Assessing learning and memory in pigs

Abstract

In recent years, there has been a surge of interest in (mini) pigs (Sus scrofa) as species for cognitive research. A major reason for this is their physiological and anatomical similarity with humans. For example, pigs possess a well-developed, large brain. Assessment of the learning and memory functions of pigs is not only relevant to human research but also to animal welfare, given the nature of current farming practices and the demands they make on animal health and behavior. In this article, we review studies of pig cognition, focusing on the underlying processes and mechanisms, with a view to identifying. Our goal is to aid the selection of appropriate cognitive tasks for research into pig cognition. To this end, we formulated several basic criteria for pig cognition tests and then applied these criteria and knowledge about pig-specific sensorimotor abilities and behavior to evaluate the merits, drawbacks, and limitations of the different types of tests used to date. While behavioral studies using (mini) pigs have shown that this species can perform learning and memory tasks, and much has been learned about pig cognition, results have not been replicated or proven replicable because of the lack of validated, translational behavioral paradigms that are specially suited to tap specific aspects of pig cognition. We identified several promising types of tasks for use in studies of pig cognition, such as versatile spatial free-choice type tasks that allow the simultaneous measurement of several behavioral domains. The use of appropriate tasks will facilitate the collection of reliable and valid data on pig cognition.

Cognitive performance of low- and normal-birth-weight piglets in a spatial hole-board discrimination task

“…Therefore, we tested the hypothesis that birth weight influences cognitive performance of pigs. We did this by using a hole-board task that is suited for assessing spatial learning and memory in pigs (23) and enables the measurement of several behavioral domains (24).…”

Behavioral Deficits and Axonal Injury Persistence after Rotational Head Injury Are Direction Dependent

“…12,[14][15][16] Unfortunately, there is a paucity of validated behavioral tests for the immature piglet model, and those used on rodents do not translate well to pigs because of their different motor abilities, handling needs, and responses to stimuli (e.g., the well-known aversion of mice to light and open spaces is not observed in pigs). [4][5][6]23 As more robust and refined behavioral tests are developed for the porcine TBI model, it will be …”

Spontaneous Object Recognition in Animals: A Test of Episodic Memory

“…Similar to rats, pigs naturally tend to explore novel aspects of their environment (Wood-Gush & Vestergaard, 1991). Pigs also have good spatial memory abilities and they are able to learn tasks quickly (e.g., Croney, 1999;Held et al, 2002;Held et al, 2005;Puppe et al, 2007; reviewed in Gieling et al, 2011). As well, wild and feral pigs have a life history in which memory is valuable; particularly because they live socially, have large foraging ranges, and have foraging habits/movement patterns/nesting sites that change with season and food availability (Graves, 1984).…”

“…The physiological similarity between humans and pigs is likely responsible for the recent increased popularity of pigs as biomedical models of human disease and cognition (for reviews, see Gieling et al, 2011;Kornum & Knudsen, 2011;Lind et al, 2007). Accordingly, pigs may also provide a more effective comparison than other species between human episodic memory and episodic-like memory in animals.…”