Entropy Information of Cardiorespiratory Dynamics in Neonates during Sleep

Abstract: Sleep is a central activity in human adults and characterizes most of the newborn infant life. During sleep, autonomic control acts to modulate heart rate variability (HRV) and respiration. Mechanisms underlying cardiorespiratory interactions in different sleep states have been studied but are not yet fully understood. Signal processing approaches have focused on cardiorespiratory analysis to elucidate this co-regulation. This manuscript proposes to analyze heart rate (HR), respiratory variability and their interrelationship in newborn infants to characterize cardiorespiratory interactions in different sleep states (active vs. quiet). We are searching for indices that could detect regulation alteration or malfunction, potentially leading to infant distress. We have analyzed inter-beat (RR) interval series and respiration in a population of 151 newborns, and followed up with 33 at 1 month of age. RR interval series were obtained by recognizing peaks of the QRS complex in the electrocardiogram (ECG), corresponding to the ventricles depolarization. Univariate time domain, frequency domain and entropy measures were applied. In addition, Transfer Entropy was considered as a bivariate approach able to quantify the bidirectional information flow from one signal (respiration) to another (RR series). Results confirm the validity of the proposed approach. Overall, HRV is higher in active sleep, while high frequency (HF) power characterizes more quiet sleep. Entropy analysis provides higher indices for SampEn and Quadratic Sample entropy (QSE) in quiet sleep. Transfer Entropy values were higher in quiet sleep and point to a major influence of respiration on the RR series. At 1 month of age, time domain parameters show an increase in HR and a decrease in variability. No entropy differences were found across ages. The parameters employed in this study help to quantify the potential for infants to adapt their cardiorespiratory responses as they mature. Thus, they could be useful as early markers of risk for infant cardiorespiratory vulnerabilities

Effects of interfood interval on discrete-trial fixed-time schedules

The typical pattern of responding generated by a fixed interval schedule of reinforcement consists of a nost reinforcement pause followed by a period of positively accelerated responding. This pattern is consistent with a temporal discrimination interpretation of FI performance. Several lines of evidence suggest that the temporal patterning on fixed interval schedules is not controlled so much by the absolute duration of the interval, as by the relative time elapsed in the interreinforcement interval (Dews, 1969; Jenkins, 1970; Shull & Brownstein, 1975; Staddon, 1972). Control by relative time is suggested by the fact that the pattern of responding remains generally unaffected by changes in absolute time across a wide variety of interval durations when the response measure is plotted as a function of relative elapsed time (Dews, 1970; Schneider, 1969; Shull, 1971). Various discrete trial procedures have been used to analyze the temporal control of responding on FI schedules. Such procedures offer the advantage of allowing the investigator to more accurately specify the number and spacing of responses in the interreinforcement interval

Early attachment : maternal voice preference in one- and three-day-old infants

The current literature on infant development points to a new appreciation of the perceptual and learning capabilities of the newborn. Sensorially precocial and sensitive to a variety of reinforcement contingencies, neonates are prepared to engage in the kinds of reciprocal social interactions necessary for the development of the mother-infant bond. This study investigates neonatal discrimination of and preference for mother's voice, a phenomenon which may function as a cornerstone of the attachment process. According to modern usage, attachment processes refer to the establishment and maintenance of proximity between an infant and a conspecific, usually the natural mother (Ainsworth, 1979). Historically, students of attachment have emphasized the role of maternal behaviors in this process. More recently, however, the reciprocal nature of the mother-infant relationship has been underscored (Ainsworth, 1972; Bell, 1974; Bowlby, 1969; Brazleton, 1978; Gewirtz, 1972; Shaffer & Emerson, 1964; Sherrod, Vietz, & Friedman, 1978; Wolff, 1969). This experiment focuses on the newborn infant’s role in the attachment process

Characterization of cardiorespiratory phase synchronization and directionality in late premature and full term infants

Objective: Though the mutual influence of cardiovascular and respiratory rhythms in healthy newborns has been documented, its full characterization is still pending. In general, the activity of many physiological subsystems has a well-expressed rhythmic character, and often an interdependency between physiological rhythms emerges early in development. Traditional methods of data analysis only address the quantification of the strength of subsystem interactions. In this work, we will investigate system interrelationships in terms of the possible presence of causal or directional interplays. Approach: In this paper, we propose a methodological application that quantifies phase coupling and its directionality in a population of newborn infants born between 35 and 40 weeks of gestational age (GA). The aim is to assess whether GA at birth significantly influences the development of phase synchronization and the directionality of the coupling between the cardiovascular and respiratory system activity. Several studies indicating irregular cardiorespiratory coupling as a leading cause of several pathologies underscore the need to investigate this phenomenon in this at-risk population. Main results: Results from our investigation show a different directionality profile as a function of GA and sleep state. Significance: These findings are a contribution to the understanding of higher risk for the documented negative outcomes in the late preterm population. Moreover, these parameters could provide a tool for the development of early markers of cardiorespiratory dysregulation in infants

