Vallar G, Bisiach E, Cerizza M, Rusconi M L
Istituto di Clinica Neurologica, Università di Milano, Italy.
Cortex. 1988 Sep;24(3):399-410. doi: 10.1016/s0010-9452(88)80003-0.
The role of the left hemisphere in decision-making processes in choice reactions to unstructured visual stimuli (Bisiach, Mini, Sterzi and Vallar, 1982) was further investigated in normal right-handed individuals. Subjects were required to provide a motor response to lateralized single dots, abstaining from giving a response when two dots were shown. In the first study, in which the disruptive effects of concurrent articulatory activity were assessed, the decision required integration of information provided to both hemispheres, as the no-go stimulus was constituted by two dots symmetrically positioned, one in each half-field. In the second study, all information relevant to the decision was available to each hemisphere, as the no-go stimulus was represented by two dots in either half-field. Since in both experiments the decision mechanism remained located in the left hemisphere, the following conclusions are drawn: (i) the right hemisphere is unable to fulfil the demands of the present decision-making task, even when either a secondary task interferes with left hemisphere processes or it has direct acces to all the relevant information; this suggests a pattern of absolute hemispheric specialization; (ii) the left hemisphere decision-making process does not rely upon any sort of articulatorily-based "inner speech" component.
在正常右利手个体中，进一步研究了左半球在对非结构化视觉刺激的选择反应决策过程中的作用（比夏克、米尼、斯泰尔齐和瓦拉尔，1982年）。要求受试者对侧向呈现的单个点做出运动反应，当出现两个点时不做反应。在第一项研究中，评估了同时进行的发音活动的干扰作用，由于不做反应的刺激由对称放置在每个半视野中的两个点组成，因此该决策需要整合提供给两个半球的信息。在第二项研究中，与决策相关的所有信息每个半球都能获取，因为不做反应的刺激由任一 半视野中的两个点表示。由于在两个实验中决策机制都位于左半球，因此得出以下结论：（i）即使次要任务干扰左半球过程或右半球可直接获取所有相关信息，右半球也无法完成当前决策任务的要求；这表明存在绝对的半球特化模式；（ii）左半球的决策过程不依赖于任何基于发音的“内心言语”成分。
