Probe-detection times during the reading of easy and difficult text.

Two experiments were conducted to determine the effects of text difficulty on cognitive capacity demands. In Experiment 1, subjects read easy and difficult text when a secondary task was either present or absent. Text was presented one word at a time, and rereading was prevented by erasing each word after it had been read. Prior studies have indicated that cognitive capacity demands decrease as text difficulty increases (e.g., Britton, Westbrook, & Holdredge, 1978). In contrast to this, the main results of Experiment 1 revealed shorter visual-probe-detection times during the reading of easy text than during the reading of difficult text. Analyses of word-reading times showed that difficult text was read slower than easy text, irrespective of probe application. Experiment 2 compared visual-probe detection with auditory-probe detection. The results again showed shorter probe reaction times during the reading of easy text than during the reading of difficult text, irrespective of probe type. There were, however, effects of probe type on the reading time of words following the visual probe. The results were taken as evidence that the reading of difficult text requires more capacity than the reading of easy text and that probes may incur modality-specific and modality-independent capacity demands.