Babies Can Sense Their Heartbeat at Just 3 Months Old, Study Shows
A new study from the University of Vienna reveals that babies as young as three months can perceive their own heartbeat. This discovery shifts the understanding of when self-awareness begins, suggesting that bodily perception β closely tied to emotions, identity, and social interaction β starts much earlier than previously believed. Researchers also found that infants gradually develop awareness of their own breathing during the second year of life. The findings offer crucial insight into how early bodily signals shape emotional and cognitive development.
Inside the Study: Babies Know Their Bodies Earlier Than We Thought
Research Institutions and Authors
As Neuroscience News reports, the study was conducted at the Wiener Kinderstudien Lab at the University of Vienna (Austria), in collaboration with researchers from the University of Potsdam (Germany) and Royal Holloway, University of London (United Kingdom). The lead author of the study is Markus TΓΌnte from the University of Vienna, and the results were published in the peer-reviewed journal eLife (https://doi.org/10.7554/eLife.91579.4).
Study Design and Participants
Measuring body awareness in infants presents a challenge because young children cannot describe their experiences verbally. To overcome this, researchers turned to eye-tracking technology, observing how long babies looked at animated figures that moved either in synchrony or slightly out of sync with their internal body signals β specifically heartbeat and breathing.
The study involved 135 infants for the heartbeat awareness portion and 120 infants for the breathing perception experiment. Infants were tested at 3 months, 9 months, and 18 months, using both cross-sectional (comparing different children of different ages) and longitudinal (following the same children over time) methods.
Innovative Methods Used
The research team used a modified version of the cardiac interoceptive sensitivity paradigm originally introduced by Maister et al. in 2017. They also developed a new experimental approach to assess, for the first time, how infants perceive their own breathing.
Child-friendly animated figures were shown on a screen. These figures either moved in perfect synchronization with the childβs heartbeat or breathing rhythm β or with a slight temporal delay. Using a sensor to track the babyβs heartbeat and breathing, researchers could precisely match the animations to the baby’s internal rhythms.
The key observation: babies looked longer at the figures that matched their own physiological rhythms, indicating they sensed the synchronicity.
What Makes This Study Different
This research is the first to demonstrate that:
- Infants as young as 3 months can detect their own heartbeat.
- The perception of breathing as an internal signal develops significantly after the first year.
- Heartbeat and breathing awareness appear to be independent systems in infancyβjust as in adults.
Previous studies on interoception (the sense of internal body signals such as heartbeat, breathing, hunger, or temperature) in infants focused mainly on children aged 5 to 7 months and only tested heartbeat awareness. This new study greatly extends both the age range (starting at 3 months) and the type of body signals studied by including breathing.
Additionally, the researchers used specification curve and mega-analytic approaches to validate their results β ensuring robustness across various analytical models.
What the Study Revealed: 5 Key Discoveries About Infant Body Awareness
1. Heartbeat Awareness Begins at 3 Months. Babies looked significantly longer at animations that matched their heartbeat even at just three months old.
Example: A three-month-old baby lying quietly in a crib may not respond to toys or sounds, but their body is already picking up the rhythm of their own heartbeat.
2. Heartbeat Perception Is Stable Across First Two Years. The ability to detect heartbeat did not show significant change between 3, 9, and 18 months.
Example: Whether a baby is being rocked in a stroller or cuddled during story time, they continue to feel their heartbeat β a steady inner rhythm they carry every day.
3. Breathing Perception Improves with Age. Unlike heartbeat perception, awareness of breathing increased notably during the second year of life.
Example: Around 18 months, a toddler may start to notice their breath speeding up when they run or slowing down when they calm down after crying.
4. Heartbeat and Breathing Are Perceived Independently. The study found no strong relationship between the two forms of interoception at 3 and 9 months, only limited links by 18 months.
Example: A baby might sense their heartbeat clearly but not yet register how their breathing changes when theyβre excited or tired.
5. Body Awareness Can Be Measured Without Language. Observing how long a baby looks at something helps researchers study early cognitive development without relying on words.
Example: When researchers show animations that move in sync with a babyβs heartbeat, and the baby watches longer, it shows awareness β without needing words.
