Anticipation of electric shock: A psychophysical study

Successive measures of emotional intensity were obtained by a two-step scaling procedure from 23 subjects anticipating an electric shock to be given at the end of a 45-min period. Half of Ss had a clock available, while the other half had to estimate apparent time. The emotional reaction was shown to increase exponentially as time before shock decreased. Heart rate also increased as time for shock was approaching, but the trend was not regular.