Understanding Conscious Awareness and High-order Cognition in Infancy
Chair(s): Lorina Naci (Trinity College Dublin, Ireland)
Abstract
One of the great frontiers of consciousness science is understanding how early consciousness arises in the development of the human infant. Accounts of the ontogeny of consciousness can be divided into two broad camps: ‘early-onset’ views, which locate the emergence of consciousness at, or shortly after, birth, and ‘late-onset’ views, which locate the emergence of consciousness significantly after birth (at least one year old). The lack of language and the very limited motor function preclude self-report or behavioural responses and, thus, prevent the direct empirical assessment of consciousness in fetuses or neonates. To circumvent this problem, some recent studies have taken another strategy, using neuroimaging measures to investigate whether some neural markers for consciousness found in adults already exist in fetuses and very young infants. For instance, the intrinsic connectivity within and across networks that are correlated with the capacity of consciousness (e.g., the default mode and frontoparietal networks) were found to be present in neonates at full-term birth or term-equivalent age. The P300-like “negative slow wave” responses (to global oddballs) — a putative EEG signature of conscious processing in adults — were observed in newborns and fetuses past 35 weeks of gestational age. We will present these and other recent findings suggesting that the capacity for consciousness is in place at birth. We will also consider key factors in the ontogeny of high-order cognition, such as sleep, social interaction and affectionate touch. Finally, we will consider the ethical implications of the early onset of consciousness in human development.
Rationale on symposium's general scientific interest
From the potential to unlock a wealth of knowledge on optimizing learning and lifelong outcomes to transforming neonatal care, understanding the ontogeny of consciousness holds great interest for scientific advancement and clinical practice.
The general scientific interest in this area is evident in a glut of expert reviews, from nearly none to seven in the last four years (Dehaene-Lambertz 2024 Journal of Cognitive Neuroscience, Passos-Ferreira 2024 Neuron, Frohlich and Bayne 2024 Acta Paediatrica, Birch 2024 The Edge of Sentience, Bayne et al. 2023 Trends in Cognitive Sciences, Ciaunica et al. 2021 Neuroscience of Consciousness, Padilla and Lagercrantz Acta Paediatrica 2020).
Rationale on complementarity of talks
Two neuroscientists, a philosopher and a consultant neonatologist, all actively engaged in infant consciousness research, will present the latest state-of-the-art developments in this field. Various technologies, including MRI, EEG and diffuse optical tomography will be merged to address the question of infant awareness, from diverse perspectives including an ethical and theoretical framework (Passos-Ferreira), data-driven evidence (Frohlich, Naci) and clinical experience on the neonatal intensive care unit (Austin). This work will inform ethical considerations of newborn consciousness for individual infants, their carers and the wider society, as well as new directions in this burgeoning field.
Rationale on timeliness/importance
The recent increased attention in infant consciousness builds on 20 years of methodological and conceptual advances in consciousness science. Historically, newborn infants routinely underwent surgical procedures without anaesthesia or analgesia, a practice that continued into the 1980s. To this day, clinicians face the challenge of balancing the potential for pain in painful medical procedures (e.g., intubations) against the risks associated with medications intended to alleviate that pain. These medical decisions would hugely benefit from empirical evidence on the timing and nature of conscious awareness in infants. We now have the tools to address scientifically these fundamental questions.
Rationale on panel inclusivity
The symposium has a diverse intellectual background with speakers in different career stages: a senior neuroscientist, a senior neonatal clinician, a tenure-track philosopher-psychologist, and a junior postdoc neuroscientist. Demographically, it has national, ethnic, and gender diversity in national origin and ethnicity (an Albanian-Canadian woman, a Brazilian woman, an American man, and an Indian-French-Australian man.) Furthermore, four universities accross mainland Europe (Unviersity of Tübingen, Germany), northern Europe (University of Cambridge, UK; Trinity College Dublin, Ireland) and the United States (New York University, USA) are represented.
