Development of Mental Rotation: A Speed-Accuracy Study

Pairs of letters and numbers were shown to 11-, l4-, and l9-year-olds. One stimulus in a pair was presented upright. The second, which was either identical to the first or a mirror image of it, was rotated 0 to 150” from the vertical. Individuals judged if the stimuli in a pair would be identical or mirror images if presented at the same orientation. They did so under instructions that emphasized accurate responses, fast responses, or fast and accurate responses. Typically, responses were (1) most accurate and slowest when accuracy was emphasized, and (2) least accurate but fastest when speed was emphasized. The data from the three instructional conditions were used to derive measures of response times in which accuracy of response was equated for the three age groups. At 95% accuracy 14and lPyear-olds mentally rotated stimuli at the same rate, which was faster than II-year-olds’ rate. At 100% accuracy, lPyear-olds mentally rotated stimuli more rapidly than both lland l4-year-olds, who did not differ from one another.