Tomasino Barbara, Werner Cornelius J, Weiss Peter H, Fink Gereon R
Institute of Neuroscience and Biophysics, Department of Medicine, Research Centre Juelich, Juelich, Germany.
Neuroimage. 2007;36 Suppl 2:T128-41. doi: 10.1016/j.neuroimage.2007.03.035. Epub 2007 Mar 31.
The role of the primary motor cortex (M1) in tasks involving action words remains controversial. Therefore, we investigated whether the previously reported involvement of M1 in processing of action words results from the semantic representation of action words per se, or if M1 activation may actually depend on whether or not subjects (explicitly or automatically) adopt a strategy of simulating the movements. Subjects silently read short phrases describing a situation which either involved a motor scene or not (STIMULUS: motor, non-motor phrases) and performed a secondary task: either they were explicitly asked to imagine the situation or they performed letter detection preventing them from using a simulation strategy (TASK: imagery vs. letter detection). In addition, phrases were presented both in 1st and 3rd person singular (
1st vs. 3rd person). This allowed us to investigate the influence of the secondary tasks (letter detection versus explicit motor imagery) on the neural activity in M1 during the processing of motor and non-motor phrases. We found differential left M1 activity in the task by stimulus interaction with enhanced M1 activation for imagery in the presence of motor phrases (vs. non-motor phrases) compared to letter detection of motor vs. non-motor phrases. This M1-activity was not differentially modulated by perspective. Therefore, M1 activation previously found in experiments of silent reading of action words may have resulted from the subjects' strategy to mentally simulate the movements during the processing of action words.
初级运动皮层（M1）在涉及动作词的任务中的作用仍存在争议。因此，我们研究了先前报道的M1参与动作词加工是源于动作词本身的语义表征，还是M1激活实际上可能取决于受试者（明确地或自动地）是否采用模拟动作的策略。受试者默读描述涉及或不涉及运动场景的情境的短语句（刺激：运动、非运动短语），并执行一项次要任务：要么明确要求他们想象情境，要么执行字母检测任务以阻止他们使用模拟策略（任务：想象与字母检测）。此外，短语以第一人称单数和第三人称单数呈现（视角：第一人称与第三人称）。这使我们能够研究次要任务（字母检测与明确的运动想象）对M1在运动和非运动短语加工过程中的神经活动的影响。我们发现，在任务与刺激的交互作用中，左侧M1活动存在差异，与字母检测相比，在存在运动短语（与非运动短语相比）时，想象会增强M1激活。这种M1活动不受视角的差异调节。因此，先前在默读动作词实验中发现的M1激活可能是由于受试者在动作词加工过程中进行心理模拟动作的策略所致。
