#GALVANIC SKIN RESPONSE LABVIEW MANUAL#

Moreover, these limitations are further exacerbated in ecological experiments if participants are free to move, requiring substantial manual interventions to correct head motion artefacts 9, 13. Other tracking methods have used a cross-correlation template matching to automate tracking but which still requires visual inspection to reliably extract temperature profiles 9, 10. This method depends heavily on clear facial landmarks to guide the manual ROI placement and is thus user dependent and time consuming, especially if data is acquired at a high sampling rate. Previous IRI studies of face have mostly relied on manual tracking to locate and extract thermal data, such that investigators manually place regions of interest (ROIs) on the intended region frame by frame 12. This has perhaps stalled its widespread adoption in psychophysiological research. However, being contact free, IRI also poses unique methodological challenges, for example motion tracking of the face and the reliable extraction of temperature signals from specific facial regions (nose, cheeks). Although IRI remains largely unexplored, a few studies have demonstrated its utility in ecologically valid studies to quantify the facial temperature profiles during discrete socio-emotional states 9вЂ“ 11. Non-invasive imaging technologies like IRI could overcome the requirement for attaching sensors and improve the ecological-validity of psychophysics studies. However, most conventional psychophysics techniques (GSR, HR) require sensors attached to the body and could compromise the emotional experience and reduce the ecological validity of the experiments 8. Psychophysics measurement techniques are essential to the investigation of the bodily responses that are an integral component of emotional experience 5 and their dysfunctions in patients with affective disorders 6, 7. IRI of face thus has the potential to be a complimentary tool to GSR and HR to quantify physiological status of the body. A thermal imaging technique uses an infra-red camera to capture temperature variations. In mammals, surface body temperature is constantly influenced by the autonomic nervous system (ANS) through the control of blood perfusion to the surface of the skin, supporting the use of thermal imaging (infra-red-imaging-IRI) in psychophysiological research 1вЂ“ 4. However, the face is a primary region for the expression of emotional states, leading to changes in facial cutaneous blood flow (вЂњblushingвЂќ or вЂњturning paleвЂќ). In psycho-physiological research, the measures to capture heart related changes (heart rate-HR) and sweat related responses have been traditionally quantified with well validated measures such as electro-cardiogram (ECG) and skin conductance (galvanic skin response-GSR) respectively. These phrases embody various distinct physiological systemic changes. Our lexicon is abundant with phrases that ascribe emotions to bodily changes: вЂњpounding heartвЂќ for fear, вЂњsweaty palmsвЂќ for anxiety, or вЂњgoing red in the faceвЂќ for embarrassment. Newer methodological developments for reliable temperature extraction promise to boost IRI use as an ecologically-valid technique in social and affective neuroscience. These results demonstrate that our methodology offers a sensitive and robust tool to capture facial physiological changes with minimal manual intervention and manual pre-processing of signals. Additionally, this response was quite rapid at around 4вЂ“5вЂ‰seconds, starting less than 2вЂ‰seconds following the GSR changes. We found that the temperatures of selected facial regions, particularly the nose tip, significantly decreased after the auditory stimulus. We compared thermal responses with psycho-physiological sensor-based tools of galvanic skin response (GSR) and electrocardiography (ECG). We applied this method to physiological responses elicited by a sudden auditory stimulus, to determine if facial temperature changes induced by a stimulus of a loud sound can be detected. Here, we developed a novel semi-automated thermal signal extraction method employing deep learning algorithms for facial landmark identification. Exploiting its potential thus depends on advances in analytical methods. Investigating facial regions and subsequent reliable signal extraction from IRI data is challenging due to head motion artefacts.

Unlike traditional physiological measures (like skin conductance and heart rate), it is uniquely contact-free, substantially enhancing its ecological validity. Thermal Imaging (Infrared-Imaging-IRI) is a promising new technique for psychophysiological research and application.

Galvanic skin response labview