This&#160;research was supported by NIH 1 U01 HL097973, NHLBI 5 R01 HL116511-02, UCSF-CTSI Grant Number UL1 TR000004, the Robert Wood Johnson Health and Society Scholars Program, and the Lisa and John Pritzker Family Foundation. The authors also wish to acknowledge Michelle Stephens for her assistance with scoring the ANS data as well as Vanessa Tearnan, Marialma Gonzales-Cruz, Yurivia Cervantes, Amy Engler, Stephanie Grover and Karen Jones-Mason for their assistance in collecting the ANS data, and Michael Coccia for his help with the data. We are also thankful to the families for their generous participation in this research and to the volunteers who helped us to test and refine this protocol, including the first author&#8217;s two children. We want to acknowledge our mentors who taught us about measuring ANS and why measuring ANS responsivity is meaningful in young children: W. Thomas Boyce, Gary Bernston, and Dave Lozano.

<ol>
	<li>Berntson, G., Quigley, K., Lozano, D., Cacioppo, J. T., Tassinary, L. G., Bernston, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+8,+Cardiovascular+Psychophysiology.">Chapter 8, Cardiovascular Psychophysiology.</a> Handbook of Psychophysiology. , (2007).</li><li>Boyce, W. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+father+involvement+moderates+biobehavioral+susceptibility+to+mental+health+problems+in+middle+childhood.">Early father involvement moderates biobehavioral susceptibility to mental health problems in middle childhood.</a> J. Am. Acad. Child Adolesc. Psychiatry. 45, 1510-1520 (2006).</li><li>Loman, M., Gunnar, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Early+experience+and+the+development+of+stress+reactivity+and+regulation+in+children.">Early experience and the development of stress reactivity and regulation in children.</a> Neurosci. Behav. Physiol. 34, 867-876 (2010).</li><li>Calkins, S. D., Graziano, P. A., Keane, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+vagal+regulation+differentiates+among+children+at+risk+for+behavioral+problems.">Cardiac vagal regulation differentiates among children at risk for behavioral problems.</a> Biol. Psychol. 74, 144-153 (2007).</li><li>Kroenke, C. H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomic+and+Adrenocortical+Reactivity+and+Buccal+Cell+Telomere+Length+in+Kindergarten+Children.">Autonomic and Adrenocortical Reactivity and Buccal Cell Telomere Length in Kindergarten Children.</a> Psychosom. Med. 73, 533-540 (2011).</li><li>Obradovi&#263;, J., Bush, N. R., Stamperdahl, J., Adler, N. E., Boyce, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biological+sensitivity+to+context:+The+interactive+effects+of+stress+reactivity+and+family+adversity+on+socioemotional+behavior+and+school+readiness.">Biological sensitivity to context: The interactive effects of stress reactivity and family adversity on socioemotional behavior and school readiness.</a> Child Dev. 81, 270-289 (2010).</li><li>Alkon, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Latino+children's+body+mass+index+at+2-3.5+years+predicts+sympathetic+nervous+system+activity+at+5+years.">Latino children's body mass index at 2-3.5 years predicts sympathetic nervous system activity at 5 years.</a> Child Obes. 10, 214-224 (2014).</li><li>Alkon, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+ontogeny+of+autonomic+measures+in+6-+and+12-month-old+infants.">The ontogeny of autonomic measures in 6- and 12-month-old infants.</a> Dev. Psychobiol. 48, 197-208 (2006).</li><li>Conradt, E., Measelle, J., Ablow, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Poverty,+Problem+Behavior,+and+Promise:+Differential+Susceptibility+Among+Infants+Reared+in+Poverty.">Poverty, Problem Behavior, and Promise: Differential Susceptibility Among Infants Reared in Poverty.</a> Psychol. Sci. 24, 235-242 (2013).</li><li>Alkon, A., Boyce, W. T., Davis, N. V., Eskenazi, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+Changes+in+Autonomic+Nervous+System+Resting+and+Reactivity+Measures+in+Latino+Children+from+6+to+60+Months+of+Age.">Developmental Changes in Autonomic Nervous System Resting and Reactivity Measures in Latino Children from 6 to 60 Months of Age.</a> J. Dev. Behav. 32, 668-677 (2011).</li><li>Alkon, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+and+contextual+influences+on+autonomic+reactivity+in+young+children.">Developmental and contextual influences on autonomic reactivity in young children.</a> Dev. Psychobiol. 42, 64-78 (2003).</li><li>Boyce, W. T., Ciccheti, D., Cohen, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Developmental Psychopathology: Developmental Neuroscience. II, 797-817 (2006).</li><li>Beauchaine, T. P., Gatzke-Kopp, L., Mead, H. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polyvagal+Theory+and+developmental+psychopathology:+emotion+dysregulation+and+conduct+problems+from+preschool+to+adolescence.">Polyvagal Theory and developmental psychopathology: emotion dysregulation and conduct problems from preschool to adolescence.</a> Biol. Psychol. 74, 174-184 (2007).</li><li> Beauchaine, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vagal+tone,+development,+and+Gray's+motivational+theory:+toward+an+integrated+model+of+autonomic+nervous+system+functioning+in+psychopathology.">Vagal tone, development, and Gray's motivational theory: toward an integrated model of autonomic nervous system functioning in psychopathology.</a> Dev. Psychopathol. 13, 183-214 (2001).</li><li>Conradt, E., Measelle, J., Poverty Ablow, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Problem+Behavior,+and+Promise:+Differential+Suceptibility+Among+Infants+Reared+in+Poverty.">Problem Behavior, and Promise: Differential Suceptibility Among Infants Reared in Poverty.</a> Psychol. Sci. 24, 235-242 (2013).</li><li>Porges, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+polyvagal+perspective.">The polyvagal perspective.</a> Biol. Psychol. 74, 116-143 (2007).</li><li>Boyce, W. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomic+reactivity+and+psychopathology+in+middle+childhood.">Autonomic reactivity and psychopathology in middle childhood.</a> Br. J. Psychiatry. 179, 144-150 (2001).</li><li>Crowell, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomic+correlates+of+attention-deficit/hyperactivity+disorder+and+oppositional+defiant+disorder+in+preschool+children.">Autonomic correlates of attention-deficit/hyperactivity disorder and oppositional defiant disorder in preschool children.</a> J. Abnorm. Psychol. 115, 174-178 (2006).