Older adults exhibit greater brain activity than young adults in a selective inhibition task by bipedal and bimanual responses: an fNIRS study

Inhibitory deficits are one of the predominant causes of cognitive aging. This study examined age-related changes in response inhibition. In this study, young and older participants performed a bimanual/bipedal response inhibition task while we measured their brain activity via functional near-infrared spectroscopy. Participants performed most trials bimanually (bipedally). However, they had to occasionally cancel both responses [Stop/Stop (SS) trials] or the response of one hand/foot while responding with the other [Go/Stop (GS) trials]. The participants produced more errors in the selective (GS) than in the nonselective canceling trials (SS), and in by-foot response more than in by-hand response trials, irrespective of their age. However, older participants made more errors in the selective cancelation (GS) trials and by-foot responses than young participants did. Older participants showed more frontal brain activity than young participants. The GS trials triggered more activity in the frontal brain areas than the SS trials irrespective of age at many channels, while older participants recruited more brain activation in the GS trials than in the SS trials compared to young participants. Overall, older participants exhibited higher activity in the right, middle, and inferior frontal gyrus than did young participants when performing selective and nonselective inhibition response. These results suggest that neural activation of the core inhibition network declines with age and that compensational recruitment of additional networks is used to yield an expanded inhibition circuit.