The influence of attention on dual-task performances and cortical excitability

摘要

In the literature researchers have endeavored to try and explain the phenomena of dualtaskudinterference. Dual-task interference refers to the finding that when people performudtwo tasks simultaneously there is often a decrease in performance compared to when theyudperform one task alone (Pashler, 1994). Despite vast amounts of research exploring this,udthere has been no unified consensus about why dual-task interference actually occurs.udThis literature review first explains the methodology termed the dual-task paradigm thatudis common used in research to study these interference effects. Following this theudcognitive explanations for dual-task interference effects, namely the resource model andudbottleneck model are explored. A number of studies are then presented that employedudboth cognitive and motor tasks to examine these effects.udAnother less common explanation presented in the literature termed the cross-talk modeludis then reviewed. Cross-talk according to Navon and Miller (1987) is defined as whenudtwo tasks use separate mechanisms that interfere with each other, rather then share orudcompete for resources. This notion of cross-talk can be interpreted from a neuraludperspective, thus neural cross-talk can be seen as referring to when an area of the cortexudactivated during the performance of one task affects a different area of the cortexudactivated during the performance of a second task resulting in interference. udThis review then explores a number of studies that used electrophysiological techniques,udsuch as transcranial magnetic stimulation and position emission tomography that presentudfindings consistent with the notion of neural cross-talk. Building on this notion of neuraludcross-talk research is then presented that suggests that neural cross-talk may play anudimportant role in behaviour. The final part of this review explores evidence to suggestudthat neural cross-talk is modifiable.udOverall, the literature presented in this review highlights the fact that further research intoudthe cause of dual-task interference is warranted. The evidence also suggests that neuralcrossudtalk may play an important role in this interference; thus neural cross-talk should beudexplored in greater depth in future research examining interference.