New Method Aims to Pinpoint When Infants Become Conscious
Author: University of Birmingham
Published: 22 Mar 2024 - Updated: 18 Jul 2026
Publication Details: Peer-Reviewed | Experimental Study
Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content
Synopsis
This research examines a new and improved approach for identifying when consciousness first emerges in human infancy, a question that has puzzled philosophers and psychologists since René Descartes. Writing in a peer-reviewed Letter to the Editor published in Trends in Cognitive Sciences, Dr Henry Taylor and Professor Andrew Bremner of the University of Birmingham respond to a recent proposal by Professor Tim Bayne and colleagues. That earlier work identified four markers of consciousness and argued that awareness begins early, from the last prenatal trimester, but Taylor and Bremner contend this overlooks a separate cluster of later-emerging markers such as pointing, intentional control, and explicit memory. Because babies cannot report their own experiences, the authors recommend grouping a broad range of markers that appear across both early and late development, rather than relying on a narrow set that points to a single age. The work matters for developmental psychologists, philosophers of mind, parents, and those interested in disability and early cognition, since a clearer understanding of when awareness arises has implications for infant care, ethics, and how we interpret the inner lives of the very young.*
At a Glance
- 1 - Some markers of consciousness only appear around three to four years of age. This shows the markers do not all point to one single moment of onset.
- 2 - Descartes himself suggested that infants might have thoughts, though simpler ones than adults. His view helped frame a debate that has continued for hundreds of years.
- 3 - The authors propose that consciousness may emerge gradually and continuously across gestation and early life, rather than switching on at a single point. They also suggest markers could arrive in separate early and late clusters.
Topic Definition
- Markers of Consciousness
Markers of Consciousness are the observable behaviors and patterns of brain activity that reliably accompany conscious awareness in adults and can therefore serve as clues to whether awareness is present in beings who cannot describe their own experiences, such as infants. Because a baby cannot tell you what it feels or perceives, scientists look for these outward signs - things like pointing to draw a partner's attention, coordinating actions toward a goal, or showing memory through imitation - and track the age at which they first appear. The core idea is that if a specific behavior or neural signature always goes hand in hand with consciousness in adults, then its appearance in a developing child gives researchers reason to believe awareness has begun. Since different markers surface at different points, from the final trimester of pregnancy through the first few years of life, grouping a broad set of them together offers a more reliable picture than depending on any one alone.
Overview
When Over the Course of Development Do Humans Become Conscious?
When the seventeenth-century French philosopher René Descartes was asked about infant consciousness by his critics, he eventually suggested that infants might have thoughts, albeit ones that are simpler than those of adults. Hundreds of years later, the issue of when human beings become conscious is a question which remains a challenge for psychologists and philosophers alike.
But now, in response to a recent article in Trends in Cognitive Sciences, two academics from the University of Birmingham have suggested an improved way to help scientists and researchers identify when babies become conscious.
In a Letter to the Editor, also published in Trends in Cognitive Sciences, Dr Henry Taylor, Associate Professor of Philosophy, and Andrew Bremner, Professor of Developmental Psychology, have explored a new approach which is being proposed, that involves identifying markers of consciousness in adults, and then measuring when babies start to exhibit larger numbers of these in development.
Dr Taylor says:
"For example, imagine that in adults, we know that a certain very specific behavior, or a specific pattern of brain activation always comes along with consciousness. Then, if we can identify when this behavior or brain activation arises in babies, we have good reason to think that this is when consciousness emerges in babies. Behaviors and brain activations like this are what we call ‘markers' of consciousness."
This kind of approach is desperately needed since babies (unlike adults) cannot tell you what they are conscious of. Professor Bremner said:
"It is really hard to establish when babies become conscious. This is mostly because infants can't report their experiences and, as most parents will know, can be rather uncooperative particularly when it comes to experimental tasks. As we can't just ask babies when they become conscious, the best approach is to try to identify a broad range of markers of consciousness, which appear in early development and late development, and then group them together, this could help us identify when consciousness emerges."
