Five-month-old infants' discrimination of visual-tactile synchronous facial stimulation

The distinction between self and other is crucial for self-awareness and for our awareness of others. However, how human beings learn to associate the face they see in the mirror with themselves is still a matter of debate. The exploration of body-related multisensory processing with infants has demonstrated that they can detect visual-tactile contingencies, suggesting the presence of early implicit body perception simply based on the spatiotemporal matching between visual and tactile stimuli alone. In the present study, we used facial stimuli to investigate 5-month-old infants' visual preference for visual-tactile temporal synchrony. Infants watched a side-by-side video display of a peer's face being systematically stroked on the cheek with a paintbrush. During the video presentation, the infant's own cheek was stroked in synchrony with one video and in asynchrony with the other. Our result demonstrates that 5-month-old infants are able to discriminate between visual-tactile synchrony and asynchrony, by showing a visual preference for the synchronous facial stimulus

Five-Month-old Infants' Discrimination of Visual-Tactile Synchronous Facial Stimulation

The distinction between self and other is crucial for self‐awareness and for our awareness of others. However, how human beings learn to associate the face they see in the mirror with themselves is still a matter of debate. The exploration of body‐related multisensory processing with infants has demonstrated that they can detect visual‐tactile contingencies, suggesting the presence of early implicit body perception simply based on the spatiotemporal matching between visual and tactile stimuli alone. In the present study, we used facial stimuli to investigate 5‐month‐old infants' visual preference for visual‐tactile temporal synchrony. Infants watched a side‐by‐side video display of a peer's face being systematically stroked on the cheek with a paintbrush. During the video presentation, the infant's own cheek was stroked in synchrony with one video and in asynchrony with the other. Our result demonstrates that 5‐month‐old infants are able to discriminate between visual‐tactile synchrony and asynchrony, by showing a visual preference for the synchronous facial stimulus

Body perception in newborns

Body ownership and awareness has recently become an active topic of research in adults using paradigms such as the “rubber hand illusion” and “enfacement” [1, 2, 3, 4, 5, 6, 7, 8, 9, 10 and 11]. These studies show that visual, tactile, postural, and anatomical information all contribute to the sense of body ownership in adults [12]. While some hypothesize body perception from birth [13], others have speculated on the importance of postnatal experience [14 and 15]. Through studying body perception in newborns, we can directly investigate the factors involved prior to significant postnatal experience. To address this issue, we measured the looking behavior of newborns presented with visual-tactile synchronous and asynchronous cues, under conditions in which the visual information was either an upright (body-related stimulus; experiment 1) or inverted (non-body-related stimulus; experiment 2) infant face. We found that newborns preferred to look at the synchronous condition compared to the asynchronous condition, but only when the visual stimulus was body related. These results are in line with findings from adults and demonstrate that human newborns detect intersensory synchrony when related to their own bodies, consistent with the basic processes underlying body perception being present at birth

Just before I recognize myself: the role of featural and multisensory cues leading up to explicit mirror self-recognition

Leading up to explicit mirror self-recognition, infants rely on two crucial sources of information: the continuous integration of sensorimotor and multisensory signals, as when seeing one's movements reflected in the mirror, and the unique facial features associated with the self. While visual appearance and multisensory contingent cues may be two likely candidates of the processes that enable self-recognition, their respective contribution remains poorly understood. In this study, 18-month-old infants saw side-by-side pictures of themselves and a peer, which were systematically and simultaneously touched on the face with a hand. While watching the stimuli, the infant's own face was touched either in synchrony or out of synchrony and their preferential looking behavior was measured. Subsequently, the infants underwent the mirror-test task. We demonstrated that infants who were coded as nonrecognizers at the mirror test spent significantly more time looking at the picture of their own face compared to the other-face, irrespective of whether the multisensory input was synchronous or asynchronous. Our results suggest that right before the onset of mirror self-recognition, featural information about the self might be more relevant in the process of recognizing one's face, compared to multisensory cues

Self or (M)other? Infants’ Sensitivity to Bodily Overlap with their Mother Reflects their Dyadic Coordination

Adults experience greater self‐other bodily overlap in romantic than platonic relationships. One of the closest relationships is between mother and infant, yet little is known about their mutual bodily representations. This study measured infants’ sensitivity to bodily overlap with their mother. Twenty‐one 6‐ to 8‐month‐olds watched their mother’s face or a stranger’s face being stroked synchronously versus asynchronously with their own face. Infants preferred synchrony only when viewing their mother, not when viewing the stranger. Infants who strongly preferred synchrony with their mother also experienced less coordination with her in naturalistic interactions. Infants thus appear sensitive to bodily overlap with their mother, and this overlap reflects dyadic coordination, supporting theoretical accounts of intersubjectivity in the development of the bodily self

Synchrony of Caresses: Does Affective Touch Help Infants to Detect Body-Related Visual–Tactile Synchrony?

