Statistical manipulation and control strategies of the n-back task

Abstract

The impact of task environments on cognitive strategies are well known and have formed the basis of many important findings in cognitive science. However, these effects are often overlooked in research design. The n-back, thought to measure working memory and executive control capacity, is especially prone to misinterpretation because of a lack of standardization in how researchers administer the task. This dissertation chronicles a set of experiments investigating experimental design variation along several dimensions. The results showed that differences in stimulus frequency distributions and the ratio of targets to lures cause variation in performance by stimulating strategic differences. Variations in n-back performance across different populations or different n-back paradigms are often interpreted in terms of resource capacity or strategic views of memory, attention, and cognitive control. Hence, the results of this work highlight the importance of understanding the connection between strategy and the environment when applying cognitive theory to tasks like the n-back.