Strategic differences in spatial tasks are explained in terms of different cognitive coordinate systems that subjects adopt such as standard versus arbitrary, task-defined axes. A theoretical account of mental rotation of individuals of low and high spatial ability solving problems from psychometric tests is instantiated as computer simulation…

The question of whether pupil diameter indicates information processing load during reading was investigated in three experiments involving 24 college students reading passages of varying difficulty. A TV camera and monitor, together with a video-recorder, were used to measure the diameter of the pupil under a reading condition and under three…