Motion tracking of parents’ infant‐ versus adult‐directed actions reveals general and action‐specific modulations

Parents tend to modulate their movements when demonstrating actions to their infants. Thus far, these modulations have primarily been quantified by human raters and for entire interactions, thereby possibly overlooking the intricacy of such demonstrations. Using optical motion tracking, the precise modulations of parents’ infant‐directed actions were quantified and compared to adult‐directed actions and between action types. Parents demonstrated four novel objects to their 14‐month‐old infants and adult confederates. Each object required a specific action to produce a unique effect (e.g. rattling). Parents were asked to demonstrate an object at least once before passing it to their demonstration partner, and they were subsequently free to exchange the object as often as desired. Infants’ success at producing the objects’ action‐effects was coded during the demonstration session and their memory of the action‐effects was tested after a several‐minute delay. Indicating general modulations across actions, parents repeated demonstrations more often, performed the actions in closer proximity and demonstrated action‐effects for longer when interacting with their infant compared to the adults. Meanwhile, modulations of movement size and velocity were specific to certain action‐effect pairs. Furthermore, a ‘just right’ modulation of proximity was detected, since infants’ learning, memory, and parents’ prior evaluations of their infants’ motor abilities, were related to demonstrations that were performed neither too far from nor too close to the infants. Together, these findings indicate that infant‐directed action modulations are not solely overall exaggerations but are dependent upon the characteristics of the to‐be learned actions, their effects, and the infant learners.     

An association between mothers’ speech clarity and infants’ speech discrimination skills

The quality of speech directed towards infants may play an important role in infants’ language development. However, few studies have examined the link between the two. We examined the correlation between maternal speech clarity and infant speech perception performance in two groups of Mandarin‐speaking mother–infant pairs. Maternal speech clarity was assessed using the degree of expansion of the vowel space, a measure previously shown to reflect the intelligibility of words and sentences. Speech discrimination in the infants (6–8 and 10–12‐month‐olds) was measured using a head‐turn task. The results show that mothers’ vowel space area is significantly correlated with infants’ speech discrimination performance. Socioeconomic data from both parents show that the result cannot be attributed to parental socioeconomic factors. This study is correlational and therefore a causal relationship cannot be firmly established. However, the results are consistent with the view that maternal speech clarity directly affects infants’ early language learning.     

The co‐construction of joint action between mothers and 2–4‐month‐old infants: the mother's role

The purpose of this longitudinal study was to describe object‐centred interactions between mothers and their 2–4‐month‐old infants, before and during the emergence of reaching and grasping movements. We hypothesized that when reaching movements emerge at around 3 months, mothers alternate between attention stimulation and reaching stimulation, before joint actions between mother and infant develop around objects. Twelve dyads were recorded when infants were 2 months, 3 months and 4 months. The interactive sessions lasted 5 min. Three age‐appropriate toys the infant could handle were available to the mother. A principal component analysis (PCA) was performed on verbal and non‐verbal maternal behaviours, motor infant behaviours and co‐occurrences of those behaviours. The developmental course of prehension in infants when playing with their mother follows similar pathways, as was described when they are observed alone. Mothers appeared to early scaffold prehension skills by verbal and non‐verbal means. Moreover, maternal behaviours change according to the infant's behaviour, and conversely, infant's behaviours influence maternal behaviours: mother plays first an active part in joint action, while later on, the infant achieves joint action when motor skills develop. Copyright © 2000 John Wiley & Sons, Ltd.     

