MEMORY REPRESENTATIONS IN NATURAL TASKS

The very limited capacity of short-term or working memory is one of th e most prominent features of human cognition. Most studies have stress ed delimiting the upper bounds of this memory in memorization tasks ra ther than the performance of everyday tasks. We designed a series of e xperiments to test the use of short-term memory in the course of a nat ural hand-eye task where subjects have the freedom to choose their own task parameters. In this case subjects choose not to operate at the m aximum capacity of short-term memory but instead seek to minimize its use. In particular, reducing the instantaneous memory required to perf orm the task can be done by serializing the task with eye movements. T hese eye movements allow subjects to postpone the gathering of task-re levant information until just before it is required. The reluctance to use short-term memory can be explained if such memory is expensive to use with respect to the cost of the serializing strategy.