Interaction and behaviour imaging: a novel method to measure mother–infant interaction using video 3D reconstruction

International audienceStudying early interaction is essential for understanding development and psychopathology. Automatic computational methods offer the possibility to analyse social signals and behaviours of several partners simultaneously and dynamically. Here, 20 dyads of mothers and their 13–36-month-old infants were videotaped during mother–infant interaction including 10 extremely high-risk and 10 low-risk dyads using two-dimensional (2D) and three-dimensional (3D) sensors. From 2D+3D data and 3D space reconstruction, we extracted individual parameters (quantity of movement and motion activity ratio for each partner) and dyadic parameters related to the dynamics of partners heads distance (contribution to heads distance), to the focus of mutual engagement (percentage of time spent face to face or oriented to the task) and to the dynamics of motion activity (synchrony ratio, overlap ratio, pause ratio). Features are compared with blind global rating of the interaction using the coding interactive behavior (CIB). We found that individual and dyadic parameters of 2D+3D motion features perfectly correlates with rated CIB maternal and dyadic composite scores. Support Vector Machine classification using all 2D–3D motion features classified 100% of the dyads in their group meaning that motion behaviours are sufficient to distinguish high-risk from low-risk dyads. The proposed method may present a promising, low-cost methodology that can uniquely use artificial technology to detect meaningful features of human interactions and may have several implications for studying dyadic behaviours in psychiatry. Combining both global rating scales and computerized methods may enable a continuum of time scale from a summary of entire interactions to second-by-second dynamics

Staying in Touch: Mothers’ and Infants’ Dyadic Touching Behaviours Across Time, Context, and Risk Status

Touch is the basis of infants’ social, emotional, and cognitive development. Yet, it remains largely understudied in developmental research. A series of three studies were designed to expand our limited knowledge of parents’ and infants’ touching behaviours, including the synchrony of maternal-infant touch, across various types of parent-child interactions over time. Study 1 utilized an extensive longitudinal design whereby healthy mother-infant dyads (N=12) were observed at 1-, 3-, 5-, 7-, and 9-months postpartum and within two normative interaction contexts (face-to-face; floor play). Study 2 implemented a longitudinal research design whereby typically developing newborns, mothers, and fathers (N=22) were observed immediately after birth and following the physiological stress of labor/delivery, and again 3- months later, following the social stress of maternal emotional unavailability via the Still-Face procedure (SF; Tronick et al., 1978). Study 3 used a cross-sectional research design examining mother-infant dyads (N=41) with high vs. low risk of maternal depressive symptomatology during instances of infant crying within the context of the SF and Separation (SP; Field et al., 1986) procedures at 4-months postpartum. Overall, results revealed that touch is a pervasive and extensive communicative modality for both infants and parents, including those at-risk, within normative and perturbed contexts, starting from birth and across the first 9-months of life. Study 1 demonstrated that during typical/playful mother-infant interactions from 1- to 9-months postpartum, dyads initially displayed behavioural matching and later transitioned toward synchronous patterns entailing the parallel use of complementary types of touch. Study 2 revealed that mothers and infants displayed an inverse pattern of tactile synchrony (coordinated, converse changes in touch) from the immediate postpartum period to the reunion period of the SF procedure 3-months later. In Study 3, mothers and infants displayed a positive pattern of tactile synchrony (coordinated, analogous changes in touch) within the context of infant crying at 4-months postpartum. However, dyads in the high depression group displayed significantly less affectionate touch. Among other findings, results from all three studies underscored the soothing and regulatory functions of touch. Findings meaningfully contribute to our knowledge of early parent-infant dynamics and support a direction toward comprehensive examinations of touch across infancy

Approximate entropy used to assess sitting postural sway of infants with developmental delay

Infant sitting postural sway provides a window into motor development at an early age. The approximate entropy, a measure of randomness, in the postural sway was used to assess developmental delay, as occurs in cerebral palsy. Parameters used for the calculation of approximate entropy were investigated, and approximate entropy of postural sway in early sitting was found to be lower for infants with developmental delay in the anterior–posterior axis, but not in the medial–lateral axis. Spectral analysis showed higher frequency features in the postural sway of early sitting of infants with typical development, suggesting a faster control mechanism is active in infants with typical development as compared to infants with delayed development, perhaps activated by near-fall events

The listening talker: A review of human and algorithmic context-induced modifications of speech

International audienceSpeech output technology is finding widespread application, including in scenarios where intelligibility might be compromised - at least for some listeners - by adverse conditions. Unlike most current algorithms, talkers continually adapt their speech patterns as a response to the immediate context of spoken communication, where the type of interlocutor and the environment are the dominant situational factors influencing speech production. Observations of talker behaviour can motivate the design of more robust speech output algorithms. Starting with a listener-oriented categorisation of possible goals for speech modification, this review article summarises the extensive set of behavioural findings related to human speech modification, identifies which factors appear to be beneficial, and goes on to examine previous computational attempts to improve intelligibility in noise. The review concludes by tabulating 46 speech modifications, many of which have yet to be perceptually or algorithmically evaluated. Consequently, the review provides a roadmap for future work in improving the robustness of speech output

