THE EFFECTS OF INERT-GAS NARCOSIS ON CERTAIN ASPECTS OF SERIAL RESPONSE-TIME

Inert gas narcosis was induced in experiment 1 with compressed air using a hyperbaric chamber at 10 ata and in experiment 2 with 35% N//2O-65% O//2 and studied using a serial choice response time task. Both breathing mixtures degraded performance in an identical manner. There was a slowing of response latency with the frequency distribution of responses being shifted to the right. There was also increased positive skewing and variability of this distribution but no indication of extra-long 'blocking' responses. Number of errors increased and the latency pattern around an error did not change shape but showed an overall slowing. In addition, the effect of N//2O on response latency was studied at two levels of stimulus brightness and an additive not an interactive relationship was found. It was concluded that these results support a model of inert gas narcosis effects on human performance which postulates that information processing throughout the perceptual-motor system is slowed but not disrupted, the exception to this rule being long-term memory where a disruption of processing occurs. Errors are accounted for by a failure to maintain accuracy constant in terms of a speed-accuracy trade-off function.