Presentations of the Symposium
Typical and Disrupted Neural Circuitry for Conscious Awareness in Human Neonates
Lorina Naci
Trinity College Dublin, Ireland
To date, it has remained unknown whether conscious awareness is present in newborn infants and whether its development is affected by premature birth. Critically, the lack of language and the very limited motor function preclude self-report or behavioural responses and, thus, prevent the assessment of infant awareness from the first days of life. To sidestep these limitations, in a series of studies, we asked a foundational question to understand the capacity for conscious experience: whether the brain mechanisms of conscious awareness are instantiated in neonates. We leveraged the world’s largest fMRI neonatal dataset – the Developing Human Connectome Project - to investigate the presence of high-order networks and their inter-relationships, small-world organization, and neural complexity in full-term born and premature neonates (N=428). We will discuss evidence suggesting that by full-term birth or term equivalent age (TEA), neonates possess key features of this brain infrastructure, including the presence the DMN, DAN and ECN networks and their anti-posed relationship (Hu et al. 2022), as well as small-world organisation (Hu et al.2024), that enable the integration of information across diverse sensory and higher-order functional units. These data suggest that functional relationship develops in healthy-born premature neonates by TEA, according to a pre-programmed developmental trajectory despite of prematurity. Conversely, they suggest that this brain infrastructure is not present before infants reach TEA. This work advances our understanding of the ontogeny of high-order networks, their inter-dynamics and organisation, as well as disruption by premature birth. I will discuss implications for understanding conscious awareness in neonates.
Inferring Infant Consciousness Using Neural Complexity
Joel Frohlich
University of Tübingen, Germany
Consciousness in adults is often associated with neural complexity, both in theoretical frameworks and a very large number of empirical findings (Sarasso et al. 2021). Although a convergence of many markers of consciousness is probably necessary to infer the developmental onset of consciousness in development (Bayne et al. 2023), one such marker might be neural complexity. However, a popular approach toward measuring neural complexity in adults as an index of consciousness involves electromagnetic stimulation (Casali et al. 2013), which presents ethical challenges in infants and fetuses (Frohlich et al. 2023). The clearest alternatives are to measure neural complexity from either sensory evoked or spontaneous perinatal brain signals. However, these approaches yield strongly divergent results. Here, I present recent results from Semeia et al. which reveal that neural complexity in preterm newborns EEG signals is driven by the growing continuity of trace alternant activity patterns. These data suggest that neural complexity increases with the efficacy of the thalamus to continuously drive the cortex. Given the importance of the thalamocortical system, as the neural substrate of consciousness, it is plausible that infant consciousness follows thalamocortical integration. On the other hand, an age-dependent drop in auditory-evoked neural complexity previously observed in fetuses and full-term newborns (Frohlich et al. 2024) likely follows from increasing structure in neural circuits, as they are sculpted from relatively unconstrained initial patterns. Efforts to develop complexity-based markers of consciousness in infants should build on these results to derive appropriate protocols for measuring infant neural complexity.
The Role of Sleep and Affectionate Touch in Enabling a Newborn Infant’s Understanding of the World
Topun Austin
University of Cambridge, UK
Emerging from an entirely different environment, the newborn infant has to adapt quickly to life outside the womb. At birth the infant must learn to self-regulate, differentiate self from non-self, engage with caregivers, while establishing feeding patterns and obtaining adequate sleep, both essential for growth and development. The importance of learning in a complex, socially driven and changing environment is often postulated as an evolutionary driver for the development of consciousness, with this process being accelerated after birth, as the infant transitions from an experience-expectant to an experience-dependent environment (Gomez-Robles et al, 2024, Kanaev et al, 2022, Kostovic et al, 2019). Sleep at all ages is essential for life; however, the role of sleep in the developing brain, and how it is intrinsically related to functional connectivity is only recently being understood (Uchitel et al, 2021). Poor sleep quality in the neonatal period is associated with lifelong developmental consequences and may result from disruption to the early organization of brain networks, impeding experience-dependent learning early in life. Likewise, the role of early social interaction, particularly with the main caregiver, is important to ensure the infants’ ability to self-regulate, again vital for their ability to consciously process the world around them (Carozza et al, 2021). New approaches using high-density diffuse optical tomography and dyadic electroencephalography provide non-invasive brain imaging which can be applied in a naturalistic environment to investigate the relationship between sleep, social interaction and early cognition that underpin early conscious perception (Uchitel et al, 2023).
Early Onset of Consciousness: Philosophical and Ethical Implications
Claudia Passos-Ferreira
New York University, USA
I will evaluate the evidence presented in this symposium regarding the onset of consciousness, and draw philosophical and ethical implications. I’ll focus especially on functional connectivity networks (Hu, Cusack, and Naci 2022); the sensory perturbational complexity index (Frohlich et al., 2023); and the development of sleep and brain functional connectivity (Uchitel, Vanhatalo, Austin 2022). This evidence tends to support an early-onset view of infant consciousness. I will discuss how various scientific and philosophical theories of consciousness might interpret these results, and I will discuss how these results bear on these theories. I will also discuss ethical implications, including implications for infant care, and possible implications of results about fetal consciousness on the ethics of abortion.
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