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Can you see what I am talking about? Human speech triggers referential expectation in four-month-old infants.

Marno H, Farroni T, Vidal Dos Santos Y, Ekramnia M, Nespor M, Mehler J - Sci Rep (2015)

Bottom Line: However, in order to successfully acquire language, one should also understand that speech is a referential, and that words can stand for other entities in the world.Our results showed that compared to other auditory stimuli or to silence, when infants were listening to speech they were more prepared to find some visual referents of the words, as signalled by their faster orienting towards the visual objects.Hence, our study is the first to report evidence that infants at a very young age already understand the referential relationship between auditory words and physical objects, thus show a precursor in appreciating the symbolic nature of language, even if they do not understand yet the meanings of words.

View Article: PubMed Central - PubMed

Affiliation: Language, Cognition and Development Lab, SISSA, Via Bonomea 265, Trieste, 34136, Italy.

ABSTRACT
Infants' sensitivity to selectively attend to human speech and to process it in a unique way has been widely reported in the past. However, in order to successfully acquire language, one should also understand that speech is a referential, and that words can stand for other entities in the world. While there has been some evidence showing that young infants can make inferences about the communicative intentions of a speaker, whether they would also appreciate the direct relationship between a specific word and its referent, is still unknown. In the present study we tested four-month-old infants to see whether they would expect to find a referent when they hear human speech. Our results showed that compared to other auditory stimuli or to silence, when infants were listening to speech they were more prepared to find some visual referents of the words, as signalled by their faster orienting towards the visual objects. Hence, our study is the first to report evidence that infants at a very young age already understand the referential relationship between auditory words and physical objects, thus show a precursor in appreciating the symbolic nature of language, even if they do not understand yet the meanings of words.

No MeSH data available.


Related in: MedlinePlus

Results of Experiment 2.Changes of pupil diameter during the speech and the gazing period. Bars represent the average ratio of infants’ pupil size during the entire period of the presentation of the female speaker in the different auditory (Speech, Backward Speech and No Speech) and the further Gaze (Object-Directed and Infant-Directed) conditions. Error bars indicate SEM.
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f5: Results of Experiment 2.Changes of pupil diameter during the speech and the gazing period. Bars represent the average ratio of infants’ pupil size during the entire period of the presentation of the female speaker in the different auditory (Speech, Backward Speech and No Speech) and the further Gaze (Object-Directed and Infant-Directed) conditions. Error bars indicate SEM.

Mentions: Pupil diameter is not only a function of the luminance reaching the eyes, but also reflects psychological processes such as attention, arousal and cognitive load323334 (Beatty, 1982; Karatekin, 2004; Porter, Troscianko, & Gilchrist, 2007), as it has been reported in numerous studies with adult subjects in the past. More recently, it has also been demonstrated that pupil diameter can be informative about psychological processes also in the case of in infants. For example, changes in pupil size have been registered in studies of object-identity violation35, object-permanence tasks36 or in response to another infant’s distress37. Thus, the aim of the analysis of pupil size changes in the present experiment was to see whether the different time latencies infants showed in the behavioural task would be due to an of increase of arousal and general attention enhancement during the presentation of speech. As there is extensive evidence showing that infants have a distinguished preference towards speech stimuli, compared to other, non-speech auditory stimuli, it is especially important to clarify whether the shorter latency in finding the visual objects is due to a generally more ‘alerted’ state that speech would induce in infants, or it is indeed due to a specific effect, reflecting their expectation to find a visual referent of speech. Thus, to answer this question we performed a pupil diameter analysis during the presentation of the female speaker in the different conditions. First, we analysed the period of the different auditory conditions (Speech, Backward Speech and No Speech), in order to see whether infants’ general attentiveness would have changed due to the different acoustic or silent cues. This analysis did not yield any significant differences between conditions. In fact, infants’ average pupil size was very similar in all the three conditions (Fig. 4). Next, we wanted to see whether the combined effect of the auditory conditions and gaze-cueing would result changes of the pupil size. To this end, we analysed changes of pupil diameter during the entire period of the presentation of both the acoustic cue (Speech, Backward Speech and No Speech) and the gaze (Object-directed vs. Infant-directed) (Fig. 5). A a 3 × 3 analysis of variance (ANOVA) with Language (Normal Speech vs. Backward Speech vs. No Speech) and Gaze (Object-Directed vs. Infant-Directed) revealed no main effect of Language or Gaze, but a significant interaction between the two factors [F(2, 42) = 7.710, p = 0.001, η2 = 0.269]. We found the same interaction when we directly compared the Speech condition with the Backward Speech [F(1, 24) = 5.771, p = 0.024, η2 = 0.194], and also in the comparison of the Speech and No Speech condition [F(1, 21) = 11.825, p = 0.002, η2 = 0.360]. In the comparison of the Backward Speech and No Speech condition, however, due to an overall increased pupil size in the Backward Speech condition we found a significant main effect of Language [F(1, 23) = 6.629, p = 0.017, η2 = 0.224], and only a marginally significant interaction of Language and Gaze [F(1, 23) = 4.336, p = 0.049, η2 = 0.159]. Further Bonferroni-corrected pairwise comparisons also revealed that pupil size reacted differently to the Object-directed gaze vs. Infant-directed gaze of the speaker only when gazing was preceded by Speech [t(24) = 2.831, p = 0.009], but not when it was preceded by Backward Speech [t(26) = 0.491, p = 0.628], or by No Speech [t(23) = −2.086, p = 0.048]. Thus, while these results clearly exclude the possibility that either normal speech would generally increase infants’ arousal, or that the backward speech and the silent movies would distract their attention, they give further evidence that infants’ searching behaviour for a potential referent is facilitated by the gaze-cueing of the speaker only when the cue appears in the context of speech.


