Name: measuring cardiac autonomic nervous system (ans) activity in toddlers - resting and developmental challenges
Uploaded: 2016-02-25T14:00:00
Description: Watch this Scientific Journal Video about Measuring Cardiac Autonomic Nervous System ANS Activity in Toddlers - Resting and Developmental Challenges at JoVE.com

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.

This study was approved by the Committee on Human Research of the University of California, San Francisco. &#160;
1. Pre-protocol Set-up (See Materials Spreadsheet for Complete List of Equipment)
<ol>
	<li>Set up the equipment by turning on the computer and connecting the ANS data acquisition unit to a power source. 
	NOTE: Do not turn the acquisition unit on.</li>
	<li>Prior to beginning any data collection, set up the ANS data collection software. Choose settings to match Figu...

<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>

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&#160;</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>0.14oz 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 second 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 seconds of &#34;Across the Universe&#34; on &#34;Rockabye Baby Lullaby Renditions of the Beatles&#34; CD</td>
		</tr>
		<tr>
			<td>audio file of final lullaby</td>
			<td>Rockabye Baby Music</td>
			<td></td>
			<td>60 seconds of &#34;Here Comes the Sun&#34; on &#34;Rockabye Baby Lullaby Renditions of the Beatles&#34; CD</td>
		</tr>
		<tr>
			<td>video file of neutral video</td>
			<td></td>
			<td></td>
			<td>2 minutes 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 reinforcer</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 ...

The overall goal of this protocol is to non-invasively monitor and assess cardiac measures of the parasympathetic and sympathetic nervous systems under resting and challenge conditions with 18-month-old children. Measures of the autonomic nervous system in young children under resting and challenging conditions can help answer key questions about how young children biologically respond to challenges they face in their environment. The main advantage of this technique is that provides a validated, standardized protocol for assessing parasympathetic and sympathetic nervous system responses in an understudied age group.This technique extends our ability to study biologic reactivity in young children, as well as investigate factors that predict variation in that reactivity, and that may provide insight into later health conditions. Demonstrating the role of child assessor will be Zoe Caron, and demonstrating the role of computer operator will be Vanessa Tearnan, research assistants from my laboratory. Begin by reviewing the protocol with the child's mother.Then, talk to the toddler in a friendly way to make the toddler comfortable before you start the protocol. Have the child assessor apply the electrodes to the child's neck and torso while the computer operator distracts the child. For this protocol, apply each electrode to the skin at least three centimeters apart from neighboring electrodes to ensure proper signal conduction.Verify this minimum distance by measuring the length between the centers of each electrode, then press on the foam around the gel to ensure that the electrode adhered to the skin. Now, gather four impedance electrodes, of which two will be placed on the neck, and two on the trunk of the child. Place the first electrode that is attached to the red negative lead on the center of the lower back.Then, place the second electrode that is attached to the white negative lead on the sternum just above the xyphoid process. Place the third electrode that is attached to the white positive lead to the left of the supersternal notch on the edge of the clavicle. Then, place the fourth electrode that is attached to the red positive lead on the back of the child's neck.Locate three electrocardiogram, or ECG electrodes. Place the first ECG electrode, attached to the brown negative lead lengthwise along the right clavicle bone. Press on the foam of the electrode, and feel the clavicle bone.Place the second ECG electrode, attached to the brown positive lead, on the left lower rib. Press on the foam of the electrode, and feel the rib bone. Then, place the third ECG grounding electrode, attached to the black negative lead, on the child's lower right rib, so that it is in line with the lower left rib electrode.Bundle and clip the lower ends of the leads to the child's clothing to minimize movement. Have the computer operator monitor the computer. Then, engage the child, and review the activities involved in the protocol with the mother.Turn on the autonomic nervous system, or ANS, data acquisition unit, to acquire the cardiac impedance and ECG signals. After five minutes, have the computer operator check the signals to make sure they look normal, and turn on the video camera. Offer the child a soft toy if they seem uncomfortable during this period.Finally, show a computer image of the child's heart activity to the mother and explain what each signal represents on the ECG. Show the heartbeats and impedance signals, which indicate blood flow through the lungs and heart. During these tasks, instruct the computer operator to push F keys to mark important protocol steps in the ANS data, as seen here.Push F11 to indicate that a task ended early, or for any major protocol problems that arise, such as an electrode falling off. Begin by opening the media player in the tablet, and playing the first one-minute lullaby. Keep the tablet out of reach of the child.Next, hold a jack-in-the-box in front of the child, but keep it slightly out of reach. Slowly rotate the arm and play the music until the sock monkey pops up. Following that, start the lemon juice task.Place two drops of concentrated lemon juice on the center of the child's tongue, slightly back from the front, so that the juice does not roll off the tongue. Wait quietly for ten seconds, with a friendly, neutral expression. Next, tell the child it is time to drink some water, and have the child assessor offer them a sip of water.Have the computer operator press the F4 key when the water is offered. Then, play a 30-second recording of a sick infant crying on the tablet. Followed by the second one-minute resting lullaby.Next, hold the tablet about 12 inches from the child's face and show the child the two-minute neutral video. This continuous monitoring of the autonomic nervous system under resting and challenge conditions with 18-month-old children is summarized in 30-second blocks within our scoring program. This software averages the child's heart rate, respiratory rate, respiratory sinus arrhythmia, and pre-ejection period during each 30-second interval.This method successfully captured significant ANS change between calming activities and developmentally challenging tasks. Decreases in respiratory sinus arrhythmia and pre-ejection period reflect autonomic reactivity through parasympathetic withdrawal and sympathetic activation, respectively. We can also assess the variability in responses, such as with heart rate, within each task, across children.This is critical for examining individual differences in ANS activity. Measuring children's autonomic responses to developmental challenges has paved the way for researchers in the fields of psycho-physiology, pediatrics, psychology, and child development to explore the relations between social experience, biology, and physical and mental health in young children. Once mastered, this protocol can be done in 20 minutes.Generally, the greatest challenge to this method is learning how to apply the electrodes quickly and accurately while being respectful of the child's emotional state. When working with young children, it's important to remember to engage the child and mother before you apply the electrodes. Also, be sensitive to the child and discontinue the tasks if the child is showing signs of significant distress.Never force a child to complete the protocol. Working with toddlers can be challenging, so you should engage children throughout the protocol. Although a child may cry when you place the electrodes on them, most 18-month-olds will shift attention to the task and stay engaged throughout the protocol.After watching this video, you should have a good understanding of how to non-invasively monitor and assess cardiac measures of the autonomic nervous system under resting and challenge conditions with 18-month-old children.