Origins of vocal-entangled gesture

Gestures during speaking are typically understood in a representational framework: they represent absent or distal states of affairs by means of pointing, resemblance, or symbolic replacement. However, humans also gesture along with the rhythm of speaking, which is amenable to a non-representational perspective. Such a perspective centers on the phenomenon of vocal-entangled gestures and builds on evidence showing that when an upper limb with a certain mass decelerates/accelerates sufficiently, it yields impulses on the body that cascade in various ways into the respiratory–vocal system. It entails a physical entanglement between body motions, respiration, and vocal activities. It is shown that vocal-entangled gestures are realized in infant vocal–motor babbling before any representational use of gesture develops. Similarly, an overview is given of vocal-entangled processes in non-human animals. They can frequently be found in rats, bats, birds, and a range of other species that developed even earlier in the phylogenetic tree. Thus, the origins of human gesture lie in biomechanics, emerging early in ontogeny and running deep in phylogeny

Infant touching behaviours during mother-infant face-to-face interactions : effects of changes in maternal emotional and physical availability in normative and at-risk populations

Mother-infant interactions are fundamental to infant socio-emotional development. Through mutually regulated exchanges in the first year of life, infants develop critical communicative and regulatory skills. Infant touch is a central channel through which infants communicate their underlying affective states, regulate their emotions, and explore their surroundings. Yet despite its importance, there is a paucity of research examining infant touch. The current dissertation was designed to investigate infants' touching behaviours during mother-infant face-to-face interactions. A series of two studies investigating infant touch in the context of infants' other communicative modalities during interactions with variations in maternal availability was conducted. Study 1 examined how touch co-occurs with distal modalities (i.e. gaze, affect), and investigated the functions of touch (i.e. communicative, regulatory, exploratory). Findings revealed that touch is organized with gaze and affect into meaningful affective displays, and that infants use touch to self-regulate and explore when mothers are emotionally unavailable. The impact of the quality of the relationship (i.e. maternal emotional availability indicators, such as sensitivity and hostility) on infants' touching behaviours was also examined. Findings demonstrated greater engagement through touch in infants with more sensitive mothers. Study 2 investigated infants' touching behaviours in an at-risk sample of depressed and non-depressed mothers exhibiting poor relationship indicators (i.e. sub-optimal emotional availability). Touch was compared during periods of emotional versus physical unavailability, revealing greater reactive types of touch during physical unavailability. Findings also highlighted the impact of maternal risk on infants' touching behaviours: infants of depressed mothers exhibited more reactive types of touch compared to infants of non-depressed mothers, and negative relationship indicators (e.g. maternal hostility, intrusiveness) predicted regulatory tactile behaviours. Taken together, the present findings contribute to current knowledge on touch during early socio-emotional development. Results underscore that infants are active participants during their social exchanges and that they vary their tactile behaviours as a function of maternal availability. The findings clarify how infants use touch (i.e. to regulate, explore) when mothers are unavailable, and imply that touch serves a communicative role during pre-verbal development. Finally, this research offers insight into the impact of maternal risk on infants' regulatory abilities and the dyadic processes of co-regulatio

A Neural Network Model for Cursive Script Production

This article describes a neural network model, called the VITEWRITE model, for generating handwriting movements. The model consists of a sequential controller, or motor program, that interacts with a trajectory generator to move a. hand with redundant degrees of freedom. The neural trajectory generator is the Vector Integration to Endpoint (VITE) model for synchronous variable-speed control of multijoint movements. VITE properties enable a simple control strategy to generate complex handwritten script if the hand model contains redundant degrees of freedom. The proposed controller launches transient directional commands to independent hand synergies at times when the hand begins to move, or when a velocity peak in a given synergy is achieved. The VITE model translates these temporally disjoint synergy commands into smooth curvilinear trajectories among temporally overlapping synergetic movements. The separate "score" of onset times used in most prior models is hereby replaced by a self-scaling activity-released "motor program" that uses few memory resources, enables each synergy to exhibit a unimodal velocity profile during any stroke, generates letters that are invariant under speed and size rescaling, and enables effortless. connection of letter shapes into words. Speed and size rescaling are achieved by scalar GO and GRO signals that express computationally simple volitional commands. Psychophysical data concerning band movements, such as the isochrony principle, asymmetric velocity profiles, and the two-thirds power law relating movement curvature and velocity arise as emergent properties of model interactions.National Science Foundation (IRI 90-24877, IRI 87-16960); Office of Naval Research (N00014-92-J-1309); Air Force Office of Scientific Research (F49620-92-J-0499); Defense Advanced Research Projects Agency (90-0083

The Effects of Vestibular Stimulation Rate and Magnitude of Acceleration on Central Pattern Generation for Chest-Wall Kinematics in Preterm Infants.

