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It has been suggested that very young infants perceive in a common auditory and visual space. Aronson and Rosenbloom (1971) attempted to demonstrate this commonality by showing that infants become distressed by discrepancies between the visually and aurally specified locations of a speaker. However, this finding has not proved easy to replicate, and the present study also failed to confirm it. There are reasons to believe that the method of Aronson and Rosenbloom does not provide a strong test of their hypothesis.The results of Aronson and Rosenbloom (1971) seemed to show that even very young infants (30-55 days old) are aware of the relationship between aurally specified and visually specified locations. Their subjects behaved as if they knew that the place where one sees a person (her visually specified location) should coincide with the direction from which her voice is heard as coming. When a speaker's voice was artificially displaced 90 deg to the right or left, all of the experimental infants exhibited distress. In particular, there was a Significantly greater incidence of tongue protrusions during the auditory displacement than during control periods. This suggested the existence of an innate (or at least quickly learned) spatial coordination among sense modalities: a common auditory-visual space. However, McGurk and Lewis (1974) were unable to replicate this result: Their subjects exhibited no distress when a speaker's voice was displaced. The study reported here was performed to explore this issue further. METHODThe eight subjects of the present experiment (two girls and six boys) ranged in age from 39 to 58 days. Their mothers served as spe~kers. Mothers and infants were not separated by a Plexiglas window, as in Aronson and Rosenbloom's (1971) study; they were in the same 10 x 10 ft curtained cubicle, 24 in. apart. The subject was placed in a semi-reclining infant seat. To his right and left were two loudspeakers, 35 in. apart. The mother spoke into a tiny sensitive microphone, held 1 in. from her mouth by a headset. She spoke relatively softly; the amplification assured that the sound heard in the infant's position was localized entirely on the basis of the loudspeakers (as judged by adult pilot subjects). The mothers stood directly behind a waist-high periscope device attached to a television camera, which thus obtained a full-face view of the infant. The entire experimental session was videotaped.Each mother talked to her infant for 4 min. During the first and third minutes both loudspeakers were set at equal volume, so that her voice appeared to be coming from a normal central location. During the second and fourth minutes one speaker was turned off (order was counterbalanced across infants), so the sound came either from the left or the right rather than from the mother directly. This procedure differed from that of Aronson and Rosenbloom; they presented the mother's voice in its normal location for either 2 or 5 min and then displaced it only once for a single minute. RESULTSTwo trained observer...

Second and fifth-grade and college-age subjects made similarity judgments on sets of three words that required attention to orthographic, phonetic, or semantic information. Accuracy and speed increased with age. Even the youngest subjects were able to perform the task of selecting a given feature of a word reasonably well. Differences in difficulty among the three tasks decreased with age, suggesting a developmental change (primarily between second and fifth grade) toward facility in extracting phonetic and semantic information from words. The presence of confusable, potentially relevant information had detrimental effects overall which decreased with age and varied with the type of task and type of distractor. For all ages, performance was better when all trials of a particular task were blocked together than when trials of the three tasks were randomly ordered. 88Printed words offer several types of information: semantic and morphological, syntactic, graphic and orthographic, and phonetic. Gibson (1971) has called these types feature classes. When reading, one's purpose determines which class of information is most relevant. Although we generally read for meaning, we may focus on orthography when correcting papers or looking up a name in the phone book, and on sound when reading poetry. Performing any of these tasks requires the ability to extract and work with one class of information in preference to another.The present study is concerned with the development of selective attention to particular classes of information offered by printed words. It has been established that 7-year-olds can attend selectively to graphic distinctive features in a search task, using strategies similar to those of adults (Gibson & Yonas, 1966), and that they can perform some types of phonemic analysis (Golden, Note 1). The present study provides a more complete test of readers' abilities to work with specific classes of information. Children of two grade levels and college students

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