Top-down knowledge rapidly acquired through abstract rule learning biases subsequent visual attention in 9-month-old infants

Effects of prenatal psychosocial stress and COVID-19 infection on infant attention and socioemotional development

BACKGROUND

The COVID-19 pandemic dramatically altered the psychosocial environment of pregnant women and new mothers. In addition, prenatal infection is a known risk factor for altered fetal development. Here we examine joint effects of maternal psychosocial stress and COVID-19 infection during pregnancy on infant attention at 6 months postpartum.

METHOD

One-hundred and sixty-seven pregnant mothers and infants (40% non-White; n = 71 females) were recruited in New York City (n = 50 COVID+, n = 117 COVID-). Infants' attentional processing was assessed at 6 months, and socioemotional function and neurodevelopmental risk were evaluated at 12 months.

RESULTS

Maternal psychosocial stress and COVID-19 infection during pregnancy jointly predicted infant attention at 6 months. In mothers reporting positive COVID-19 infection, higher prenatal psychosocial stress was associated with lower infant attention at 6 months. Exploratory analyses indicated that infant attention in turn predicted socioemotional function and neurodevelopmental risk at 12 months.

CONCLUSIONS

These data suggest that maternal psychosocial stress and COVID-19 infection during pregnancy may have joint effects on infant attention at 6 months. This work adds to a growing literature on the effects of the COVID-19 pandemic on infant development, and may point to maternal psychosocial stress as an important target for intervention.

IMPACT

This study found that elevated maternal psychosocial stress and COVID-19 infection during pregnancy jointly predicted lower infant attention scores at 6 months, which is a known marker of risk for neurodevelopmental disorder. In turn, infant attention predicted socioemotional function and risk for neurodevelopmental disorder at 12 months. These data suggest that maternal psychosocial stress may modulate the effects of gestational infection on neurodevelopment and highlight malleable targets for intervention.

Controlling the input: How one-year-old infants sustain visual attention

Traditionally, the exogenous control of gaze by external saliencies and the endogenous control of gaze by knowledge and context have been viewed as competing systems, with late infancy seen as a period of strengthening top-down control over the vagaries of the input. Here we found that one-year-old infants control sustained attention through head movements that increase the visibility of the attended object. Freely moving one-year-old infants (n = 45) wore head-mounted eye trackers and head motion sensors while exploring sets of toys of the same physical size. The visual size of the objects, a well-documented salience, varied naturally with the infant's moment-to-moment posture and head movements. Sustained attention to an object was characterized by the tight control of head movements that created and then stabilized a visual size advantage for the attended object for sustained attention. The findings show collaboration between exogenous and endogenous attentional systems and suggest new hypotheses about the development of sustained visual attention.

Regional activity and effective connectivity within the frontoparietal network during precision walking with visual cueing: an fNIRS study

Precision walking (PW) incorporates precise step adjustments into regular walking patterns to navigate challenging surroundings. However, the brain processes involved in PW control, which encompass cortical regions and interregional interactions, are not fully understood. This study aimed to investigate the changes in regional activity and effective connectivity within the frontoparietal network associated with PW. Functional near-infrared spectroscopy data were recorded from adult subjects during treadmill walking tasks, including normal walking (NOR) and PW with visual cues, wherein the intercue distance was either fixed (FIX) or randomly varied (VAR) across steps. The superior parietal lobule (SPL), dorsal premotor area (PMd), supplementary motor area (SMA), and dorsolateral prefrontal cortex (dlPFC) were specifically targeted. The results revealed higher activities in SMA and left PMd, as well as left-to-right SPL connectivity, in VAR than in FIX. Activities in SMA and right dlPFC, along with dlPFC-to-SPL connectivity, were higher in VAR than in NOR. Overall, these findings provide insights into the roles of different brain regions and connectivity patterns within the frontoparietal network in facilitating gait control during PW, providing a useful baseline for further investigations into brain networks involved in locomotion.

