Abstract
Retaining information in an active and accessible state over the short-term is critical for any cognitive activity. It has been estimated that immediate visual memory (also known as short-term memory or working memory) can maintain only about four objects simultaneously. However, the basic determinants of this capacity limit remain a matter of debate. For example, whether capacity is reduced as object complexity increases is yet unresolved. On the other hand, many researchers agree that in change detection tasks – which are widely used to investigate capacity limits of immediate memory – similarity between the memory and the test items (memory-test similarity) negatively affects change detection performance. In contrast, similarity between memory items (memory-array similarity) has been shown recently to benefit performance, at least for simple objects. In the present study, similarity continua were used to manipulate memory-test and memory-array similarity for both simple and complex objects, in order to thoroughly examine the impact of complexity and memory-array similarity on the retention of information in memory. Results show that the number of memory representations is fixed across object complexity, but that their resolution (or precision) decreases as complexity increases. In contrast, memory-array similarity increases mnemonic resolution, an increase that even compensates for the deleterious effect of complexity.
Natural Sciences and Engineering Research Council of Canada (NSERC).