The neurobiological basis of emotions and their connection to facial expressions in non-human mammals: insights in nonverbal communication.

This research investigates the link between emotions and facial expressions in non-human mammals. The core focus is on bridging neurobiological understanding of emotions with facial expressions as observed through the Animal Facial Action Coding System (AnimalFACS), a tool used to analyze facial movements in animals.

Emotional Processing in Animals

The animal body, like humans, processes emotions through different neurological structures primarily found in the limbic system. These include the:

• Hypothalamus
• Hypophysis
• Hippocampus
• Prefrontal cortex
• Amygdala

In this system, the amygdala plays a key role, interfacing with the motor cortex and directing the facial muscles through the facial nerve. This supports the research findings that facial expressions in mammals mirror their internal emotional state.

Facial Action Coding System (FACS)

The Facial Action Coding System (FACS) is a method to objectively assess the facial movements in humans using an anatomical understanding. AnimalFACS is a variant of this system, specifically adapted to eight animal species – including household animals like dogs, cats, horses, and certain nonhuman primates (such as chimpanzees, orangutans, gibbons, macaques, and common marmosets).

Linking Facial Expressions to Emotional States

The main aim of the research is to associate specific facial expressions with corresponding emotional states and affective contexts in animals. The use of AnimalFACS provides an evidence-based platform for this exploration. If researchers can characterize each facial expression in line with different contexts, it can help decipher whether the animal is exhibiting a positive or negative emotional response to a certain event.

Advancements in Nonverbal Communication

The findings from this research can significantly impact nonverbal communication between humans and animals. The ability to interpret the emotional state of an animal through their facial expressions could improve the quality of human-animal interaction and help in understanding their behavioral patterns.