</li><li>Raine, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomic+nervous+system+factors+underlying+disinhibited,+antisocial,+and+violent+behavior.+Biosocial+perspectives+and+treatment+implications.">Autonomic nervous system factors underlying disinhibited, antisocial, and violent behavior. Biosocial perspectives and treatment implications.</a> Ann. N.Y. Acad. Sci. 794, 46-59 (1996).</li><li>Boyce, W. T., Alkon, A., Tschann, J. M., Chesney, M. A., Alpert, B. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dimensions+of+psychobiologic+reactivity:+Cardiovascular+responses+to+laboratory+stressors+in+preschool+children.">Dimensions of psychobiologic reactivity: Cardiovascular responses to laboratory stressors in preschool children.</a> Ann. Behav. Med. 17, 315-323 (1995).</li><li>Bush, N. R., Boyce, W. T., Lewis, M., Rudolph, K. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Contributions+of+Early+Experience+to+Biological+Development+and+Sensitivity+to+Context.">The Contributions of Early Experience to Biological Development and Sensitivity to Context.</a> Handbook of Developmental Psychopathology. , 287-309 (2014).</li><li>Matthews, K. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Handbook of Stress, Reactivity, and Cardiovascular Disease. , (1986).</li><li>Alkon, A., Wolff, B., Boyce, W., Maholmes, V., King, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Oxford Handbook of Poverty and Child Development. , (2012).</li><li>Berntson, G. G., Cacioppo, J. T., Quigley, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomic+cardiac+control.+I.+Estimation+and+validation+from+pharmacological+blockades.">Autonomic cardiac control. I. Estimation and validation from pharmacological blockades.</a> Psychophysiology. 31, 572-585 (1994).</li><li>Sherwood, A., Allen, M. T., Obrist, P. A., Langer, A. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+beta-adrenergic+influences+on+cardiovascular+and+metabolic+adjustments+to+physical+and+psychological+stress.">Evaluation of beta-adrenergic influences on cardiovascular and metabolic adjustments to physical and psychological stress.</a> Psychophysiology. 23, 89-104 (1986).</li><li>Calkins, S. D., Keane, S. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiac+vagal+regulation+across+the+preschool+period:+Stability,+continuity,+and+implications+for+childhood+adjustment.">Cardiac vagal regulation across the preschool period: Stability, continuity, and implications for childhood adjustment.</a> Dev. Psychobiol. 45, 101-112 (2004).</li><li>Quigley, K., Stifter, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+comparative+validation+of+sympathetic+reactivity+in+children+and+adults.">A comparative validation of sympathetic reactivity in children and adults.</a> Psychophysiology. 43, 116-143 (2006).</li><li>Sherwood, A., Royal, S., Hutcheson, J., Turner, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+impedance+cardiographic+measurements+using+band+and+spot+electrodes.">Comparison of impedance cardiographic measurements using band and spot electrodes.</a> Psychophysiology. 29, 734-741 (1992).</li><li>Allen, M. T., Matthews, K. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Hemodynamic+responses+to+laboratory+stressors+in+children+and+adolescents:+the+influences+of+age,+race,+and+gender.">Hemodynamic responses to laboratory stressors in children and adolescents: the influences of age, race, and gender.</a> Psychophysiology. 34, 329-339 (1997).</li><li>van Dijk, A. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measuring+cardiac+autonomic+nervous+system+(ANS)+activity+in+children.">Measuring cardiac autonomic nervous system (ANS) activity in children.</a> J. Vis. Exp. , (2013).</li><li>Treadwell, M. J., Alkon, A., Styles, L., Boyce, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Autonomic+nervous+system+reactivity:+children+with+and+without+sickle+cell+disease.">Autonomic nervous system reactivity: children with and without sickle cell disease.</a> Nurs. Res. 60, 197-207 (2011).</li><li>Stifter, C. A., Dollar, J. M., Cipriano, E. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Temperament+and+emotion+regulation:+the+role+of+autonomic+nervous+system+reactivity.">Temperament and emotion regulation: the role of autonomic nervous system reactivity.</a> Dev. Psychobiol. 53, 266-279 (2011).</li><li>Bar-Haim, Y., Marshall, P. J., Fox, N. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+changes+in+heart+period+and+high-frequency+heart+period+variability+from+4+months+to+4+years+of+age.">Developmental changes in heart period and high-frequency heart period variability from 4 months to 4 years of age.</a> Dev. Psychobiol. 37, 44-56 (2000).</li><li>Beauchaine, T. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+Markers+of+Emotional+and+Behavioral+Dysregulation+in+Externalizing+Psychopathology.">Physiological Markers of Emotional and Behavioral Dysregulation in Externalizing Psychopathology.</a> Monogr. Soc. Res. 77, 79-86 (2012).</li><li>Kamarck, T. W., Lovallo, W. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiovascular+reactivity+to+psychological+challege:+Conceptual+and+measurement+considerations.">Cardiovascular reactivity to psychological challege: Conceptual and measurement considerations.</a> Psychosom. Med. 65, 9-21 (2003).</li><li>Fox, N. A., Schmidt, L. A., Henderson, H. A., Marshall, P. J., Cacioppo, J. T., Tassinary, L. G., Bernston, G. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chapter+20,+Developmental+Psychophysiology:+Conceptual+and+Methodological+Issues.">Chapter 20, Developmental Psychophysiology: Conceptual and Methodological Issues.</a> Handbook of Psychophysiology. , 453-481 (2007).</li><li>Gilissen, R., Koolstra, C., van Ijzendoorn, M., Bakermans-Kranenburg, M., van der Veer, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Physiological+reactions+of+preschoolers+to+fear-inducing+film+clips:+Effects+of+temperamental+fearfulness+and+quality+of+the+parent-child+relationship.">Physiological reactions of preschoolers to fear-inducing film clips: Effects of temperamental fearfulness and quality of the parent-child relationship.</a> Dev. Psychobiol. 49, 187-195 (2007).</li><li>Bush, N. R., Alkon, A., Stamperdahl, J., Obradovi&#263;, J., Boyce, W. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Differentiating+Challenge+Reactivity+from+Psychomotor+Activity+in+Studies+of+Children’s+Psychophysiology:+Considerations+for+Theory+and+Measurement.">Differentiating Challenge Reactivity from Psychomotor Activity in Studies of Children’s Psychophysiology: Considerations for Theory and Measurement.</a> J. Exp. Child Psychol. 110, 62-79 (2011).</li></ol>

