I.R.C.C.S. S. Lucia, 00179 Rome, Italy.
J Cogn Neurosci. 2010 Mar;22(3):554-70. doi: 10.1162/jocn.2009.21197.
We carried out an fMRI study with a twofold purpose: to investigate the relationship between networks dedicated to semantic and visual processing and to address the issue of whether semantic memory is subserved by a unique network or by different subsystems, according to semantic category or feature type. To achieve our goals, we administered a word-picture matching task, with within-category foils, to 15 healthy subjects during scanning. Semantic distance between the target and the foil and semantic domain of the target-foil pairs were varied orthogonally. Our results suggest that an amodal, undifferentiated network for the semantic processing of living things and artifacts is located in the anterolateral aspects of the temporal lobes; in fact, activity in this substrate was driven by semantic distance, not by semantic category. By contrast, activity in ventral occipito-temporal cortex was driven by category, not by semantic distance. We interpret the latter finding as the effect exerted by systematic differences between living things and artifacts at the level of their structural representations and possibly of their lower-level visual features. Finally, we attempt to reconcile contrasting data in the neuropsychological and functional imaging literature on semantic substrate and category specificity.
我们进行了一项 fMRI 研究，目的有二：一是研究专门用于语义和视觉处理的网络之间的关系；二是根据语义类别或特征类型，探讨语义记忆是由一个独特的网络还是由不同的子系统来支持。为了达到我们的目标，我们在 15 名健康受试者扫描期间进行了一项字词-图片匹配任务，其中包括同类别干扰项。目标与干扰项之间的语义距离和目标-干扰项对的语义域是正交变化的。我们的结果表明，一个位于颞叶前外侧的、无差别的、用于生物和人工制品语义处理的模态网络；事实上，该基质中的活动是由语义距离驱动的，而不是由语义类别驱动的。相比之下，腹侧枕颞叶皮层的活动是由类别驱动的，而不是由语义距离驱动的。我们将后一种发现解释为在其结构表示和可能的低级视觉特征水平上，生物和人工制品之间的系统性差异所产生的影响。最后，我们试图调和神经心理学和功能成像文献中关于语义基质和类别特异性的对比数据。
