Increased Brain Activation for Dual Tasking with 70-Days Head-Down Bed Rest

Peng Yuan; Vincent Koppelmans; Patricia A Reuter-Lorenz; Yiri E De Dios; Nichole E Gadd; Scott J Wood; Roy Riascos; Igor S Kofman; Jacob J Bloomberg; Ajitkumar P Mulavara; Rachael D Seidler

doi:10.3389/fnsys.2016.00071

Increased Brain Activation for Dual Tasking with 70-Days Head-Down Bed Rest

Front Syst Neurosci. 2016 Aug 23:10:71. doi: 10.3389/fnsys.2016.00071. eCollection 2016.

Authors

Affiliations

¹ School of Kinesiology, University of Michigan Ann Arbor, MI, USA.
² Department of Psychology, University of Michigan Ann Arbor, MI, USA.
³ Wyle Science, Technology and Engineering Group Houston, TX, USA.
⁴ Department of Psychology, Azusa Pacific University Azusa, CA, USA.
⁵ The University of Texas Health Science Center Houston, TX, USA.
⁶ NASA Johnson Space Center Houston, TX, USA.
⁷ NASA Johnson Space CenterHouston, TX, USA; Universities Space Research AssociationHouston, TX, USA.
⁸ School of Kinesiology, University of MichiganAnn Arbor, MI, USA; Department of Psychology, University of MichiganAnn Arbor, MI, USA; Neuroscience Program, Medical School, University of MichiganAnn Arbor, MI, USA.

Abstract

Head-down tilt bed rest (HDBR) has been used as a spaceflight analog to simulate the effects of microgravity exposure on human physiology, sensorimotor function, and cognition on Earth. Previous studies have reported that concurrent performance of motor and cognitive tasks can be impaired during space missions. Understanding the consequences of HDBR for neural control of dual tasking may possibly provide insight into neural efficiency during spaceflight. In the current study, we evaluated how dual task performance and the underlying brain activation changed as a function of HDBR. Eighteen healthy men participated in this study. They remained continuously in the 6° head-down tilt position for 70 days. Functional MRI for bimanual finger tapping was acquired during both single task and dual task conditions, and repeated at 7 time points pre-, during- and post-HDBR. Another 12 healthy males participated as controls who did not undergo HDBR. A widely distributed network involving the frontal, parietal, cingulate, temporal, and occipital cortices exhibited increased activation for dual tasking and increased activation differences between dual and single task conditions during HDBR relative to pre- or post-HDBR. This HDBR-related brain activation increase for dual tasking implies that more neurocognitive control is needed for dual task execution during HDBR compared to pre- and post-HDBR. We observed a positive correlation between pre-to-post HDBR changes in dual-task cost of reaction time and pre-to-post HDBR change in dual-task cost of brain activation in several cerebral and cerebellar regions. These findings could be predictive of changes in dual task processing during spaceflight.

Keywords: brain activity; dual task; fMRI; head-down bed rest; microgravity analog.