Structural Brain Changes after Traditional and Robot-Assisted Multi-Domain Cognitive Training in Community-Dwelling Healthy Elderly

<div><p>The purpose of this study was to investigate if multi-domain cognitive training, especially robot-assisted training, alters cortical thickness in the brains of elderly participants. A controlled trial was conducted with 85 volunteers without cognitive impairment who were 60 years old or older. Participants were first randomized into two groups. One group consisted of 48 participants who would receive cognitive training and 37 who would not receive training. The cognitive training group was randomly divided into two groups, 24 who received traditional cognitive training and 24 who received robot-assisted cognitive training. The training for both groups consisted of daily 90-min-session, five days a week for a total of 12 weeks. The primary outcome was the changes in cortical thickness. When compared to the control group, both groups who underwent cognitive training demonstrated attenuation of age related cortical thinning in the frontotemporal association cortices. When the robot and the traditional interventions were directly compared, the robot group showed less cortical thinning in the anterior cingulate cortices. Our results suggest that cognitive training can mitigate age-associated structural brain changes in the elderly.</p><p>Trial Registration</p><p>ClnicalTrials.gov <a href="https://clinicaltrial.gov/ct2/show/NCT01596205?term=NCT01596205&rank=1" target="_blank">NCT01596205</a></p></div

Correlation of changes in cognitive functions and changes in cortical thickness.

<p>(A) In the traditional group, changes in the raw scores of visual memory are positively correlated with those of cortical thickness in the right inferior temporalgyrus and right subgenual cingulate region (uncorrected <i>P</i> < 0.001). (B) For the robot group, changes in the raw scores of executive function are positively correlated with those of left temoporo-parietal junction as well as left inferior temporal gyrus (uncorrected P <0.001).</p

Flow of participants in this study.

<p>The similarity index was defined as follows:similarity index = 2 * nnz(A and B)/(nnz(A) + nnz(B)) where A and B are the baseline and post-intervention connectivity from binary matrices, respectively and nnz refers to the number of non-zero elements in a matrix. If the two binary matrices were the same, the similarity index was assigned a value of 1. We excluded subjects with a similarity index lower than 0.5 in our statistical analyses to reduce the artifactual effects related to the different times of scanning.</p

Comparisons of traditional and robot intervention.

<p>Comparisons of traditional and robot intervention.</p

Topographical changes in cortical thickness.

<p>(A) Compared to the control group, the intervention group shows attenuated cortical thinning on heteromodal association cortices such as the bilateral medial prefrontal and right middle temporal gyrus. (B) When the traditional and robot groups were directly compared, significantly reduced cortical thinning on the bilateral anterior cingulate cortices and right inferior temporal cortex was evident in the robot group. No area demonstrated less cortical thinning in the traditional group than the robot group.</p

Topographical changes in nodal strength.

<p>(A) There are no significant differences in regional nodal strength between the control and the intervention group. (B)The robot group shows increased nodal strength in the rectus gyrus than the traditional group.</p