Sensitivity to vocal emotions emerges in newborns at 37 weeks gestational age
Xinlin Hou1, Peng Zhang1,2, Licheng Mo3
1Department of Pediatrics, Peking University First Hospital, Beijing, China.
Insights
Neonates develop the ability to perceive vocal emotions around 37 weeks gestational age (GA). This enhanced emotional sensitivity, crucial for social development, emerges after 37 weeks GA.
Area of Science:
- Developmental Neuroscience
- Neonatal Perception
- Auditory Processing
Background:
- Emotional responsiveness in neonates is vital for communication.
- Understanding the onset of emotional sensitivity and its link to gestational age (GA) is crucial for early social-emotional development.
Purpose of the Study:
- To investigate the developmental trajectory of emotional vocal perception in neonates.
- To determine the relationship between gestational age and the ability to discern emotional prosody.
Main Methods:
- 120 healthy neonates were grouped by gestational age (35-40 weeks).
- Event-related potentials (ERPs) and the odd-ball paradigm were used during natural sleep.
- Neonates were exposed to vocal stimuli with happy/neutral prosodies and acoustically matched control sounds.
Main Results:
- A significant developmental change in perceptual acuity for emotional vocal expressions was observed at 37 weeks GA.
- Neonates at or beyond 37 weeks GA showed a mismatch response to positive emotional prosody, absent in younger neonates and control sounds.
- Neonates younger than 37 weeks GA did not exhibit this discrimination ability.
Conclusions:
- Gestational age significantly shapes early perceptual abilities for emotional vocal cues.
- The findings suggest a critical period around 37 weeks GA for developing sensitivity to vocal emotions.
- This research contributes to understanding early social-emotional development and neurodevelopmental disorders.
Abstract:
Emotional responsiveness in neonates, particularly their ability to discern vocal emotions, plays an evolutionarily adaptive role in human communication and adaptive behaviors. The developmental trajectory of emotional sensitivity in neonates is crucial for understanding the foundations of early social-emotional functioning. However, the precise onset of this sensitivity and its relationship with gestational age (GA) remain subjects of investigation. In a study involving 120 healthy neonates categorized into six groups based on their GA (ranging from 35 and 40 weeks), we explored their emotional responses to vocal stimuli. These stimuli encompassed disyllables with happy and neutral prosodies, alongside acoustically matched nonvocal control sounds. The assessments occurred during natural sleep states using the odd-ball paradigm and event-related potentials. The results reveal a distinct developmental change at 37 weeks GA, marking the point at which neonates exhibit heightened perceptual acuity for emotional vocal expressions. This newfound ability is substantiated by the presence of the mismatch response, akin to an initial form of adult mismatch negativity, elicited in response to positive emotional vocal prosody. Notably, this perceptual shift's specificity becomes evident when no such discrimination is observed in acoustically matched control sounds. Neonates born before 37 weeks GA do not display this level of discrimination ability. This developmental change has important implications for our understanding of early social-emotional development, highlighting the role of gestational age in shaping early perceptual abilities. Moreover, while these findings introduce the potential for a valuable screening tool for conditions like autism, characterized by atypical social-emotional functions, it is important to note that the current data are not yet robust enough to fully support this application. This study makes a substantial contribution to the broader field of developmental neuroscience and holds promise for future research on early intervention in neurodevelopmental disorders.
