Me, a bird-brain? thank you for the compliment
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—like dog, cat and hamster.
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, Optimal Foraging in Semantic Memory published in Psychological Review, 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 this study scientists from the University of Warwick and Indiana University asked asked 141 undergraduates (46 men and 95 women) at Indiana University to name as many animals as they could in three minutes.
The responses were then analysed using a categorisation 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.
They and then compared the results with a classic model of optimal foraging in the real world, the marginal value theorem, which predicts how long animals will stay in one patch before jumping to another.
The similarity to animal behaviour is evident from studies on foraging behaviour. A bird’s food tends to be clumped together in a specific patch – for example on a bush laden with berries.
But when the berries on a bush are depleted to the point where the bird’s energy is best focused on another more fruitful bush, it will move on.
This kind of behaviour is predicted by the marginal value theorem, for a wide variety of animals.
The conclusion therefore is that people who most closely adhered to the marginal value theorem produced more items from memory.
I hypothesise that this result also shed light onto the way human attention has perhaps evolved. Humans use the same strategies to forage in memory as animals do for food in the wild.
This study raises interesting ideas to test the mechanisms that those with ‘good’ memories use, as opposed to a population of people who have ‘poor’ memories. It also enticingly poses a mechanism that could be explored to improving your own memory.