Villa-Sánchez Bernardo, Hooyman Andrew, Schaefer Sydney Y
School of Biological and Health Systems Engineering, Arizona State University, 501 E. Tyler Mall, 85287, Tempe, AZ, USA.
Department of Physical Therapy, Chapman University, Irvine, CA, USA.
Exp Brain Res. 2025 May 29;243(7):157. doi: 10.1007/s00221-025-07110-y.
Transcranial direct current stimulation (tDCS) has shown mixed results in cognitive and motor functions, raising questions about its efficacy and/or the potential influence of psychological factors. Expectations about treatment efficacy (a placebo-like mechanism) might explain this mixed tDCS success. Recent research has begun to examine the expectations of tDCS on performance. However, it is unclear how malleable individual tDCS expectations are within the motor domain. This study investigated how informational priming influences participants' expectations of tDCS on motor function and whether prior tDCS knowledge influences this effect. One hundred ninety-eight participants were recruited and assigned into high or low expectation priming groups. A modified expectation assessment scale, which measured expected tDCS-related motor performance, was administered before and after receiving information about tDCS efficacy. The high-expectation priming group was exposed to evidence of such efficacy, while the low-expectation priming group received information emphasizing the lack of evidence of tDCS efficacy. Expectations of tDCS efficacy for all motor domains significantly increased in the high-expectation priming group and decreased in the low-expectation priming group. Furthermore, after priming, the high-expectation priming group had significantly higher expectations than the low-expectation priming group. Interestingly, participants in the high-expectation priming group with prior knowledge of tDCS showed no change in expectations. Notably, these findings demonstrate that expectations about tDCS's efficacy on motor performance are malleable depending on the information type and prior tDCS knowledge. Future studies are encouraged to control or assess participants' expectations of tDCS to optimize its effect on motor outcomes.
经颅直流电刺激（tDCS）在认知和运动功能方面的结果参差不齐，这引发了人们对其疗效和/或心理因素潜在影响的质疑。对治疗效果的期望（一种类似安慰剂的机制）可能解释了tDCS这种参差不齐的成功。最近的研究已开始考察tDCS对表现的期望。然而，在运动领域内个体对tDCS的期望有多容易改变尚不清楚。本研究调查了信息启动如何影响参与者对tDCS对运动功能的期望，以及先前的tDCS知识是否会影响这种效应。招募了198名参与者并将其分为高期望启动组或低期望启动组。在接收有关tDCS疗效的信息之前和之后，使用一种经过修改的期望评估量表，该量表测量与tDCS相关的预期运动表现。高期望启动组接触到这种疗效的证据，而低期望启动组收到强调缺乏tDCS疗效证据的信息。高期望启动组中所有运动领域对tDCS疗效的期望显著增加，而低期望启动组则下降。此外，启动后，高期望启动组的期望显著高于低期望启动组。有趣的是，有tDCS先验知识的高期望启动组参与者的期望没有变化。值得注意的是，这些发现表明，对tDCS对运动表现疗效的期望会根据信息类型和先前的tDCS知识而改变。鼓励未来的研究控制或评估参与者对tDCS的期望，以优化其对运动结果的影响。