Research

Education

JoVE Core

JoVE Journal

Anatomy and Physiology

Medicine

Unit 1

The Autonomic Nervous System

SCIENTISTS IN ACTION

Quantitative Autonomic Testing

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

Portable Intermodal Preferential Looking (IPL): Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism

Portable Intermodal Preferential Looking IPL: Investigating Language Comprehension in Typically Developing Toddlers and Young Children with Autism

One  of the defining characteristics of autism spectrum disorder (ASD) is difficulty  with language and communication.1  Children with ASD's onset of ...

Measuring Cardiac Autonomic Nervous System (ANS) Activity in Children

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 ...

Carotid Artery Infusions for Pharmacokinetic and Pharmacodynamic Analysis of Taxanes in Mice

When proposing the use of a drug, drug combination, or drug delivery into a novel system, one must assess the pharmacokinetics of the drug in the study ...

Electrophysiological Measurement of Noxious-evoked Brain Activity in Neonates Using a Flat-tip Probe Coupled to Electroencephalography

Pain is an unpleasant sensory and emotional experience. In non-verbal patients, it is very difficult to measure pain, even with pain assessment tools. ...

A Drosophila In Vivo Injury Model for Studying Neuroregeneration in the Peripheral and Central Nervous System

A Drosophila In Vivo Injury Model for Studying Neuroregeneration in the Peripheral and Central Nervous System

The regrowth capacity of damaged neurons governs neuroregeneration and functional recovery after nervous system trauma. Over the past few decades, various ...

Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System

Impact of Intracardiac Neurons on Cardiac Electrophysiology and Arrhythmogenesis in an Ex Vivo Langendorff System

Since its invention in the late 19th century, the Langendorff ex vivo heart perfusion system continues to be a relevant tool for studying a broad spectrum ...

A Flow Cytometry-based Assay for Measuring Mitochondrial Membrane Potential in Cardiac Myocytes After Hypoxia/Reoxygenation

Timely and efficient reperfusion of the occluded coronary artery is the best strategy for decreasing myocardial infarct size in patients with a ST-segment ...

Semi-Minimal Invasive Method to Induce Myocardial Infarction in Rats and the Assessment of Cardiac Function by an Isolated Working Heart System

Myocardial infarction (MI) remains the main contributor to morbidity and mortality worldwide. Therefore, research on this topic is mandatory. An easily ...

In vitro Assessment of Cardiac Reprogramming by Measuring Cardiac Specific Calcium Flux with a GCaMP3 Reporter

Cardiac reprogramming has become a potentially promising therapy to repair a damaged heart. By introducing multiple transcription factors, including ...