Attentional Modulation of Human Auditory Cortex

描述(申请人提供)：尽管传统上主要基于解剖学分析和对其他灵长类物种的功能数据的推断，人类听觉皮质被细分为听觉皮质区域，但关于人类听觉皮质组织仍有许多有待发现的地方。从其他物种推断功能数据是有问题的，因为人类对语音处理的专门化可能已经显著改变了听觉皮质组织。我们提出了两组实验，使用高分辨率功能磁共振成像(FMRI)和改进的基于地标的映射程序来提供人类听觉皮质区域的详细功能图。由于我们的初步结果表明，与注意力相关的激活等于或超过刺激本身产生的激活，因此在所有实验中，注意力都将受到控制和操纵。对无人注意的刺激的激活将阐明自动感觉反应，而与注意力相关的激活差异将阐明听觉中涉及的可选的、更高认知的操作。实验1-3将使用简单的刺激来获得人类的听觉场图，类似于在猕猴身上获得的场图。实验4-7将使用语音和语音控制刺激来表征与语音相关的激活。重复的单一受试者测试和改进的成像程序将允许在处理简单的声音、音节和连贯的语音过程中以前所未有的细节绘制听觉皮质区域。

DESCRIPTION (provided by applicant): Although human auditory cortex has traditionally been subdivided into auditory cortical fields based largely on anatomical analysis and the extrapolation of functional data from other primate species, much remains to be discovered about human auditory cortical organization. Extrapolating functional data from other species is problematic because the human specialization for speech processing may have significantly altered auditory cortical organization. We propose two groups of experiments using high-resolution functional magnetic resonance imaging (fMRI) and improved landmark-based mapping procedures to provide detailed functional maps of human auditory cortical fields. Since our preliminary results indicate that attention-related activations equal or exceed those produced by the stimuli themselves, attention will be controlled and manipulated in all experiments. Activations to nonattended stimuli will elucidate automatic sensory responses, whereas attention-related differences in activations will clarify the optional, higher-cognitive operations involved in audition. Experiments 1-3 will use simple stimuli to derive auditory field maps in humans similar to those obtained in macaques. Experiments 4-7 will use speech and speech-control stimuli to characterize speech-related activations. Repeated single-subject testing and improved imaging procedures will permit auditory cortical fields to be mapped with unprecedented detail during the processing of simple sounds, syllables and coherent speech.