Abstract: Cerebral lateralization is the portioning of the cognitive functions between the two cerebral hemispheres. Several factors, like embryological manipulations, light exposure, health conditions, sex and age can influence the left-right brain asymmetries and contribute to increasing the variability in the strength and direction of laterality within most species. We investigated the influence of an environmental constraint, namely space availability, as a new source of variation on laterality in an adult vertebrate model, the donkey. In a baseline condition we tested whether donkeys show a motor lateralization bias at population level, while in an experimental condition we manipulated space availability to verify if a reduction in this parameter could represent a new source of variation in laterality. Results show that donkeys are lateralized at population level with a strong bias to standing with the right forelimb advanced over the left and that a reduction of space availability is an important source of variation in the laterality strength and direction within this species. The comparative analysis of the environmental and developmental factors that give origin to neural and behavioural laterality in animal models will be very important for a better understanding of the evolutionary origin of such multifaceted phenomenon.

Abstract: Scientists and equestrians continually seek to achieve a clearer understanding of equine learning behaviour and its implications for training. Behavioural and learning processes in the horse are likely to influence not only equine athletic success but also the usefulness of the horse as a domesticated species. However given the status and commercial importance of the animal, equine learning behaviour has received only limited investigation. Indeed most experimental studies on equine cognitive function to date have addressed behaviour, learning and conceptualisation processes at a moderately basic cognitive level compared to studies in other species. It is however, likely that the horses with the greatest ability to learn and form/understand concepts are those, which are better equipped to succeed in terms of the human-horse relationship and the contemporary training environment. Within equitation generally, interpretation of the behavioural processes and training of the desired responses in the horse are normally attempted using negative reinforcement strategies. On the other hand, experimental designs to actually induce and/or measure equine learning rely almost exclusively on primary positive reinforcement regimes. Employing two such different approaches may complicate interpretation and lead to difficulties in identifying problematic or undesirable behaviours in the horse. The visual system provides the horse with direct access to immediate environmental stimuli that affect behaviour but vision in the horse is of yet not fully investigated or understood. Further investigations of the equine visual system will benefit our understanding of equine perception, cognitive function and the subsequent link with learning and training. More detailed comparative investigations of feral or free-ranging and domestic horses may provide useful evidence of attention, stress and motivational issues affecting behavioural and learning processes in the horse. The challenge for scientists is, as always, to design and commission experiments that will investigate and provide insight into these processes in a manner that withstands scientific scrutiny.

Abstract: Groups comprising eight rats initially were exposed to response-independent water deliveries, then to conditions under which a lever-press response raised an empty dipper immediately or after a resetting delay of 15, 30, or 45 s. When their performance was compared to that of control animals using a 90% confidence level, six rats in the immediate-reinforcement group met the primary criterion for response acquisition during a single 6-h session; 4, 4, and 3 did so in the 15, 30, and 45 s delay groups, respectively. Similar evidence of acquisition was obtained when a 95% confidence level was used. With a 99% confidence level, however, evidence of acquisition was not compelling. Although these data appear to provide the first demonstration of response acquisition in the absence of handshaping or autoshaping under conditions where the putative reinforcer is both conditioned and delayed, they also demonstrate that whether response acquisition occurs depends, in part, on how it is defined.