The authors declare that they have no competing financial interests.

This study revealed that, within a sample of 18 month-old children, standardized resting and challenge tasks designed to elicit responses from a range of domains (startle, sensory, social, resting) led to a range of ANS responses. The mean ANS responses found under these resting and challenge conditions were similar to ANS values reported by others who have measured ANS responsiveness with young children using similar tasks 8,11,27,29. The mean levels of the ANS measures found in our sample are between those t...

Individual differences in children&#8217;s autonomic nervous system (ANS) reactivity play an important role in the development and maintenance of physical and mental health problems 12-16. A growing body of evidence reveals that individual differences in ANS measures at rest and reactivity are predictive of variations in children&#8217;s internalizing and externalizing psychopathology 4,9,17-19 and physical health 7,20. In addition to these direct or main effects of ANS functioning, an accumulating body of studies have found that children&#8217;s reactivity can interact with contextual risk factors, such as adverse events or marital conflict, to moderate those effects on children&#8217;s wellbeing and health (see reference&#160;21 for a review). Despite this growing evidence that children&#8217;s autonomic reactivity plays a role in health across the life course, and the accompanying interest in those processes, there is need for additional research examining the development of ANS functioning in children under three years of age.
The ANS consists of two branches, the parasympathetic and sympathetic nervous systems. It regulates the function of internal organs (e.g.,&#160;heart rate, respiration, digestion, and sexual arousal), largely through unconscious mechanisms, in response to everyday and adverse experiences 1. The parasympathetic nervous system (PNS) is the &#8216;rest and restorative&#8217; system that maintains a low resting heart rate and restorative state when sleeping or relaxing The sympathetic nervous system (SNS) is the &#8216;fight or flight&#8217; system that responds to emergencies or threatening situations by accelerating one&#8217;s heart rate 23. Respiratory sinus arrhythmia (RSA) is a reliable index of the PNS influence on cardiac functioning, and pre-ejection period (PEP) is a reliable index of the SNS influence on cardiac functioning. Both RSA and PEP have been found to be valid measures through experimental pharmacological blockade in samples of adults 24,25. More recently, this work has been extended into child and adolescent samples, further establishing RSA and PEP as valid and reliable measures of ANS activity throughout development 8,26,27. Reliable impedance cardiography measurements (PEP) using band and spot electrodes have been used for considerable time in adult samples 28. More recently, parallel measurement and analytic techniques have also been shown to be reliable and valid in samples of children 11,29,30, although collection of PEP measures in young children is rare.
There is an extant large body of literature on PNS functioning in infants and young children, including vagal tone and respiratory sinus arrhythmia measures. There are fewer studies of the SNS using PEP, and very few simultaneously examining both the parasympathetic and sympathetic nervous systems, which is critical for building understanding of their highly integrated functioning. Of the few studies of young children&#8217;s PEP, most find that their protocols do not produce significant group level changes in PEP in response to challenges 8,31. Studies have demonstrated that there is stability in resting PNS measures starting in infancy and they have relations with temperament, behavior, and health,13,16,26,32,33 but there is a limited understanding of SNS responding and its stability over time, relations to development, and the factors that shape that its developmental trajectory. PNS responses have been attributed primarily to social engagement 16 and SNS responses proposed to reflect &#8220;fight or flight responses&#8221; 1 as well as reward sensitivity (see reference&#160;34 for a review). In young children, it is challenging to simulate specific challenges in a laboratory and to engage them due to their short attention span. There are also measurement challenges for toddlers who may experience discomfort with the seven spot electrodes needed to measure PNS and SNS simultaneously. In addition, within the fields of developmental science, there few standards about how to elicit &#8220;stress reactivity&#8221; sufficiently while also respecting children&#8217;s developmental needs and the ethics in working with children. This article presents information on the administration and scoring of a standardized protocol comprised of resting and challenging conditions designed to elicit parasympathetic and sympathetic nervous system responses from 18 month old children.
ANS reactivity is typically conceptualized as the physiological response to a discrete external stimulus relative to a comparison or resting state, which varies across individual organisms 22. Examination of the early life etiology of mental and physical health problems has led scientists to be particularly interested in understanding children&#8217;s reactivity to situations that evoke adaptive responding or can be thought of as stressful challenges. The preponderance of literature refers to this phenomenon as &#8220;stress reactivity&#8221;, although encountering challenging stimuli has the potential to elicit responses across a broad range of domains. Thus, the protocol described below was designed to elicit ANS responses across multiple domains including two forms of rest (while listening to a soothing lullaby and while watching a calm, neutral video) and three developmentally-appropriate challenges for 18-month olds: anticipation/startle (jack-in-the-box), sensory (lemon juice), and socioemotional (listening to a sick infant cry). The protocol was adapted from our existing protocols for 12 month olds 8 and 3-5 year olds 11, in order to make it developmentally-challenging, engaging and tolerable for toddlers (18-21 months).
Here we present the Developmental Challenges Protocol (DCP) and ANS data from the 18 month old study visit of the Stress, Eating and Early Development (SEED) Study of pregnant women and their offspring. Maternal participants with healthy pregnancies were recruited&#160;during 2013-14 for a study of gestational weight gain and prenatal stress and were overweight, low income, and racially and ethnically diverse. Parents&#8217; informed consent for the study of her offspring was obtained just after birth and again prior to the start of the data collection for the study reported here, when the offspring were 18-21 months of age during 2014-2015.

