PDF(Pubmed)
Abstract：
Reading depends on a brain region known as the \"visual word form area\" (VWFA) in the left ventral occipitotemporal cortex. This region\'s function is debated because its stimulus selectivity is not absolute, it is modulated by a variety of task demands, and it is inconsistently localized. We used fMRI to characterize the combination of sensory and cognitive factors that activate word-responsive regions that we precisely localized in 16 adult humans (4 male). We then presented three types of character strings: English words, pseudowords, and unfamiliar characters with matched visual features. Participants performed three different tasks while viewing those stimuli: detecting real words, detecting color in the characters, and detecting color in the fixation mark. There were three primary findings about the VWFA\'s response: (1) It preferred letter strings over unfamiliar characters even when the stimuli were ignored during the fixation task. (2) Compared with those baseline responses, engaging in the word reading task enhanced the response to words but suppressed the response to unfamiliar characters. (3) Attending to the stimuli to judge their color had little effect on the response magnitudes. Thus, the VWFA is uniquely modulated by a cognitive signal that is specific to voluntary linguistic processing and is not additive. Functional connectivity analyses revealed that communication between the VWFA and a left frontal language area increased when the participant engaged in the linguistic task. We conclude that the VWFA is inherently selective for familiar orthography, but it falls under control of the language network when the task demands it.
摘要：
阅读取决于左腹侧枕颞皮层中称为“视觉单词形式区域”（VWFA）的大脑区域。这个区域的功能是有争议的，因为它的刺激选择性不是绝对的，它受到各种任务需求的调节，而且本地化不一致。我们使用功能磁共振成像来表征感觉和认知因素的组合，这些因素激活了我们在16名成年人（4名男性）中精确定位的单词反应区域。然后，我们提出了三种类型的字符串：英语单词，伪词,和不熟悉的字符匹配的视觉特征。参与者在观看这些刺激时执行了三种不同的任务：检测真实的单词，检测字符中的颜色，并检测固定标记中的颜色。关于VWFA的反应有三个主要发现：（1）即使在固定任务期间忽略了刺激，它也更喜欢字母字符串而不是陌生字符；（2）与那些基线反应相比，参与单词阅读任务增强了对单词的反应，但抑制了对陌生字符的反应。（3）参加刺激判断其字体颜色对响应幅度影响不大。因此，VWFA由特定于自愿性语言处理的认知信号进行唯一调节，并且不是加性的。功能连通性分析显示，当参与者参与语言任务时，VWFA和左额叶语言区域之间的交流增加。我们得出的结论是，VWFA对熟悉的正字法具有固有的选择性，但是当任务需要时，它就处于语言网络的控制之下。重要性声明“视觉单词形式区域”（VWFA）的功能是有争议的。一些研究人员强调它对单词的自下而上的视觉选择性，因此，该地区的通用名称。其他人则认为，它的活动是通过控制注意力或语言的区域的反馈来解释的。为了寻求清晰，我们调查了驱动VWFA的因素:看到单词，视觉上注意单词，或者试着读单词。这些因素本身都不够。我们的结果支持一个混合模型：VWFA对单词具有固有的选择性，但是它的功能是通过自愿的语言处理来重塑的。因此，通过对感官输入的综合分析，任务要求,和网络连接，我们为有关这一重要地区的辩论提供了一些解决方案。
