Dogs display context-dependent behavioral responses to subtle owner-derived multimodal stimuli

Dogs (Canis familiaris) can discriminate explicit human emotions using various sensory modalities. However, their sensitivity to subtle human-derived emotional cues accompanied by physiological changes, but lacking clear behavioral cues, remains poorly understood. This study investigated whether dogs could perceive owner-derived emotional cues when suppressing explicit expressions.

Owners were assigned to either stress or relaxation conditions designed to induce stress or relaxation, respectively. Following the experimental manipulation, facial video, voice, and olfactory samples were collected during a standardized reading task and simultaneously presented to the dogs. The behavioral responses and heart rate variability (HRV) of the dogs during stimulus presentation were recorded.

Owners exhibited elevated physiological arousal during both the control and stress induction periods, whereas negative mood increased only during stress induction. In response to these owner-derived stimuli, dogs under the stress condition displayed greater stimulus-directed attention toward control-derived stimuli than toward stress-derived stimuli. No clear effects of condition or stimulus type on dog HRV were observed; however, SDNN-based physiological synchrony between owners and dogs tended to increase with stress-derived stimuli.

Our results suggest that dogs respond to complex owner-derived stimuli in a context-dependent manner. These findings suggest that dogs may respond to subtle combinations of owner-derived cues that reflect physiological arousal, subjective emotional state, and task-related influences.