Penhune V B, Zatorre R J, MacDonald J D, Evans A C
Department of Neuropsychology and Cognitive Neuroscience, Montreal Neurological Institute and Hospital, McGill University, Montreal, Quebec, Canada.
Cereb Cortex. 1996 Sep-Oct;6(5):661-72. doi: 10.1093/cercor/6.5.661.
The gyral morphology of the region of the primary auditory cortex (PAC) in the human brain is highly variable, and possible asymmetries between the hemispheres have been noted since the beginning of the century. We mapped the location and extent of PAC as identified from gross anatomical landmarks in magnetic resonance scans that had been transformed into Talairach-Tournoux stereotaxic space. Individual maps were averaged to produce a probabilistic map of the region which can be co-registered with any image of brain structure or function that has been similarly transformed. The map can be used to localize a region of interest, such as a lesion, or an activation focus from position omission tomography or functional magnetic resonance imaging, within a specified range of probability. We also measured the total volume of the region and found a significant L > R asymmetry both on average and in the majority of subjects. Automatic segmentation of the volumes into grey and white matter revealed larger volumes of white, but not grey matter on the left. This larger volume of cortical connecting fibres may be related to the known left-hemisphere dominance for speech, and a preferential role for left PAC in processing temporal aspects of auditory stimuli is suggested.
人类大脑初级听觉皮层（PAC）区域的脑回形态高度可变，自本世纪初以来，人们就注意到了半球之间可能存在的不对称性。我们通过磁共振扫描中的大体解剖标志确定了PAC的位置和范围，并将其转换为Talairach-Tournoux立体定向空间。对个体图谱进行平均，以生成该区域的概率图谱，该图谱可与经过类似转换的任何脑结构或功能图像进行配准。该图谱可用于在指定概率范围内定位感兴趣区域，如病变或正电子发射断层扫描或功能磁共振成像中的激活焦点。我们还测量了该区域的总体积，发现平均而言以及在大多数受试者中，存在显著的左大于右的不对称性。将体积自动分割为灰质和白质后发现，左侧白质体积较大，但灰质体积并非如此。这种较大体积的皮质连接纤维可能与已知的左半球语言优势有关，并提示左PAC在处理听觉刺激的时间方面具有优先作用。
