EAAIDD DOI: 10.1352/1944-7558-118.6.416
AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2013, Vol. 118, No. 6, 416–418
A Psychophysiology of Developmental Disabilities: A Personal and Historical Perspective Stephen W. Porges
In the early 1970s, as a curious young assistant professor in the Department of Psychology at the University of Illinois at Urbana–Champaign, my colleagues asked me to apply heart rate monitoring to study the intellectually impaired. Although many of my colleagues were dedicated to the study of developmental disabilities, this was a new area for me. The University of Illinois had a physical center and an administrative structure to expand the behavioral sciences into the study of typically and atypically developing children, and the Children’s Research Center was the epicenter of this research interest. The Center was headed by Bob Sprague and included several researchers—Steve Asher, Ann Brown, Joe Campione, Mark Gold, and Keith and Marcia Scott—who conducted research on mentally challenged children. The research conducted at the Center was well funded and was a high priority for both the State of Illinois and the National Institutes of Health. In retrospect, this was a special time and special place for the study of normal and atypical development. I recall one meeting in which approximately 35 faculty members across several departments and colleges on the University of Illinois at Urbana–Champaign campus self-identified as developmental psychologists. It was an optimistic time, and there were expectations that physiological monitoring would provide a portal to better understand individuals with limited language skills and cognitive resources. In the 1970s, the State of Illinois was committed to improving the quality of children with developmental disabilities. There were statefunded centers for treatment and research and state-funded research grants. For example, in Chicago, the state funded an intramural research program in a facility on the University of Illinois Medical School campus known as the Illinois State Pediatric Institute. This facility was located adjacent to another state-funded research program 416
known as the Illinois State Psychiatric Institute. These large buildings housed basic and clinical researchers focused on understanding and improving the lives of individuals with developmental disabilities and mental health disorders. During the mid-1970s, in this background of interest and enthusiasm for research to study atypical development, I received a grant from the State of Illinois, Department of Mental Health and Developmental Disabilities to study heart rate patterns in ‘‘retarded and nonretarded’’ adolescents. To conduct this research, I borrowed from my colleague, Bob Sprague, a van that had been modified into a two-room research laboratory. With a graduate student, Mary Humphrey, and the help of a couple of talented undergraduates, we drove the van to local schools to collect the data. To do a simple study, we packed about 200 pounds of equipment into the van, including a Beckman Dynograph, an FM tape recorder, a 6-foot equipment rack containing relays programmed to display the stimulus via a slide projector and to record the responses through button presses, and a TV monitor and camera to reduce fear and uncertainty for the participants by enabling them to observe each other participating. The study resulted in a publication in the American Journal of Mental Deficiency (Porges & Humphrey, 1977), which was the former name of the American Journal on Intellectual and Developmental Disabilities. What has changed in the decades since my paper with Mary and this issue of the Journal on Intellectual and Developmental Disabilities? From my perspective, there have been three major interrelated changes. First, in 1977, it would have been virtually impossible to find sufficient intellectual material on heart rate monitoring in special populations to fill an issue of any journal. In the mid-1970s, only a few researchers studied autonomic function in special populations. Most notable was Rathe Karrer. Rathe was a psychoPsychophysiology of Developmental Disabilities
AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2013, Vol. 118, No. 6, 416–418
physiologist who worked at the above-mentioned Illinois State Pediatric Institute. Rathe was instrumental in moving psychophysiology into the study of developmental disabilities (e.g., Karrer, 1966) and into the emerging area of developmental psychophysiology (Karrer, 1976). Second, the resources needed to monitor heart rate in an experimental setting required expensive equipment and technically trained scientists, who often had to design, fabricate, and modify equipment to conduct their research. Thus, being a psychophysiologist in the early days of the discipline required technical skills to maintain the equipment and even to obtain the ECG signal from amplifiers with poor noise rejection. In addition, the quantification of heart rate was extremely time consuming. In