Infant's action skill dynamically modulates parental action demonstration in the dyadic interaction

When interacting with infants, human adults modify their behaviours in an exaggerated manner. Previous studies have demonstrated that infant‐directed modification affects the infant's behaviour. However, little is known about how infant‐directed modification is elicited during infant–parent interaction. We investigated whether and how the infant's behaviour affects the mother's action during an interaction. We recorded three‐dimensional information of cup movements while mothers demonstrated a cup‐nesting task during interaction with their infants aged 11 to 13 months. Analyses revealed that spatial characteristics of the mother's task demonstration clearly changed depending on the infant's object manipulation. In particular, the variance in the distance that the cup was moved decreased after the infant's cup nesting and increased after the infant's task‐irrelevant manipulation (e.g. cup banging). This pattern was not observed for mothers with 6‐ to 8‐month‐olds, who do not have the fine motor skill to perform the action. These results indicate that the infant's action skill dynamically affects the infant‐directed action and suggest that the mother is sensitive to the infant's potential to learn a novel action. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=VNS2IHwLIhg&feature=youtu.be     

Infants prefer motionese to adult‐directed action

In two studies, we investigated infants’ preference for infant‐directed (ID) action or ‘motionese’ ( Brand, Baldwin & Ashburn, 2002 ) relative to adult‐directed (AD) action. In Study 1, full‐featured videos were shown to 32 6‐ to 8‐month‐olds, who demonstrated a strong preference for ID action. In Study 2, infants at 6–8 months (n= 28) and 11–13 months (n= 24) were shown either standard ID and AD clips, or clips in which demonstrators’ faces were blurred to obscure emotional and eye‐gaze information. Across both ages, infants showed evidence of preferring ID to AD action, even when faces were blurred. Infants did not have a preference for still‐frame images of the demonstrators, indicating that the ID preference arose from action characteristics, not demonstrators’ general appearance. These results suggest that motionese enhances infants’ attention to action, possibly supporting infants’ learning.     

Infants' perception of goal‐directed actions on video

Imitation studies and object search studies show that infants have difficulties using action information presented on video to guide their own behaviour. The present study investigated whether infants also have problems interpreting information shown on video relative to real live information. It was examined whether 6‐month‐olds interpret an action with a salient action effect as goal‐directed when it is performed by an actor on a video‐screen and when it is performed by a live actor. A video presentation of a goal‐directed action display was presented to one group of infants, and another group received the same action display, matched in all details, live on a stage. Results indicate that 6‐month‐olds in the video group as well as in the live group interpreted the human action as goal‐directed. Moreover, comparison across both groups revealed no difference in the overall looking pattern between the video and the live presentation group. Thus, our findings show that infants as young as 6 months of age can take important information from video clips and interpret televised actions in meaningful ways that is equivalent to their interpretation of live actions.     

Maternal Responsiveness,Intrusiveness, and Negativity During Play with Infants: Contextual Associations and Infant Cognitive Status in A Low‐Income Sample

Maternal parenting behaviors during a mother–infant play interaction were examined in a sample of 160 low‐income mothers and their 15‐month‐old infants. Maternal responsive/didactic, intrusive, and negative behaviors were coded from videotapes and examined in relation to mothers’ age, marital status, stressful life events, and depressive symptoms, and infants’ cognitive scores at 15 and 25 months. Younger maternal age and increases in stressful life events were associated with increases in mothers’ negative behaviors whereas being married was positively associated with mothers’ responsive/didactic behaviors and inversely associated with their negative and intrusive behaviors. Mothers’ depressive symptoms were inversely associated with both responsive/didactic and intrusive behaviors and predicted lower cognitive scores in infants at 15 months, but not 25 months. Maternal responsive/didactic behaviors predicted infant cognitive scores at both ages after controlling for maternal characteristics and other parenting behaviors. Intrusiveness moderated associations between both responsive/didactic and negative parenting behaviors and infant 25‐month cognition. Maternal age, marital status, psychological resources, and contextual sources of stress play a central role in the quality of parenting among low‐income mothers, and positive mother–infant interactions are strong predictors of infants’ early cognitive status.     

