A new study is putting two of the most influential tools for assessing newborn behavior side by side, asking whether the way clinicians measure an infant’s earliest movements, reflexes and responses can shape how that infant’s development is understood. Published in Pediatric Research, the paper, “Neonatal neurobehavior: a tale of two scales contrasting the NICU Network Neurobehavioral Scale with the NeoNatal Neurobehavioral Scale,” examines the distinctions between the NICU Network Neurobehavioral Scale and the NeoNatal Neurobehavioral Scale, two structured approaches designed to capture the complex neurological and behavioral world of newborn babies.
The study is authored by J.R. Amick, L. Liszka, M. Liggett and colleagues, and is dated 29 July 2026. Its subject is especially important in neonatal medicine because newborn behavior is not random or merely a collection of primitive reflexes. Tiny changes in muscle tone, alertness, eye movement, consolability, sucking, habituation and reactions to sound or light can provide clues about how an infant’s nervous system is adapting to life outside the womb.
For clinicians working in neonatal intensive care units, those clues can be difficult to interpret. Premature infants, babies exposed to medications, newborns recovering from illness and infants experiencing withdrawal may all display unusual patterns of movement or regulation. Yet the same behavior can carry different meanings depending on when it is observed, how the examination is structured and which assessment scale is used. A newborn who is difficult to soothe, for example, may be responding to pain, overstimulation, neurological immaturity or withdrawal-related stress.
The NICU Network Neurobehavioral Scale, commonly known as the NNNS, was developed specifically for infants at increased medical or developmental risk. It combines neurological examination with behavioral observation, assessing factors such as muscle tone, reflexes, attention, arousal, self-regulation and signs of stress. The scale can also record subtle behaviors that may not be visible during a routine physical examination, including changes in color, tremors, startles, frantic movements or difficulty maintaining an organized state.
The NeoNatal Neurobehavioral Scale belongs to a different tradition of newborn assessment. It is designed to explore how an infant responds to social and sensory experiences while also evaluating neurological function. Depending on the examination protocol, areas may include habituation to repeated stimuli, orientation toward a face or voice, motor organization, range of state, regulation, reflexes and signs of stress. Rather than treating the newborn as a passive patient, this approach presents the infant as an active participant in an ongoing interaction with the environment.
That distinction matters because neonatal neurobehavior is highly state-dependent. A baby who is deeply asleep may respond differently from one who is quietly alert, and an infant who has just undergone a medical procedure may show a very different pattern from one who has been resting. Feeding, temperature, pain, medication, gestational age and the surrounding level of noise can all influence performance. The two scales may therefore emphasize different aspects of the same infant’s abilities, vulnerabilities and coping strategies.
By contrasting the tools, the authors focus attention on a long-standing challenge in developmental medicine: how to translate a brief clinical examination into meaningful information about the brain. Neither scale is a direct “window” into the newborn brain, and neither can predict a child’s future on its own. Instead, each provides a structured snapshot of how neurological systems and behavior are functioning at a particular moment. The value of that snapshot depends on training, timing, context and careful interpretation.
The comparison also has implications for research. Studies that use different neurobehavioral scales may appear to measure the same outcome while actually capturing different dimensions of infant development. One instrument may be more sensitive to stress signals and neurological organization, while another may reveal differences in attention, interaction and regulation. If researchers do not account for those distinctions, results from separate studies can be difficult to compare, potentially obscuring which early behaviors are most strongly linked to later outcomes.
The paper arrives as neonatal care increasingly moves beyond survival rates toward a deeper understanding of quality of life and long-term development. Advances in intensive care have helped more premature and medically fragile infants survive, but these children may remain vulnerable to later difficulties involving learning, attention, motor coordination, sensory processing and emotional regulation. Reliable early assessments could help clinicians identify infants who may benefit from developmental support, while also offering researchers a more precise way to study how early medical experiences affect the developing nervous system.
The significance of the “tale of two scales” is therefore not that one instrument can simply replace the other. Instead, the comparison highlights that newborn behavior is multidimensional and that every assessment tool carries its own priorities, terminology and assumptions. As neonatal medicine becomes more individualized, understanding exactly what each scale measures—and what it does not—will be essential. The newborn examination may last only a short time, but the interpretation of those fragile signals can influence clinical decisions, research conclusions and the way medicine understands the earliest stages of human development.
Subject of Research: Neonatal neurobehavioral assessment and the comparison of the NICU Network Neurobehavioral Scale with the NeoNatal Neurobehavioral Scale.
Article Title: Neonatal neurobehavior: a tale of two scales contrasting the NICU Network Neurobehavioral Scale with the NeoNatal Neurobehavioral Scale.
Article References: Amick, J.R., Liszka, L., Liggett, M. et al. “Neonatal neurobehavior: a tale of two scales contrasting the NICU Network Neurobehavioral Scale with the NeoNatal Neurobehavioral Scale.” Pediatric Research (2026). https://doi.org/10.1038/s41390-026-05187-x
Image Credits: AI Generated
DOI: 10.1038/s41390-026-05187-x
Keywords: neonatal neurobehavior, newborn assessment, NICU, NICU Network Neurobehavioral Scale, NeoNatal Neurobehavioral Scale, premature infants, infant development, neurological examination, neonatal intensive care.
