Table of Contents
Emotions and the Autonomic Nervous System
Common techniques employed in neuroscience often limit the scope of research on neurovascular elements of human social interaction. Such techniques mostly involve the use of contact measurement instruments such as electrodes on the skin of the test subjects. However, these kinds of instruments tend to intervene with spontaneous behavior. Functional magnetic resonance imaging is a non-contact technique in which test subjects are exposed to active radiation and requires them to remain immobile for long periods of time.
Thermal imaging technology is one such technique that offers a suitable solution to overcome these problems. With the help of thermal imaging cameras, infrared radiation produced by the subject can be recorded without actually exposing the subjects to any kind of radiation. In addition, scientists can use this technology to collect data in real time, thus enabling the test subjects to move freely and naturally.
According to Dr. Arcangelo Merla, who serves as Director of the Infrared Imaging Lab at the ITAB – Institute for Advanced Biomedical Technology, University of Chieti-Pescara (Italy), this technology can be used to investigate the neurobiological foundations of social interactions, particularly in ecological contexts by leveraging the contact-free nature of thermal imaging.
Merla informed that the FLIR thermal imaging camera proved quite useful in one particular study, wherein researchers attempted to forge a synchrony in autonomic responses between child and mother. With the help of thermal imaging cameras, the team was able to achieve reliable measures of autonomic responses which were captured concurrently for both mothers and their children, without the drawbacks involved in other techniques for physiological data collection.
On the other hand, the physiological part has been vastly ignored, although the psychological part of social interactions has been studied at large. In spite of considerable interest in neuroscience on empathy and its significance to infant development, prior studies explored maternal empathy mostly by utilizing verbal reports and in certain cases by functional neuroimaging. Only some studies have reported about the potential involvement of physiological responses during interactions between child and parent.
Figure 1. In this experiment the toy is prepared to brake during playing (mishap). The mother observes the scene from behind a one-way mirror. Both the child and the mother are observed using a thermal imaging camera.
Merla further informed that he has used thermal imaging technology in a number of medical applications, such as diseases linked to peripheral nervous, micro/macro circulatory, muscle-skeletal, autoimmune and cutaneous systems.
Emotions and the Autonomic Nervous System
Researchers have proposed that visceral responses that are mediated autonomically are closely associated with the experience of emotions. Such explicit response of empathy is typically called a common neural coding of the perception of one's own and the other individual's feelings. Merla explained that it is hence feasible that empathy also represents a direct sharing of variations in body physiology between individuals. This suggests that changes in the thermal data indicate internal processes that are particularly active in the presence of emotional stimuli.
Figure 2. Graphical representation of temperature variations of the nasal tip and maxillary area averaged for a group of children and for a group of mothers. The graphs illustrate the absence of a correlation between thermal variations in the mother and the child during the neutral baseline phase (graphs on the left). By contrast, a strong correlation in thermal variations between children and their mothers is shown during the emotional phases of the experiment (graphs on the right).
During the test, the experimenter invited children to play with a toy, which was designed to actually break during play, giving the notion that the child had accidentally broken the toy. Mothers were made to watch the interaction between their children and the experimenter via a one-way mirror from another room. Two highly sensitive cooled FLIR SC 7000 Series thermal imaging cameras were employed to observe both mother and child.
To calculate thermal changes over time and their connection between mothers and their children, variations in cutaneous temperature for precise facial regions of interest, i.e. the nasal tip and the maxillary area, were measured. These regions were then chosen based on prior studies conducted in humans and primates. However, since the test subjects did not remained still, it proved quite difficult to monitor these facial regions. The FLIR SC7000 series of thermal imaging cameras enabled rapid data acquisition. Merla informed that a tracking algorithm was applied to the thermal imaging video footage and allowed to ensure correct localization of the defined facial regions of interest on each processed frame.
Figure 3. In these cut-outs of the thermal footage clear temperature variations in various facial regions of both the mother and the child can be observed after the toy was broken (mishap) and when the child was soothed afterwards by the experimenter.
According to Merla, the present research has demonstrated that at the time of experiment, the emotional distress which occurred as a result of toy breaking led to thermal changes in the child’s facial regions of interest. The facial thermal changes noted in the mothers were unexpectedly similar to those noted in the child. Also, mothers’ facial thermal modulations clearly linked with their children’s corresponding modulations. Therefore, mother-child interactions have revealed a situation-specific synchronicity between the autonomic reactions displayed by each partner.
Without interfering with natural behavior, physiological links of emotional reactions were studied in an interactive experimental framework, thanks to the versatility of the FLIR SC7000 Series thermal imaging cameras. Hence, thermal imaging technology proves to be an exceptional tool which can be employed to investigate the neurobiological foundations of social interactions.
FLIR was founded in 1978, originally providing infrared imaging systems that were installed on vehicles for use in conducting energy audits. Later, the company expanded its focus to other applications and markets for its technology, in particular, designing and selling stabilized thermal imaging systems for aircraft used by law enforcement. FLIR has since grown substantially due to increasing demand for infrared products across a growing number of markets combined with the execution of a series of acquisitions. Today they are one of the world leaders in the design, manufacture and marketing of thermal imaging and stabilized camera systems for a wide variety of applications in the commercial, industrial and government markets, internationally as well as domestically.
The company's thermography business primarily consists of the design and manufacture of hand-held thermal imaging systems that can detect and measure minute temperature differences, which are useful for a wide variety of industrial and commercial applications. Uses for the company's Thermography products include high-end predictive and preventative maintenance, research and development, test and measurement, leak detection and scientific analysis. A growing distribution network has enabled FLIR to penetrate existing and emerging markets and applications worldwide.
This information has been sourced, reviewed and adapted from materials provided by FLIR.
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