After tachistoscopic exposure of a row of letters, recall functions show bowing and skewedness similar to the standard serial position curve that results from sequential presentation of elements. A similar curve is generated by recall of binary elements presented briefly and simultaneously. Prior investigators have interpreted this effect as an internal, post-exposure, sequential processing of the pattern from left to right as determined by reading habits. In this experiment, 48 children (16 from each of grades 2, 4, and 6) who read Hebrew as well as English were shown patterns of Hebrew letters, of English letters, and of binary elements. Recall of Hebrew letters showed right primacy. Recall of English letters showed left primacy. The report of binary patterns presented after language patterns showed a persistence of the directional sets established by the preceding language. When English and Hebrew patterns were mixed, the expected directionality was produced for each language, but recall of binary patterns after mixed language patterns showed neither left nor right primacy. The perceptual serial position phenomenon was shown to be a temporary perceptual set. References and figures are included. (Author/DE)