Felisa Holmberg
Young People and Horses
Help for issues with young people
[Research Study Author(s):] Amy Victoria Smith, Leanne Proops, Kate Grounds, Jennifer Wathan and Karen McComb
[Publisher/Date:] The Royal Society in February 2016
Evidence suggests horses are among the handful of non-human animals capable of distinguishing between positive and negative human facial cues This study is one of the first to present such evidence.
The study used a combination of gaze laterality and heart rate in assessing the subjects’ responses to stimuli. Gaze laterality—the direction in which an animal looks when presented with a stimulus—is a reflection on hemispheric specialization for processing stimuli. The right hemisphere of the brain generally processes negative stimuli, though there is contradictory evidence as to whether there is lateralization of responses to positive stimuli. Based off of this, if animals were able to distinguish between positive and negative human facial expressions they would display left-gaze bias for negative expressions and either no gaze bias or right-gaze bias for positive stimuli. Additionally, the horse’s heart rate was expected to increase when faced with negative stimuli.
The study included twenty-eight horses from five different stables in Sussex and Surrey, UK, and ran between April 2014 and February 2015. Twenty-one geldings and seven mares participated in the study, ranging in ages four to twenty-four years old. The stimuli presented to the test subjects consisted of four color photographs of two different men, each displaying a positive (happy) expression and a negative (angry) expression, and all trials were conducted by a female team. Heart rate measurements were taken between 5 seconds before and 5 seconds after the stimulus was presented and then for a final four minutes afterwards to monitor recovery time. Behavioral responses were blind-coded on video for analysis. Horses were judged on the initial direction they looked as well as the time they spent looking left, middle, or right.
In testing, more horses showed left-gaze bias than right in response to negative stimuli and there was also a left-gaze bias in looking time. There was no right-gaze bias displayed to positive stimuli, however, supporting a lack of evidence of lateralization of response to positive stimuli. Horses’ heart rates showed a significant increase when confronted with the negative stimuli versus positive, although heart rate recovery time was not affected by whether the stimulus was positive or negative.
To view the research in its entirety: http://rsbl.royalsocietypublishing.org/content/12/2/20150907