In a discussion about previous research, scientists affirmed the complex nature of the relationship between a person's overall thinking ability, the physical structure of their brain, and their performance on "dual-task" activities. A dual-task activity involves walking while simultaneously performing a mental task, such as counting backwards. The decline in performance on either walking or the mental task during this activity is known as the dual-task cost (DTC).
The researchers acknowledged that a person's cognitive, or thinking, performance could be an early step in a chain of events that affects walking ability. They also noted that walking performance itself can serve as an indirect measure, or a "proxy," for a person's cognitive health.
To better understand these connections, future research will examine a specific brain network called the cingulo-opercular network, which is involved in attention and focus. This will be done using targeted cognitive tests and a brain scanning method known as resting-state functional Magnetic Resonance Imaging (fMRI). This type of scan measures brain activity and connectivity while a person is at rest.
The researchers also recognized the limitations of a technique they previously used, called single-voxel magnetic resonance spectroscopy (MRS). MRS is a method that measures the chemical makeup of brain tissue. The previous work used a "single-voxel" approach, which means it analyzed the chemistry in only one small, specific spot in the brain—the primary motor cortex, the area that controls voluntary movement.
It was agreed that other brain regions are more suitable for studying the early brain changes associated with neurodegenerative diseases. These regions are the anterior cingulate cortex (ACC) and the posterior cingulate cortex (PCC), which are involved in higher-level thinking and memory. Future studies will use more advanced methods, including multi-voxel spectroscopy, to measure the chemistry in these specific areas. Additionally, another imaging technique called diffusion imaging will be used to look at the brain's white matter tracts, which are the communication pathways or "wiring" that connect different brain regions.
To improve the precision of their experiments, the researchers plan to directly measure a person's cognitive performance while they are walking. This will be accomplished by using integrated digital voice capture to record their answers to mental tasks and eye-tracking technology to monitor their visual attention. They also intend to use "adaptive" dual-task tests, where the difficulty of the mental task changes based on the person's performance.
Finally, the researchers supported the need to address the variations that exist among people diagnosed with Mild Cognitive Impairment (MCI). MCI is a condition with memory and thinking problems that are more severe than normal age-related changes but not serious enough to be defined as dementia. Because MCI affects people differently, future studies will group participants based on their specific subtype of MCI. The research will also include systemic biomarkers, which are substances measured in the body (such as in the blood) that can provide additional information about an individual's health status.
