Let’s Talk About Sex, Baby

Why? Because babies making funny faces is freakin’ hilarious… That’s Why

First things first…

https://www.youtube.com/watch?v=U5xkxTfVLSA

Male vs. Female• There are significant differences in brain

structure between male and female– Slight differences in the brain anatomy

of men and women. •On average, women’s brains are smaller.

But…• Size is not the key

however• Number of neurons is

more critical– On average, women

have 11% more neurons

– “Extra” neurons are found in 2 layers of cerebral cortex •recognition of

language, melodies, and tone of voice

The Corpus Callosum• Neural bridge connecting right and left

hemispheres – Best documented anatomical difference

•Larger in women than in men•Researchers from UCLA examined 146

cadavers– Rear portion up to 23% larger in women

than in men• Are women better able to integrate the left and

right brain?– Unknown, not demonstrated to date– Significant only if it contained more neurons

Sex Hormones and Development

• The most important factor in differentiation of males and females and in differentiating individuals within a sex is the level of exposure to various sex hormones early in life

• Sex hormones can stimulate or repress the development of neurons

• The brain of a developing fetus is bathed in sex hormones

• At birth, environmental & cultural factors are acting on the already differently wired brains of boys and girls.

Say What?!

The Role of Testosterone

• Testes produce male hormones, or androgens – Testosterone– Organize development and

male behaviors early in life

• Female anatomy (and most “feminine” behavior) is the default mode in the absence of androgens

The Effect of Hormones is Life-altering

• Effects of early exposure to sex hormones are lifelong

• Changes are 'organizational' • Alter brain function permanently during a

critical period in prenatal or early postnatal development.

• Administering the same sex hormones later in development or in the adult has no similar effect

Animal Studies• A male rodent deprived of androgens

immediately after birth (by castration or by a drug that blocks androgens) – Male sexual behavior is reduced, and female

sexual behavior is expressed.

Animal Studies

• If androgens are administered to a female directly after birth, she will display more male sexual behavior and less female behavior in adulthood

Hate cats, but that’s stinkin’ hilarious

Human Studies• Controlled experiments in humans

are not ethically feasible – Scientists have studied defects

which affect hormone levels• Boys with a syndrome that

makes them insensitive to testosterone are better at language than their unaffected brothers, but they are less adept at spatial tasks

CAH & DES in Girls• The birth defect, CAH causes production of high

levels of testosterone during fetal development in girls.– CAH girls score better on spatial and mathematical tests

• Girls exposed to the hormone DES in utero (a drug given to prevent miscarriage) are also exposed to excess testosterone. – DES girls are entirely feminine in all other respects. – DES girls do better than their normal sisters in spatial and

mathematical tasks

The Role of the Hypothalamus• Regulates reproductive behavior • Connects to the pituitary (master endocrine)

gland• One region of the hypothalamus is visibly larger

in male rats than in females – this size difference is under hormonal control.

• Scientists have also found parallel sex differences in a clump of nerve cells in the human brain– parts of the interstitial nucleus of the anterior

hypothalamus are larger in men than in women

The Hypothalamus & Sexual Orientation

• Sexual orientation and gender identity have been related to anatomical variation in the hypothalamus

Male Dominated Tasks

• On average, men perform better than women in spatial tasks – Tests that require the subject to imagine

rotating or manipulating an object – Navigating through a route

• More accuracy in tests of target-directed motor skills--that is, in guiding or intercepting projectiles

• Better at mathematical reasoning tests

• They do well on tests that involve mentally rotating an object or manipulating it in some fashion, such as imagining turning this three-dimensional object

• Or determining where the holes punched in a folded piece of paper will fall when the paper is unfolded:

• Men also are more accurate than women in target-directed motor skills, such as guiding or intercepting projectiles:

• Men do better on disembedding tests, in which they have to find a simple shape, such as the one on the left, once it is hidden within a more complex figure:

• And men tend to do better than women on tests of mathematical reasoning:

Female Dominated Tasks

• Women, on average, excel in language tasks:– tests that measure recall of words – tests to find words that begin with a specific letter

or fulfill some other constraint.

• Women are better than men at rapidly identifying matching items

• Women also excel at certain precision manual tasks

• Women tend to perform better than men on tests of perceptual speed, in which subjects must rapidly identify matching items for example, pairing the house on the far left with its twin:

• Women remember whether an object, or a series of objects, has been displaced:

• Women outperform men on tests of ideational fluency, for example, subjects must list objects that are the same color.

