Takeuchi Hikaru, Taki Yasuyuki, Sassa Yuko, Sekiguchi Atsushi, Nagase Tomomi, Nouchi Rui, Fukushima Ai, Kawashima Ryuta
Smart Ageing International Research Center, Institute of Development, Aging and Cancer, Tohoku University Sendai, Japan.
Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University Sendai, Japan.
Front Hum Neurosci. 2015 Dec 21;9:681. doi: 10.3389/fnhum.2015.00681. eCollection 2015.
In intervention studies of cognitive training, the challenging cognitive tests, which were used as outcome measures, are generally completed in more than a few hours. Here, utilizing the control groups' data from three 1-week intervention studies in which young healthy adult subjects underwent a wide range of cognitive tests and T1-weighted magnetic resonance imaging (MRI) before and after the intervention period, we investigated how regional gray matter (GM) density (rGMD) of the subjects changed through voxel-based morphometry (VBM). Statistically significant increases in rGMD were observed in the anatomical cluster that mainly spread around the bilateral dorsal anterior cingulate cortex (dACC) and the right superior frontal gyrus (rSFG). Moreover, mean rGMD within this cluster changes were significantly and positively correlated with performance changes in the Stroop task, and tended to positively correlate with performance changes in a divergent thinking task. Affected regions are considered to be associated with performance monitoring (dACC) and manipulation of the maintained information including generating associations (rSFG), and both are relevant to the cognitive functions measured in the cognitive tests. Thus, the results suggest that even in the groups of the typical "control group" in intervention studies including those of the passive one, experimental or non-experimental factors can result in an increase in the regional GM structure and form the association between such neural changes and improvements related to these cognitive tests. These results suggest caution toward the experimental study designs without control groups.
在认知训练的干预研究中，用作结果指标的具有挑战性的认知测试通常需要几个多小时才能完成。在此，我们利用三项为期1周的干预研究中对照组的数据，这些研究中年轻健康的成年受试者在干预期前后接受了广泛的认知测试和T1加权磁共振成像（MRI），我们通过基于体素的形态学测量（VBM）研究了受试者的区域灰质（GM）密度（rGMD）如何变化。在主要分布于双侧背侧前扣带回皮质（dACC）和右侧额上回（rSFG）周围的解剖学簇中观察到rGMD有统计学意义的增加。此外，该簇内的平均rGMD变化与Stroop任务中的表现变化显著正相关，并且与发散思维任务中的表现变化呈正相关趋势。受影响的区域被认为与表现监测（dACC）以及对包括产生联想在内的所保持信息的处理（rSFG）有关，并且两者都与认知测试中测量的认知功能相关。因此，结果表明，即使在干预研究中典型的“对照组”群体中，包括被动对照组，实验或非实验因素都可能导致区域GM结构增加，并形成这种神经变化与这些认知测试相关改善之间的关联。这些结果表明在没有对照组的实验研究设计中要谨慎。