Triadic interactions support infants’ emerging understanding of intentional actions

Infants’ understanding of the intentional nature of human action develops gradually across the first year of life. A key question is what mechanisms drive changes in this foundational social‐cognitive ability. The current studies explored the hypothesis that triadic interactions in which infants coordinate attention between a social partner and an object of mutual interest promote infants’ developing understanding of others as intentional agents. Infants’ spontaneous tendency to participate in triadic engagement was assessed in a semi‐structured play session with a researcher. Intentional action understanding was assessed by evaluating infants’ ability to visually predict the goal of an intentional reaching action. Study 1 (N = 88) revealed that 8‐ to 9‐month‐olds who displayed more bouts of triadic engagement showed better concurrent reasoning about the goal of an intentional reaching action. Study 2 (N = 114) confirmed these findings using a longitudinal design and demonstrated that infants who displayed more bouts of triadic engagement at 6–7 months were better at prospectively reasoning about the goal of an intentional reaching action 3 months later. Cross‐lagged path analyses revealed that intentional action understanding at 6–7 months did not predict later triadic engagement, suggesting that early triadic engagement supports later intentional action processing and not the other way around. Finally, evidence from both studies revealed the unique contribution of triadic over dyadic forms of engagement. These results highlight the importance of social interaction as a developmental mechanism and suggest that infants enrich their understanding of intentionality through triadic interactions with social partners.     

The Effectiveness of an Attachment‐Based Intervention in Promoting Foster Mothers’ Sensitivity toward Foster Infants

Infants in foster care need sensitive, responsive caregivers to promote their healthy outcomes. The current study examined the effectiveness of the Attachment and Biobehavioral Catch‐up Intervention, a short‐term, targeted, attachment‐based intervention program designed to promote sensitive caregiving behavior among foster mothers. Ninety‐six foster mother–infant dyads participated in this study; 44 dyads were assigned to the Attachment and Biobehavioral Catch‐up Intervention, and 52 dyads were assigned to a control intervention. Results of hierarchical linear modeling indicated that foster mothers who were assigned to the Attachment and Biobehavioral Catch‐up Intervention showed greater improvements in their sensitivity from pre‐ to postintervention assessment time points when compared with foster mothers who were assigned to the control intervention. We conclude that a short‐term, targeted, attachment‐based intervention is effective in changing foster mothers’ responsiveness to their foster infants, which is critical for foster infants’ healthy socioemotional adjustment.     

Baby steps: investigating the development of perceptual–motor couplings in infancy

There are cells in our motor cortex that fire both when we perform and when we observe similar actions. It has been suggested that these perceptual‐motor couplings in the brain develop through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, there is no direct evidence that associative learning also underlies the initial formation of perceptual–motor couplings in the developing brain. With the present study we addressed this question by manipulating infants’ opportunities to associate the visual and motor representation of a novel action, and by investigating how this influenced their sensorimotor cortex activation when they observed this action performed by others. Pre‐walking 7–9‐month‐old infants performed stepping movements on an infant treadmill while they either observed their own real‐time leg movements (Contingent group) or the previously recorded leg movements of another infant (Non‐contingent control group). Infants in a second control group did not perform any steps and only received visual experience with the stepping actions. Before and after the training period we measured infants’ sensorimotor alpha suppression, as an index of sensorimotor cortex activation, while they watched videos of other infants’ stepping actions. While we did not find greater sensorimotor alpha suppression following training in the Contingent group as a whole, we nevertheless found that the strength of the visuomotor contingency experienced during training predicted the amount of sensorimotor alpha suppression at post‐test in this group. We did not find any effects of motor experience alone. These results suggest that the development of perceptual–motor couplings in the infant brain is likely to be supported by associative learning during correlated visuomotor experience.     