• Women also outperform men on tests of verbal fluency, in which participants must list words that begin with the same letter.

• Women do better on precision manual tasks-that is, those involving fine-motor coordination - such as placing the pegs in holes on a board:

• Women do better than men on mathematical calculation tests:

Who Needs Directions?

• Studies show that men complete a computer simulation of a maze or labyrinth task more quickly and with fewer errors than women do.

• A different study used a path on a tabletop map to measure route learning.– Although men learned the route in fewer trials and with

fewer errors, women remembered more of the landmarks, such as pictures of different types of buildings, than men did.

• Women use landmarks as a strategy to orient themselves in everyday life more than men do.

Landmark Memory

• Research suggests that women have superior landmark memory

• Researchers tested the ability of individuals to recall objects and their locations within a confined space, such as in a room or on a tabletop – Women were better able to remember whether items

had changed places

• Other investigators found that women are superior at a memory tasks such as remembering the location of pictures on cards turned over in pairs

• At this kind of object location, in contrast to other spatial tasks, women have the advantage

Lost your keys?

• Don’t be proud, just ask your wife where you put them last…

The Evidence from PET & FMRI

• Positron emission tomography (PET) & functional magnetic resonance imaging (FMRI) can reveal how male & female brains actually function.

• By detecting areas of the brain using the most blood glucose, PET pinpoints active regions.– Glucose is the basic fuel of all cells in the body,

including brain cells. – Thus, active regions of the brain use more glucose

than quiescent areas. – Glucose is radio-labed– The brain areas in use then will emit more

radioactivity, which can be detected by the PET scan.

Even though it may seem strange, the vast majority of sex occurs in the

brain

Your Brain is the Largest Sex Organ you have

Cleveland Clinic StudyCleveland Clinic Study

Asked 10,000 men one questionAsked 10,000 men one question

““Does your wife show you her love?Does your wife show you her love?””

Men who answered yes, lived Men who answered yes, lived

statistically, significantly longer than statistically, significantly longer than

the men who answered no!the men who answered no!

Your life may depend on your love lifeYour life may depend on your love life

Can 10,000 Men Be Wrong?Can 10,000 Men Be Wrong?

Hormones of Love Epinephrine Epinephrine – Typically – Typically

increasesincreases

Makes your heart flutter Makes your heart flutter

and you get those and you get those

butterflies in your stomach butterflies in your stomach

(really excited to see (really excited to see

them!)them!)

Go to a scary movie so Go to a scary movie so

she’ll get scared and cling she’ll get scared and cling

to youto you

Or be a big pansy and hide behind her instead…

That’s weak, bro

More pictures of folks getting scared outta they minds

Best BF ever…

• Totally unphased

Look at that face!No fear, staring it down son!

OG of the Haunted House right there

Don’t worry babe, I got

this…

DopamineDopamine – Triggers the reward systems in the – Triggers the reward systems in the

brainbrain

Increases with novelty (when things are new Increases with novelty (when things are new

and fresh = exciting and awesome)and fresh = exciting and awesome)

Makes you want to be with them all the time, Makes you want to be with them all the time,

obsess over them and always thin about themobsess over them and always thin about them

SerotoninSerotonin – I can’t stop thinking of you – I can’t stop thinking of you

Lowers in people who are newly in loveLowers in people who are newly in love

You’re crazy about them… literallyYou’re crazy about them… literally

Low serotonin levels are also foundLow serotonin levels are also found

in those that have OCD (that’s why you’re so in those that have OCD (that’s why you’re so

obsessive)obsessive)

Oxytocin Oxytocin – the “cuddle” hormone– the “cuddle” hormone

Released when people touch (sexually or non-Released when people touch (sexually or non-

sexually)sexually)

Gives you that sense of trust, security and Gives you that sense of trust, security and

attachmentattachment

Responsible for the intense bond b/w a mom and Responsible for the intense bond b/w a mom and

her babyher baby

Dopamine Serotonin Norepinephrine

Science of Love and HeartbreakThe Science behind Lovehttps://www.youtube.com/watch?feature=player_detailpage&v=sU7lpX6dvF8

https://www.youtube.com/watch?feature=player_detailpage&v=EJaY0pOdJfY#t=29

The Science Behind Heartbreakhttps://www.youtube.com/watch?v=lGglw8eAikY