Hunter Michael D, Griffiths Timothy D, Farrow Tom F D, Zheng Ying, Wilkinson Iain D, Hegde Nakul, Woods William, Spence Sean A, Woodruff Peter W R
Sheffield Cognition and Neuroimaging Laboratory, Academic Department of Psychiatry, University of Sheffield, Sheffield, UK.
Brain. 2003 Jan;126(Pt 1):161-9. doi: 10.1093/brain/awg015.
We used functional imaging of normal subjects to identify the neural substrate for the perception of voices in external auditory space. This fundamental process can be abnormal in psychosis, when voices that are not true external auditory objects (auditory verbal hallucinations) may appear to originate in external space. The perception of voices as objects in external space depends on filtering by the outer ear. Psychoses that distort this process involve the cerebral cortex. Functional magnetic resonance imaging was carried out on 12 normal subjects using an inside-the-scanner simulation of 'inside head' and 'outside head' voices in the form of typical auditory verbal hallucinations. Comparison between the brain activity associated with the two conditions allowed us to test the hypothesis that the perception of voices in external space ('outside head') is subserved by a temperoparietal network comprising association auditory cortex posterior to Heschl's gyrus [planum temporale (PT)] and inferior parietal lobule. Group analyses of response to 'outside head' versus 'inside head' voices showed significant activation solely in the left PT. This was demonstrated in three experiments in which the predominant lateralization of the stimulus was to the right, to the left or balanced. These findings suggest a critical involvement of the left PT in the perception of voices in external space that is not dependent on precise spatial location. Based on this, we suggest a model for the false perception of externally located auditory verbal hallucinations.
我们利用对正常受试者的功能成像来确定在外部听觉空间中感知声音的神经基质。在精神病状态下，这个基本过程可能会出现异常，此时并非真正外部听觉对象的声音（幻听）可能会显得源自外部空间。将声音感知为外部空间中的对象取决于外耳的过滤作用。扭曲这一过程的精神病涉及大脑皮层。我们对12名正常受试者进行了功能磁共振成像，采用扫描仪内模拟“脑内”和“脑外”声音的方式，模拟典型的幻听。对与这两种情况相关的大脑活动进行比较，使我们能够检验这样一个假设，即外部空间中声音（“脑外”）的感知是由一个颞顶网络支持的，该网络包括位于颞横回[颞平面（PT）]后方的听觉联合皮层和顶下小叶。对“脑外”与“脑内”声音反应的组分析显示，仅在左侧颞平面有显著激活。这在三个实验中得到了证实，在这些实验中，刺激的主要侧化方向分别为右侧、左侧或平衡。这些发现表明，左侧颞平面在外部空间声音感知中起关键作用，且不依赖于精确的空间位置。基于此，我们提出了一个关于外部定位的幻听错误感知的模型。
