Disturbance of Information in Superior Parietal Lobe during Dual-task Interference in a Simulated Driving Task

Performing a secondary task while driving causes a decline in driving performance. This phenomenon, called dual-task interference, can have lethal consequences. Previous fMRI studies have looked at the changes in the average brain activity to uncover the neural correlates of dual-task interference. From these results, it is unclear whether the overall modulations in brain activity result from general effects such as task difficulty, attentional modulations, and mental effort or whether it is caused by a change in the responses specific to each condition due to dual-task interference. To overcome this limitation, here, we used multi-voxel pattern analysis (MVPA) to interrogate the change in the information content in multiple brain regions during dual-task interference in simulated driving. Participants performed a lane change task in a simulated driving environment, along with a tone discrimination task with either short or long-time onset difference (Stimulus Onset Asynchrony, SOA) between the two tasks. Behavioral results indicated a robust dual-task effect on driving RT. MVPA revealed regions that carry information about the driving direction, including the superior parietal lobe (SPL), visual, and motor regions. Comparing the decoding accuracies across short and long SOA conditions, we showed lower accuracies in the SPL region in short than long SPA conditions. This change in accuracy was not observed in the visual and motor regions. In addition, the classification accuracy in the SPL was inversely correlated with participants reaction time in the driving task. These findings suggest that the dual-task interference in driving may be related to the disturbance of information processing in the SPL region. Significance StatementDuring real-world driving, when a driver wants to make a turn at an intersection and simultaneously respond to a cell phone call, his reaction time slows down. This effect is called dual-task interference. Here, we aimed to examine its neural mechanisms using a paradigm that consisted of a driving turn task and a tone discrimination task in a simulated environment. Results showed that the information for the driving turn was disturbed in the superior parietal lobe (SPL) during dual-task interference. We suggest that the driving performance decline in the presence of the secondary task might be related to the disturbance of information in the SPL.