OWLET: An automated, open-source method for infant gaze tracking using smartphone and webcam recordings

Groundbreaking insights into the origins of the human mind have been garnered through the study of eye movements in preverbal subjects who are unable to explain their thought processes. Developmental research has largely relied on in-lab testing with trained experimenters. This constraint provides a narrow window into infant cognition and impedes large-scale data collection in families from diverse socioeconomic, geographic, and cultural backgrounds. Here we introduce a new open-source methodology for automatically analyzing infant eye-tracking data collected on personal devices in the home. Using algorithms from computer vision, machine learning, and ecological psychology, we develop an online webcam-linked eye tracker (OWLET) that provides robust estimation of infants' point of gaze from smartphone and webcam recordings of infant assessments in the home. We validate OWLET in a large sample of 7-month-old infants (N = 127) tested remotely, using an established visual attention task. We show that this new method reliably estimates infants' point-of-gaze across a variety of contexts, including testing on both computers and mobile devices, and exhibits excellent external validity with parental-report measures of attention. Our platform fills a significant gap in current tools available for rapid online data collection and large-scale assessments of cognitive processes in infants. Remote assessment addresses the need for greater diversity and accessibility in human studies and may support the ecological validity of behavioral experiments. This constitutes a critical and timely advance in a core domain of developmental research and in psychological science more broadly.

Eight-Month-Old Infants Meta-Learn by Downweighting Irrelevant Evidence

Infants learn to navigate the complexity of the physical and social world at an outstanding pace, but how they accomplish this learning is still largely unknown. Recent advances in human and artificial intelligence research propose that a key feature to achieving quick and efficient learning is meta-learning, the ability to make use of prior experiences to learn how to learn better in the future. Here we show that 8-month-old infants successfully engage in meta-learning within very short timespans after being exposed to a new learning environment. We developed a Bayesian model that captures how infants attribute informativity to incoming events, and how this process is optimized by the meta-parameters of their hierarchical models over the task structure. We fitted the model with infants' gaze behavior during a learning task. Our results reveal how infants actively use past experiences to generate new inductive biases that allow future learning to proceed faster.

Sensitive caregiving and reward responsivity: A novel mechanism linking parenting and executive functions development in early childhood

Sensitive caregiving is an essential aspect of positive parenting that influences executive functions development, but the mechanisms underlying this association are less clear. Using data from the Family Life Project, a large prospective longitudinal sample of 1292 families residing in rural, predominately low-income communities, the current study examined whether sensitive caregiving impacts executive functions development by shaping behavioral reward processing systems in early postnatal life. Results indicated that higher levels of sensitive caregiving during infancy were associated with heightened reward responsivity at age 4, which in turn predicted superior executive functions ability at age 5. Notably, children's reward responsivity partially mediated the relationship between sensitive caregiving in infancy and executive functions ability at school entry. These findings add to prior work on early experience and children's executive functions and highlight caregiver scaffolding of developing reward processing systems as a potential foundational mechanism for supporting adaptive behavior and self-regulation across the lifespan.

Top-down knowledge surpasses selection history in influencing attentional guidance

Visual attention is influenced by the characteristics of the stimuli (bottom-up), their task relevance (top-down), and prior experience (e.g., selection history and learning). However, it is largely unclear how learning and selection history interact with top-down attentional guidance. We combined trial-and-error learning with a spatial cueing protocol to test whether previously learned target-defining features continued to capture attention if participants were instructed to search for a new target feature (Experiment 1) or had to learn a new target feature (Experiment 2). It turned out that the previously learned feature quickly stopped capturing attention when the target feature changed (Experiment 1; even before participants learned the new target-defining feature, in Experiment 2). Finally, in Experiment 3, in which participants learned to search for targets defined by two redundant features (color and orientation), we found possible reasons for the dominance of the instructed feature over learning. Participants reported using only the target color for their search. Consequently, only cues with a target color captured attention. The unused target orientation only captured attention in participants aware of both target-defining features (13 out of 23) and only if the orientation was presented in the target color. We conclude that knowledge of target-defining features and their use as search criterion is critical for attentional guidance, while previously learned target features either influence attentional guidance only contingent on such deliberately selected top-down based attentional control settings or may influence visual search but not attentional guidance.

