Department of Physiology and Pharmacology, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy.
Neuroscience. 2011 Jan 26;173:110-5. doi: 10.1016/j.neuroscience.2010.11.011. Epub 2010 Nov 11.
Human and animals are able to decide that A>C after having learnt that A>B and B>C. This basic property of logical thinking has been studied by transitive inference (TI) tasks. It has been hypothesized that subjects displace the premises of the inference on a mental line to solve the task. An evidence in favor of this interpretation is the observation of the symbolic distance effect, that is the improvement of the performance as the distance between items increases. This effect has been interpreted as support to the hypothesis that ability to perform TI tasks follows the same rules and is mediated by the same brain circuits involved in the performance of spatial tasks. We tested ten subjects performing a TI on an ordered list of Japanese characters while they were fixating either leftwards or rightwards, to evaluate whether the eye position modulated the performance in making TI as it does in spatial tasks. Our results show a significant linear decrease of the reaction time with the increase of the symbolic distance and a shift of this trend towards lower reaction times when subjects were fixating to the left. We interpret this eye position effect as a further evidence that spatial and reasoning tasks share the same underlying mechanisms and neural substrates. The eye position effect also points to a parietal cortex involvement in the neural circuit involved in transitive reasoning.
人类和动物在学习了 A>B 和 B>C 后，能够得出 A>C 的结论。这种逻辑思维的基本属性已经通过传递推理 (TI) 任务进行了研究。有人假设，被试者会在心理线上转移推理的前提来解决任务。支持这种解释的一个证据是观察到符号距离效应，即随着项目之间距离的增加，表现会提高。这种效应被解释为支持这样一种假设，即执行 TI 任务的能力遵循相同的规则，并由参与空间任务的相同大脑回路介导。我们测试了 10 名受试者，让他们在一个有序的日语字符列表上执行 TI，同时他们的注视点向左或向右，以评估注视点是否像在空间任务中那样调节了执行 TI 的表现。我们的结果显示，反应时间随着符号距离的增加而呈显著的线性下降，当被试者注视左边时，这种趋势的反应时间会降低。我们将这种注视位置效应解释为空间和推理任务共享相同的潜在机制和神经基质的进一步证据。注视位置效应还指向参与传递推理的神经回路的顶叶皮层的参与。