<table><tbody><tr><td>ANS equipment</td><td></td><td></td><td></td></tr><tr><td>Laptop and power cord&amp;nbsp;</td><td>Dell</td><td>60-0107-3.0</td><td>Mindware BioLab software requires a PC with 2 USB ports</td></tr><tr><td>ANS data collection software</td><td>Mindware</td><td>contact company</td><td>BioLab acquisition program</td></tr><tr><td>ANS data acquisition unit and cords</td><td>Mindware</td><td>50-3711-08</td><td>BioNex 8-slot Chassis</td></tr><tr><td>Snap leads</td><td>Mindware</td><td>93-0498-00</td><td>2 white, 2 red, 2 brown, 1 black</td></tr><tr><td>Spot electrodes</td><td>Kendall</td><td>31112496</td><td>130 model; 7 for each assessment + extras-to be sealed in a ziplock bag at all times)</td></tr><tr><td>ANS scoring/editing software</td><td>Mindware</td><td>contact company</td><td>HRV Analysis, version 3.1.0F and IMP Analysis, version 3.1.0I</td></tr><tr><td></td><td></td><td></td><td></td></tr><tr><td>Protocol equipment</td><td></td><td></td><td></td></tr><tr><td>tablet computer</td><td>Apple</td><td></td><td>iPad; for playing audio and video clips</td></tr><tr><td>portable speaker</td><td>Polariod</td><td>PBT510</td><td></td></tr><tr><td>Jack in the Box</td><td>Schylling</td><td>SMJB</td><td>Sock Monkey theme</td></tr><tr><td>Lemon juice</td><td>ReaLemon</td><td>98077</td><td>0.14 oz shelf-stable packets</td></tr><tr><td>Pasture pipettes</td><td>Grainger</td><td>6FAV9</td><td>1 ml size, disposable</td></tr><tr><td>Portion cups</td><td>Dart Solo Con</td><td>250PC</td><td>2.5 oz, disposable, plastic</td></tr><tr><td>audio files of baby cry</td><td>Alkon lab</td><td></td><td>30 sec clip recorded in a neonatal intensive care unit</td></tr><tr><td>audio file of baseline lullaby</td><td>Rockabye Baby Music</td><td></td><td>60 sec of &quot;Across the Universe&quot; on &quot;Rockabye Baby Lullaby Renditions of the Beatles&quot; CD</td></tr><tr><td>audio file of final lullaby</td><td>Rockabye Baby Music</td><td></td><td>60 sec of &quot;Here Comes the Sun&quot; on &quot;Rockabye Baby Lullaby Renditions of the Beatles&quot; CD</td></tr><tr><td>video file of neutral video</td><td></td><td></td><td>2 min of Baby Einstein video</td></tr><tr><td>Retractable measuring tape</td><td>Rollfix</td><td>TM04</td><td></td></tr><tr><td></td><td></td><td></td><td></td></tr><tr><td>Miscellaneous materials</td><td></td><td></td><td></td></tr><tr><td>Surge protector</td><td></td><td></td><td>to plug in all electronics</td></tr><tr><td>2-prong adapter for surge protector</td><td></td><td></td><td></td></tr><tr><td>Video camera</td><td>Sony</td><td></td><td>Handycam HDR-CX440</td></tr><tr><td>Video Encoder, power and input cords</td><td>Mindware</td><td>50-8614-01</td><td>optional; to sync video and ANS data files</td></tr><tr><td>Baby wipes and gauze</td><td></td><td></td><td>for cleaning and drying oily skin</td></tr><tr><td>Toys</td><td></td><td></td><td>to distract children during assessment</td></tr><tr><td>Visual aids</td><td></td><td></td><td>pictures of child with electrodes on, description of protocol to show participants</td></tr><tr><td>Script of protocol for research assistants</td><td></td><td></td><td></td></tr><tr><td>Charging cords for tablet and speaker</td><td></td><td></td><td></td></tr><tr><td>Doll and stickers</td><td></td><td></td><td>for demonstration if necessary</td></tr></tbody></table>