Associations Between Brain Structure and Connectivity in Infants and Exposure to Selective Serotonin Reuptake Inhibitors During Pregnancy

Importance Selective serotonin reuptake inhibitor (SSRI) use among pregnant women is increasing, yet the association between prenatal SSRI exposure and fetal neurodevelopment is poorly understood. Animal studies show that perinatal SSRI exposure alters limbic circuitry and produces anxiety and depressive-like behaviors after adolescence, but literature on prenatal SSRI exposure in humans is limited and mixed. Objective To examine associations between prenatal SSRI exposure and brain development using structural and diffusion magnetic resonance imaging (MRI). Design, Setting, and Participants A cohort study conducted at Columbia University Medical Center and New York State Psychiatric Institute included 98 infants: 16 with in utero SSRI exposure, 21 with in utero untreated maternal depression exposure, and 61 healthy controls. Data were collected between January 6, 2011, and October 25, 2016. Exposures Selective serotonin reuptake inhibitors and untreated maternal depression. Main Outcomes and Measures Gray matter volume estimates using structural MRI with voxel-based morphometry and white matter structural connectivity (connectome) using diffusion MRI with probabilistic tractography. Results The sample included 98 mother (31 [32%] white, 26 [27%] Hispanic/Latina, 26 [27%] black/African American, 15 [15%] other) and infant (46 [47%] boys, 52 [53%] girls) dyads. Mean (SD) age of the infants at the time of the scan was 3.43 (1.50) weeks. Voxel-based morphometry showed significant gray matter volume expansion in the right amygdala (Cohen d = 0.65; 95% CI, 0.06-1.23) and right insula (Cohen d = 0.86; 95% CI, 0.26-1.14) in SSRI-exposed infants compared with both healthy controls and infants exposed to untreated maternal depression (P < .05; whole-brain correction). In connectome-level analysis of white matter structural connectivity, the SSRI group showed a significant increase in connectivity between the right amygdala and the right insula with a large effect size (Cohen d = 0.99; 95% CI, 0.40-1.57) compared with healthy controls and untreated depression (P < .05; whole connectome correction). Conclusions and Relevance Our findings suggest that prenatal SSRI exposure has an association with fetal brain development, particularly in brain regions critical to emotional processing. The study highlights the need for further research on the potential long-term behavioral and psychological outcomes of these neurodevelopmental changes

Beyond the Bayley: Neurocognitive Assessments of Development During Infancy and Toddlerhood

The use of global, standardized instruments is conventional among clinicians and researchers interested in assessing neurocognitive development. Exclusively relying on these tests for evaluating effects may underestimate or miss specific effects on early cognition. The goal of this review is to identify alternative measures for possible inclusion in future clinical trials and interventions evaluating early neurocognitive development. The domains included for consideration are attention, memory, executive function, language and socio-emotional development. Although domain-based tests are limited, as psychometric properties have not yet been well-established, this review includes tasks and paradigms that have been reliably used across various developmental psychology laboratories

Behavioral Coping Phenotypes and Associated Psychosocial Outcomes of Pregnant and Postpartum Women During the COVID-19 Pandemic

The impact of COVID-19-related stress on perinatal women is of heightened public health concern given the established intergenerational impact of maternal stress-exposure on infants and fetuses. There is urgent need to characterize the coping styles associated with adverse psychosocial outcomes in perinatal women during the COVID-19 pandemic to help mitigate the potential for lasting sequelae on both mothers and infants. This study uses a data-driven approach to identify the patterns of behavioral coping strategies that associate with maternal psychosocial distress during the COVID-19 pandemic in a large multicenter sample of pregnant women (N = 2876) and postpartum women (N = 1536). Data was collected from 9 states across the United States from March to October 2020. Women reported behaviors they were engaging in to manage pandemic-related stress, symptoms of depression, anxiety and global psychological distress, as well as changes in energy levels, sleep quality and stress levels. Using latent profile analysis, we identified four behavioral phenotypes of coping strategies. Critically, phenotypes with high levels of passive coping strategies (increased screen time, social media, and intake of comfort foods) were associated with elevated symptoms of depression, anxiety, and global psychological distress, as well as worsening stress and energy levels, relative to other coping phenotypes. In contrast, phenotypes with high levels of active coping strategies (social support, and self-care) were associated with greater resiliency relative to other phenotypes. The identification of these widespread coping phenotypes reveals novel behavioral patterns associated with risk and resiliency to pandemic-related stress in perinatal women. These findings may contribute to early identification of women at risk for poor long-term outcomes and indicate malleable targets for interventions aimed at mitigating lasting sequelae on women and children during the COVID-19 pandemic

