The neural substrates of enhanced response Inhibition induced by attentional capture in older adults with a higher moderate-to-vigorous physical activity: a VBM and resting-state functional connectivity study.

Older adults with higher MVPA exhibited superior behavioral performance in both inhibitory and attentional control compared to those with lower MVPA.

• Participants aged 60-79 years were categorized into a higher physical activity group (HG) and a lower physical activity group (LG) using ActiGraph GT3X+ accelerometers.
• Participants completed three novel versions of the stop-signal task (SST) designed to assess component processes of response inhibition.
• The HG showed superior performance in inhibitory control and attentional control tasks compared to the LG.
• The positive relationship between MVPA and response inhibition was associated with effective attentional resource allocation for faster attentional capture.

Grey matter volume (GMV) differed between the HG and LG in the right inferior frontal gyrus (rIFG) and the left superior frontal gyrus (lSFG).

• Voxel-based morphometry (VBM) analysis was used to assess structural brain differences between the two groups.
• The rIFG and lSFG were identified as regions where GMV differed significantly between HG and LG.
• These frontal subregions are implicated in different cognitive processes involved in response inhibition.
• The benefit from rIFG enhancement may be realized through optimizing attentional capture.

Resting-state functional connectivity (rsFC) was greater in the HG than the LG when using the rIFG, lSFG, or right pre-supplementary motor area (rpre-SMA) as seed regions.

• Resting-state functional MRI was collected in addition to structural MRI.
• Seed-based rsFC analyses were conducted using rIFG, lSFG, and rpre-SMA as seed regions.
• The HG demonstrated greater rsFC than the LG for all three seed regions.
• The rpre-SMA was included as a seed region despite not showing a significant GMV difference between groups.

GMV and rsFC jointly accounted for group differences in response inhibition and attentional control induced by MVPA.

• Partial correlation analyses were conducted to examine the relationship between neural measures (GMV and rsFC) and behavioral performance.
• Both structural (GMV) and functional (rsFC) brain measures contributed to explaining MVPA-related group differences in cognitive performance.
• Distinct frontal subregions participated in different cognitive processes: response inhibition and attentional control were associated with different neural substrates.
• The rIFG was specifically implicated in attentional capture processes within the response inhibition task.

Response inhibition is more sensitive to aging than other forms of inhibitory control, and MVPA can promote response inhibition and age-related brain structure and function in the frontal cortex.

• Existing work primarily focuses on the direct influence of MVPA on response inhibition without examining component task processes.
• The study specifically examined how MVPA affects the component task processes involved in response inhibition, not just the overall function.
• Frontal cortex structure and function were the primary neural targets of interest given their relevance to aging and inhibitory control.
• The stop-signal task was used in three novel versions to dissociate component processes of response inhibition.