Newborns modulate their crawling in response to their native language but not another language

Human newborns can propel themselves to their mother's breast when positioned skin to skin on her abdomen just after birth. For decades, researchers have considered this primitive crawling behavior a spinal reflex, immune to supra spinal control. However, recent research suggests that neonatal crawling is already responsive to visual and olfactory stimuli processed at a supra spinal level. Here we report that a few hours post birth, French newborns can also modulate their crawling in response to their native language – a source of information that is processed supra-spinally. The crawling patterns of 23 French-born newborns were recorded on video and via an infrared motion capture system during two randomly ordered 2-min trials. The newborns were secured on a mini skateboard to facilitate arm and leg movements during their crawling propulsion. They heard a repetitive sequence of the same sentences either in French, their native language, or in English, a rhythmically different and hence discriminable unfamiliar language, on each trial. In French, compared to English, crawling was enhanced, with significantly more arm and leg steps and significantly more and larger trunk rotations in the cephalo-caudal axis. Moreover, newborns rotated their heads and trunk toward the appropriate loud speaker when hearing French but not English. These preliminary findings suggest that newborn crawling is not a simple stereotyped reflex under spinal control, but a complex pattern that can be modulated in response to higher-order, supra-spinally processed stimuli. The findings open fascinating questions about the range of stimuli to which newborn crawling is responsive.     

Newborns discriminate utterance-level prosodic contours

Prosody is the fundamental organizing principle of spoken language, carrying lexical, morphosyntactic, and pragmatic information. It, therefore, provides highly relevant input for language development. Are infants sensitive to this important aspect of spoken language early on? In this study, we asked whether infants are able to discriminate well-formed utterance-level prosodic contours from ill-formed, backward prosodic contours at birth. This deviant prosodic contour was obtained by time-reversing the original one, and super-imposing it on the otherwise intact segmental information. The resulting backward prosodic contour was thus unfamiliar to the infants and ill-formed in French. We used near-infrared spectroscopy (NIRS) in 1-3-day-old French newborns (n = 25) to measure their brain responses to well-formed contours as standards and their backward prosody counterparts as deviants in the frontal, temporal, and parietal areas bilaterally. A cluster-based permutation test revealed greater responses to the Deviant than to the Standard condition in right temporal areas. These results suggest that newborns are already capable of detecting utterance-level prosodic violations at birth, a key ability for breaking into the native language, and that this ability is supported by brain areas similar to those in adults.

Research Highlights

• At birth, infants have sophisticated speech perception abilities.
• Prosody may be particularly important for early language development.
• We show that newborns are already capable of discriminating utterance-level prosodic contours.
• This discrimination can be localized to the right hemisphere of the neonate brain.

     

The neonate brain's sensitivity to repetition-based structure: Specific to speech?

Newborns are able to extract and learn repetition-based regularities from the speech input, that is, they show greater brain activation in the bilateral temporal and left inferior frontal regions to trisyllabic pseudowords of the form AAB (e.g., “babamu”) than to random ABC sequences (e.g., “bamuge”). Whether this ability is specific to speech or also applies to other auditory stimuli remains unexplored. To investigate this, we tested whether newborns are sensitive to regularities in musical tones. Neonates listened to AAB and ABC tones sequences, while their brain activity was recorded using functional Near-Infrared Spectroscopy (fNIRS). The paradigm, the frequency of occurrence and the distribution of the tones were identical to those of the syllables used in previous studies with speech. We observed a greater inverted (negative) hemodynamic response to AAB than to ABC sequences in the bilateral temporal and fronto-parietal areas. This inverted response was caused by a decrease in response amplitude, attributed to habituation, over the course of the experiment in the left fronto-temporal region for the ABC condition and in the right fronto-temporal region for both conditions. These findings show that newborns’ ability to discriminate AAB from ABC sequences is not specific to speech. However, the neural response to musical tones and spoken language is markedly different. Tones gave rise to habituation, whereas speech was shown to trigger increasing responses over the time course of the study. Relatedly, the repetition regularity gave rise to an inverted hemodynamic response when carried by tones, while it was canonical for speech. Thus, newborns’ ability to detect repetition is not speech-specific, but it engages distinct brain mechanisms for speech and music.

Research Highlights

• The ability of newborns’ to detect repetition-based regularities is not specific to speech, but also extends to other auditory modalities.
• The brain mechanisms underlying speech and music processing are markedly different.

     

Chasing perception in domestic cats and dogs

Animal Cognition - Chasing motion is often used to study the perception of inanimate objects as animate. When chasing interaction and independent motions between two agents are displayed...     

Interpolation and Amalgamation; Pushing the Limits. Part II

This is the second part of the paper [Part I] which appeared in the previous issue of this journal.