Memory searches 'like animals hunting'

BEIJING — Researchers at the UK’s University of Warwick and Indiana University in the US have identified parallels between animals looking for food in the wild and humans searching for items within their memory.

The study, Optimal Foraging in Semantic Memory, published in Psychological Review, asked 141 undergraduates (46 men and 95 women) at Indiana University to name as many animals as they could in three minutes, and then analyzed the responses using a categorization scheme and also a semantic space model, called BEAGLE, which identifies clusters in the memory landscape based on the way words are related to one another in natural language.

The result suggests that Humans move between ‘patches’ in their memory using the same strategy as bees flitting between flowers for pollen, or birds searching among bushes for berries.

“When faced with a memory task, we focus on specific clusters of information and jump between them like a bird between bushes. For example, when hunting for animals in memory, most people start with a patch of household pets, such as dog, cat and hamster,” said Dr Thomas Hills, associate professor in the psychology department at the University of Warwick.

“But then as this patch becomes depleted, they look elsewhere. They might then alight on another semantically distinct ‘patch’, for example predatory animals such as lion, tiger and jaguar.”

The study shows that people who either stay too long or not long enough in one ‘patch’ did not recall as many animals as those who better judged the best time to switch between patches.

In other words, people who most closely adhered to the marginal value theorem produced more items.