Oscillatory entrainment to our early social or physical environment and the emergence of volitional control

An individual’s early interactions with their environment are thought to be largely passive; through the early years, the capacity for volitional control develops. Here, we consider: how is the emergence of volitional control characterised by changes in the entrainment observed between internal activity (behaviour, physiology and brain activity) and the sights and sounds in our everyday environment (physical and social)? We differentiate between contingent responsiveness (entrainment driven by evoked responses to external events) and oscillatory entrainment (driven by internal oscillators becoming temporally aligned with external oscillators). We conclude that ample evidence suggests that children show behavioural, physiological and neural entrainment to their physical and social environment, irrespective of volitional attention control; however, evidence for oscillatory entrainment beyond contingent responsiveness is currently lacking. Evidence for how oscillatory entrainment changes over developmental time is also lacking. Finally, we suggest a mechanism through which periodic environmental rhythms might facilitate both sensory processing and the development of volitional control even in the absence of oscillatory entrainment

Form-function relationship in the amplitude and frequency modulations of infant - directed speech: A predictive processing perspective

Infants prefer infant-directed speech (IDS) over adult-directed speech (ADS). IDS is thought to serve specific functions compared to ADS: - Attracting infant attention to the speech signal - Conveying clear opportunities for easier word segmentation. Two independent domains of complexity that are embedded in the speech stream: - Amplitude complexity: Lower amplitude complexity associates with greater ease in identifying word boundaries ​ - ​Frequency complexity: Higher fre q uency complexity associates with more attention eliciting speech attention by inducing uncertaint

Functional imaging of the developing brain with wearable high-density diffuse optical tomography: a new benchmark for infant neuroimaging outside the scanner environment

Studies of cortical function in the awake infant are extremely challenging to undertake with traditional neuroimaging approaches. Partly in response to this challenge, functional near-infrared spectroscopy (fNIRS) has become increasingly common in developmental neuroscience, but has significant limitations including resolution, spatial specificity and ergonomics. In adults, high-density arrays of near-infrared sources and detectors have recently been shown to yield dramatic improvements in spatial resolution and specificity when compared to typical fNIRS approaches. However, most existing fNIRS devices only permit the acquisition of ∼20-100 sparsely distributed fNIRS channels, and increasing the number of optodes presents significant mechanical challenges, particularly for infant applications. A new generation of wearable, modular, high-density diffuse optical tomography (HD-DOT) technologies has recently emerged that overcomes many of the limitations of traditional, fibre-based and low-density fNIRS measurements. Driven by the development of this new technology, we have undertaken the first study of the infant brain using wearable HD-DOT. Using a well-established social stimulus paradigm, and combining this new imaging technology with advances in cap design and spatial registration, we show that it is now possible to obtain high-quality, functional images of the infant brain with minimal constraints on either the environment or on the infant participants. Our results are consistent with prior low-density fNIRS measures based on similar paradigms, but demonstrate superior spatial localization, improved depth specificity, higher SNR and a dramatic improvement in the consistency of the responses across participants. Our data retention rates also demonstrate that this new generation of wearable technology is well tolerated by the infant population

Evidence-based guidelines for use of probiotics in preterm neonates

<p>Abstract</p> <p>Background</p> <p>Current evidence indicates that probiotic supplementation significantly reduces all-cause mortality and definite necrotising enterocolitis without significant adverse effects in preterm neonates. As the debate about the pros and cons of routine probiotic supplementation continues, many institutions are satisfied with the current evidence and wish to use probiotics routinely. Because of the lack of detail on many practical aspects of probiotic supplementation, clinician-friendly guidelines are urgently needed to optimise use of probiotics in preterm neonates.</p> <p>Aim</p> <p>To develop evidence-based guidelines for probiotic supplementation in preterm neonates.</p> <p>Methods</p> <p>To develop core guidelines on use of probiotics, including strain selection, dose and duration of supplementation, we primarily used the data from our recent updated systematic review of randomised controlled trials. For equally important issues including strain identification, monitoring for adverse effects, product format, storage and transport, and regulatory hurdles, a comprehensive literature search, covering the period 1966-2010 without restriction on the study design, was conducted, using the databases PubMed and EMBASE, and the proceedings of scientific conferences; these data were used in our updated systematic review.</p> <p>Results</p> <p>In this review, we present guidelines, including level of evidence, for the practical aspects (for example, strain selection, dose, duration, clinical and laboratory surveillance) of probiotic supplementation, and for dealing with non-clinical but important issues (for example, regulatory requirements, product format). Evidence was inadequate in some areas, and these should be a target for further research.</p> <p>Conclusion</p> <p>We hope that these evidence-based guidelines will help to optimise the use of probiotics in preterm neonates. Continued research is essential to provide answers to the current gaps in knowledge about probiotics.</p

The Sub-Second Dynamics of Spontaneous Mimicry: An Electromyography Study Tracking Infant Caregiver Dyads during Free Play