The role of sensorimotor experience in the development of mimicry in infancy

During social interactions we often have an automatic and unconscious tendency to copy or ‘mimic’ others’ actions. The dominant view on the neural basis of mimicry appeals to an automatic coupling between perception and action. It has been suggested that this coupling is formed through associative learning during correlated sensorimotor experience. Although studies with adult participants have provided support for this hypothesis, little is known about the role of sensorimotor experience in supporting the development of perceptual‐motor couplings, and consequently mimicry behaviour, in infancy. Here we investigated whether the extent to which an observed action elicits mimicry depends on the opportunity an infant has had to develop perceptual‐motor couplings for this action through correlated sensorimotor experience. We found that mothers’ tendency to imitate their 4‐month‐olds’ facial expressions during a parent‐child interaction session was related to infants’ facial mimicry as measured by electromyography. Maternal facial imitation was not related to infants’ mimicry of hand actions, and instead we found preliminary evidence that infants’ tendency to look at their own hands may be related to their tendency to mimic hand actions. These results are consistent with the idea that mimicry is supported by perceptual‐motor couplings that are formed through correlated sensorimotor experience obtained by observing one's own actions and imitative social partners.     

The link between infant attention to goal‐directed action and later theory of mind abilities

Various studies have shown that infants in their first year of life are able to interpret human actions as goal‐directed. It is argued that this understanding is a precondition for understanding intentional actions and attributing mental states. Moreover, some authors claim that this early action understanding is a precursor of later Theory of Mind (ToM) development. To test this, we related 6‐month‐olds’ performance in an action interpretation task to their performance in ToM tasks at the age of 4 years. Action understanding was assessed using a modified version of the Woodward‐paradigm ( Woodward, 1999 ). At the age of 4 years, the same children were tested with the German version of the ToM scale developed by Wellman and Liu (2004 ). Results revealed a correlation between infants’ decrement of attention to goal‐directed action and their ability to solve a false belief task at the age of 4 years with no modulation by language abilities. Our results indicate a link between infant attention to goal‐directed action and later theory of mind abilities.     

Infants’ unprovoked acts of force toward others

Infants harm others at higher rates than older children and adults. A common explanation is that infants fail to regulate their frustration, becoming aggressive when they do not get what they want. The present research investigated whether infants also use force against others without provocation, for instance because they seek to explore the consequences of hitting or try to pet someone using too much force. Two studies with infants aged 11 to 24 months investigated infants’ use of force against others in everyday life using maternal report (Study 1) and direct observation (Study 2). In both studies, a large proportion of infants’ acts of force were unprovoked and occurred without signs of infant distress. Unlike provoked acts, unprovoked acts showed a decrease late in the second year and were positively associated with reports of infant pleasure‐proneness. The presence of unprovoked acts of harm may reflect that infants’ actions are not reliably guided by an aversion for harming others and may provide unique opportunities for early moral development.     

One‐year‐old infants use teleological representations of actions productively

Two experiments investigated whether infants represent goal‐directed actions of others in a way that allows them to draw inferences to unobserved states of affairs (such as unseen goal states or occluded obstacles). We measured looking times to assess violation of infants' expectations upon perceiving either a change in the actions of computer‐animated figures or in the context of such actions. The first experiment tested whether infants would attribute a goal to an action that they had not seen completed. The second experiment tested whether infants would infer from an observed action the presence of an occluded object that functions as an obstacle. The looking time patterns of 12‐month‐olds indicated that they were able to make both types of inferences, while 9‐month‐olds failed in both tasks. These results demonstrate that, by the end of the first year of life, infants use the principle of rational action not only for the interpretation and prediction of goal‐directed actions, but also for making productive inferences about unseen aspects of their context. We discuss the underlying mechanisms that may be involved in the developmental change from 9 to 12 months of age in the ability to infer hypothetical (unseen) states of affairs in teleological action representations.     

