How multitasking can improve judgments

Research has revealed that multitasking impedes performance across a variety of tasks. Emergency room nurses that are interrupted multiple times while treating a patient can be more likely to make medication errors. Driving while speaking on a mobile phone significantly increases the probability of an automobile accident. At the same time, however, experienced golfers putt better when distracted than experienced golfers who are focusing on performance. Distractions resulting from the presence of other people can increase an individual's performance, too. Why?

Addressing the Contradictions

In a forthcoming issue of Psychological Science, one of the world's top-ranked empirical journals in psychology, a team of researchers from the University of Basel helps to clarify these apparent contradictions. Lead author Janina Hoffmann, a Ph.D. student in Economic Psychology, and her co-authors Dr. Bettina von Helversen and Prof. Dr. Jörg Rieskamp, find that the type of judgment strategy that an individual employs strongly conditions how the "cognitive load" induced by multitasking affects performance. Higher cognitive load can actually improve performance when the task can be best completed using a less demanding, similarity-based strategy that informs judgments by retrieving past instances from memory.

The study is supported by the findings of two experiments conducted at the University of Basel. The first study exposed 90 participants to variable cognitive loads as they were asked to solve a judgment task whose solution was best achieved through the use of a similarity-based strategy (predicting how many cartoon characters another cartoon character could catch). Most participants switched to using a similarity-based strategy and produced more accurate judgments. The second study then exposed 60 participants to a linear task whose solution was not conducive to similarity-based strategies but rather rule- based strategies. Those participants who employed a similarity-based strategy made poorer judgments. The experiments were conducted with financial support from the Swiss National Science Foundation.

Moving Forward

Cognitive load does not per se lead to worse performance, but rather it can, dependent on strategy choice, lead to better performance. The researchers believe that it is important to decipher cognitive strategies that people choose under given levels of cognitive load. Hoffmann claims, "A better understanding of these cognitive strategies may permit future studies to predict the precise circumstances under which people can solve a problem particularly well."