Behavior Genetics of the Horse (Equus caballus) - Genetics and the Behavior of Domestic Animals - page 277

lateralized learning. Information processed and learned in one hemisphere of
the brain transfers to the opposite hemisphere in an experience-dependent
manner. Studies report interhemispheric transfer of memory in species as
diverse as fish, amphibians, reptiles, birds, and mammals ( Robbins and
Rogers, 2006; Vallortigara and Rogers, 2005 ). In cattle, Robbins and Phillips
(2010) report the first example of experience-dependent lateralized learning
in a mammal. In herd-splitting experiments conducted on dairy and beef cat-
tle, a single experimenter walked repeatedly through herds, either empty-
handed or while carrying various novel objects. At first, the cattle viewed
the experimenter using their left eyes (right hemisphere). After habituating
to the experimenter carrying various objects, the cattle then switched to
viewing the experimenter with the right eye (left hemisphere). This direc-
tional shift in viewing preference was experience-dependent. Robbins and
Phillips (2010) suggest that the reversal of preference from the left eye
(when the stimuli is novel) to the right eye (when the stimuli becomes famil-
iar) “frees up” the left eye to simultaneously watch for new threats.
Switching Sides
There is no known experimental evidence of experience-dependent latera-
lized learning in horses. However, it may be safe to assume that this well-
conserved pattern of lateralized learning exists in all mammals ( Robbins and
Phillips, 2010 ). During horse training, the first author switches sides when a
horse shows a lateralized response. He also uses hair whorl positions (i.e.,
left or right side of the forehead) to predict a lateralized response before it
occurs. For example: if a left whorl horse shows resistance to having a sad-
dle placed on its back from the left side, switching to a right-side presenta-
tion speeds habituation. Switching sides can also help when training a horse
to lunge in a circle. For example, the first author starts a horse in a circle in
the preferred direction, then switches to the non-preferred direction. When
the horse shows signs of fear (head high, head turned to the outside, etc.), he
turns the back to the preferred direction. Never forcing the horse to continu-
ously travel for long in the non-preferred direction over time has a calming
effect. Our hypothesis is that a majority of lateralized behaviors observed
during riding, or during ground handling, are motivated by fear.
In summary, preventing lateral behavior before it occurs is easier than try-
ing to correct it once it's been conditioned. Experience-dependent lateralized
learning may be the way horses learn about and come to accept handling and
training by humans. They first look at novelty using the eye system geared to
detect possible danger. When no danger is perceived, the opposite eye system
takes over and learning progress without fear inhibiting learning. The non-
intrusive neonatal foal handling method used by the first author allows foals
to learn in the way they are meant to learn. Foals look at him several times
from both sides before approaching and touching him for the first time. By