Use of Cognitive Capacity in Reading: A Performance Operating Characteristic

Abstract

The cognitive capacity used in cognitive tasks can be measured with a secondary task technique (also called the dual task technique). Interpretation of results obtained with this technique depends on the assumption that the primary and secondary tasks require the same limited-capacity cognitive processing system. The present experiment tested this assumption by constructing a performance operating characteristic, in which the allocation of processing resources for the primary and secondary tasks was varied by instructions, and performance on the two tasks was observed. As the quality of performance on one task increased, performance on the other task decreased. It was concluded that the primary and secondary tasks shared processing resources. This means that performance on one task can be used as an indicator of processing resources allocated to the other. Implications of performance operating characteristics for secondary task methodology were discussed.