Real-World Multitasking from a Cognitive Neuroscience Perspective

This chapter examines the demands made by multitasking situations in the real world, and argues that the human brain systems critical in dealing with them may be surprisingly circumscribed. Four kinds of evidence are considered: single-case studies of patients with selective multitasking problems; group studies of the relationship between multitasking failures and other cognitive control problems; the neuroanatomical locus of multitasking deficits according to group lesion studies, and evidence from functional imaging. These studies suggest three distinct brain systems are involved in supporting the retrospective memory, prospective memory and planning demands of multitasking, and tentative suggestions for the neuroanatomical correlates of these systems are proposed. In a recent television program, the U.S. astronaut Jerry Linenger described his experiences aboard the Mir space station: “We had many system failures and they were in need of your constant attention. Many days I’d start an experiment in the morning and then I’d run over and help hacksaw through a pipe and plug the ends and then run back to my experiments. I’d have three or four watches on with alarms set to different things that I’d have to run back to. So I was multitasking in order to try to get everything accomplished.’’ Although, at first sight, Jerry Linenger’s use of the term multitasking accords well with the Compact Oxford English Dictionary definition: the “ability to perform concurrent tasks or jobs by interleaving,’’ his account suggests something more complex than interleaving tasks in a multipletask sense. The situation he faced also required further mental activities, such as prioritization, planning, and prospective memory (i.e., the realization of a delayed intention; Ellis 1996). The ability to deal with such complex situations is clearly important to effectiveness in everyday life. Neurological patients who have lost this ability are severely handicapped, especially in work situations. However, although the present volume is testament to recent advances in understanding many situations which have some relevance to aspects of multitasking (e.g. dualor multiple-task paradigms, task switching etc), more complex situations akin to those faced by Jerry Linenger have been rarely studied within an experimental psychology or cognitive neuroscience framework. Indeed, the complexity of such situations would seem to 20