Signal in the noise: Dimensions of predictability in the home auditory environment are associated with neurobehavioral measures of early infant sustained attention

The home auditory environment influences the development of early language abilities, and excessive noise exposure is increasingly linked with deficits in language and reading scores in children. However, fewer studies have considered the role of noise exposure in shaping the development of attentional processing in early infancy, a foundational neurocognitive skill relevant for learning. Here, we used passive at-home auditory recording to investigate how multiple dimensions of infants' home auditory environments, including both the quantity and the predictability of auditory input, impacts neural and behavioral measures of sustained attention in a sociodemographically diverse sample of 3-month-old infants (N = 98 infants, 62 males; age M = 3.48 months, SD = 0.39; 52% Hispanic/Latino). Results indicated that infants who were exposed to more predictable patterns of auditory input in the home demonstrated longer overall time in sustained attention during laboratory assessments. In addition, infants' who experienced more predictable auditory input also demonstrated greater relative increases in electroencephalography frontal theta power during periods of sustained attention, a neural marker relevant to information processing and attentional control. These findings provide novel evidence into the importance of the predictability of early environmental inputs in shaping developing cortical circuitry and attentional systems from the first months of postnatal life.

Infants' anticipatory eye movements: feature-based attention guides infants' visual attention

When looking for an object, we identify it by selectively focusing our attention to a specific feature, known as feature-based attention. This basic attentional system has been reported in young children; however, little is known of whether infants could use feature-based attention. We have introduced a newly developed anticipation-looking task, where infants learned to direct their attention endogenously to a specific feature based on the learned feature (color or orientation), in 60 preverbal infants aged 7-8 months. We found that preverbal infants aged 7-8 months can direct their attention endogenously to the specific target feature among irrelevant features, thus showing the feature-based attentional selection. Experiment 2 bolstered this finding by demonstrating that infants directed their attention depending on the familiarized feature that belongs to a never-experienced object. These results that infants can form anticipation by color and orientation reflect they could drive their attention through feature-based selection.

Statistical Learning in Vision

Vision and learning have long been considered to be two areas of research linked only distantly. However, recent developments in vision research have changed the conceptual definition of vision from a signal-evaluating process to a goal-oriented interpreting process, and this shift binds learning, together with the resulting internal representations, intimately to vision. In this review, we consider various types of learning (perceptual, statistical, and rule/abstract) associated with vision in the past decades and argue that they represent differently specialized versions of the fundamental learning process, which must be captured in its entirety when applied to complex visual processes. We show why the generalized version of statistical learning can provide the appropriate setup for such a unified treatment of learning in vision, what computational framework best accommodates this kind of statistical learning, and what plausible neural scheme could feasibly implement this framework. Finally, we list the challenges that the field of statistical learning faces in fulfilling the promise of being the right vehicle for advancing our understanding of vision in its entirety. Expected final online publication date for the Annual Review of Vision Science, Volume 8 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The development of visual attention in early infancy: Insights from a free-viewing paradigm

Theories of visual attention suggest a cascading development of subfunctions such as alertness, spatial orientation, attention to object features, and endogenous control. Here, we aimed to track infants' visual developmental steps from a primarily exogenously to more endogenously controlled processing style during their first months of life. In this repeated measures study, 51 infants participated in seven fortnightly assessments at postterm ages of 4-16 weeks. Infants were presented with the same set of static and dynamic paired comparison stimuli in each assessment. Visual behavior was evaluated by a newly introduced scoring scheme. Our results confirmed the suggested visual developmental hierarchy and clearly demonstrated the suitability of our scoring scheme for documenting developmental changes in visual attention during early infancy. Besides the general ontogenetic course of development, we also discuss intra- and interindividual differences which may affect single assessments, and highlight the importance of repeated measurements for reliable evaluation of developmental changes.

Pre-symptomatic intervention for autism spectrum disorder (ASD): defining a research agenda

Autism spectrum disorder (ASD) impacts an individual's ability to socialize, communicate, and interact with, and adapt to, the environment. Over the last two decades, research has focused on early identification of ASD with significant progress being made in understanding the early behavioral and biological markers that precede a diagnosis, providing a catalyst for pre-symptomatic identification and intervention. Evidence from preclinical trials suggest that intervention prior to the onset of ASD symptoms may yield more improved developmental outcomes, and clinical studies suggest that the earlier intervention is administered, the better the outcomes. This article brings together a multidisciplinary group of experts to develop a conceptual framework for behavioral intervention, during the pre-symptomatic period prior to the consolidation of symptoms into diagnosis, in infants at very-high-likelihood for developing ASD (VHL-ASD). The overarching goals of this paper are to promote the development of new intervention approaches, empirical research, and policy efforts aimed at VHL-ASD infants during the pre-symptomatic period (i.e., prior to the consolidation of the defining features of ASD).

