In sync: Physiological correlates of behavioral synchrony in infants and mothers.

Abstract

Infant–mother behavioral synchrony is thought to scaffold the development of self-regulation in the first years of life. During this time, infants’ and mothers’ physiological regulation may contribute to dyadic synchrony and, in infants, dyadic synchrony may support infants’ physiological regulation. Because the sympathetic nervous system (SNS) and parasympathetic nervous system (PNS) serve different regulatory functions, the current study aimed to elucidate relations between infants’ and mothers’ SNS and PNS functioning and dyadic behavioral synchrony. Skin conductance (SC; SNS index), respiratory sinus arrhythmia (RSA; PNS index), heart period (HP; index of joint SNS and PNS arousal), and behavioral synchrony were assessed in 6-month-old infants (N = 140) and their mothers during a mild social stressor, the Face-to-Face Still-Face paradigm (Tronick, Als, Adamson, Wise, & Brazelton, 1978). Synchrony was related to infants’ and mothers’ PNS and to mothers’ broad autonomic arousal but not to SNS-specific arousal. Higher levels of behavioral synchrony were associated with lower infant RSA but with higher mother HP and RSA at baseline and in each Face-to-Face Still-Face paradigm episode. Therefore, lower RSA infants may have required more synchronous engagement with mothers to support regulation, while higher RSA, less aroused mothers may have been particularly well-attuned to infants’ emotions. Findings suggest that each individual’s physiological state may contribute to the behavioral functioning of the dyad.

Forms and Functions of Affective Synchrony

“…The amount of affective synchrony a caregiver-infant dyad achieves is a function of how much co-regulatory support the infant needs and how much co-regulatory support the caregiver is able to provide. A recent study examined the relationship between infant-mother behavioral synchrony and parasympathetic nervous system (PNS) and SNS activity during the mildly stressful still face paradigm (Busuito et al, 2019). Babies with lower PNS activity-infants who might need greater co-regulatory support-elicited more synchronous behavior from their mothers.…”

Infant-adult synchrony in spontaneous and nonspontaneous interactions

“…Due to our focus on the torso motion, other behavioral and biological markers sensitive to interactional synchrony were not considered. Synchrony can in fact be measured at different levels [ 146 ], such as psycho-physiological (e.g., galvanic skin response [ 13 , 155 ], heartbeat rate [ 20 , 70 ], and breath rate [ 4 , 156 ]); neurophysiological (e.g., alpha, beta, and gamma frequency bands [ 157 , 158 ]); linguistic (e.g., vocal rhythm and tone [ 52 ], utterance length [ 159 ], and speaking rate [ 160 ]); and behavioral (e.g., body limbs motion [ 2 , 46 , 119 , 120 ], gaze direction [ 50 , 51 , 161 ], facial expressions of emotions [ 42 , 84 , 85 ] and gestures [ 2 , 3 , 162 ]). Future work should take into account these synchrony levels, which may require a combination of different data capture and analysis strategies and other interactional contexts.…”

“…Interpersonal synchrony is defined as the spontaneous coordination of the interactants' body patterns in time and form [1][2][3][4]. When two or more individuals interact in social settings, they tend to coordinate at behavioral [5][6][7][8][9][10][11], physiological [12][13][14][15][16][17][18][19][20], and linguistic levels [21][22][23][24][25][26]. This phenomenon has been observed between adults chatting in an affiliative and argumentative way [27][28][29], solving joint tasks in a competitive or cooperative setting [30,31], playing sports games [32][33][34], dancing [35,36], or performing music together [37,38].…”

“…These matching episodes occurred during less than 40% of the entire interaction time [ 42 , 49 , 56 , 73 ]. Furthermore, less synchronized and asynchronous exchanges have been found when one or both individuals disengage from the interaction due to changes in interactional goals [ 74 ] and the physiological and psychological functioning [ 13 , 70 , 75 ]. For instance, dyadic synchrony is affected by infants' physiological immaturity at birth and infant negative reactivity [ 76 , 77 ].…”

Measuring Dynamics of Infant-Adult Synchrony Through Mocap

“…Time series measurement and analysis have been used in studies examining the concordance between infant-parent biological and behavioral rhythms (Feldman et al, 2011), as well as the consequences of early mother-infant synchronization for the development of selfcontrol (Feldman et al, 1999), symbolic play and internal state talk (Feldman and Greenbaum, 1997), and empathy (Feldman, 2007). They have also been implemented to inquire how motherinfant coordination is impacted by their physiological states (Busuito et al, 2019), maternal hair cortisol levels (Tarullo et al, 2017), and emotional dysregulation in mothers with mood disorders (Lotzin et al, 2016).…”