Rämä Pia, Poremba Amy, Sala Joseph B, Yee Lydia, Malloy Megan, Mishkin Mortimer, Courtney Susan M
Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD, USA.
Cereb Cortex. 2004 Jul;14(7):768-80. doi: 10.1093/cercor/bhh037. Epub 2004 Apr 14.
In order to ascertain whether the neural system for auditory working memory exhibits a functional dissociation for spatial and nonspatial information, we used functional magnetic resonance imaging and a single set of auditory stimuli to study working memory for the location and identity of human voices. The subjects performed a delayed recognition task for human voices and voice locations and an auditory sensorimotor control task. Several temporal, parietal, and frontal areas were activated by both memory tasks in comparison with the control task. However, during the delay periods, activation was greater for the location than for the voice identity task in dorsal prefrontal (SFS/PreCG) and parietal regions and, conversely, greater for voices than locations in ventral prefrontal cortex and the anterior portion of the insula. This preferential response to the voice identity task in ventral prefrontal cortex continued during the recognition test period, but the double dissociation was observed only during maintenance, not during encoding or recognition. Together, the present findings suggest that, during auditory working memory, maintenance of spatial and nonspatial information modulates activity preferentially in a dorsal and a ventral auditory pathway, respectively. Furthermore, the magnitude of this dissociation seems to be dependent on the cognitive operations required at different times during task performance.
为了确定听觉工作记忆的神经系统是否对空间和非空间信息表现出功能分离，我们使用功能磁共振成像和一组听觉刺激来研究人类声音位置和身份的工作记忆。受试者对人类声音和声音位置执行延迟识别任务以及听觉感觉运动控制任务。与控制任务相比，两种记忆任务均激活了几个颞叶、顶叶和额叶区域。然而，在延迟期，背侧前额叶（SFS/中央前回）和顶叶区域对位置的激活大于对声音身份任务的激活，相反，腹侧前额叶皮层和岛叶前部对声音的激活大于对位置的激活。腹侧前额叶皮层对声音身份任务的这种优先反应在识别测试期持续存在，但仅在维持期间观察到双重分离，在编码或识别期间未观察到。总之，目前的研究结果表明，在听觉工作记忆期间，空间和非空间信息的维持分别优先调节背侧和腹侧听觉通路的活动。此外，这种分离的程度似乎取决于任务执行期间不同时间所需的认知操作。
