Yousem D M, Maldjian J A, Siddiqi F, Hummel T, Alsop D C, Geckle R J, Bilker W B, Doty R L
Department of Radiology, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104, USA.
Brain Res. 1999 Feb 13;818(2):480-7. doi: 10.1016/s0006-8993(98)01276-1.
On standardized tests of odor identification and odor detection, women tend to score better than men at nearly all age groups. We sought to determine if these findings would translate to differences between the sexes in the volume of activated brain when odors are presented to subjects as the stimulants for functional magnetic resonance imaging (FMRI) experiments. The activation maps of eight right-handed women (mean age 25.3 years old, range 20-44, S.D. 8.3 years) were compared with those of 8 right-handed men (mean age 30.5, range 18-37, S.D. 6.5 years) given the same olfactory nerve stimuli in an FMRI experiment at 1.5 T. Olfactory stimuli were delivered to the patients in a passive fashion using a Burghart OM4-B olfactometer with a nose piece inserted into the patients' nostrils. We used agents (eugenol, phenyl ethyl alcohol, or phenyl ethyl alcohol alternating with hydrogen sulfide) that were selective for olfactory nerve stimulation in the nose. The odorants were delivered to both nostrils for 1 s every 4 s during a 30 s 'on-period'. During the 30 s 'off-period', the patient received room air at the same flow rate. The women's group-averaged activation maps showed up to eight times more activated voxels than men for specific regions of the brain (frontal and perisylvian regions). The left and right inferior frontal regions showed a statistically significant increase in activation in women at p<0.01. In general, more women showed activation than men. The results suggest that (1) FMRI activation maps in subject groups can demonstrate correlates to psychophysical tests of olfaction, and (2) one must control for gender when performing odor-stimulated FMRI experiments.
在气味识别和气味检测的标准化测试中，几乎在所有年龄组中，女性的得分往往都比男性高。我们试图确定，当将气味作为功能磁共振成像（FMRI）实验的刺激物呈现给受试者时，这些发现是否会转化为两性在大脑激活量上的差异。在1.5T的FMRI实验中，将八名右利手女性（平均年龄25.3岁，范围20 - 44岁，标准差8.3岁）的激活图谱与八名右利手男性（平均年龄30.5岁，范围18 - 37岁，标准差6.5岁）的激活图谱进行比较，这些受试者接受相同的嗅神经刺激。使用带有鼻夹插入患者鼻孔的Burghart OM4 - B嗅觉计，以被动方式向患者输送嗅觉刺激。我们使用了对鼻腔嗅神经刺激具有选择性的试剂（丁香酚、苯乙醇或苯乙醇与硫化氢交替使用）。在30秒的“开启期”内，每隔4秒向两个鼻孔输送1秒的气味剂。在30秒的“关闭期”内，患者以相同流速接受室内空气。女性组平均激活图谱显示，大脑特定区域（额叶和颞叶周围区域）的激活体素比男性多多达八倍。左、右下额叶区域女性的激活在统计学上有显著增加，p<0.01。总体而言，显示出激活的女性比男性更多。结果表明：（1）受试者组的FMRI激活图谱可以证明与嗅觉心理物理学测试相关；（2）在进行气味刺激的FMRI实验时必须控制性别因素。