Early Body Signals and Cognitive Abilities
The discovery that infants can sense internal signals like their heartbeat and breathing lays the groundwork for understanding how bodily awareness supports the development of cognition. Interoception β our ability to perceive internal bodily states β is increasingly recognized as a foundational layer of consciousness. In infants, this early sensitivity may serve as the very first form of self-perception, long before they learn to recognize themselves in a mirror or refer to themselves by name.
Body awareness is not just physical β it is closely tied to the brainβs ability to regulate emotions, make decisions, and interpret social cues. For example, sensing a racing heartbeat can alert a child to internal excitement or distress, which helps develop early emotional intelligence. The stable perception of the heartbeat from three months onward could act as a sort of internal compass, helping infants maintain a sense of physiological consistency as they encounter new environments and experiences.
Moreover, interoception is thought to influence attention and learning. A child who can detect internal discomfort may better communicate needs, reducing frustration and allowing more cognitive resources to be directed toward exploration and interaction. This is especially important in the first years of life, when every interaction is an opportunity to build neural connections.
Researchers also believe that disruptions in interoception may be linked to developmental conditions. Studies in older children and adults have shown altered interoceptive processing in individuals with autism spectrum disorder, anxiety, and eating disorders. Understanding how this awareness begins β and how it typically unfolds β could help clinicians detect signs of atypical development earlier, offering more effective and targeted interventions during critical developmental windows.
By revealing that infants can detect internal rhythms well before they can speak or walk, the study offers a compelling view of how deeply interconnected the body and brain are from the very beginning of life.ive processes related to self-awareness are present far earlier than language or conscious memory.
How a Babyβs Heartbeat Sense Is Reshaping What We Know About Early Development
The findings from this study are more than a fascinating insight into infant perception β they could redefine how we understand early human development and how we support it across medicine, education, and family life.
For developmental psychologists, the study challenges long-held assumptions that self-awareness only emerges in the second year of life. If babies can detect their own heartbeat at just three months, it suggests that the roots of self-perception form much earlier β and perhaps lay the groundwork for later emotional and cognitive milestones. This could shift theories about when consciousness begins and how identity takes shape.
From a medical standpoint, early body awareness may turn out to be a key marker in identifying neurodevelopmental conditions. Disruptions in interoception have been linked to autism, anxiety, and other disorders later in life. If clinicians can track how infants respond to their internal signals, it could open the door to earlier diagnosis and targeted interventions β well before symptoms become more visible.
In education and parenting, these results highlight the importance of tuning into a childβs physical experience even in infancy. Programs that incorporate breathing awareness, emotional coaching, or physical self-regulation might be more effective if they align with the natural timeline of bodily awareness development. Parents, too, can benefit from understanding that babies arenβt just reacting to external stimuli β theyβre also processing whatβs happening inside their own bodies.
Digital tools can also play a growing role in this process. Applications like BabyBright by CogniFit are designed to help parents monitor developmental milestones, offering guidance on whether a babyβs cognitive development is on track for their age. In light of this study, such tools highlight the growing importance of supporting early development β helping caregivers become more attuned to subtle aspects of infant behavior and interaction.
And from a broader societal perspective, this research reinforces the need to support mental and emotional well-being from the very start of life. The earliest interactions between caregivers and babies β responding to hunger, soothing distress, regulating rhythm β are not just acts of care. They are part of the babyβs emerging sense of self.
In short, a baby sensing their heartbeat may seem like a small thing. But it might just be the first signal in a lifetime of self-awareness.
Conclusion: The Earliest Form of Self-Awareness May Start with a Heartbeat
The discovery that 3-month-old babies can sense their heartbeat reshapes how we understand the origins of self-awareness and emotional development. By demonstrating both cardiac and respiratory interoception in infants β and showing that these processes unfold independently β this study opens up new frontiers in developmental science.
The research also underscores the sophistication of even the youngest minds. Before babies can speak, walk, or point, they may already possess a foundational connection to their inner world. In recognizing these early signals, scientists take a step closer to understanding the roots of consciousness, emotion, and human identity itself.