the 1960s and early 1970s, quantification was done with a ruler directly from paper recordings of ECG. By the mid 1970s, the ‘‘advanced’’ laboratories were using FM tape recorders to store the signals and using digital computers to score the ECG offline from the FM tapes. A few laboratories had sufficient resources to use a dedicated digital computer to run their experiments and to collect the heart rate data in real time. In the Porges and Humphrey study, the cost of the equipment required to monitor heart rate was more than $10,000, and the equipment weighed more than 100 pounds. Our technology was state of the art, and we collected ECG data on magnetic tape. The tape recorder, which weighed about 50 pounds, was then moved to a dedicated computer, where the tapes were ‘‘digitized,’’ and the time between sequential heartbeats computed. By 1978, we had a stand-alone computer in my laboratory and were able to calculate the beat-tobeat heart rate in real time. The computer system cost approximately $50,000. Today the equipment needed for such a study could be purchased for less than $2,000, including equipment required to present the experimental stimuli and to collect and analyze heart rate data. In addition, the contemporary equipment would have a higher standard of performance (i.e., more precise and more accurate) than that found in the most advanced laboratories of the 1970s. Third, unlike the 1970s at the University of Illinois, when a large cluster of faculty were assembled on one campus to study atypical development, today faculty with these interests are dispersed across disciplines and research centers worldwide. However, interactions with S. W. Porges
EAAIDD DOI: 10.1352/1944-7558-118.6.416
colleagues and collaborators may be even more frequent than in the 1970s, when laboratories and offices were in close proximity. Today researchers are connected, not through the physical proximity of laboratories or offices, but through Internetbased communications that enable synchronous and asynchronous communication independent of distance and time zone. The past decades have witnessed exponential improvements in the technologies used to monitor physiological signals. Devices have become smaller, less expensive, easier to use, more accurate, and more reliable. These shifts in cost and reliability have been paralleled by increased opportunities to apply physiological monitoring in research settings. To monitor heart rate in a special population, researchers do not need major grants or significant seed money from their institutions. With a modest research budget, no more expensive than the cost of devices used to monitor behavior, researchers can now address interesting questions in special populations. At present, physiological monitoring is a technology that can be synchronized with behavioral monitoring. The current issue of the American Journal on Intellectual and Developmental Disabilities illustrates the effective transition of heart rate monitoring, from a technology that was expensive and rarely used to one that is now easily integrated into research studying developmental disabilities. The papers in this issue provide examples of three formerly divergent paradigms to further our understanding of developmental disabilities. First, the studies illustrate how heart rate monitoring can interface with single-subject behavioral paradigms to identify physiological state changes that covary with states of anxiety (Moskowitz) and selfinjurious behavior (Symons; Hall). Second, the studies illustrate how traditional psychophysiological paradigms can be used to demonstrate physiological state changes during social interactions and challenges (Klusek, Tonnsen). And third, the studies illustrate how measures of autonomic state are related to clinical symptoms (Tonnsen). Continued research following the theme of these papers will, by identifying neurophysiological states that support specific symptoms (e.g., anxiety, self injurious behaviors), provide insights into treatment and clinical management of children with developmental disabilities. 417
AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2013, Vol. 118, No. 6, 416–418
References Karrer, R. (1966). Autonomic nervous system functions and behavior: A review of experimental studies with mental defectives. In N. R. Ellis (Ed.), International review of research in mental retardation, (Vol. 2, pp. 57–83). New York, NY: Academic Press. Karrer, R. (1976). Developmental psychophysiology of mental retardation: Concepts and studies. Springfield, IL: Thomas. Porges, S. W., & Humphrey, M. M. (1977). Cardiac and respiratory responses during
418
EAAIDD DOI: 10.1352/1944-7558-118.6.416
visual search in non-retarded children and retarded adolescents. American Journal of Mental Deficiency, 82, 162–169.
Author: Stephen W. Porges (e-mail: stephen_porges@med. unc.edu), University of North Carolina School of Medicine, Department of Psychiatry, 387 Medical School Wing D, Campus Box 7160, Chapel Hill, NC 27599-7160, USA.