Spontaneous mimicry (SM) is a ubiquitous feature of human communication (Heyes, 2021; Meltzoff & Williamson, 2017). Research shows that SM is both reflexive and flexible (Wang & Hamilton, 2012). It is sensitive to cues that signify implicit social rules and social hierarchy, suggesting that it is at least partly socially shaped. However, we have yet to map the ontogeny of SM, or its developmental factors (Slaughter, 2021). A marked difference in SM behaviour has been observed in atypical populations (e.g., ASD; Arnold & Winkielman, 2020) increasing the onus for further study. In infants, facial mimicry has been studied extensively and is the central focus of a long running debate surrounding the presence of SM in early infancy (Slaughter, 2021). However, most of these studies have used lab-based tasks or non-naturalistic block-design paradigms (Slaughter, 2021; Meltzoff & Williamson, 2017). The few studies that have observed naturalistic interactions used hand-coded video data, scoring onset and offsets of actions: mimicry was operationalised as an action onset in the observer that occurs within a specific timespan of a prior action onset in the interacting partner (Markodimitraki & Kalpidou, 2019). Here, SM behaviour is gauged in terms of frequency and total number of mimicked actions. They do not measure the magnitude of the action i.e. they cannot record graded changes in action. Employing electromyography (EMG) allows us to decipher moment-to-moment dynamics and sub-second changes. In the present study, we investigated facial SM behaviour in free-play interactions between 5-months-old infants and their caregivers. EMG electrodes are placed on the facial regions that overly the corrugator supercilii (frowning/eyebrow-movement) in both caregiver and infant. Lab based investigation of SM in infants have found evidence of infant SM of eyebrow movement at this age range (De Klerk et al., 2018). The caregiver and infant were tested while during tabletop free play sessions. The obtained EMG signal is rectified, band-pass filtered and z-scored. Artefacts are rejected by identifying and removing outliers that fall outside of one standard deviation above or below the mean. Cross-correlations are carried out to obtain a comprehensive overview of the temporal correspondence between the partners’ EMG waveforms. Granger causality analyses are also conducted on the EMG-waveforms of the interacting partners to identify if changes in the facial action of one predicts changes in that of the other. Based on our reading of the literature we had predicted that the cross correlations will be significant when the caregiver’s waveform is lagged (mother mimics the infant) but not when the infant’s waveform is lagged. Our target sample size is 20 dyads, and we are currently at the centriole. In our preliminary analyses (N - 9 dyads), in contrast to our expectations, the cross correlations were significant when the caregiver’s waveform preceded the infant’s (infant’s waveform is lagged). This was seen at lags between .2 and .6 seconds. Granger causality analyses will be performed to test if each of the waveforms can significantly predict the other. Control analysis will be performed with shuffled datasets to rule out spurious results

Assessing the Efficacy of Open-Source Solutions to Automated Facial Coding: A Methods-Comparison Study with EMG

Facial expressions are central components of face-to-face interactions and non-verbal communication. Most studies have measured changes in facial configuration by manually hand-coding videos of participants’ faces. This is relatively easy to setup and has facilitated theoretical developments in many fields e.g. spontaneous mimicry (REF). However, hand-coding does not track graded changes in action magnitude: they typically report onsets and offsets alone (REF). Without the action gradient, facial dynamics are reduced to binary events that do not differ in topography or temporal quality. The ideal alternative, Electromyography (EMG), requires wired sensors be placed on skin. This spawns the possibility of participant discomfort, introduces the requirement for resources and limits ecological validity. Automated facial coding may provide an optimal trade-off: non-intrusive instruments that assess magnitude. Cross-correlations will be used to assess the degree to which the opensource auto-coder package (Mémoire IRCGN [https://github.com/LafLaurine/imac2-memoire-ircgn]) can approximate EMG data (Corrugator supercilii) in naturalistic, face-to-face interactions between mother-infant dyads (N - 10 dyads; infant age range 4-6 months). The videos will also be hand-coded enabling for the findings to link to the published literature

Determination of MICING

Our work was focused on a new assay for characterising clinically important yeast. This assay was developed due to the need for new diagnostic methods for recognising potentially virulent strains of increasingly important non-albicans yeast pathogens, such as Saccharomyces cerevisiae and Candida glabrata. With the great diversity among strains for virulence and virulence factors, identification to the species level is not sufficienttherefore, testing for specific virulent traits remains the best option. We show here that the proposed assay uncovers the relationships between the three most important yeast virulence traits in a single test: the ability of a strain to invade solid medium, while resisting the presence of an antimycotic and high temperature (37 °C). We combined the quantitative agar invasion assay with classical antimycotic susceptibility testing into a single assay. Similarly to the minimal inhibitory concentration (MIC) value, we defined the MICING (minimal inhibitory concentration of antimycotic for invasive growth) as the concentration of an antimycotic above which the yeast invasive growth is significantly repressed. In this study, we tested three of the most common antimycotics: fluconazole, itraconazole and amphotericin B. The response of yeast strains invasion was characteristic of each antimycotic, indicating their mechanisms of action. In addition to MICING, the assay provides quantitative information about the superficial and invasive growth, and also about the relative invasion, which helps in identifying clinically important yeast, such as azole-resistant and/or invasive strains of S. cerevisiae and C. glabrata