brain and gender

7/28/2019 Brain and Gender

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Genders of the Brainby Catherine Genevieve B. Lagunzad, Ph.D.

IntroductionThe brain is an amazing organ. It

makes us think, allows us to feel

sadness and pain and tells us to sleepat night and wake up in the morning.What our eyes can see or what ourears can hear would mean very littleunless processed by this gray andwhite matter. The seat of love is notreally the heart but the brain. Our urgeto show love, our biological function ofproducing eggs or sperms, even whatwe are as man or woman, depend onthe processes that occur in the brain.

The Human BrainThe human brain has threemajor divisions namely, the forebrain,the midbrain and the hindbrain. Referto Table 1 and Figure 1 for the mainparts of the major divisions and someof their corresponding functions.

The cerebrum of the forebrain,in humans, is so large that it practicallyenvelops the rest of the other parts ofthe brain. The cerebrum is divided into

two convoluted halves, the left and theright hemispheres. It look just like theconvoluted edible seed of walnut? Thetwo hemispheres are connected by thecorpus callosum, a thick bundlecontaining more than 200 million nervefibers (axons).

Each hemisphere is further splitby deep grooves into four lobes,namely the frontal, parietal, temporaland occipital lobes. The functionalrole of each lobe is mapped out inFigure 2. Note that sense of smell islocated in the frontal, motor andsensory information of the limbs in theparietal, vision in the occipital andhearing in the temporal lobes.

Ascending sensory nerve tractscross descending motor tracts. Thus,sensory information from the right side

of the body is detected in the leftcerebral hemisphere, while motorcommands from the left hemisphere

affect muscles and organs on the rightside of the body.Although the left hemisphere

contains exactly the same lobes as thatof the right hemisphere, it was noted,that muscle control of speech restslargely on the left temporal lobe. It isfurther speculated that the lefthemisphere is the rational, engineeringand debating part while the righthemisphere is the intuitive, artistic and

musical part of the brain.Differences between the male brainand female brain

One marked difference betweenthe male and female brains is the sizeof the corpus callosum that connectsthe left and right cerebral hemispheres.Using special surgical procedure incats, researchers showed thatinformation reaching one half of thebrain was unavailable to the other half

in the absence of the corpus callosum.Who do you think has a larger corpuscallosum, a man or a woman?

Female brains, in general, havelarger corpus callosum. This mayindicate very close communicationbetween the two cerebral hemispheres.It was further observed that femalesuse both sides of the brain equally forverbal and visual activities, emotionalresponses and in predicting three-dimensional shapes of objects.

Males on the other hand use oneside of the brain exclusively forparticular activities. For instance, right-handed men use exclusively the leftcerebral hemisphere for verbalactivities and the right for emotionalresponses, visual tasks and in


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predicting three-dimensional objectsfrom a two-dimensional perspective.Aptitudes and Attitudes

Based on studies, there is astatistically significant difference in the

aptitudes and attitudes exhibited by thedifferent sexes. It must be understoodhowever, that all kinds of talents andbehaviors can exist normally in bothmales and females.

At infancy, baby boys can raisetheir heads higher but baby girls smileearlier and more often even in sleep.

As they grow older, boys are lessfearful, more active and cling less totheir moms. Baby girls are less

exploratory, learn to talk early andusually make friends more easily. Girlshave good motor control of their handsand hence have better penmanshipthan boys. Boys have good hand-eyecoordination hence can controlmovements involving large groups ofmuscles better than girls.

In general, more men excel atsolving mathematical problems inschool but more women excel in testsof grammar and spelling. Men canmentally rotate objects in space andcan estimate measurements of sizeand distance more accurately thanwomen. Women can better senseemotional messages in conversations,facial expressions and body movement.

Women have better peripheraland night vision but men can see moreclearly in bright light. Women havekeener sense of smell, taste andhearing. Men have a better sense ofdirection and can easily locate placesusing a map.Why are there differences

Humans exhibit two biologicalsexes or gender namely, male andfemale. Aside from biological gender,there are also other expressions ofgender differences such as gender

identity and sexual orientation. Whilebiological gender is largely genetic,gender identity and sexual orientationare believed to be largely influencedby social and cultural environment.

This remains an issue for debate.Gender identity is a personalknowledge and recognition of the selfas male or female. Sexual orientationrefers to whether one is attracted to amale or a female. There are someresearchers who believe that likebiological gender, gender identity andsexual orientation are determined atconception and are controlled atspecific centers of the brain.

Differences between males andfemales begin during pregnancy. Thekind and amount of sex hormonespresent during pregnancy translate intostructural and organizationaldifferences between male and femalebrains.

Mothers produce the female sexhormone estrogen while the testes ofmale fetuses produce testosterone.The amount of hormones and thesustained production of thesehormones affect the sexualdevelopment of the embryos. Estrogenfrom the mother influences thedevelopment of the female sex organand the female brain. Testosteroneproduced by the testes of the malefetus overcomes the maternal estrogenand promotes the development of themale brain.

If testosterone levels are notsustained, a male fetus may developmale sex organs but may not havesufficient testosterone to develop amale brain pattern. This is believed tobe one reason why some biologicalmales experience conflicts in genderidentity and sexual orientation.

Females may also experiencegender conflicts. This on the other


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hand, may be a result of accidentalexposure to high levels of testosteroneproduced in the adrenal glands of themother or of the fetus at conception.Lessons to Learn

Knowing the structural andfunctional differences between thesexes can help us better understandourselves. Hopefully, we will becomemore aware of our aptitudes andattitudes so that we can exertdeliberate efforts to overcome ourdifficulties and enhance our strengths.

At the same time, we can betterappreciate why we look and behavedifferently from the opposite sex.

Moreover, we can be morecompassionate and less judgmental for

people who experience conflicts in theirbiological gender, gender identity andsexual orientation.

After all, we all share the sameneed, to be accepted for who we are

and to be recognized as a contributingand useful member of our society.ReferencesBenjamin, C., Garman, G. and Feinston, J. Human Biology.Gadpaille, W. J. 1995. Grolier MultimediaEncyclopedia.Raven, P.H. and Johnson, G.B. 1998.Understanding Biology. WCB Publishers,Ubuque.Ripich, D. Case Western Reserve University)

Table 1. The Major Divisions of theHuman Brain

Division Main Parts Function

Forebrain Cerebrum Coordinating center, sensory association, memory

Limbic system

Thalamus

Hypothalamus

Responsible for deep-seated, unconscious drivesand emotions

Coordinating center and relay station for sensoryand motor signals

Regulates body temperature, solute-waterbalance, respiration and breathing; directs

hormone-producing pituitary glandPituitary gland Master endocrine gland; controls growth,

metabolism and hormone production of otherglands of endocrine system

Pineal gland Endocrine gland that secretes melatonin; as light-sensing organ, it controls circadian rhythms inreproductive function

Reticularformation

Regulatory function of accenting sensoryinformation when awake and dampening themduring sleep

Midbrain Coordinates and relays visual (sight) and auditory

(hearing) informationHindbrain Pons Transverse connections with cerebrum, also

connects forebrain and spinal cord.

Cerebellum Coordinates motor activities for refined bodymovement; maintains posture, orientation in spaceand balance

Medullaoblongata

Reflex centers involve in respiration,cardiovascular functions and gastric secretions


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Figure 1. Main Parts of the Human Brain

Figure 2. The four lobes of each cerebral hemisphere of the brain

brain and gender

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