Psychophysiology of Developmental Disabilities
AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2013, Vol. 118, No. 6, 416–418
A Psychophysiology of Developmental Disabilities: A Personal and Historical Perspective Stephen W. Porges
In the early 1970s, as a curious young assistant professor in the Department of Psychology at the University of Illinois at Urbana–Champaign, my colleagues asked me to apply heart rate monitoring to study the intellectually impaired. Although many of my colleagues were dedicated to the study of developmental disabilities, this was a new area for me. The University of Illinois had a physical center and an administrative structure to expand the behavioral sciences into the study of typically and atypically developing children, and the Children’s Research Center was the epicenter of this research interest. The Center was headed by Bob Sprague and included several researchers—Steve Asher, Ann Brown, Joe Campione, Mark Gold, and Keith and Marcia Scott—who conducted research on mentally challenged children. The research conducted at the Center was well funded and was a high priority for both the State of Illinois and the National Institutes of Health. In retrospect, this was a special time and special place for the study of normal and atypical development. I recall one meeting in which approximately 35 faculty members across several departments and colleges on the University of Illinois at Urbana–Champaign campus self-identified as developmental psychologists. It was an optimistic time, and there were expectations that physiological monitoring would provide a portal to better understand individuals with limited language skills and cognitive resources. In the 1970s, the State of Illinois was committed to improving the quality of children with developmental disabilities. There were statefunded centers for treatment and research and state-funded research grants. For example, in Chicago, the state funded an intramural research program in a facility on the University of Illinois Medical School campus known as the Illinois State Pediatric Institute. This facility was located adjacent to another state-funded research program 416
known as the Illinois State Psychiatric Institute. These large buildings housed basic and clinical researchers focused on understanding and improving the lives of individuals with developmental disabilities and mental health disorders. During the mid-1970s, in this background of interest and enthusiasm for research to study atypical development, I received a grant from the State of Illinois, Department of Mental Health and Developmental Disabilities to study heart rate patterns in ‘‘retarded and nonretarded’’ adolescents. To conduct this research, I borrowed from my colleague, Bob Sprague, a van that had been modified into a two-room research laboratory. With a graduate student, Mary Humphrey, and the help of a couple of talented undergraduates, we drove the van to local schools to collect the data. To do a simple study, we packed about 200 pounds of equipment into the van, including a Beckman Dynograph, an FM tape recorder, a 6-foot equipment rack containing relays programmed to display the stimulus via a slide projector and to record the responses through button presses, and a TV monitor and camera to reduce fear and uncertainty for the participants by enabling them to observe each other participating. The study resulted in a publication in the American Journal of Mental Deficiency (Porges & Humphrey, 1977), which was the former name of the American Journal on Intellectual and Developmental Disabilities. What has changed in the decades since my paper with Mary and this issue of the Journal on Intellectual and Developmental Disabilities? From my perspective, there have been three major interrelated changes. First, in 1977, it would have been virtually impossible to find sufficient intellectual material on heart rate monitoring in special populations to fill an issue of any journal. In the mid-1970s, only a few researchers studied autonomic function in special populations. Most notable was Rathe Karrer. Rathe was a psychoPsychophysiology of Developmental Disabilities
AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2013, Vol. 118, No. 6, 416–418
physiologist who worked at the above-mentioned Illinois State Pediatric Institute. Rathe was instrumental in moving psychophysiology into the study of developmental disabilities (e.g., Karrer, 1966) and into the emerging area of developmental psychophysiology (Karrer, 1976). Second, the resources needed to monitor heart rate in an experimental setting required expensive equipment and technically trained scientists, who often had to design, fabricate, and modify equipment to conduct their research. Thus, being a psychophysiologist in the early days of the discipline required technical skills to maintain the equipment and even to obtain the ECG signal from amplifiers with poor noise rejection. In addition, the quantification of heart rate was extremely time consuming. In the 1960s and early 