Magalhães Thamires N C, Maldonado Ted, Jackson T Bryan, Hicks Tracey H, Herrejon Ivan A, Rezende Thiago J R, Symm Abigail C, Bernard Jessica A
Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX, 77840, United States of America.
Department of Psychology, Indiana State University, Terre Haute, USA.
Brain Imaging Behav. 2025 Apr;19(2):384-394. doi: 10.1007/s11682-025-00975-1. Epub 2025 Feb 4.
Here, we explore the relationship between transcranial direct current stimulation (tDCS) and brain-behavior interactions. We propose that tDCS perturbation allows for the investigation of relationships between brain volume and behavior. We focused on the hippocampus (HPC) and cerebellum (CB) regions that are implicated in our understanding of memory and motor skill acquisition. Seventy-four young adults (mean age: 22 ± 0.42 years, mean education: 14.7 ± 0.25 years) were randomly assigned to receive either anodal, cathodal, or sham stimulation. Following stimulation, participants completed computerized tasks assessing working memory and sequence learning in a magnetic resonance imaging (MRI) environment. We investigated the statistical interaction between CB and HPC volumes. Our findings showed that individuals with larger cerebellar volumes had shorter reaction times (RT) on a high-load working memory task in the sham stimulation group. In contrast, the anodal stimulation group exhibited faster RTs during the low-load working memory condition. These RT differences were associated with the cortical volumetric interaction between CB-HPC. Literature suggests that anodal stimulation down-regulates the CB and here, those with larger volumes perform more quickly, suggesting the potential need for additional cognitive resources to compensate for cerebellar downregulation or perturbation. This new insight suggests that tDCS can aid in revealing structure-function relationships, due to greater performance variability, especially in young adults. It may also reveal new targets of interest in the study of aging or in diseases where there is also greater behavioral variability.
在此，我们探讨经颅直流电刺激（tDCS）与脑-行为相互作用之间的关系。我们提出，tDCS 扰动有助于研究脑容量与行为之间的关系。我们聚焦于海马体（HPC）和小脑（CB）区域，这些区域与我们对记忆和运动技能习得的理解有关。74 名年轻成年人（平均年龄：22±0.42 岁，平均受教育年限：14.7±0.25 年）被随机分配接受阳极、阴极或假刺激。刺激后，参与者在磁共振成像（MRI）环境中完成评估工作记忆和序列学习的计算机化任务。我们研究了 CB 和 HPC 体积之间的统计相互作用。我们的研究结果表明，在假刺激组中，小脑体积较大的个体在高负荷工作记忆任务上的反应时间（RT）较短。相比之下，阳极刺激组在低负荷工作记忆条件下表现出更快的反应时间。这些反应时间差异与 CB-HPC 之间的皮质体积相互作用有关。文献表明，阳极刺激会下调 CB，在此，体积较大的个体表现得更快，这表明可能需要额外的认知资源来补偿小脑下调或扰动。这一新见解表明，由于表现出更大的变异性，尤其是在年轻成年人中，tDCS 有助于揭示结构-功能关系。它还可能揭示衰老研究或存在更大行为变异性的疾病研究中的新感兴趣靶点。