Can you see what I am talking about? Human speech triggers referential expectation in four-month-old infants.

Marno H, Farroni T, Vidal Dos Santos Y, Ekramnia M, Nespor M, Mehler J - Sci Rep (2015)

Results of Experiment 2.Changes of pupil diameter during the speech and the gazing period. Bars represent the average ratio of infants’ pupil size during the entire period of the presentation of the female speaker in the different auditory (Speech, Backward Speech and No Speech) and the further Gaze (Object-Directed and Infant-Directed) conditions. Error bars indicate SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555167&req=5

f5: Results of Experiment 2.Changes of pupil diameter during the speech and the gazing period. Bars represent the average ratio of infants’ pupil size during the entire period of the presentation of the female speaker in the different auditory (Speech, Backward Speech and No Speech) and the further Gaze (Object-Directed and Infant-Directed) conditions. Error bars indicate SEM.
Mentions: Pupil diameter is not only a function of the luminance reaching the eyes, but also reflects psychological processes such as attention, arousal and cognitive load323334 (Beatty, 1982; Karatekin, 2004; Porter, Troscianko, & Gilchrist, 2007), as it has been reported in numerous studies with adult subjects in the past. More recently, it has also been demonstrated that pupil diameter can be informative about psychological processes also in the case of in infants. For example, changes in pupil size have been registered in studies of object-identity violation35, object-permanence tasks36 or in response to another infant’s distress37. Thus, the aim of the analysis of pupil size changes in the present experiment was to see whether the different time latencies infants showed in the behavioural task would be due to an of increase of arousal and general attention enhancement during the presentation of speech. As there is extensive evidence showing that infants have a distinguished preference towards speech stimuli, compared to other, non-speech auditory stimuli, it is especially important to clarify whether the shorter latency in finding the visual objects is due to a generally more ‘alerted’ state that speech would induce in infants, or it is indeed due to a specific effect, reflecting their expectation to find a visual referent of speech. Thus, to answer this question we performed a pupil diameter analysis during the presentation of the female speaker in the different conditions. First, we analysed the period of the different auditory conditions (Speech, Backward Speech and No Speech), in order to see whether infants’ general attentiveness would have changed due to the different acoustic or silent cues. This analysis did not yield any significant differences between conditions. In fact, infants’ average pupil size was very similar in all the three conditions (Fig. 4). Next, we wanted to see whether the combined effect of the auditory conditions and gaze-cueing would result changes of the pupil size. To this end, we analysed changes of pupil diameter during the entire period of the presentation of both the acoustic cue (Speech, Backward Speech and No Speech) and the gaze (Object-directed vs. Infant-directed) (Fig. 5). A a 3 × 3 analysis of variance (ANOVA) with Language (Normal Speech vs. Backward Speech vs. No Speech) and Gaze (Object-Directed vs. Infant-Directed) revealed no main effect of Language or Gaze, but a significant interaction between the two factors [F(2, 42) = 7.710, p = 0.001, η2 = 0.269]. We found the same interaction when we directly compared the Speech condition with the Backward Speech [F(1, 24) = 5.771, p = 0.024, η2 = 0.194], and also in the comparison of the Speech and No Speech condition [F(1, 21) = 11.825, p = 0.002, η2 = 0.360]. In the comparison of the Backward Speech and No Speech condition, however, due to an overall increased pupil size in the Backward Speech condition we found a significant main effect of Language [F(1, 23) = 6.629, p = 0.017, η2 = 0.224], and only a marginally significant interaction of Language and Gaze [F(1, 23) = 4.336, p = 0.049, η2 = 0.159]. Further Bonferroni-corrected pairwise comparisons also revealed that pupil size reacted differently to the Object-directed gaze vs. Infant-directed gaze of the speaker only when gazing was preceded by Speech [t(24) = 2.831, p = 0.009], but not when it was preceded by Backward Speech [t(26) = 0.491, p = 0.628], or by No Speech [t(23) = −2.086, p = 0.048]. Thus, while these results clearly exclude the possibility that either normal speech would generally increase infants’ arousal, or that the backward speech and the silent movies would distract their attention, they give further evidence that infants’ searching behaviour for a potential referent is facilitated by the gaze-cueing of the speaker only when the cue appears in the context of speech.

Bottom Line: However, in order to successfully acquire language, one should also understand that speech is a referential, and that words can stand for other entities in the world.Our results showed that compared to other auditory stimuli or to silence, when infants were listening to speech they were more prepared to find some visual referents of the words, as signalled by their faster orienting towards the visual objects.Hence, our study is the first to report evidence that infants at a very young age already understand the referential relationship between auditory words and physical objects, thus show a precursor in appreciating the symbolic nature of language, even if they do not understand yet the meanings of words.

View Article: PubMed Central - PubMed

Affiliation: Language, Cognition and Development Lab, SISSA, Via Bonomea 265, Trieste, 34136, Italy.

ABSTRACT
Infants' sensitivity to selectively attend to human speech and to process it in a unique way has been widely reported in the past. However, in order to successfully acquire language, one should also understand that speech is a referential, and that words can stand for other entities in the world. While there has been some evidence showing that young infants can make inferences about the communicative intentions of a speaker, whether they would also appreciate the direct relationship between a specific word and its referent, is still unknown. In the present study we tested four-month-old infants to see whether they would expect to find a referent when they hear human speech. Our results showed that compared to other auditory stimuli or to silence, when infants were listening to speech they were more prepared to find some visual referents of the words, as signalled by their faster orienting towards the visual objects. Hence, our study is the first to report evidence that infants at a very young age already understand the referential relationship between auditory words and physical objects, thus show a precursor in appreciating the symbolic nature of language, even if they do not understand yet the meanings of words.

No MeSH data available.


Related in: MedlinePlus