Abstract:
Feature-based visual attention refers to preferential selection and processing of visual stimuli based on their nonspatial attributes, such as color or shape. Recent studies have highlighted the inferior frontal junction (IFJ) as a control region for feature but not spatial attention. However, the extent to which IFJ contributes to spatial versus feature attention control remains a topic of debate. We investigated in humans of both sexes the role of IFJ in the control of feature versus spatial attention in a cued visual spatial (attend-left or attend-right) and feature (attend-red or attend-green) attention task using fMRI. Analyzing cue-related fMRI using both univariate activation and multivoxel pattern analysis, we found the following results in IFJ. First, in line with some prior studies, the univariate activations were not different between feature and spatial attentional control. Second, in contrast, the multivoxel pattern analysis decoding accuracy was above chance level for feature attention (attend-red vs attend-green) but not for spatial attention (attend-left vs attend-right). Third, while the decoding accuracy for feature attention was above chance level during attentional control in the cue-to-target interval, it was not during target processing. Fourth, the right IFJ and visual cortex (V4) were observed to be functionally connected during feature but not during spatial attention control, and this functional connectivity was positively associated with subsequent attentional selection of targets in V4, as well as with behavioral performance. These results support a model in which IFJ plays a crucial role in top-down control of visual feature but not visual spatial attention.SIGNIFICANCE STATEMENT Past work has shown that the inferior frontal junction (IFJ), a prefrontal structure, is activated by both attention-to-feature (e.g., color) and attention-to-location, but the precise role of IFJ in the control of feature- versus spatial-attention is debated. We investigated this issue in a cued visual spatial (attend-left or attend-right) and feature (attend-red or attend-green) attention task using fMRI, multivoxel pattern analysis, and functional connectivity methods. The results show that (1) attend-red versus attend-green can be decoded in single-trial cue-evoked BOLD activity in IFJ but not attend-left versus attend-right and (2) only right IFJ modulates V4 to enhance task performance. This study sheds light on the function and hemispheric specialization of IFJ in the control of visual attention.
摘要:
基于特征的视觉注意是指基于视觉刺激的非空间属性的优先选择和处理,如颜色或形状。最近的研究强调了下额叶交界处(IFJ)作为特征而不是空间注意力的控制区域。然而,IFJ对空间和特征注意力控制的贡献程度仍然是一个争论的话题。我们使用fMRI在两性人类中调查了IFJ在提示视觉空间(左参加或右参加)和特征(红色参加或绿色参加)注意任务中控制特征与空间注意的作用。使用单变量激活和多体素模式分析分析提示相关功能磁共振成像,我们在IFJ中发现了以下结果。首先,根据之前的一些研究,单变量激活在特征和空间注意控制之间没有差异。第二,相比之下,对于特征注意力(参加-红色vs参加-绿色),多体素模式分析解码精度高于机会水平,但对于空间注意力(参加-左vs参加-右)则不高于机会水平。第三,而在线索到目标间隔的注意控制期间,特征注意力的解码精度高于机会水平,这不是在目标处理过程中。第四,右IFJ和视觉皮层(V4)被观察到在功能连接期间,而不是在空间注意力控制期间,并且这种功能连接与V4中随后的目标注意选择以及行为表现呈正相关。这些结果支持IFJ在自上而下控制视觉特征而不是视觉空间注意力中起关键作用的模型。过去的工作表明,额叶下交界处(IFJ),前额叶结构,被关注功能激活(例如,颜色)和注意位置,但是IFJ在控制特征注意力和空间注意力方面的确切作用是有争议的。我们使用fMRI在提示视觉空间(左出席或右出席)和特征(出席红色或出席绿色)注意力任务中调查了这个问题,多体素模式分析,和功能连接方法。结果表明,(1)可以在IFJ的单次试验提示诱发的BOLD活动中解码参加红色与参加绿色,但不能在参加左与参加右活动中解码;(2)仅右侧IFJ调节V4以增强任务性能。这项研究揭示了IFJ在控制视觉注意力方面的功能和半球专业化。