Online speech synthesis using a chronically implanted brain–computer interface in an individual with ALS

Brain–computer interfaces (BCIs) that reconstruct and synthesize speech using brain activity recorded with intracranial electrodes may pave the way toward novel communication interfaces for people who have lost their ability to speak, or who are at high risk of losing this ability, due to neurological disorders. Here, we report online synthesis of intelligible words using a chronically implanted brain-computer interface (BCI) in a man with impaired articulation due to ALS, participating in a clinical trial (ClinicalTrials.gov, NCT03567213) exploring different strategies for BCI communication. The 3-stage approach reported here relies on recurrent neural networks to identify, decode and synthesize speech from electrocorticographic (ECoG) signals acquired across motor, premotor and somatosensory cortices. We demonstrate a reliable BCI that synthesizes commands freely chosen and spoken by the participant from a vocabulary of 6 keywords previously used for decoding commands to control a communication board. Evaluation of the intelligibility of the synthesized speech indicates that 80% of the words can be correctly recognized by human listeners. Our results show that a speech-impaired individual with ALS can use a chronically implanted BCI to reliably produce synthesized words while preserving the participant’s voice profile, and provide further evidence for the stability of ECoG for speech-based BCIs

Fetal cardiac dysfunction in intrahepatic cholestasis of pregnancy is associated with elevated serum bile acid concentrations

BackgroundIntrahepatic cholestasis of pregnancy (ICP) is associated with increased stillbirth risk. This study aimed to assess the relationship between bile acid concentrations and fetal cardiac dysfunction in ICP with or without ursodeoxycholic acid (UDCA) treatment.MethodsBile acid profiles and NT-proBNP, a marker of ventricular dysfunction, were assayed in umbilical venous serum from 15 controls and 76 ICP cases (36 untreated, 40 UDCA-treated). Fetal ECG traces were obtained from 43 controls and 48 ICP cases (26 untreated, 22 UDCA-treated). PR interval length and heart rate variability parameters (RMSSD, SDNN) were measured in two behavioural states (quiet and active sleep). Partial correlation coefficients (r) and median [IQR] are reported.ResultsIn untreated ICP, fetal total serum bile acids (TSBA, r=0.49, p=0.019), their hydrophobicity index (r=0.20, p=0.039), glycocholate (r=0.56, p=0.007) and taurocholate (r=0.44, p=0.039) positively correlated with fetal NT-proBNP. Maternal TSBA (r=0.40, p=0.026) and alanine aminotransferase (r=0.40, p=0.046) also positively correlated with fetal NT-proBNP. No significant correlations to NT-proBNP were observed in the UDCA-treated cohort. Fetal PR interval length positively correlated with maternal TSBA in untreated (r=0.46, p=0.027) and UDCA-treated ICP (r=0.54, p=0.026). Fetal RMSSD in active sleep (9.6 [8.8,11.3] vs. 8.7 [7.6,9.6] ms, p=0.028) and SDNN in quiet sleep (11.0 [9.5,14.9] vs. 7.9 [5.1,9.7] ms, p=0.013) and active sleep (25.4 [21.0,32.4] vs. 18.2 [14.7,25.7] ms, p=0.003) were significantly higher in untreated ICP cases than controls. Heart rate variability values in UDCA-treated cases did not differ to controls.ConclusionsElevated fetal and maternal serum bile acid concentrations in untreated ICP are associated with an abnormal fetal cardiac phenotype characterised by increased NT-proBNP concentration, PR interval length and heart rate variability. UDCA treatment partially attenuates this phenotype

Stable Decoding from a Speech BCI Enables Control for an Individual with ALS without Recalibration for 3 Months

Brain-computer interfaces (BCIs) can be used to control assistive devices by patients with neurological disorders like amyotrophic lateral sclerosis (ALS) that limit speech and movement. For assistive control, it is desirable for BCI systems to be accurate and reliable, preferably with minimal setup time. In this study, a participant with severe dysarthria due to ALS operates computer applications with six intuitive speech commands via a chronic electrocorticographic (ECoG) implant over the ventral sensorimotor cortex. Speech commands are accurately detected and decoded (median accuracy: 90.59%) throughout a 3-month study period without model retraining or recalibration. Use of the BCI does not require exogenous timing cues, enabling the participant to issue self-paced commands at will. These results demonstrate that a chronically implanted ECoG-based speech BCI can reliably control assistive devices over long time periods with only initial model training and calibration, supporting the feasibility of unassisted home use