Mother-child dyadic interactions shape children’s social brain and theory of mind Social cognition develops through a complex interplay between neural maturation and environmental factors, yet the neurobehavioral mechanisms underlying this process remain unclear. Using a naturalistic fMRI paradigm, we investigated the effects of age and parental caregiving on social brain development and Theory of Mind (ToM) in 34 mother-child dyads. The functional maturity of social brain networks was positively associated with age, while mother-child neural synchronization during movie viewing was related to dyadic relationship quality. Crucially, parenting and child factors interactively shaped social cognition outcomes, mediated by ToM abilities. Our findings demonstrate the dynamic interplay of neurocognitive development and interpersonal synchrony in early childhood social cognition, and provide novel evidence for neurodevelopmental plasticity and reciprocal determinism. This integrative approach, bridging brain, behavior, and parenting environment, advances our understanding of the complex mechanisms shaping social cognition. The insights gained can inform personalized interventions promoting social competence, emphasizing the critical importance of nurturing parental relationships in facilitating healthy social development.
Longitudinal trajectories of brain development from infancy to school age and their relationship with literacy development Reading is one of the most complex skills that we utilize daily, and it involves the early development and interaction of various lower-level subskills, including phonological processing and oral language. These subskills recruit brain structures, which begin to develop long before the skill manifests and exhibit rapid development during infancy. However, how longitudinal trajectories of early brain development in these structures support long-term acquisition of literacy subskills and subsequent reading is unclear. Children underwent structural and diffusion MRI scanning at multiple timepoints between infancy and second grade and were tested for literacy subskills in preschool and decoding and word reading in early elementary school. We developed and implemented a reproducible pipeline to generate longitudinal trajectories of early brain development. We then examined whether these trajectories were associated with literacy (sub)skills or influenced by familial risk of reading difficulty and children’s home literacy environments, two common literacy-related covariates. Results showed that individual differences in curve features (e.g., intercepts and slopes) for longitudinal trajectories of volumetric, surface-based, and white matter organization measures were linked directly to phonological processing and indirectly to early elementary school decoding and word reading skills via phonological processing. Altogether, these findings suggest that the brain bases of phonological processing, previously identified as one of the strongest behavioral predictors of decoding and word reading skills, may already begin to develop by birth but undergo further refinement between infancy and preschool. The present study underscores the importance of considering academic skill acquisition from the very beginning of life.
Leveraging Context for Perceptual Prediction Using Word Embeddings Word embeddings derived from large language corpora have been successfully used in cognitive science and artificial intelligence to represent linguistic meaning. However, there is continued debate as to how well they encode useful information about the perceptual qualities of concepts. This debate is critical to identifying the scope of embodiment in human semantics. If perceptual object properties can be inferred from word embeddings derived from language alone, this suggests that language provides a useful adjunct to direct perceptual experience for acquiring this kind of conceptual knowledge. Previous research has shown mixed performance when embeddings are used to predict perceptual qualities. Here, we tested if we could improve performance by leveraging the ability of Transformer-based language models to represent word meaning in context. To this end, we conducted two experiments. Our first experiment investigated noun representations. We generated decontextualized (“charcoal”) and contextualized (“the brightness of charcoal”) Word2Vec and BERT embeddings for a large set of concepts and compared their ability to predict human ratings of the concepts’ brightness. We repeated this procedure to also probe for the shape of those concepts. In general, we found very good prediction performance for shape, and a more modest performance for brightness. The addition of context did not improve perceptual prediction performance. In Experiment 2, we investigated representations of adjective–noun phrases. Perceptual prediction performance was generally found to be good, with the nonadditive nature of adjective brightness reflected in the word embeddings. We also found that the addition of context had a limited impact on how well perceptual features could be predicted. We frame these results against current work on the interpretability of language models and debates surrounding embodiment in human conceptual processing.
