Assessing positive emotional states in dogs using heart rate and heartrate variability
2016 (English)In: Physiology and Behavior, ISSN 0031-9384, E-ISSN 1873-507X, Vol. 155, 102-111 p.Article in journal (Refereed) Published
Since most animal species have been recognized as sentient beings, emotional state may be a good indicator ofwelfare in animals. The goal of this study was to manipulate the environment of nine beagle research dogs tohighlight physiological responses indicative of different emotional experiences. Stimuli were selected to be amore or a less positive food (meatball or food pellet) or social reward (familiar person or less familiar person).That all the stimuli were positive and of different reward value was confirmed in a runway motivation test.Dogs were tested individually while standing facing a display theatre where the different stimuli could beshown by lifting a shutter. The dogs approached and remained voluntarily in the test system. They were testedin four sessions (of 20 s each) for each of the four stimuli. A test session consisted of four presentation phases(1st exposure to stimulus, post exposure, 2nd exposure, and access to reward). Heart rate (HR) and heart ratevariability (HRV) responses were recorded during testing in the experimental room and also when lying restingin a quiet familiar room. A newmethod of ‘stitching’ short periods of HRV data together was used in the analysis.When testing different stimuli, no significant differenceswere observed in HR and LF:HF ratio (relative power inlow frequency (LF) and the high-frequency (HF) range), implying that the sympathetic tone was activated similarlyfor all the stimuli and may suggest that dogs were in a state of positive arousal. A decrease of HF was associatedwith the meatball stimulus compared to the food pellet and the reward phase (interacting with the personor eating the food) was associated with a decrease in HF and RMSSD (root mean square of successive differencesof inter-beat intervals) compared to the preceding phase (looking at the person or food). This suggests that parasympatheticdeactivation is associated with a more positive emotional state in the dog. A similar reduction in HFandRMSSDwas found in the test situation compared to the resting situation. This is congruentwith the expectedautonomic effects related to postural shift i.e. sympathetic activation and parasympathetic withdrawal, duringstanding versus lying, but it cannot explain the parasympathetic deactivation in response to the more positivestimuli since the dogs were always standing in the test situation.Wediscuss the systematic pattern of responses,which support that increased HRand LF:HF ratio are associatedwithemotional arousal, but add the newproposalthat a combined decrease inRMSSD and HFmay reflect a more positively valencedemotional state evenwhen anindividual is already in a positive psychological state.
Place, publisher, year, edition, pages
Elsevier, 2016. Vol. 155, 102-111 p.
Positive psychology Emotion Autonomic nervous system Welfare Dog Stimulus
Ecology Behavioral Sciences Biology
IdentifiersURN: urn:nbn:se:liu:diva-123379DOI: 10.1016/j.physbeh.2015.11.027ISI: 000369455200013PubMedID: 26631546OAI: oai:DiVA.org:liu-123379DiVA: diva2:882249
Funding agencies: Swedish University of Agricultural Sciences ; Swedish Research Council Formas [221-2010-35]2015-12-142015-12-142016-03-03