Duration Ratings as an Index of Processing Resources Required for Cognitive Tasks.

Six experiments provided tests of the effectiveness of subjective duration ratings as an index of the processing resources required in cognitive tasks. Duration ratings reflected significant differences between the resources needed to process high- and low-frequency words (Experiments 1, 5, and 6), and ambiguous and unambiguous words (Experiments 1 and 2), and produced an interaction between memory load and word frequency (Experiment 6). However, participants tended to assign higher ratings to larger stimuli (Experiments 1, 4, and 5); for example, words in upper case received higher ratings than words in lower case. Although physical size of stimuli is an important factor to consider, subjective duration estimates provide a useful measure for understanding cognitive processing. This conclusion is supported by the current replication of several findings in the cognitive literature, including the word-frequency and lexical-ambiguity effects.