| OBJECTTo analyze brain active structures relating to number recognize, simple and complex addition calculation with fMRI(functional MRI, fMRI)between genders.MARTIAL AND METHODSTwenty right-handed young volunteers(ten men and ten women,age from 21 to 24, averaging age is 22.4±0.8 years) received the experiment following block design. There are three tasks in the experiment, arabic number identifying, one digit simply addition calculation and two digit complex addition calculation respectively. In number identifying, the identified numbers are one digit or two digit numbers, for example '90 32 2'. When the identified numbers include one '0' at least, volunteers are asked to press left button while without '0', they are requied to press right button. In simply addition calculation, every addend which is choosed randomly and every summand is smaller than or equal to 5, such as '1+3=5'. All addends and results don't include digit '0'. Volunteers are asked to judge the results whether right or wrong. If they consider the result is right, they have to press the left button; while if they judge the results is wrong, they are asked to press the right button. In complex addition calculation, every addend and summand is two digit random number and every calculation process doesn't have carry operation. The results all are two digit numbers too. All addends and results don't include digit '0'. The answer style of the task is the same as simply one. The identying and the simply's showing time are all 2000 ms in every block which is composed of 10 items and the the complex's showing time is 4000 ms in every block which is composed of 8 items. All tasks repeat twice. Every interval between tasks and the time after task finishing all are 20 ms. Behavior data is processed by Statistical Package for the Social Sciences (SPSS) 13.0 software. The analyzed targets are reaction time and correct rate between genders. Funtcional data process and brain activate structures analysis were done by AFNI (Analysis of Functional Neuroimages, AFNI) software. Then compareing the differentia of braim active structure between genders in three tasks.RESULTSThe behavior data show that in number identifying task the reaction time in male is 649.33ms and in female is 727.83ms while the correct rate in male is 95.7% and in female is 95.8%, respectively. In simply addition calculation task, the reaction time in male is 834.65 ms and in female is 874.52 ms while the correct rate in male is 90.4% and in female is 90.6%, respectively. in complex addition calculation task, the reaction time in male is 1737.28 ms and in female is 1867.70 ms while the correct rate in male is 88.5% and in female is 92.6%, respectively. There are no statistic differentia bewteen genders in reaction time and correct rate in both number identifying and simply addition calculation tasks. While it has statistic differentia bewteen genders in reaction time and correct rate in complex calculation task.Brain functional analysis (AFNI) results show that most of frontal-parietal areas activitied are in left side in both genders. Males can be found their medial temporal lobule and parietal areas activitied stronger than females'. In male the voxel of this position is 4779 mm~3 while in female is 1944 mm~3. In parietal lobule, the most distinct differentia between genders are the area which centers in postcentral gyrus extending to inferior parietal lobe and left precuneus. The voxel of two areas in male are 20682 mm~3 and 2457 mm~3 respectively and the intensity of both areas are F=7. The voxel of two analogous areas in female are 2187 mm~3 å'Œ 513 mm~3 respectively and the intensity of both are F=5.In simply addition task, males had a activitied area in left frontal lobe (voxel 4212 mm~3, intensity F=8) which extended from left superior frontal gyrus to bilateral medial cortex of the frontal lobe while female hadn't. Males had a big areas (voxel 21708 mm~3, intensity F=7) activitied in left prefrontal-parietal cotex while in the analogous location female's activitied brain areas is at interior parietal lobe. Voxel of that area is 2530 mm~3 and the intensity of both parts are F=5. Both genders have left precuneus activated while male have a additional one in right side.In complex addition task, males' activitied brain areas are prefer to right side and female's to left side. In frontal lobule, almost all parts are activated in female, include dorsal lateral left superior frontal gyrus, bilateral middle frontal gyrus, inferior frontal gyrus, medial frontal part, anterior part of frontal lobule, anterior and inferior parts of frontal lobule and orbital-frontal gyrus. Some of these areas connect with postcentral gyrus. In male, activate area includes anterior part of right dorsal superior frontal gyrus, bilateral anterior part of middle frontal part, right anterior and medial parts of middle frontal gyrus, left interior frontal gyrus and medial part of left frontallobule.In parietal areas, the dominate side of activated brain areas in female is left side and in male is right side. The activitied areas of females mostly are at bilateral precuneus and left inferior parietal lobule. Others include right superior parietal lobe, left postcentral gyrus, et al. The most distinct brain area is left precuneus(voxel 11383 mm~3, intensity F=7) which extends to cuneus downwards. While the distinctly activitied areas in males is one right brain areas which focus on right superior parietal lobule and right intraparietal sulcus. The area (voxel 7206 mm~3, intensity F=8) includes right superior parietal lobe, precuneus, supramarginal gyrus and extends to occipital lobule. In male,the additional brain area includes right postcentral gyrus. Both males and females activate some part of temporal lobule which included bilateral superior temporal gyrus in males and left superior temporal gyrus and middle temporal gyrus in female.CONCLUSIONSDifferent genders are different in activated brain areas structure during carrying out number identifying, simply addition and complex addition calculation tasks. That implys genders mathematics congitive ability differentia has themselves' biological foundation. |
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