Efficient multitasking: parallel versus serial processing of multiple tasks.

Rico Fischer,Franziska Plessow

doi:10.3389/fpsyg.2015.01366

Abstract

In the context of performance optimizations in multitasking, a central debate has unfolded in multitasking research around whether cognitive processes related to different tasks proceed only sequentially (one at a time), or can operate in parallel (simultaneously). This review features a discussion of theoretical considerations and empirical evidence regarding parallel versus serial task processing in multitasking. In addition, we highlight how methodological differences and theoretical conceptions determine the extent to which parallel processing in multitasking can be detected, to guide their employment in future research. Parallel and serial processing of multiple tasks are not mutually exclusive. Therefore, questions focusing exclusively on either task-processing mode are too simplified. We review empirical evidence and demonstrate that shifting between more parallel and more serial task processing critically depends on the conditions under which multiple tasks are performed. We conclude that efficient multitasking is reflected by the ability of individuals to adjust multitasking performance to environmental demands by flexibly shifting between different processing strategies of multiple task-component scheduling.

Highlights

A central aim in cognitive psychology and cognitive neuroscience research on multitasking is to understand and optimize the underlying processes in order to increase efficiency when dealing with multiple tasks at the same time
Starting from the question of what constitutes adaptive multitasking performance, we reviewed empirical evidence for two processing modes in multitasking that are not mutually exclusive, i.e., serial versus parallel task-component processing
Demonstrating that parallel task processing is possible when performing more than one task at a time has challenged the view that the frequently observed multitasking costs represent an inevitable consequence of a structural capacity limitation

Summary

Introduction

A central aim in cognitive psychology and cognitive neuroscience research on multitasking is to understand and optimize the underlying processes in order to increase efficiency when dealing with multiple tasks at the same time. Most researchers explain typical performance decrements in multitasking with a structural capacity limitation, a so-called processing bottleneck (e.g., Pashler, 1998), at which certain cognitive processes proceed serially (i.e., one at a time only). Such a conceptualization of multitasking excludes the possibility of parallel (i.e., simultaneous) cognitive processing of multiple. Others argue that parallel processing is generally possible (e.g., by means of capacity sharing, Tombu and Jolicoeur, 2003), but that serial processing reflects the more efficient and primarily pursued multitasking strategy (e.g., Logan and Gordon, 2001; Miller et al, 2009). To provide a more complete picture on the debate of parallel versus serial processing, we will discuss under which circumstances adopting a more parallel processing strategy represents the favorable multitasking solution

Capabilities and Limitations of the Cognitive System for Multitasking

Findings

Conclusion