Stereotyped Spatiotemporal Dynamics of Spontaneous Activity in Visual Cortex Prior to Eye Opening Over the course of development, functional sensory representations emerge in the visual cortex. Prior to eye opening, modular patterns of spontaneous activity form long-range networks that may serve as a precursor for mature network organization. Although the spatial structure of these networks has been well studied, their temporal features, which may contribute to their continued plasticity and development, remain largely uncharacterized. To address this, we imaged hours of spontaneous network activity in the visual cortex of developing ferrets of both sexes utilizing a fast calcium indicator (GCaMP8m) and wide-field imaging at high temporal resolution (50 Hz). The spatial structure of this activity was highly modular, exhibiting distributed and spatially segregated active domains and long-range correlated networks on the timescale of tens of milliseconds. We found that the majority of events showed a clear dynamic component in which the patterns of active modules shifted over the course of events lasting a few hundred milliseconds. Although only a minority of events were well fit with a linear traveling wave, more complex spatiotemporal patterns occurred in repeated and stereotyped motifs across hours of imaging. Finally, we found that the most frequently occurring single-frame spatial activity patterns were predictive of future activity and separable spatiotemporal trajectories extending over many hundreds of milliseconds. Together, our results demonstrate that spontaneous activity in the early developing cortex exhibits a stereotyped spatiotemporal structure on fast timescales, suggesting a potential role in the maturation and refinement of future functional representations.
Beyond volume: Unraveling the genetics of human brain geometry Brain geometry affects brain function. A quantitative encoding of form is provided by the Laplace-Beltrami operator’s spectrum of eigenvalues (LBS). We examined LBS genetics of 22 subcortical brain structures and cerebellum in 19,862 healthy White-British UK Biobank participants by multivariate genome-wide association study on the first 49 eigenvalues each. Controlling for surface and volume, we identified 80 unique variants influencing the shapes of one or several structures, with the highest yield (37 variants) for brain stem. The previously known influence of several of these loci on basic morphology, such as volume, is thus shown to also influence complex shape. Known associations of observed loci with blood pressure, neurodegeneration, alcohol consumption, and mental disorders hint at preclinical stages of these conditions potentially mediating the genetic effect on brain morphology. Significant correlations between LBS of several brain structures and the polygenic risks of hypertension, ischemic stroke, and schizophrenia evince brain shapes as early biomarkers.
A flexible hippocampal population code for experience relative to reward To reinforce rewarding behaviors, events leading up to and following rewards must be remembered. Hippocampal place cell activity spans spatial and non-spatial episodes, but whether hippocampal activity encodes entire sequences of events relative to reward is unknown. Here, to test this possibility, we performed two-photon imaging of hippocampal CA1 as mice navigated virtual environments with changing hidden reward locations. We found that when the reward moved, a subpopulation of neurons updated their firing fields to the same relative position with respect to reward, constructing behavioral timescale sequences spanning the entire task. Over learning, this reward-relative representation became more robust as additional neurons were recruited, and changes in reward-relative firing often preceded behavioral adaptations following reward relocation. Concurrently, the spatial environment code was maintained through a parallel, dynamic subpopulation rather than through dedicated cell classes. These findings reveal how hippocampal ensembles flexibly encode multiple aspects of experience while amplifying behaviorally relevant information.
Voltage imaging reveals circuit computations in the raphe underlying serotonin-mediated motor vigor learning As animals adapt to new situations, neuromodulation is a potent way to alter behavior, yet mechanisms by which neuromodulatory nuclei compute during behavior are underexplored. The serotonergic raphe supports motor learning in larval zebrafish by visually detecting distance traveled during swims, encoding action effectiveness, and modulating motor vigor. We tracked the raphe’s input-output computations at millisecond timescales using voltage and neurotransmitter imaging and found that swimming opens a gate for visual input to cause spiking in serotonergic neurons, enabling the encoding of action outcomes and filtering out learning-irrelevant visual signals. Specifically, swim commands initially inhibited serotonergic neurons via γ-aminobutyric acid (GABA). Immediately after, membrane voltage increased via post-inhibitory rebound, allowing swim-induced visual motion to evoke firing through glutamate, triggering serotonin release to modulate future motor vigor. Ablating local GABAergic neurons impaired raphe coding and motor learning. Thus, serotonergic neuromodulation arises from action-outcome coincidence detection within the raphe.
Immanuel Kant’s Schema of object perception and cognition In the Critique of Pure Reason, Kant proposed a detailed system of mental processes and constructs that might lead to a person’s perceiving and comprehending an object in the outside world. The diffuse and extended original, found largely impenetrable and hence neglected in most modern discourse, is here revisited and presented in an updated contemporary idiom, with the aim of showing some structure in the mental world that may serve as a counterpart to definable states of the real world when attempts are made to find correlations between the two.