MATERNAL SELF‐REPORTED DEPRESSIVE SYMPTOMS AND MATERNAL CORTISOL LEVELS INTERACT TO PREDICT INFANT CORTISOL LEVELS

Three basic findings have emerged from research on maternal depressive symptoms and offspring hypothalamic–pituitary–adrenal functioning: (a) Mothers’ depressive symptoms are positively associated with their offsprings’ cortisol stress response, (b) numerous individual and interpersonal maternal characteristics moderate this association, and (c) maternal and infant cortisol levels are highly correlated. In combination, these findings have suggested that maternal cortisol levels may moderate the relation between maternal depressive symptoms and infant cortisol responsivity; the current study assessed this hypothesis. Participants were 297 mother–infant dyads who were recruited from the community. Maternal depressive symptoms were assessed via self‐report. Dyads participated in two differentially stressful infant challenges when infants were 16 and 17 months old. Mother and infant salivary cortisol was collected before and after challenges. Results indicate that maternal cortisol levels moderated associations between maternal depressive symptoms and infant cortisol levels across both challenges. Infants showed higher cortisol levels if their mothers had both higher depressive symptoms and higher cortisol levels, as compared to infants of mothers with higher depressive symptoms and lower cortisol, and to infants of mothers with lower depressive symptoms and either higher or lower cortisol levels. We discuss findings in relation to environmental and biological factors that may contribute to the intergenerational transmission of depressive symptoms.     

Mothers' Perceptions of Infants Labelled ‘Depressed’

Forty-four depressed and non-depressed mothers participated in a videotaped interaction with their own infant and then rated the videotape using the Infant Stereotyping Scale and the Interaction Rating Scale. In addition, one half of the mothers rated a videotape of an unfamiliar infant who was labelled psychologically ‘depressed’ and the other half rated a videotape of the same infant with no label given. Both the depressed and non-depressed mothers rated the ‘depressed’ labelled infant more negatively than the non-labelled infant on the attributes of physical potency, cognitive competence, sociability and difficult behaviour. Physical appearance was the only rating that was not biased by the ‘depressed’ label. Mothers' ratings of their own infants were more positive than their ratings of the non-labelled stimulus infant. Depressed mothers did not see their infants more negatively except on one rating. They rated the physical appearance of their own infant more negatively than non-depressed mothers.     

THERAPISTS’ EXPERIENCES OF MOTHER–INFANT PSYCHOANALYTIC TREATMENT: A QUALITATIVE STUDY

As part of a larger research project in Sweden, a qualitative study investigated psychotherapists’ experiences of mother–infant psychoanalysis (MIP). A randomized controlled trial compared two groups of mother–infant dyads with psychological problems. One had received Child Health Center care, and the other received MIP. Previous articles on long‐term effects have found that mothers who had received MIP were less depressed throughout a posttreatment period of 3½ years, and their children showed better global functioning and psychological well‐being. The present study's objectives were to describe the therapist's experiences of MIP and deepen the understanding of the MIP process. Six months after treatment began, all therapists were interviewed. Transcribed interviews with therapists from 10 (of 33 total) MIP treatments were randomly selected and analyzed in detail by thematic analysis. Therapists worked successfully with mother and infant together and found different ways of cooperation during MIP sessions. Therapists reported overall positive experiences; however, in cases where mothers needed more personal attention, it would be important to adapt the method to them.     

Infant–mother social referencing interactions: Description and antecedents in maternal sensitivity and infant irritability

The purpose of the study was to describe naturally occurring infant and maternal behaviours in terms of social referencing in a stranger wariness situation, and to explore antecedents to such behaviouts in early maternal sensitivity and infant irritability. One hundred and ten 10-months-old infants and their mothers were videotaped. Infant social referencing behaviour was defined as puzzled looks directed at mother's face after the infant had discovered the stranger. Almost half of the infants looked with a puzzled expression at their mothers immediately after discovering the stranger, and a majority of the mothers sent a positive message back to the infants. Twenty per cent of the infants never looked at their mothers and 20% of the mothers did not respond when their infants turned to them. Infants whose mothers had responded positively to the referencing look showed positive responses to the stranger to a higher degree than infants who did not reference or those who were not responded to. Antecedents to infant and mother interactive behaviours were sought in maternal sensitivity (general sensitivity, physical contact, responsiveness, intrusiveness, response to distress, and effectiveness in comforting) and in infant irritability as observed when the infants were 4 months old. It was found that infants who did not reference their mothers for information at 10 months had experienced less sensitive mothering 6 months earlier and had also shown more irritability.