1970s, quantification was done with a ruler directly from paper recordings of ECG. By the mid 1970s, the ‘‘advanced’’ laboratories were using FM tape recorders to store the signals and using digital computers to score the ECG offline from the FM tapes. A few laboratories had sufficient resources to use a dedicated digital computer to run their experiments and to collect the heart rate data in real time. In the Porges and Humphrey study, the cost of the equipment required to monitor heart rate was more than $10,000, and the equipment weighed more than 100 pounds. Our technology was state of the art, and we collected ECG data on magnetic tape. The tape recorder, which weighed about 50 pounds, was then moved to a dedicated computer, where the tapes were ‘‘digitized,’’ and the time between sequential heartbeats computed. By 1978, we had a stand-alone computer in my laboratory and were able to calculate the beat-tobeat heart rate in real time. The computer system cost approximately $50,000. Today the equipment needed for such a study could be purchased for less than $2,000, including equipment required to present the experimental stimuli and to collect and analyze heart rate data. In addition, the contemporary equipment would have a higher standard of performance (i.e., more precise and more accurate) than that found in the most advanced laboratories of the 1970s. Third, unlike the 1970s at the University of Illinois, when a large cluster of faculty were assembled on one campus to study atypical development, today faculty with these interests are dispersed across disciplines and research centers worldwide. However, interactions with S. W. Porges
EAAIDD DOI: 10.1352/1944-7558-118.6.416
colleagues and collaborators may be even more frequent than in the 1970s, when laboratories and offices were in close proximity. Today researchers are connected, not through the physical proximity of laboratories or offices, but through Internetbased communications that enable synchronous and asynchronous communication independent of distance and time zone. The past decades have witnessed exponential improvements in the technologies used to monitor physiological signals. Devices have become smaller, less expensive, easier to use, more accurate, and more reliable. These shifts in cost and reliability have been paralleled by increased opportunities to apply physiological monitoring in research settings. To monitor heart rate in a special population, researchers do not need major grants or significant seed money from their institutions. With a modest research budget, no more expensive than the cost of devices used to monitor behavior, researchers can now address interesting questions in special populations. At present, physiological monitoring is a technology that can be synchronized with behavioral monitoring. The current issue of the American Journal on Intellectual and Developmental Disabilities illustrates the effective transition of heart rate monitoring, from a technology that was expensive and rarely used to one that is now easily integrated into research studying developmental disabilities. The papers in this issue provide examples of three formerly divergent paradigms to further our understanding of developmental disabilities. First, the studies illustrate how heart rate monitoring can interface with single-subject behavioral paradigms to identify physiological state changes that covary with states of anxiety (Moskowitz) and selfinjurious behavior (Symons; Hall). Second, the studies illustrate how traditional psychophysiological paradigms can be used to demonstrate physiological state changes during social interactions and challenges (Klusek, Tonnsen). And third, the studies illustrate how measures of autonomic state are related to clinical symptoms (Tonnsen). Continued research following the theme of these papers will, by identifying neurophysiological states that support specific symptoms (e.g., anxiety, self injurious behaviors), provide insights into treatment and clinical management of children with developmental disabilities. 417
AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2013, Vol. 118, No. 6, 416–418
References Karrer, R. (1966). Autonomic nervous system functions and behavior: A review of experimental studies with mental defectives. In N. R. Ellis (Ed.), International review of research in mental retardation, (Vol. 2, pp. 57–83). New York, NY: Academic Press. Karrer, R. (1976). Developmental psychophysiology of mental retardation: Concepts and studies. Springfield, IL: Thomas. Porges, S. W., & Humphrey, M. M. (1977). Cardiac and respiratory responses during
418
EAAIDD DOI: 10.1352/1944-7558-118.6.416
visual search in non-retarded children and retarded adolescents. American Journal of Mental Deficiency, 82, 162–169.
Author: Stephen W. Porges (e-mail: stephen_porges@med. unc.edu), University of North Carolina School of Medicine, Department of Psychiatry, 387 Medical School Wing D, Campus Box 7160, Chapel Hill, NC 27599-7160, USA.
Psychophysiology of Developmental Disabilities
