• Vigilance;
  • Catecholamines;
  • Glucose;
  • Performance


This investigation was to determine the interrelationships among circulating concentrations of adrenaline, noradrenaline, glucose, and “free” fatty acids ([A], [NA], [G], and [FFA], respectively) in 11 men at rest and while performing “mental” work, i.e., a visual monitoring task. They performed the task and on another occasion served in a control condition where they merely watched slide projections. Basal levels of both [A] and [NA] were inversely related to [G]. [A] increased initially during the task but later returned to its basal level. The decline in [A] paralleled performance in the task. [A] declined to below its basal level in the control condition. [NA] was not related to performance in the task. [G] and [FFA] were elevated with respect to corresponding basal levels in both the task and the control condition. The bearing of the results upon current theories of human vigilance and psychophysiological mobilization during mental work was discussed.