Bodily self-awareness, that is the ability to sense and recognize our body as our own, involves the encoding and integration of a wide range of multisensory and motor signals. Infants’ abilities to detect synchrony and bind together sensory information in time and space critically contribute to the process of gradual bodily self-awareness. In particular, early tactile experiences may have a crucial role in promoting self-other differentiation and developing bodily self-awareness. More specifically affective touch, slow and gentle touch linked to the neurophysiologically specialized system of C-tactile afferents, provides both information about the body from within (interoception) and outside (exteroception), suggesting it may be a key component contributing to the experience of bodily self-awareness. The present study aimed to investigate the role of affective touch in the formation and modulation of body perception from the earliest stages of life. Using a preferential looking task, 5-month-old infants were presented with synchronous and asynchronous visuo–tactile body-related stimuli. The socio-affective valence of the tactile stimuli was manipulated by means of the velocity [CT-optimal (slow) touch vs. CT-suboptimal (fast) touch] and the source of touch (human hand vs. brush). For the first time, we show that only infants that were stroked using a brush at slow velocity displayed a preference for the visual–tactile synchronous video, suggesting that CT-optimal touch might help infants to detect body-related visual–tactile synchrony, independently from the source of touch. Our results are in line with findings from adults and indicate that affective touch might have a critical role in the early development of bodily self-awareness

Infant and Child Multisensory Attention Skills: Methods, Measures, and Language Outcomes

Intersensory processing (e.g., matching sights and sounds based on audiovisual synchrony) is thought to be a foundation for more complex developmental outcomes including language. However, the body of research on intersensory processing is characterized by different measures, paradigms, and research questions, making comparisons across studies difficult. Therefore, Manuscript 1 provides a systematic review and synthesis of research on intersensory processing, integrating findings across multiple methods, along with recommendations for future research. This includes a call for a shift in the focus of intersensory processing research from that of assessing average performance of groups of infants, to one assessing individual differences in intersensory processing. Individual difference measures allow researchers to assess developmental trajectories and understand developmental pathways from basic skills to later outcomes. Bahrick and colleagues introduced the first two new individual difference measures of intersensory processing: The Multisensory Attention Assessment Protocol (MAAP) and The Intersensory Processing Efficiency Protocol (IPEP). My prior research using the MAAP has shown that accuracy of intersensory processing at 12 months of age predicted 18- and 24-month child language outcomes. Moreover, it predicted child language to a greater extent than well-established predictors, including parent language input and SES (Edgar et al., under review)! Manuscript 2 extends this research to examine both speed and accuracy of intersensory processing using the IPEP. A longitudinal sample of 103 infants were tested with the IPEP to assess relations between intersensory processing at 6 months of age and language outcomes at 18, 24, and 36 months, while controlling for traditional predictors, parent language input and SES. Results demonstrate that even at 6 months, intersensory processing predicts 18-, 24-, and 36-month child language skills, over and above the traditional predictors. This novel finding reveals the powerful role of intersensory processing in shaping language development and highlights the importance of incorporating individual differences in intersensory processing as a predictor in models of developmental pathways to language. In turn, these findings can inform interventions where intersensory processing can be used as an early screener for children at risk for language delays

Detection of Modality-Specific Properties in Unimodal and Bimodal Events during Prenatal Development

Predictions of the Intersensory Redundancy Hypothesis (IRH) state that early in development information presented to a single sense modality (unimodal) selectively recruits attention to and enhances perceptual learning of modality-specific properties of stimulation at the expense of amodal properties, while information presented redundantly across two or more modalities (bimodal) results in enhanced perceptual learning of amodal properties. The present study explored these predictions during prenatal development by assessing bobwhite quail embryos’ detection of pitch, a modality-specific property, under conditions of unimodal and redundant bimodal stimulation. Chicks’ postnatal auditory preferences between the familiarized call and the same call with altered pitch were assessed following hatching. Unimodally-exposed chicks significantly preferred the familiarized call over the pitch-modified call, whereas bimodally-exposed chicks did not prefer the familiar call over the pitch-modified call. Results confirm IRH predictions, demonstrating unimodal exposure facilitates learning of modality-specific properties, whereas redundant bimodal stimulation interferes with learning of modality-specific properties

Newborns' preference for female voices as a function of spectral composition

Research with human fetuses and neonates has demonstrated that last trimester fetuses can hear in utero and that neonates prefer auditory stimuli which are experienced prenatally to novel auditory stimuli. This study was conducted to determine if prenatal experience with the lower frequencies of the maternal voice influence postnatal voice preferences. Tape recordings of maternal voices were low-pass filtered at 1000 Hz in order to simulate intrauterine recordings of maternal voices. Neonates were placed in a discriminated-operant choice task in which they could choose between a recording of the maternal unfiltered voice and the maternal low-pass voice. A second group of neonates was presented the same recordings to assess neonates' preferences for low-pass (nonmaternal) female voices in general. The same unfiltered voice recordings were high-pass filtered at 1000 Hz and the high-pass and unfiltered versions of these voices were presented to a third group of neonates to assess their preferences. The high-pass voices were different from any voices experienced while the unfiltered voices were more similar to maternal prenatal voices