Nasal temperature drop in response to a playback of conspecific fights in chimpanzees: A thermo-imaging study

Abstract

Emotion is one of the central topics in animal studies and is likely to attract attention substantially in the coming years. Recent studies have developed a thermo-imaging technique to measure the facial skin temperature in the studies of emotion in humans and macaques. Here we established the procedures and techniques needed to apply the same technique to great apes. We conducted two experiments respectively in the two established research facilities in Germany and Japan. Total twelve chimpanzees were tested in three conditions in which they were presented respectively with the playback sounds (Exp. 1) or the videos (Exp.2) of fighting conspecifics, control sounds/videos (allospecific display call: Exp. 1; resting conspecifics: Exp.2), and no sound/image.Behavioral, hormonal (salivary cortisol) and heart-rate responses were simultaneously recorded. The nasal temperature of chimpanzees linearly dropped up to 1.5 degree in two minutes, and recovered to the baseline in two minutes, in the experimental but not control conditions. We found the related changes in excitement behavior and heart-rate variability, but not in salivary cortisol, indicating that overall responses were involved with the activities of sympathetic nervous system but not with the measureable activities of the hypothalamus-pituitary-adrenal (HPA) axis. The influence of general activity (walking, eating) was not negligible but controllable in experiments. We propose several techniques to control those confounding factors. Overall, thermo-imaging is a promising technique that should be added to the traditional physiological and behavioral measures in primatology and comparative psychology.

The dot-probe task to measure emotional attention: A suitable measure in comparative studies?

“…A relatively new method allows the noninvasive measurement of facial skin temperature with thermal cameras. This technique is already successfully applied in emotion perception studies with both humans (e.g., Nhan & Chau, 2010) and macaque monkeys (Kuraoka & Nakamura, 2011), and recently with chimpanzees as well (Kano, Hirata, Deschner, Behringer, & Call, 2016). It is a promising technique from which data even heart rates can be derived, yet it is expensive and dependent on general activity as walking and eating, even though this is to some extent controllable in an experimental setting (Kano et al, 2016).…”

Dolor y Termografía

“…Estudios recientes en iTF muestran que los estímulos desagradables decrementan la temperatura nasal. Por ejemplo, un estímulo auditivo desagradable como escuchar una pelea (Kano, Hirata, Deschner, Behringer & Call, 2016) o visual mediante la exposición de una imagen (Kosonogov et al, 2017) …”

Untitled

“…Estudios recientes en iTF muestran que los estímulos desagradables decrementan la temperatura nasal. Por ejemplo, un estímulo auditivo desagradable como escuchar una pelea (Kano, Hirata, Deschner, Behringer & Call, 2016) o visual mediante la exposición de una imagen (Kosonogov et al, 2017) (Figura 3).…”