Infrared thermal imaging in affective neuroscience: insights to the self from the peripheral nervous system.

Changes in peripheral physiology lay in the unconscious and occur as a response to external challenges, whether is to fight a virus (e.g. fever) a predator (e.g Fight or Flight) or even to face a social challenge. Autonomic adaptation carries its own physiological print and by harnessing the power given by homeostatic balance, distinctions can be made between arousal and parasympathetic restoration. Conventional physiological methods restrict the way in which experimental designs can be performed. Functional Infrared Thermal Imaging (fITI) provides an alternative for physiological monitoring that enables experimental paradigms that resemble real life situations. With the use of thermal imaging the following studies were set to examine self-conscious emotions in a naturalistic experimental setting while advancing methodologically the technique of fITI. In the following chapters the potentialities and limits of fITI are illustrated (Chapter 2) and three studies are presented where fITI has been applied to investigate the autonomic signature of guilt in children (Chapter 3); the facial imprints of autonomic contagion in mother and child (Chapter 4); the role of social proximity and gaze in modulating facial temperature (Chapter 5). FITI has managed to reliably and systematically collect physiological thermal changes between affective states illustrating a new pathway for contact-free autonomic monitoring in the arena of self-conscious emotions

Seeing a blush on the visible and invisible spectrum: a functional thermal infrared imaging study

So far blushing has been examined in the context of a negative rather than a positive reinforcement where visual displays of a blush were based on subjective measures. The current study used infrared imaging to measure thermal patterns of the face while with the use of a video camera quantified on the visible spectrum alterations in skin color related to a compliment. To elicit a blush a three-phase dialog was adopted ending or starting with a compliment on a female sample (N = 22). When the dialog ended with a compliment results showed a linear increase in temperature for the cheek, and forehead whereas for the peri-orbital region a linear decrease was observed. The compliment phase marked the highest temperature on the chin independent of whether or not the experiment started with a compliment contrary to other facial regions, which did not show a significant change when the experiment started with a compliment. Analyses on the visible spectrum showed that skin pigmentation was getting deep red in the compliment condition compared to the serious and social dialog conditions for both the forehead and the cheeks. No significant association was observed between temperature values and erythrocyte displays on the forehead and cheek. Heat is the physiological product of an arousing social scenario, however, preconceived notions about blushing propensity seem to drive erythrocyte displays and not necessarily conscious awareness of somatic sensations

Thermal infrared imaging in psychophysiology: potentialities and limits

Functional infrared thermal imaging (fITI) is considered an upcoming, promising methodology in the emotional arena. Driven by sympathetic nerves, observations of affective nature derive from muscular activity subcutaneous blood flow as well as perspiration patterns in specific body parts. A review of 23 experimental procedures that employed fITI for investigations of affective nature is provided, along with the adopted experimental protocol and the thermal changes that took place on selected regions of interest in human and nonhuman subjects. Discussion is provided regarding the selection of an appropriate baseline, the autonomic nature of the thermal print, the experimental setup, methodological issues, limitations, and considerations, as well as future directions

Proximity and gaze influences facial temperature: a thermal infrared imaging study. Frontiers in psychology

Direct gaze and interpersonal proximity are known to lead to changes in psycho-physiology, behavior and brain function. We know little, however, about subtler facial reactions such as rise and fall in temperature, which may be sensitive to contextual effects and functional in social interactions. Using thermal infrared imaging cameras 18 female adult participants were filmed at two interpersonal distances (intimate and social) and two gaze conditions (averted and direct). The order of variation in distance was counterbalanced: half the participants experienced a female experimenter's gaze at the social distance first before the intimate distance (a socially "normal" order) and half experienced the intimate distance first and then the social distance (an odd social order). At both distances averted gaze always preceded direct gaze. We found strong correlations in thermal changes between six areas of the face (forehead, chin, cheeks, nose, maxilliary, and periorbital regions) for all experimental conditions and developed a composite measure of thermal shifts for all analyses. Interpersonal proximity led to a thermal rise, but only in the "normal" social order. Direct gaze, compared to averted gaze, led to a thermal increase at both distances with a stronger effect at intimate distance, in both orders of distance variation. Participants reported direct gaze as more intrusive than averted gaze, especially at the intimate distance. These results demonstrate the powerful effects of another person's gaze on psycho-physiological responses, even at a distance and independent of context

Representation of the coding performed for each participant according to thematic group.

<p>Representation of the coding performed for each participant according to thematic group.</p

Mean scores and standard deviations for participant’s answers to each of the three questions according to their experience while watching the film.

<p>Mean scores and standard deviations for participant’s answers to each of the three questions according to their experience while watching the film.</p