measuring cardiac autonomic nervous system (ans) activity in toddlers - resting and developmental challenges

The autonomic nervous system (ANS) consists of two branches, the parasympathetic and sympathetic nervous systems, and controls the function of internal organs (e.g., heart rate, respiration, digestion) and responds to everyday and adverse experiences 1. ANS measures in children have been found to be related to behavior problems, emotion regulation, and health 2-7. Therefore, understanding the factors that affect ANS development during early childhood is important. Both branches of the ANS affect young children&#8217;s cardiovascular responses to stimuli and have been measured noninvasively, via external monitoring equipment, using valid and reliable measures of physiological change 8-11. However, there are few studies of very young children with simultaneous measures of the parasympathetic and sympathetic nervous systems, which limits understanding of the integrated functioning of the two systems. In addition, the majority of existing studies of young children report on infants&#8217; resting ANS measures or their reactivity to commonly used mother-child interaction paradigms, and less is known about ANS reactivity to other challenging conditions. We present a study design and standardized protocol for a non-invasive and rapid assessment of cardiac autonomic control in 18 month old children. We describe methods for continuous monitoring of the parasympathetic and sympathetic branches of the ANS under resting and challenge conditions during a home or laboratory visit and provide descriptive findings from our sample of 140 ethnically diverse toddlers using validated equipment and scoring software. Results revealed that this protocol can produce a range of&#160;physiological responses to both resting and developmentally challenging conditions, as indicated by changes in heart rate and indices of parasympathetic and sympathetic activity. Individuals demonstrated&#160;variability in resting levels, responses to challenges, and challenge reactivity, which provides additional evidence that this protocol is useful for the examination of ANS individual differences for toddlers.

The SEED study enrolled&#160;162&#160;mother-child dyads (37% African American; 30% Latina; 16% white; 17% other or multiracial). For the 18 month visit, we completed the in-person assessment with 140 children (87% of the enrolled sample); 6 participants moved away, and the remaining participants were unreachable or unavailable for this visit. The refusal rate for ANS data collection component of the visit was 3/140 (2%) for mothers available for this visit. Three visits were conducted after 21 months (more than 3 months...

Watch this Scientific Journal Video about Measuring Cardiac Autonomic Nervous System ANS Activity in Toddlers - Resting and Developmental Challenges at JoVE.com

Measuring Cardiac Autonomic Nervous System ANS Activity in Toddlers - Resting and Developmental Challenges

We describe the methods for continuous monitoring of the autonomic nervous system under resting and challenge conditions with 18 month old children. Results revealed that this protocol can produce meaningful physiological responses in both branches of the autonomic nervous system and elicit significant individual variability in patterns of responses.

Measuring Cardiac Autonomic Nervous System (ANS) Activity in Toddlers - Resting and Developmental Challenges

The autonomic nervous system (ANS) consists of two branches, the parasympathetic and sympathetic nervous systems, and controls the function of internal ...

measuring-cardiac-autonomic-nervous-system-ans-activity-toddlers

Research

Education

JoVE Journal

JoVE Core

Introduction to Psychology

Anatomy and Physiology

Medicine

Unit 1

Biopsychology

The Autonomic Nervous System

SCIENTISTS IN ACTION

15.2K Views.  University of California, San Francisco. We describe the methods for continuous monitoring of the autonomic nervous system under resting and challenge conditions with 18 month old children. Results revealed that this protocol can produce meaningful physiological responses in both branches of the autonomic nervous system and elicit significant individual variability in patterns of responses.

Video: Measuring Cardiac Autonomic Nervous System ANS Activity in Toddlers - Resting and Developmental Challenges

Quantitative Assessment of Cortical Auditory-tactile Processing in Children with Disabilities

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology to quantitatively assess children&#39;s cortical processing of light touch, speech sounds and the multisensory processing of the 2 stimuli, without requiring active subject participation or causing children discomfort. To accomplish this we developed a dual channel, time and strength calibrated air puff stimulator that allows both tactile stimulation and sham control. We combined this with the use of event-related potential methodology to allow for high temporal resolution of signals from the primary and secondary somatosensory cortices as well as higher order processing. This methodology also allowed us to measure a multisensory response to auditory-tactile stimulation.

