Gender Differences in Human Brain: A Review

Abstract

Why do men and women think differently? Why do they behave differently in stressed situations? Why do women act more emotionally as compared to men? Why do men and women excel at different types of tasks? Why do boys like to play with cars and trucks and superman? These are the common questions which arise commonly in minds.The human brain is a highly complex organ. Studies of perception, cognition, memory and neural functions have found apparent gender differences. These differences may be attributed to various genetic, hormonal, and environmental factors and do not reflect any overall superiority advantage to either sex. Both sexes are equal in intelligence, but tend to operate differently. Men and women appear to use different parts of the brain to encode memories, sense emotions, recognize faces, solve certain problems and make decisions. Indeed, when men and women of similar intelligence and aptitude perform equally well, their brains appear to go about it differently, as if nature had separate blueprints. Sex differences in the brain may play a role in learning processes, language development, and progression of neurologicallybased diseases. Sex differences need to be considered in studying brain structure and function and may raise the possibility of sex-specific treatments for neurological diseases. In this article it is reviewed that how does the brain of a male look and function differently from a female's brain, and what accounts for these differences?Keywords: Human brain, gender differences, brain aging, neurological disorders, learning. ANATOMICAL DIFFERENCESSeveral postmortem and structural neuroimaging studies in humans have shown the following morphological differences that are likely to reflect an interaction between developmental influences, experience, and hormone actions on the mature brain. Size & WeightThe adult human brain weighs on average about 3lb (1.5 kg) [1] with a size of around 1130 cm 3 in women and 1260 cm 3 in men although there is substantial individual variation [2]. Male brains are about 10% larger than female brains and weigh 11-12% more than that of a woman. Men's heads are also about 2% bigger than women's. This is due to the larger physical stature of men. Male's larger muscle mass and larger body size requires more neurons to control them. The brain weight is related to the body weight partly because it increases with increasing height [3]. This difference is also present at birth. A boy's brain is between 12-20% larger than that of a girl. The head circumference of boys is also larger (2%) than that of girls. However, when the size of the brain is compared to body weight at this age, there is almost no difference between boys and girls. So, a girl baby and a boy baby who weigh the same will have similar brain sizes. Brain VolumeSexual dimorphisms of adult brain volumes were more evident in the cortex, with women having larger volumes, relative to cerebrum size, particularly in frontal and medial *Address correspondence to this author at the Department of Anato...

Structural Brain Sex Differences in Parkinson’s Disease: A Voxel-Based Morphometry Study

“…On average, male brains are larger than female brains, with a 130 cm 3 difference in the circumference [39]. Moreover, there is 10% increase in the size of male brains, including an increase in weight by 11% to 12% [40]. Furthermore, it is presumed that height plays a role in increasing the weight of the brain due to more neurons being required to control bigger bodies [40,41].…”

“…Moreover, there is 10% increase in the size of male brains, including an increase in weight by 11% to 12% [40]. Furthermore, it is presumed that height plays a role in increasing the weight of the brain due to more neurons being required to control bigger bodies [40,41]. Males and females have brain regional differences regarding the volume of the brain cortex; frontal and medial paralimbic cortices are larger in volume when correlated to cerebrum size.…”

“…Males and females have brain regional differences regarding the volume of the brain cortex; frontal and medial paralimbic cortices are larger in volume when correlated to cerebrum size. Males have larger front medial cortex and amygdala and hypothalamus volumes when correlated to cerebrum size [40]. Sex steroids have a major impact on developmental studies because of their role in changing the structure of the homologous structures in the brain [40,42].…”

“…Males have larger front medial cortex and amygdala and hypothalamus volumes when correlated to cerebrum size [40]. Sex steroids have a major impact on developmental studies because of their role in changing the structure of the homologous structures in the brain [40,42]. Sexual brain dimorphism was investigated in a recent metaanalysis study that included 126 studies for overall volume analysis and 24 studies that had performed voxel-based morphometry for regional volume and density meta-analysis [43].…”

“…Furthermore, the loss was detected in females with PD only in the right insula (t=4.2, MNI coordinates: 34, 0, 12), the right centeral opercular cortex (t=4.134, MNI coordinates: 40,2,14), and the right inferior frontal gyrus (pars opercularis; t=3.6, MNI coordinates: 36, 10, 24) ( Figure 3). …”