Infant sensitivity to audio-visual discrepancy: A failure to replicate

Abstract

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...

Developmental Changes in Locating Voice and Sound in Space

“…Bedford (2001) pointed out that an object identity decision is essential for producing the ventriloquism effect. Young infants’ high tolerance to audio-visual spatial discrepancy, presented in the ‘split mother’ experiments ( McGurk and Lewis, 1974 ; Condry et al, 1977 ) may be explained by this illusion. However, in this study, since E2 first appeared next to E1 in front of the infants and then disappeared from their view for calling from other locations, the infants could easily recognize that there were two strangers (E1 and E2) involved.…”

“…A number of studies of inter-modal perception in early infancy have provided evidence that infants are sensitive to the temporal synchrony of sound and vision ( Lewkowicz, 1986 ; Bahrick, 1988 ), and to the discrepancy between phonetic information in lips and in voice ( Kuhl and Meltzoff, 1984 ; Patterson and Werker, 1999 ). However, they are not so sensitive to spatial discrepancy ( McGurk and Lewis, 1974 ; Condry et al, 1977 ). When being called from outside of their immediate visual field, the 4-month-olds in this study when they did not search, kept looking intently at E1 in front of them, as if asking E1 “Are you calling me?” despite E1’s silent ‘third party role.’ Their responses seemed to be dominated by their visual engagement with E1.…”

“…They said that the spatial dislocation was a violation of the young infants’ perceptual world, in which the speaker and the voice typically share the same spatial location. However, several studies report failure to replicate or confirm the finding that infants were distressed by discrepancies, in infants of about the same age (39–58 days old, Condry et al, 1977 ) and in an older age group (1, 4, and 7 months of age, McGurk and Lewis, 1974 ). McGurk and Lewis, however, observed that infants at 4 and 7 months responded to the mother’s voice from an active loudspeaker, indicating that older infants’ sound localization was active, even while they continued looking at their mothers’ faces, but these infants did not show distress.…”

The intermodal representation of speech in newborns

“…However, since they never presented the heard voice in the same location as the seen mouth, it is perhaps not surprising that newborns did not respond to changes in the position of the heard voice. Condry, Halton, and Neisser (1977) also reported a failure to replicate the results of Aronson and Rosenbloom. Since their presentation procedure necessitated the hiding of the speaker's mouth, this result is hardly surprising and in no way weakens the conclusions of Aronson and Rosenbloom.…”

Infants' reactions to perceptual paradox during mother–infant interaction.

“…However, the reliability of findings that infants are distressed by perceptual paradox has been questioned because of failures to replicate the findings (e.g., Condry, Haltom, & Neisser, 1977;Field, 1977;McGurk & Lewis, 1974). Spelke and Owsley (1979) have suggested that one of the main problems with studies of perceptual paradox is the inherent ambiguity of the behavioral indices of affect that have been used.…”