We continuously process sensory and cognitive events while engaged in everyday activities such as walking. For example, we successfully navigate the aisles of a shopping center as we rehearse a shopping list and contemplate the necessary ingredients for that evening's dinner. Brain processes have evolved to handle concurrent processing of sensory, cognitive, and motor functions. However, research using dual-task designs to test multitask performance has provided clear evidence for costs associated with performing two or more tasks at the same time. This is particularly true for individuals with multiple sclerosis (MS), a brain disorder characterized by impairments in gait and cognition. Hence, walking while simultaneously performing cognitively demanding tasks such as talking or texting is particularly challenging for individuals with MS. Studies have found greater slowing of walking speed while reciting alternate letters of the alphabet compared to healthy individuals. Such findings indicate MS-specific limitations in the allocation of attentional resources across multiple tasks.

Little is known about brain functions underlying our ability to divide attention across two or more tasks during such mobile actions, largely due to difficulties to observe brain processes during walking. For example, imaging technology such as functional magnetic resonance imaging requires participants to rather artificially sit motionless or lie prone, hardly a naturalistic approach. Our goal is to address this knowledge gap, using a newly developed Mobile Brain-Body Imaging (MOBI) system that integrates electroencephalographic (EEG) brain activity recordings with simultaneously acquired foot-force sensor data and 3D infrared camera images to monitor brain activity, gait pattern, and body posture while participants walk on a treadmill. We will test the hypothesis that mobility issues in MS are associated with a specific deficit in the flexible reallocation of attentional resources across sensory, cognitive, and motor processes during walking.

The successful completion of this research represents a first step in addressing a little understood question about the cortical contribution to mobility issues in MS. Advancing our understanding in this area might lead to the discovery of objective brain measures to enhance diagnostic and therapeutic assessments of MS. The ultimate goal of this research effort will be to help improve mobility and quality of life in MS patients.