密切相关，且瞳孔大小随问题难度增加而增大。这些发现与俄罗斯最近关于瞳孔反射与定向和大脑刺激相关的研究有关。
