Department of Psychology, New York University, 6 Washington Place, New York, NY 10003, USA.
Brain Res. 2013 Aug 7;1525:26-38. doi: 10.1016/j.brainres.2013.06.002. Epub 2013 Jun 13.
Neurons in the dorsal frontal and parietal cortex are thought to transform incoming visual signals into the spatial goals of saccades, a process known as target selection. Here, we used functional magnetic resonance imaging (fMRI) to test how target selection may generalize beyond visual transformations when auditory and semantic information is used for selection. We compared activity in the frontal and parietal cortex when subjects made visually, aurally, and semantically guided saccades to one of four differently colored dots. Selection was based on a visual cue (i.e., one of the dots blinked), an auditory cue (i.e., a white noise burst was emitted at one of the dots' location), or a semantic cue (i.e., the color of one of the dots was spoken). Although neural responses in frontal and parietal cortex were robust, they were non-specific with regard to the type of information used for target selection. Decoders, however, trained on the patterns of activity in the intraparietal sulcus could classify both the type of cue used for target selection and the direction of the saccade. Therefore, we find evidence that the posterior parietal cortex is involved in transforming multimodal inputs into general spatial representations that can be used to guide saccades.
背侧额顶叶皮层中的神经元被认为将传入的视觉信号转化为扫视的空间目标，这个过程被称为目标选择。在这里，我们使用功能磁共振成像（fMRI）来测试当使用听觉和语义信息进行选择时，目标选择如何在超越视觉转换的情况下进行概括。我们比较了被试在进行视觉、听觉和语义引导的扫视时，前额叶和顶叶皮层的活动情况，目标是指向四个不同颜色的点中的一个。选择基于视觉线索（即其中一个点闪烁）、听觉线索（即在其中一个点的位置发出一声白噪声爆发）或语义线索（即一个点的颜色被说出）。尽管前额叶和顶叶皮层的神经反应很强烈，但它们对于用于目标选择的信息类型没有特异性。然而，在顶内沟的活动模式上训练的解码器可以对用于目标选择的线索类型和扫视的方向进行分类。因此，我们发现证据表明，后顶叶皮层参与将多模态输入转换为通用的空间表示，这些表示可以用于引导扫视。
