Task-evoked pupillary responses, processing load, and the structure of processing resources.

@article{Beatty1982TaskevokedPR,
  title={Task-evoked pupillary responses, processing load, and the structure of processing resources.},
  author={J. Thomas Beatty},
  journal={Psychological bulletin},
  year={1982},
  volume={91 2},
  pages={276-92}
}
A physiological measure of processing load or "mental effort" required to perform a cognitive task should accurately reflect within-task, between-task, and betweenindividual variations in processing demands. This article reviews all available experimental data and concludes that the task-evoked pupillary response fulfills these criteria. Alternative explanations are considered and rejected. Some implications for neurophysiological and cognitive theories of processing resources are discussed. 
Highly Influential
This paper has highly influenced 91 other papers. REVIEW HIGHLY INFLUENTIAL CITATIONS