Traveling companions add complexity and hinder performance in the spatial behavior of rats

Abstract

We sought to uncover the impact of the social environment on the spatial behavior of rats. ood-deprived rats were trained in a spatial task of collecting food items from 16 equispaced bjects. Following training, they were tested, first alone and then with a similarlytrained age-mate. It was found that the presence of another rat substantially altered the ats' spatial behavior. Lone rats collected the food items faster while traveling a shorter distance, eflecting a higher efficiency of task completion. When accompanied by a partner, owever, the rats traveled together, visiting the same set of objects in each trip with one of hem leading. Whether alone or with a partner, rats continued to revisit the same objects; owever, more such revisits occurred with a partner. We argue that revisiting objects is not ecessarily an error, since returning to past places is an important aspect of rats' natural ehavior. Revisiting an object following food depletion implies that searching for food was ot the main driving force in the rats' spatial behavior. Specifically, despite food deprivation, ats were more attentive to one another than to the food. This could be adaptive, since foraging nd feeding in groups is a way of poison avoidance in wild rats. Finally, the addition of social component added complexity to the environment since the rats organized their spatial ehavior in reference to one another in addition to their organization in the physical surrounding. onsequently, when tested with a partner, spatial behavior was less structured, ess predictable and more chaotic.