Effects of cognitive effort on recall of target words were examined by four experiments using undergraduates as subjects. In all experiments anagram solving tasks were used, where the task difficulty levels were manipulated in order to vary the amount of effort. In Experiment I-A, 15 subjects generated meaningful words from the presented anagrams. In Experiment I-B, targets were presented at the beginning of each trial, and 15 subjects were asked to judge whether they could construct target words from scrambled letters. Procedures for Experiment II were similar to those for experiment I-A, except that anagram stimuli themselves had meanings. Fifteen subjects were asked to generate words with different meanings from anagram. Results of Experiment I and II suggested that the more is the cognitive effort required for the anagram solving, the greater becomes the retention of items when they were recognized as a unit before the task. Experiment III, in which solution time was limited to 10 seconds, demonstrated that effort effects cannot be attributable to processing times. Factors underlying the effects of cognitive effort on word recall were discussed.
