Cognitive training-induced short-term functional and long-term structural plastic change is related to gains in global cognition in healthy older adults: a pilot study

Abstract

Computerized cognitive training (CCT) is a safe and inexpensive intervention to enhance cognitive performance in the elderly. However, the neural underpinning of CCT-induced effects and the timecourse by which such neural changes occur are unknown. Here, we report on results from a pilot study of healthy older adults who underwent three 1-h weekly sessions of either multidomain CCT program (n = 7) or an active control intervention (n = 5) over 12 weeks. Multimodal magnetic resonance imaging (MRI) scans and cognitive assessments were performed at baseline and after 9 and 36 h of training. Voxel-based structural analysis revealed a significant Group × Time interaction in the right post-central gyrus indicating increased gray matter density in the CCT group compared to active control at both follow-ups. Across the entire sample, there were significant positive correlations between changes in the post-central gyrus and change in global cognition after 36 h of training. A post-hoc vertex-based analysis found a significant between-group difference in rate of thickness change between baseline and post-training in the left fusiform gyrus, as well as a large cluster in the right parietal lobe covering the supramarginal and post-central gyri. Resting-state functional connectivity between the posterior cingulate and the superior frontal gyrus, and between the right hippocampus and the superior temporal gyrus significantly differed between the two groups after 9 h of training and correlated with cognitive change post-training. No significant interactions were found for any of the spectroscopy and diffusion tensor imaging data. Though preliminary, our results suggest that functional change may precede structural and cognitive change, and that about one-half of the structural change occurs within the first 9 h of training. Future studies are required to determine the role of these brain changes in the mechanisms underlying CCT-induced cognitive effects.

Keywords: cognitive training; healthy older adults; hippocampus; magnetic resonance imaging; post-central gyrus; posterior cingulate.

Figure 1

Baseline whole-brain functional connectivity map for the posterior cingulate seed across the whole sample (p = 0.001, cluster size threshold >130) on a standardized single T1 template. Hot areas represent voxels positively correlated with the seed and cool areas negative correlations.

Figure 2

Baseline whole-brain functional connectivity map for the right hippocampus seed across the whole sample (p = 0.001, cluster size threshold >130) on a standardized single T1 template. Hot areas represent voxels positively correlated with the seed and cool areas negative correlations.

Figure 3

Study design and participant flow.

Figure 4

VBM changes in the post-central gyrus at FU1 and 2 (+3 weeks and 3 months, respectively, left) and correlations between post-central gyrus change in FU2 and change in raw global cognition score at FU1 (red) and 2 (blue, right).

Figure 5

Vertex-based analysis of the left inferior temporal gyrus.

Figure 6

Vertex-based analysis of the right supramarginal and post-cental gyri.

Figure 7

FC changes between the posterior cingulate and superior frontal gyrus at FU1 (+3 weeks) and correlations with raw global cognition score change at the same timepoint (+3 weeks, red) and at a delayed timepoint (+3 months, blue).

Figure 8

FC changes between the right hippocampus and superior temporal gyrus at FU1 (+3 weeks) and correlations with raw global cognition score change at the same timepoint (+3 weeks, red) and at a delayed timepoint (+3 months, blue).