Department of Psychological and Brain Sciences, Dartmouth College, 6207 Moore Hall, Hanover, NH 03755, United States.
Department of Psychological and Brain Sciences, Dartmouth College, 6207 Moore Hall, Hanover, NH 03755, United States.
Brain Res. 2020 Jan 1;1726:146483. doi: 10.1016/j.brainres.2019.146483. Epub 2019 Oct 1.
When two individuals view the same item, they do not necessarily perceive an item in the same way. If an individual is presented with a stimulus to be recalled later, the information that is encoded is dependent on the features of the stimulus to which one attends. Past studies have shown that, on the group level, verbal and visual information (e.g., words and pictures) are encoded in disparate regions of the brain. However, this account conflates external and internal representational formats, and it also neglects individual differences in attention. In this study, we examined neural and behavioral patterns associated with individual differences in attention to verbal representations-both external and internal. We found that the encoded neural representation of semantic content (meaningful words and pictures) varied as a function of individual differences in verbal attention, independent of the stimulus presentation format. Individuals who demonstrated an attentional bias toward words showed similar multivariate BOLD activity patterns within an a priori speech production network when encoding object names as when encoding pictures of objects. This result indicates that these individuals encode both words and pictures verbally. These effects were not found for non-semantic stimuli (pronounceable non-words and nonsense pictures). Importantly, as expected, no individual differences in neural representation were found in a separate network of regions known to process semantic content independent of format. These results highlight inter-individual divergence and convergence in internal representations of encoded semantic content. SIGNIFICANCE STATEMENT: This study shows how tendencies to attend to word representations is associated with individual differences in encoded neural representations. Individuals who selectively attend to words instead of pictures process semantically meaningful information in language regions of the brain, regardless of whether the information was originally presented as a word or a picture. Though all participants encoded words and pictures similarly in regions that are known to represent domain-general semantic information, only the individuals who were biased towards word representations additionally processed both words and pictures in modality-specific verbal regions. These results demonstrate both the convergence and divergence between individuals that occurs during encoding of meaningful information.
当两个人观察同一件物品时，他们并不一定会以同样的方式感知该物品。如果一个人被呈现一个稍后要回忆的刺激，那么被编码的信息取决于一个人关注的刺激的特征。过去的研究表明，在群体水平上，言语和视觉信息（例如，单词和图片）被编码在大脑的不同区域。然而，这种解释混淆了外部和内部的表示格式，也忽略了注意力的个体差异。在这项研究中，我们研究了与个体对言语表示的注意力差异相关的神经和行为模式——包括外部和内部的言语表示。我们发现，语义内容的编码神经表示（有意义的单词和图片）随着言语注意力的个体差异而变化，而与刺激呈现格式无关。当以编码物体名称的方式编码物体的图片时，表现出对单词注意力偏向的个体在一个预先设定的言语产生网络内显示出相似的多元大脑活动模式。这一结果表明，这些个体以言语方式编码单词和图片。对于非语义刺激（可发音的非单词和无意义的图片）则没有发现这些效果。重要的是，正如预期的那样，在一个已知独立于格式处理语义内容的区域的分离网络中没有发现神经表示的个体差异。这些结果突出了编码语义内容的内部表示中的个体差异的发散和收敛。 意义：这项研究表明，对单词表示的倾向如何与编码神经表示的个体差异相关。与选择性地关注图片相比，个体更倾向于关注单词，他们会在大脑的语言区域处理语义上有意义的信息，而不论信息最初是以单词还是图片呈现。尽管所有参与者在已知代表一般语义信息的区域中以类似的方式编码单词和图片，但只有对单词表示有偏见的个体还会在特定模态的言语区域中处理单词和图片。这些结果表明，在有意义信息的编码过程中，个体之间既会发生收敛，也会发生发散。