Attentional blink in preverbal infants

Primary cognitive processes, such as spatial attention, are essential to our higher cognitive abilities and develop dramatically in the first year of life. The spatial aspect of infants' working memory is equivalent to that of adults. However, it is unclear whether this is true for the temporal domain. Thus, we investigated the temporal aspect of infants' working memory using an attentionally demanding task by focusing on the attentional blink effect, in which the identification of the second of the two brief targets is impaired when inter-target lags are short. We argue that finding a similar pattern of the attentional blink in preverbal infants and adults indicates that infants can complete the consolidation of the first target into working memory at a similar temporal scale as adults. In this experiment, we presented 7- to 8-month-old infants with rapid serial visual streams at a rate of 100 ms/item, including two female faces as targets, and examined whether they could identify the targets by measuring their preference to novel faces compared to targets. The temporal separation between the two targets was 200 or 800 ms. We found that the infants could identify both targets under the longer lag, but they failed to identify the second target under the shorter lag. The adult experiment using the same temporal separation as in the infant experiment revealed the attentional blink effect. These results suggest that 7- to 8-month-old infants can consolidate two items into working memory by 800 ms but not by 200 ms.

All contexts are not created equal: Social stimuli win the competition for organizing reinforcement learning in 9-month-old infants

Previous work has shown that infants as young as 8 months of age can use certain features of the environment, such as the shape or color of visual stimuli, as cues to organize simple inputs into hierarchical rule structures, a robust form of reinforcement learning that supports generalization of prior learning to new contexts. However, especially in cluttered naturalistic environments, there are an abundance of potential cues that can be used to structure learning into hierarchical rule structures. It is unclear how infants determine what features constitute a higher-order context to organize inputs into hierarchical rule structures. Here, we examine whether 9-month-old infants are biased to use social stimuli, relative to non-social stimuli, as a higher-order context to organize learning of simple visuospatial inputs into hierarchical rule sets. Infants were presented with four face/color-target location pairings, which could be learned most simply as individual associations. Alternatively, infants could use the faces or colorful backgrounds as a higher-order context to organize the inputs into simpler color-location or face-location rules, respectively. Infants were then given a generalization test designed to probe how they learned the initial pairings. The results indicated that infants appeared to use the faces as a higher-order context to organize simpler color-location rules, which then supported generalization of learning to new face contexts. These findings provide new evidence that infants are biased to organize reinforcement learning around social stimuli.

Learning in Infancy Is Active, Endogenously Motivated, and Depends on the Prefrontal Cortices

A common view of learning in infancy emphasizes the role of incidental sensory experiences from which increasingly abstract statistical regularities are extracted. In this view, infant brains initially support basic sensory and motor functions, followed by maturation of higher-level association cortex. Here, we critique this view and posit that, by contrast and more like adults, infants are active, endogenously motivated learners who structure their own learning through flexible selection of attentional targets and active interventions on their environment. We further argue that the infant brain, and particularly the prefrontal cortex (PFC), is well equipped to support these learning behaviors. We review recent progress in characterizing the function of the infant PFC, which suggests that, as in adults, the PFC is functionally specialized and highly connected. Together, we present an integrative account of infant minds and brains, in which the infant PFC represents multiple intrinsic motivations, which are leveraged for active learning.

Adaptive rule learning of event sequences during the A-not-B task in 9-month-old infants

Prior work indicates that infants can use social information to organize simple audiovisual inputs into predictable rules by 8 months of age. However, it is unclear whether infants can use social information to organize more complex events into predictable rules that can be used to guide motor action. To examine these issues, we tested 9-month-old infants using a modified version of an A-not-B task, in which hiding event sequences were paired with different experimenters, who could be used to organize the events into rules that guide action. We predicted that infants' reaching accuracy would be better when the experimenter changes when the toy's hiding location changes, relative to when the experimenter stays the same, as this should cue a novel rule used to guide action. Experiments 1 and 2 validated this prediction. Experiment 3 showed that reaching accuracy was better when the toy's hiding location switched but was consistent with the rule associated with the experimenter, relative to when the toy's hiding location repeated but was inconsistent with the rule associated with the experimenter. These data suggest that infants can use the identities of experimenters to organize events into predictable rules that guide action in the A-not-B task.