In the recent article the researchers (Prof. Tim Bayne and colleagues) suggested four specific markers of consciousness, some of which are present in the late stages of gestation, and others which are found in early infancy. Based on this, the study argues that consciousness emerges early (from the last prenatal trimester).
But Professor Bremner and Dr Taylor say that this ignores other markers of consciousness. Previous research has identified a separate cluster of markers. These include:
- Pointing (bringing a social partner's attention to an object and checking).
- Intentional control (intentional means-end coordination of actions - e.g., pulling a support to retrieve a distal object).
- Explicit memory (deferred imitation of actions).
Dr Taylor said:
"One of the complicated issues is that it does not look like all the markers point to the same age for the emergence of consciousness. The ones mentioned by Bayne and colleagues suggest somewhere between the third trimester of pregnancy and early infancy, but other markers suggest the age might be around one year old. In fact, at the really extreme end, some markers only emerge at around 3-4 years. Because there are so many different markers of consciousness which appear in early and late development it is extremely hard to come to a conclusion."
Professor Bremner concluded:
"We propose that a broad approach to markers, including those that emerge in early and late stage, is needed. We also recommend that a range of developmental models of the onset of consciousness should be considered. For instance, it may be that some markers emerge in one cluster in early development, with others in a later cluster. As well as this there may be a continuous and gradual emergence of certain markers stretching over gestation and throughout early life."
"We think that by clustering this broad selection of markers, we may finally be able to answer the question which has given us pause for thought for thousands of years. But it's important to bear in mind that the answer may not be a simple one!"
University of Birmingham
The University of Birmingham is ranked amongst the world's top 100 institutions. Its work brings people from across the world to Birmingham, including researchers, teachers and more than 8,000 international students from over 150 countries.
Frequently Asked Questions
NOTE: Researched FAQs by Disabled World (DW)
What are the four markers of consciousness mentioned in the original proposal?
The article references four specific markers suggested by Professor Tim Bayne and colleagues, some present in the late stages of gestation and others in early infancy, though the piece focuses on the response rather than listing each one in detail.
Why can't scientists simply ask babies when they become conscious?
Infants cannot report their own experiences and are often uncooperative during experimental tasks, so researchers must rely on observable behaviors and brain activity instead of direct self-reports to infer when awareness begins.
What journal published this response by the Birmingham academics?
The response appeared as a Letter to the Editor in the journal Trends in Cognitive Sciences, the same publication that carried the original article the two academics were responding to.
How does the emergence of consciousness relate to disability research?
Understanding when and how awareness develops can inform how clinicians and caregivers interpret the responses of infants and individuals who cannot communicate verbally, which has relevance for early developmental assessment and care.
Does the study claim to have a definitive answer about infant consciousness?
No, the authors are clear that the answer may not be simple. They argue that a broad approach and multiple developmental models are needed rather than a single fixed point of onset.
What is deferred imitation and why does it matter here?
Deferred imitation is when a child reproduces an action they observed earlier, which serves as evidence of explicit memory. It is one of the later-emerging markers the authors say should be included in the analysis.
Who were the two University of Birmingham academics behind this work?
The response was authored by Dr Henry Taylor, an Associate Professor of Philosophy, and Andrew Bremner, a Professor of Developmental Psychology, both based at the University of Birmingham.
Insights, Analysis, and Developments
Editorial Note: What makes this debate so compelling is that it sits at the crossroads of philosophy, neuroscience, and everyday parenting, where a seemingly simple question resists any tidy answer. The Birmingham researchers are careful not to overclaim, stressing instead that no single behavior or brain pattern can settle the matter on its own, and that the honest response may well be a range of overlapping timelines rather than one fixed date. For families, clinicians, and researchers working with infants and children with developmental differences, this measured stance is a reminder that awareness is not an all-or-nothing switch but something that likely unfolds in stages, and that how we choose to define and measure it shapes the conclusions we reach.*
Attribution/Source(s): This peer reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally authored by University of Birmingham and published on 22 Mar 2024, this content may have been edited for style, clarity, or brevity.
* Editorial additions by Ian C. Langtree.