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology to quantitatively assess infants and children&#39;s cortical processing of light touch, speech sounds, and the multisensory processing of the 2 stimuli, without requiring active subject participation or causing discomfort in vulnerable patients.

Objective and easy measurement of sensory processing is extremely difficult in nonverbal or vulnerable pediatric patients. We developed a new methodology ...

Behavior

Quantitative Autonomic Testing

Disorders associated with dysfunction of autonomic nervous system are quite common yet frequently unrecognized. Quantitative autonomic testing can be invaluable tool for evaluation of these disorders, both in clinic and research. There are number of autonomic tests, however, only few were validated clinically or are quantitative. Here, fully quantitative and clinically validated protocol for testing of autonomic functions is presented. As a bare minimum the clinical autonomic laboratory should have a tilt table, ECG monitor, continuous noninvasive blood pressure monitor, respiratory monitor and a mean for evaluation of sudomotor domain. The software for recording and evaluation of autonomic tests is critical for correct evaluation of data. The presented protocol evaluates 3 major autonomic domains: cardiovagal, adrenergic and sudomotor. The tests include deep breathing, Valsalva maneuver, head-up tilt, and quantitative sudomotor axon test (QSART). The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores (CASS). Detailed protocol is provided highlighting essential aspects of testing with emphasis on proper data acquisition, obtaining the relevant parameters and unbiased evaluation of autonomic signals. The normative data and CASS algorithm for interpretation of results are provided as well.

Standardized, comprehensive and fully quantitative testing of autonomic functions is described. The autonomic tests consist of evaluation of all three major autonomic domains including cardiovagal, adrenergic and sudomotor. The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores.

Disorders associated with dysfunction of autonomic nervous system are quite common yet frequently unrecognized. Quantitative autonomic testing can be ...

Infant Auditory Processing and Event-related Brain Oscillations

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral and temporal changes that are characteristic of human language. These abilities lay the foundation for effective language acquisition; allowing infants to hone in on the sounds of their native language. Invasive procedures in animals and scalp-recorded potentials from human adults suggest that simultaneous, rhythmic activity (oscillations) between and within brain regions are fundamental to sensory development; determining the resolution with which incoming stimuli are parsed. At this time, little is known about oscillatory dynamics in human infant development. However, animal neurophysiology and adult EEG data provide the basis for a strong hypothesis that rapid auditory processing in infants is mediated by oscillatory synchrony in discrete frequency bands. In order to investigate this, 128-channel, high-density EEG responses of 4-month old infants to frequency change in tone pairs, presented in two rate conditions (Rapid: 70 msec ISI and Control: 300 msec ISI) were examined. To determine the frequency band and magnitude of activity, auditory evoked response averages were first co-registered with age-appropriate brain templates. Next, the principal components of the response were identified and localized using a two-dipole model of brain activity. Single-trial analysis of oscillatory power showed a robust index of frequency change processing in bursts of Theta band (3 - 8 Hz) activity in both right and left auditory cortices, with left activation more prominent in the Rapid condition. These methods have produced data that are not only some of the first reported evoked oscillations analyses in infants, but are also, importantly, the product of a well-established method of recording and analyzing clean, meticulously collected, infant EEG and ERPs. In this article, we describe our method for infant EEG net application, recording, dynamic brain response analysis, and representative results.

High-density electroencephalography (dEEG) is being used increasingly to study brain development and plasticity in the early years of life. Here we present an application of sophisticated analysis techniques that builds on traditional EEG recording to understand the oscillatory dynamics of rapid auditory processing in the infant brain.

Rapid auditory processing and acoustic change detection abilities play a critical role in allowing human infants to efficiently process the fine spectral ...

Psychophysiological Assessment of the Effectiveness of Emotion Regulation Strategies in Childhood

Effective regulation of emotion is one of the most important skills that develops in childhood. Research interest in this area is expanding, but empirical work has been limited by predominantly correlational investigations of children's skills. Relatedly, a key conceptual challenge for emotion scientists is to distinguish between emotion responding and emotion regulatory processes. This paper presents a novel method to address these conceptual and methodological issues in child samples. An experimental paradigm that assesses the effectiveness with which children regulate emotion is described. Children are randomly assigned to use specific emotion regulation strategies, negative emotions are elicited with film clips, and changes in subsequent psychophysiology index the extent to which emotion regulation is effective. Children are instructed to simply watch the emotion-eliciting film (control), distract themselves from negative emotions (cognitive distraction), or reframe the situation in a way that downplays the importance of the emotional event (cognitive reappraisal). Cardiac physiology, continuously acquired before and during the emotional task, serves as an objective measure of children's unfolding emotional responding while viewing evocative films. Key comparisons in patterns of obtained physiological reactivity are between the control and emotion regulation strategy conditions. Representative results from this approach are described, and discussion focuses on the contribution of this methodological approach to developmental science.

A detailed protocol for an experimental paradigm to assess the effectiveness with which children regulate emotion is described. Children are randomly assigned to use specific emotion regulation strategies, negative emotions are elicited with film clips, and changes in subsequent psychophysiology index the extent to which emotion regulation is effective.

Effective regulation of emotion is one of the most important skills that develops in childhood. Research interest in this area is expanding, but empirical ...

