Holistic and analytic processes in the comparison of letters

College students made “same-different” judgments about successively presented pairs of letters whose degree of difference, in terms of the number of line segments out of register, was systematically varied. Reaction time was found to decrease with increases in the degree of difference in “different” responses, as well as to depend on the number of line segments present in the second (probe) letter. “Same” responses were much faster than different responses and were unaffected by the number of segments in the probe letter. This pattern of results suggests analytic (component-by-component) processing of “different” letters and holistic processing of “same” letters. The results have important implications for studies of multi-letter comparisons, in which it is commonly assumed that letter comparisons are holistic in nature.