Gentilucci Maurizio
Dipartimento di Neuroscienze, Sezione di Fisiologia Umana, Via Volturno 39, 43100 Parma, Italy.
Exp Brain Res. 2003 Nov;153(2):260-5. doi: 10.1007/s00221-003-1600-8. Epub 2003 Aug 20.
Results of kinematic studies on the control of the reaching-grasping motor act (Gentilucci 2003, Exp Brain Res 149:395-400) suggest that grasp is guided by a single motor representation, which codes all the possible types of interactions with the objects. Neuroimaging studies in humans (Chao and Martin 2000, Neuroimage 12:478-484; Grabowski et al. 1998, Neuroimage 7:232-243; Grafton et al. 1997, Neuroimage 6:231-236; Martin et al. 1995, Science 270:102-105) suggest that these representations are coded in the premotor cortex and are automatically activated when naming the object or viewing it without the execution of an overt action. If an object motor representation is accessed by language, naming of object properties related to sensory-motor transformation can automatically influence the object motor representation. This hypothesis was verified by behavioural experiments (Gentilucci and Gangitano 1998, Eur J Neurosci 10:752-756; Gentilucci et al. 2000, Exp Brain Res 133:468-490; Glover and Dixon 2002, Exp Brain Res 146:383-387), which showed that automatic reading (and probably silent naming; MacLeod 1991, Psychol Bull 109:163-203) of adjectives related to object properties analysed for planning the reaching-grasping motor act influenced the control of the arm movement. In a new study it was determined whether the class of a word can be a factor selectively influencing motor control. Participants were required to reach for and grasp an object located either on the right or on the left, and to place it on the opposite side. Either a verb ("place" SPOSTA versus "lift" ALZA) or an adjective ("lateral" LATERALE versus "high" ALTO) was printed on the target. A greater influence of the verbs than of the adjectives was observed on the kinematics of the action. In particular, when the verb ALZA was printed on the object, hand-path height and vertical component of arm velocity were higher than when the adjective ALTO was presented on the object. The data support the hypothesis that the object motor representation is mainly coded in terms of possible interactions with the object.
关于伸手抓握动作控制的运动学研究结果（Gentilucci 2003，《实验脑研究》149:395 - 400）表明，抓握动作由单一运动表征引导，该表征对与物体所有可能的相互作用类型进行编码。对人类的神经影像学研究（Chao和Martin 2000，《神经影像学》12:478 - 484；Grabowski等人1998，《神经影像学》7:232 - 243；Grafton等人1997，《神经影像学》6:231 - 236；Martin等人1995，《科学》270:102 - 105）表明，这些表征在前运动皮层中编码，并且在命名物体或观看物体而不执行明显动作时会自动激活。如果通过语言访问物体运动表征，与感觉运动转换相关的物体属性命名可以自动影响物体运动表征。这一假设已通过行为实验得到验证（Gentilucci和Gangitano 1998，《欧洲神经科学杂志》10:752 - 756；Gentilucci等人2000，《实验脑研究》133:468 - 490；Glover和Dixon 2002，《实验脑研究》146:383 - 387），这些实验表明，对用于规划伸手抓握动作而分析的与物体属性相关的形容词进行自动阅读（可能还有默读；MacLeod 1991，《心理学通报》109:163 - 203）会影响手臂运动的控制。在一项新研究中，确定了单词类别是否可以成为选择性影响运动控制的一个因素。参与者被要求伸手去抓握位于右侧或左侧的一个物体，并将其放置在另一侧。目标上印有一个动词（“放置”SPOSTA与“举起”ALZA）或一个形容词（“横向的”LATERALE与“高的”ALTO）。观察到动词对动作运动学的影响比形容词更大。特别是，当动词ALZA印在物体上时，手部路径高度和手臂速度的垂直分量比物体上呈现形容词ALTO时更高。这些数据支持了物体运动表征主要根据与物体可能的相互作用进行编码的假设。