Use of a Video Scoring Anchor for Rapid Serial Assessment of Social Communication in Toddlers

Reciprocal social behavior (RSB), an early-emerging capacity to engage in social contingency&#8212;which is foundational for both social learning and social competency&#8212;is hypothesized to be disrupted in autism spectrum disorder (ASD). The ability to quantify the full range of RSB during the toddler period, when core symptoms of ASD often arise, is pivotal for evaluating early risk for ASD, characterizing social development, and tracking response to early interventions. However, important parameters of variation in RSB&#8212;especially prior to the development of verbal language&#8212;can be nuanced and difficult to characterize using questionnaire-based methods. To address this challenge, we developed a system for measuring quantitative variation in RSB in toddlers (ages 18 - 30 months) that incorporated not only standard questionnaire data from caregivers but also a novel set of video-referenced items, through which a respondent compares the behavior of a subject to that observed in a short video of a young child manifesting a highly competent level of social communication. Testing of this measure in a general population sample of twins confirmed that both the video-referenced items and the RSB Total Score (video-referenced items plus non-video-referenced items) displayed unimodal, continuous distributions, strong internal consistency, marked preservation of individual differences, and extremely high heritability. In addition, video-referenced items were particularly sensitive to quantifying incremental changes in social communication, a major element of RSB, over the course of early childhood development. Scores on the vrRSB clearly differentiated children with and without ASD and these data comprise an initial validation of this promising method for quantifying early RSB&#8212;cross-sectionally, over time, and as a function of early intervention.

Here we present a protocol for administration of the video-referenced rating of reciprocal social behavior (vrRSB) using a paper or online version. This survey quantifies RSB, a prerequisite for social competence, in toddlers through &#34;video-referenced&#34; items whereby a subject is compared to a reference child shown in a three-minute video.

Reciprocal social behavior (RSB), an early-emerging capacity to engage in social contingency&#8212;which is foundational for both social learning and ...

Measuring Cardiac Autonomic Nervous System (ANS) Activity in Children

The autonomic nervous system (ANS) controls mainly automatic bodily functions that are engaged in homeostasis, like heart rate, digestion, respiratory rate, salivation, perspiration and renal function. The ANS has two main branches: the sympathetic nervous system, preparing the human body for action in times of danger and stress, and the parasympathetic nervous system, which regulates the resting state of the body.
ANS activity can be measured invasively, for instance by radiotracer techniques or microelectrode recording from superficial nerves, or it can be measured non-invasively by using changes in an organ's response as a proxy for changes in ANS activity, for instance of the sweat glands or the heart. Invasive measurements have the highest validity but are very poorly feasible in large scale samples where non-invasive measures are the preferred approach. Autonomic effects on the heart can be reliably quantified by the recording of the electrocardiogram (ECG) in combination with the impedance cardiogram (ICG), which reflects the changes in thorax impedance in response to respiration and the ejection of blood from the ventricle into the aorta. From the respiration and ECG signals, respiratory sinus arrhythmia can be extracted as a measure of cardiac parasympathetic control. From the ECG and the left ventricular ejection signals, the preejection period can be extracted as a measure of cardiac sympathetic control. ECG and ICG recording is mostly done in laboratory settings. However, having the subjects report to a laboratory greatly reduces ecological validity, is not always doable in large scale epidemiological studies, and can be intimidating for young children. An ambulatory device for ECG and ICG simultaneously resolves these three problems.
Here, we present a study design for a minimally invasive and rapid assessment of cardiac autonomic control in children, using a validated ambulatory device 1-5, the VU University Ambulatory Monitoring System (VU-AMS, Amsterdam, the Netherlands,<a href="http://www.vu-ams.nl" target="_blank"> www.vu-ams.nl</a>).

Measuring Cardiac Autonomic Nervous System ANS Activity in Children

Measurement of autonomic nervous system activity usually confines the researcher and participant to the laboratory, which may provide an intimidating environment to children. The VU University Ambulatory Monitoring System (VU-AMS) device can record cardiac autonomic control in any setting. The VU-AMS proved very amenable to testing in children.

The autonomic nervous system (ANS) controls mainly automatic bodily functions that are engaged in homeostasis, like heart rate, digestion, respiratory ...

An Electrophysiology Protocol to Measure Reward Anticipation and Processing in Children

We present a protocol designed to measure the neural correlates of reward in children. The protocol allows researchers to measure both reward anticipation and processing. Its purpose is to create a reward task that is appropriate for young children with and without autism while controlling reward properties between two conditions: social and nonsocial. The current protocol allows for comparisons of brain activity between social and nonsocial reward conditions while keeping the reward itself identical between conditions. Using this protocol, we found evidence that neurotypical children demonstrate enhanced anticipatory brain activity during the social condition. Furthermore, we found that neurotypical children anticipate social reward more robustly than children with autism diagnoses. As the task uses snacks as a reward, it is most appropriate for young children. However, the protocol may be adapted for use with adolescent or adult populations if snacks are replaced by monetary incentives. The protocol is designed to measure electrophysiological events (event-related potentials), but it may be customized for use with eye-tracking or fMRI.

This protocol is designed to measure reward anticipation and processing in young children with and without autism. Specifically, the protocol is designed to study the neural correlates of reward during social and nonsocial conditions while controlling for reward between conditions.

We present a protocol designed to measure the neural correlates of reward in children. The protocol allows researchers to measure both reward anticipation ...

Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions

The aim of this study was to generate a method for calculating heart rate variability (HRV) from electrocardiogram (ECG) waveforms. The waveforms were recorded by a HR monitor that participants (youth with cerebral palsy (CP)) wore during active video game (AVG) sessions. The AVG sessions were designed to promote physical activity and fitness (aerobic performance) in participants. The goal was to evaluate the feasibility of AVGs as a physical therapy (PT) intervention strategy. The maximum HR (mHR) was determined for each participant and the Target Heart Rate Zone (THRZ) was calculated for each of three exercise phases in the 20 min AVG session: (warm-up at 40-60% mHR, conditioning at 60-80% mHR, and cool down at 40-60% mHR). Each participant played three 20 min games during the AVG session. All games were played while sitting on a bench because many youth with CP cannot stand for extended periods of time. Each game condition differed with participants using hand icons only, hand and feet icons together or feet icons only to collect objects. The objective of the game (called KOLLECT) is to collect objects to gain points and avoid hazards to not lose points. Hazards were used in the warm-up and cool down phases only to promote slower, controlled movement to maintain HR in the target heart rate zone (THRZ). There were no hazards in the conditioning phase to promote higher levels and more intense physical activity. Analytic methods were used to generate HRV (selected time-domain and frequency-domain measures) from ECG data to examine aerobic workload. Recent applications of HRV indicate that short-term measurements (5 min bouts) are appropriate and that HRV biofeedback may help improve symptoms and the quality of life in a variety of health conditions. Although HR is a well-accepted clinical measure to examine aerobic performance and intensity in PT interventions, HRV may provide information of the autonomic system functions, recovery and adaptation during AVG sessions.

This protocol describes a method for calculating Heart Rate Variability (HRV) from electrocardiogram (ECG) waveforms. Waveforms from continuous heart rate (HR) recordings during active video game (AVG) sessions were used to measure the aerobic performance of youth with cerebral palsy (CP).

The aim of this study was to generate a method for calculating heart rate variability (HRV) from electrocardiogram (ECG) waveforms. The waveforms were ...

Autonomic Function Following Concussion in Youth Athletes: An Exploration of Heart Rate Variability Using 24-hour Recording Methodology

Participation in organized sports makes a significant contribution to youth development, but places youth at a higher risk for sustaining a concussion. To date, return-to-activity decision-making has been anchored in the monitoring of self-reported concussion symptoms and neurocognitive testing. However, multi-modal assessments that corroborate objective physiological measures with traditional subjective symptom reporting are needed and can be valuable. Heart rate variability (HRV) is a non-invasive physiological indicator of the autonomic nervous system, capturing the reciprocal interplay between the sympathetic and parasympathetic nervous systems. There is a dearth of literature exploring the effect of concussion on HRV in youth athletes, and developmental differences preclude the application of adult findings to a pediatric population. Further, the current state of HRV methodology has primarily included short-term (5-15 min) recordings, by using resting state or short-term physical exertion testing to elucidate changes following concussion. The novelty in utilizing a 24 h&#160;recording methodology is that it has the potential to capture natural variation in autonomic function, directly related to the activities a youth athlete performs on a regular basis. Within a prospective, longitudinal research setting, this novel approach to quantifying autonomic function can provide important information regarding the recovery trajectory, alongside traditional self-report symptom measures. Our objectives regarding a 24 h recording methodology were to (1) evaluate the physiological effects of a concussion in youth athletes, and (2) describe the trajectory of physiological change, while considering the resolution of self-reported post-concussion symptoms. To achieve these objectives, non-invasive sensor technology was implemented. The raw beat-to-beat time intervals captured can be transformed to derive time domain and frequency domain measures, which reflect an individual&#39;s ability to adapt and be flexible to their ever-changing environment. By using non-invasive heart rate technology, autonomic function can be quantified outside of a traditional controlled research setting.

We demonstrate a 24 h heart rate recording methodology to evaluate the influence of concussion across the recovery trajectory in youth athletes, within an ecologically valid context.

Participation in organized sports makes a significant contribution to youth development, but places youth at a higher risk for sustaining a concussion. To ...

Quantified Assessment of Infant's Gross Motor Abilities Using a Multisensor Wearable

Developing objective and quantitative methods of early gross motor assessment is essential to better understand neurodevelopment and to support early therapeutic interventions. Here, we&#160;present&#160;a method to quantify gross motor performance using a multisensor wearable, MAIJU (Motility Assessment of Infants with a JUmpsuit), which offers an automated, scalable,&#160;quantitative, and objective assessment using&#160;a fully automated cloud-based pipeline. This wearable suit is equipped with four movement sensors that record synchronized data to a mobile phone utilizing a low-energy Bluetooth connection. An offline analysis in the cloud server generates fully analyzed results within minutes for each recording. These results include a graphical report of the recording session and a detailed result matrix that gives second-by-second classifications for posture, movement, infant carrying, and free playtime. Our recent results show the virtue of such&#160;quantified motor assessment&#160;providing&#160;a potentially&#160;effective method for distinguishing variations in the infant&#39;s gross motor development.

This paper outlines the assessment of infants' gross motor performance with a multisensor wearable and its fully automated deep learning-based analysis pipeline. The method quantifies the posture and movement patterns of infants from lying supine until they master walking independently.

Developing objective and quantitative methods of early gross motor assessment is essential to better understand neurodevelopment and to support early ...