The Susceptibility of Intellectual Functions to a Depressant Drug

F rankenhaeuser , M., and B eckman , M. The susceptibility of intellectual functions to a depressant drug. Scand. J. Psychol ., 1961, 2 , 93–99.—The performance of 32 subjects in tests on four intellectual factors (verbal, numerical, inductive and spatial) during the inhalation of nitrous oxide (30 per cent N 2 O and 70 per cent O 2 ) and a control mixture (30 per cent N 2 and 70 per cent O 2 ) were compared . The drug caused a highly significant deterioration in the performance of all four tests. Both speed and accuracy of performance were impaired. The problem of a possible differential susceptibility to the drug of the various intellectual functions wag attacked by a statistical analysis of the differences between the tests with regard to changes in performance during drug inhalation. No reliable differences in extent of impairment between the four tests could be demonstrated.