The average person has probably never wondered about what a pig remembers, however researchers at Memorial University have a good reason for wanting to find out.

Amy-Lee Kouwenberg is a graduate student in the Department of Psychology’s Cognitive and Behaviour Ecology Program (CABE). She is currently doing her master’s of science thesis on whether or not pigs have episodic-like memory.

“Pigs are great for psychological research and neuroscience because their brains are arguably more similar to human brains than rats,” said Ms. Kouwenberg.

"They are thought to have highly developed mental abilities, but there hasn’t been a lot of actual research on their brain function and learning.”

Under the supervision of Dr. Carolyn Walsh and Dr. Gerard Martin, Ms. Kouwenberg spent last summer conducting a series of tests on Yucatan miniature pigs being raised in a specialized breeding facility on Mount Scio Rd., to determine exactly what pigs do remember.

“Episodic memory is basically remembering the what, when and where aspects of a previously experienced event,” said Ms. Kouwenberg. “We know that it happens in humans because they can tell us, but obviously animals can’t do the same. It also requires a sense of self and the ability to move mentally in time, which is difficult to show in animals.

“Episodic-like memory loosens that definition – so if we can get the animals to show an integrated memory of what: an object; where: its location in a test pen; and which: the context in which it occurs, that’s a pretty good step towards showing they have episodic-like memory and until now, that’s never been done in pigs. It’s been done in rats and primates, but nothing in between. “

Because pigs have a natural tendency to prefer items they have never seen before, Ms. Kouwenberg was able to expose the pigs to different objects in different locations and contexts and measure the length of time the pigs spent with each object.

“In order for the object to be familiar or unfamiliar, they had to remember the object, where they had seen it before and in what context it occurred,” she said.

“The only way the object would be less familiar is if they remembered all three of these things together and we actually found that they did. So we were able to conclusively show the first evidence of episodic-like memory in pigs.”

“It’s quite exciting because human episodic memory is considered a part of consciousness, and of course there’s the big question, are animals conscious or are they not,” added Ms. Kouwenberg.

“So in the huge picture it has some implications in that if we can show this, maybe we can show further evidence of the kinds of memory which indicate consciousness. Having a test for cognitive function is also quite handy for people who work on physiology and nutrition, to see if, for example, the starvation of a certain nutrient affects their episodic memory.”

Ms. Kouwenberg believes her study could be just the beginning of this particular line of pig research at MUN. There have already been a number of potential follow-up studies identified for the near future.

“We’d like to look into the differences we found between males and females,” she said.

“Females seem to respond to tests differently in much of the pig research that has been done, but it may just be that they’re more intimidated by the testing arena. So we’d like to look into that more. We’d also like to look into varying the delay between the exposure to the object and the test to see if the pigs remember the objects over a longer time. Episodic memory also depends on the hippocampus, and impairment of the hippocampus appears to reduce ability for episodic like memory. So we could also look into how that might affect the pigs’ memories.

“This is something that definitely has potential for further study,” she added. “These were pretty exciting results to get. Now that we have that answer, there are so many more questions we could ask.”