Use the navigation bar above to access articles and more discussions on this topic.
| Author |
Message |
    
Robert N. Oglesby DVM
Moderator
Username: dro
Post Number: 20870
Registered: 1-1997
| | Posted on Tuesday, Jun 17, 2008 - 10:53 am: |   |
This report suggests horses preferentially use their left eye to veiw a image with a negative stimulus and their right eye to view novel (new) images. There was no preference for positive images. However these preferences were not strong. From a training standpoint could this mean horses may view a novel stimulus introduced on the left side as more positive than if introduced on the left? This is interesting and not the first time we have seen reports of laterality when horses are dealing with visual stimului, for more see Training & Conditioning Horses » Behavior and Training » Working Around Horses Safely » Research Study: Asymmetry of flight and escape turning responses in horses .
DrO
Physiol Behav. 2008 Mar 12;
Laterality and emotions: Visual laterality in the domestic horse (Equus caballus) differs with objects' emotional value.
De Boyer Des Roches A, Richard-Yris MA, Henry S, Ezzaouia M, Hausberger M.
UMR CNRS 6552 Ethologie-Evolution-Ecologie, Universite de Rennes 1, Avenue du General Leclerc, Campus de Beaulieu, F-35042 Rennes Cedex, France.
Lateralization of emotions has received great attention in the last decades, both in humans and animals, but little interest has been given to side bias in perceptual processing. Here, we investigated the influence of the emotional valence of stimuli on visual and olfactory explorations by horses, a large mammalian species with two large monocular visual fields and almost complete decussation of optic fibres. We confronted 38 Arab mares to three objects with either a positive, negative or neutral emotional valence (novel object). The results revealed a gradient of exploration of the 3 objects according to their emotional value and a clear asymmetry in visual exploration. When exploring the novel object, mares used preferentially their right eyes, while they showed a slight tendency to use their left eyes for the negative object. No asymmetry was evidenced for the object with the positive valence. A trend for an asymmetry in olfactory investigation was also observed. Our data confirm the role of the left hemisphere in assessing novelty in horses like in many vertebrate species and the possible role of the right hemisphere in processing negative emotional responses. Our findings also suggest the importance of both hemispheres in the processing positive emotions. This study is, to our knowledge, the first to demonstrate clearly that the emotional valence of a stimulus induces a specific visual lateralization pattern.
|
Elizabeth Kaufman
Member
Username: ekaufman
Post Number: 583
Registered: 3-2007
| | Posted on Wednesday, Jun 18, 2008 - 9:29 am: | |
So DrO, o you think it's significant to the study that these are adult mares who have likely been handled mostly from their left sides?
Would it be a better study to repeat the exercise with unhandled horses, or with youngsters that were somehow raised in a laterally-neutral way?
It's hard not notice the likelihood that the vast majority of human intervention on this study group would have come from the left, even since they were small. I just don't know whether that impacts the study. |
Robert N. Oglesby DVM
Moderator
Username: dro
Post Number: 20883
Registered: 1-1997
| | Posted on Thursday, Jun 19, 2008 - 7:47 am: | |
I think regular horsemanship could confound the results since the horses are trained in a "lateral manner". But there is a basis for assuming laterality of learning and identification from examining other species. We will have to wait to see how this issue plays out.
DrO |
