Achievement

Human beings rely on multiple cognitive processes: perception, memory, and decision-making, that work cooperatively during performance of natural tasks. To study cooperativity, Melissa Kibbe devised a novel task in which subjects searched through an array of hidden visual objects (revealed via a mouse click or eye fixation) for a set of 3 that fell into a common class. Classification rules ranged in complexity (based on a single feature or presence/absence of multiple features). Kibbe found that as complexity increases people increased the number of visits and revisits to locations, showing a tradeoff between complexity and reliance on memory. These reflect genuine human cognitive limits; computer simulations showed that performance of an ideal observer without memory limits does not depend on the classification rule. Kibbe’s results support a unitary pool of cognitive resources that are allocated dynamically during natural task performance.