A Note on the Influence of Climatic Factors on Psychophysiological Investigations

investigators have been aware that climatic factors may significantly affect their research, the influence of these factors has never been adequately taken into account in such studies. Those who have dealt with peripheral physio-logical recordings have often been cognizant of the importance of controlling for tempera-ture, but have less often taken relative hu-midity into consideration, and have only rarely accounted for the influence of baro-metric pressure.2'0 | " • 9 These investigators tend to fall into three groups: physiologists, psychophysiologists, and heating and ventilat-ing engineers ([the latter having contributed much in this field). The physiologists and heating and ventilat-ing engineers have known for some time that physiological adjustments to temperature changes of the order of daily fluctuations may require several hours, whereas acclimatization to more extreme temperature shifts, such as occur between seasons, may take considerably longer. They have therefore taken this knowl-edge into account in conducting their experi-ments, allowing their subjects several hours for acclimatization. ^ 12 The psychophysiologists have usually not used such a long period of acclimatization