The vestibular system of the fetus is responsive to accelerations in utero by 25 weeks gestational age (Hooker, 1969). However, the restrictive environment of the crib/isolette in the neonatal intensive care unit (NICU) and decreased positional changes limits vestibular experience and associated neural activity among preterm infants. This project was developed to test a set of hypotheses concerning the role of vestibular inputs on respiratory and oromotor systems during suck and early feeding development in preterm infants. Linear acceleration of the vestibular otoliths was achieved using a customized glider chair, the VestibuGlide System, developed in the Communication Neuroscience Laboratories at the University of Kansas. The VestibuGlide system features an integrated position-servo motor and a digital controller to generate physiologically appropriate sinusoidal displacements of the glider chair in the horizontal plane at specified rates (.5, .65, .8, .95 Hz) and accelerations (.21, .36, and .51 m/s2). It was hypothesized that providing this type of input to the vestibular apparatus will modify the central patterning of chest wall motion, and secondarily may alter suck and feed development during a critical period of brain development. Twelve preterm infants (7F/5M, birth GA 32; 6, BW 1927g) were recruited from the NICU at Stormont-Vail Regional Hospital in Topeka. Each infant received the 15 minute gliding protocol starting at 32 wks PMA, 3x/day before a scheduled feed for 10 days. Infants were fitted with two soft cloth Respitrace¢â inductance bands around the rib cage and abdomen to measure respiratory rate. The gliding protocol alternates between baseline and stimulus conditions every minute. During baseline conditions, the glider chair was stationary. Respiration, suck dynamics, and pulse-oximetry were recorded and monitored throughout the study. On average, infants received 24 VestibuGlide sessions. Stimulus condition had a significant effect for the in rib cage [F (7, 77) = 25.53, p < 0.01] and abdominal [F (7, 77) = 23.60, p < 0.01] breaths per minute (BPM). In general, infants increased their respiratory rate in response to the VestibuGlide stimulus. Stimulus number 7 provided the highest acceleration to the infant and induced significantly higher BPM than stimuli 1, 4, and 5 for the rib cage and stimuli 1 and 4 for the abdomen. It is clear that acceleration has the largest influence over the respiratory central pattern generator (rCPG) and is capable of inducing significant changes in chest wall kinematics. In spite of the increases in BPM during vestibular stimulation, infants maintained stable oxygen saturation (SpO2) and pulse rate throughout the VestibuGlide study. In fact, stimulus condition had a significant effect on SpO2, F (7, 77) = 2.57, p <.05. Infants had higher SpO2 during stimulus conditions 3, 4, and 6 compared to baseline conditions; however, after a Bonferroni-correction these differences could not reach statistical significance. Infants are able to modify their respiratory rate in response to vestibular stimulus while maintaining their SpO2and pulse. All infants were offered a Soothie¢â pacifier during each VestibuGlide session. Vestibular stimulation had no effect on NNS development. Oral feeds were measured in days to achieve ¡Ã90% oral feed for two consecutive days. A daily oral feed percentage was calculated across the eight daily feeds for all infants in the study and was compared to a cohort of 12 untreated preterm infants matched for birth GA (n=12, 7F/5M, GA 33; 2, BW 1950g) from an ongoing NIH trial underway in the mentor¡¯s laboratory (NIH R01 DC003311, Barlow-PI) recruited from Stormont-Vail Healthcare NICU in Topeka, KS and Overland Park Regional Medical Center NICU in Overland Park, KS. ANOVA revealed no difference in the oral feed growth slopes between the VestibuGlide treated infants and the control infants: F (1, 22) = .25, p =.625. On average, VestibuGlide infants advanced their oral feeds at 8.17% per day; whereas, control infants advanced their oral feeds at 9.47% per day. The length of stay in the NICU was measured from the admission date (birth date) to the discharge date for all infants in the VestibuGlide study and 15 untreated preterm control infants matched for birth GA (n=15 8F/7M, GA 32; 5, BW 1888g). ANOVA revealed a significant difference between the two groups F (1, 26) = 4.82, p=.03. The VestibuGlide group discharged from the hospital 9 days sooner than the control infants resulting in a substantial reduction in hospitalization costs (~$31,500/infant). Overall, vestibular stimulation delivered to the preterm infant between 32 and 34 weeks PMA effectively modulates respiratory rate and resets the rCPG

General dynamics of the physical-chemical systems in mammals

Biodynamic regulator chain models for physical chemical systems in mammal