Blinch Jarrod, Gooch Catherine E, Clark Allison R, Murrin Bryce, Bayouth Kathryn
Department of Kinesiology & Sport Management, Texas Tech University, Box 43011, Lubbock, TX, 79409, USA.
Exp Brain Res. 2025 Feb 5;243(3):58. doi: 10.1007/s00221-025-07010-1.
The movement preparation of bimanual asymmetric reaching movements is longer than bimanual symmetric movements. This bimanual asymmetric cost is small for spatially cued movements and large with symbolic cues. Previous research on these bimanual asymmetric costs has relied on mean reaction time. The goal of the present study was to better understand the sensorimotor mechanisms of spatially and symbolically cued bimanual asymmetric costs by employing reaction time distribution analysis. Reaction time distributions were described with the ex-Gaussian parameters of [Formula: see text], [Formula: see text], and [Formula: see text]. Forty-eight young adults made bimanual symmetric and asymmetric reaching movements that were spatially or symbolically cued. With spatial cues, there was a small cost to [Formula: see text] for bimanual asymmetric movements compared to symmetric ones. This was depicted as a 4.8 ms rightward shift to the reaction time distribution. The bimanual asymmetric cost with spatial cues is likely caused by the temporal coupling of bimanual asymmetric movements. With symbolic cues, there was a large cost to [Formula: see text] and small costs to [Formula: see text] and [Formula: see text]. This was depicted as the Gaussian and exponential components of the distribution having longer and more disperse reaction time for asymmetric movements. The bimanual asymmetric cost with symbolic cues is likely caused by two factors: stimulus-response translation of two different symbolic cues and temporal coupling of bimanual asymmetric movements. The bimanual asymmetric cost to µ with symbolic cues is likely a combination of both factors, with stimulus-response translation contributing more than temporal coupling. The bimanual asymmetric costs to σ and τ are exclusively caused by stimulus-response translation.
双手不对称够物动作的运动准备时间比双手对称动作更长。对于空间线索提示的动作，这种双手不对称成本较小；而对于符号线索提示的动作，该成本则较大。以往关于这些双手不对称成本的研究依赖于平均反应时间。本研究的目的是通过采用反应时间分布分析，更好地理解空间线索和符号线索提示的双手不对称成本的感觉运动机制。反应时间分布用[公式：见正文]、[公式：见正文]和[公式：见正文]的前高斯参数来描述。48名年轻成年人进行了空间线索或符号线索提示的双手对称和不对称够物动作。在空间线索提示下，与对称动作相比，双手不对称动作的[公式：见正文]成本较小。这表现为反应时间分布向右偏移4.8毫秒。空间线索提示下的双手不对称成本可能是由双手不对称动作的时间耦合引起的。在符号线索提示下，[公式：见正文]成本较大，而[公式：见正文]和[公式：见正文]成本较小。这表现为不对称动作的分布的高斯和指数成分具有更长、更分散的反应时间。符号线索提示下的双手不对称成本可能由两个因素引起：两种不同符号线索的刺激-反应转换以及双手不对称动作的时间耦合。符号线索提示下对µ的双手不对称成本可能是这两个因素的综合结果，其中刺激-反应转换的贡献大于时间耦合。对σ和τ的双手不对称成本完全由刺激-反应转换引起。
