Geophysical variables and behavior: XXXVIII. Effects of ionized air on the performance of a vigilance task

The effects of positively or negatively ionized air on the performance of a visual vigilance task were investigated. The ion level was 100,000 ions/cm3, +/- 10,000. Also investigated were the effects of task-induced stress and nonstress. 40 male college students were required to press a hand-held switch as soon as they detected a signal on a simulated cathode-ray display. Each subject monitored the display continuously for 3 hr. in a room specially equipped for ion exposure and for control of light and noise. All subjects received continuous identical false feedback about their performance. Half of the subjects (the stress group) were told that they would receive an electric shock when their performance fell below an acceptable level. The false feedback was programmed so subjects in this group believed that they were in danger of receiving a shock, but none were actually administered. Analysis indicated that the percentage of signals detected was higher in the presence of negatively ionized air than in the presence of positively ionized air. Also performance-contingent stress resulted in better performance than nonstress.