Neural Mechanisms in Learned Multitasking Improvements

University Of California-San Francisco, San Francisco CA

Investigators

Abstract

The overall aim of this project is to understand how the brain enables learned improvements in multitasking ability. Multitasking is a complex cognitive process that is prevalent in everyday life, from texting while walking to driving while reading a street sign. It is well established that during multitasking, both tasks are associated with performance declines, as compared to when the tasks are independently performed. Fortunately, through practice and learning, multitasking costs may be reduced. Yet, how the brain enables us to enhance multitasking performance remains elusive. This project investigates these questions by studying whether training can improve multitasking performance, as well as the changes in brain responses that accompany such improvement. It will also use interventions that impact brain activity and that may themselves produce multitasking improvement. The importance of the current project is in advancing the limited scientific knowledge in this domain, and in enabling multiple activities and outcomes that will be relevant to society more broadly. Apart from the scientific work, this project will offer several volunteer opportunities for high school and college students. For all these positions, women, persons with disabilities and minorities in STEM education will be highly encouraged to apply. Second, the knowledge generated by this research will be disseminated to the public through open-source publications, public lectures, and media outlets. These findings will enhance our understanding of multitasking ability, and developing therapeutics to target populations who suffer from this cognitive decline or learning disorders. The overall aim of this project is to address the hypothesis that regions within prefrontal cortex rely on theta band (4-7 Hz) oscillations to enhance and optimize multitasking ability. To achieve this, transcranial alternating current stimulation (tACS) will be applied in the theta band above prefrontal cortex while participants are engaged in multitasking: visual discrimination with a concurrent visuomotor tracking task. Transcranial stimulation will be applied on three consecutive days while participants are engaged in multitasking. Participants will be assessed one day and one month after tACS to assess whether theta stimulation above the prefrontal cortex facilitates learned improvements in multitasking. Additionally, electroencephalography (EEG) data will be used to assess changes in oscillatory activity that supports learned multitasking improvements. It is hypothesized that tACS stimulations that impact theta oscillations will be particularly effective in improving multitasking performance, potentially impacting frontal theta EEG oscillatory power. To evaluate whether these learned multitasking improvements arise from alterations within the prefrontal cortex, magnetic resonance imaging (MRI) data will be collected from each participant and used to form individualized models of the tACS-induced electric fields in the brain. It is hypothesized that due to anatomical differences that impede tACS current flow to the brain, participants with greater modeled electric fields in the medial prefrontal cortex will exhibit the greatest increases in prefrontal theta oscillations and the largest improvements in multitasking ability. The proposed research will provide a direct assessment of mechanisms by which brain networks give rise to learned improvements in multitasking ability. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.