Male-Female Brain Differences

 

Everyone knows that men and women are different. Men have 4% more brain cells than women, and about 100 grams more brain tissue. Many women ask why men need more brain tissue in order to get the same things done? Even though men seem to have more brain cells, it is reported that women have more dendritic connections between brain cells. It is reported that women can transfer data between the right and left hemisphere faster than man. Men tend to be more left brained, while women have greater access to both sides.

Researches show that females, on average, have a larger deep limbic system than males. This gives females several advantages and disadvantages. Due to the larger deep limbic brain women are more in touch with their feelings, they are generally better able to express their feeling than men. They have an increased ability to bond and be connected to others (that is why women are the primary caretakers for children – there is no society on earth where men are primary caretakers for children). Female have a more acute sense of smell, which is likely to have developed from an evolutionary need for the mother to recognize her young.

But, aside from external anatomic and sexual differences, scientists know also that there are many other subtle differences in the way the brain from men and women processes language, information, emotion, cognition, etc.

One of the most interesting differences appears in the way men and women estimate time, judge speed of things, carry out mental mathematical calculations, orient in space and visualize objects in three dimensions, etc. In all these tasks, women and men are strictly different, as they are too in the way their brains process language. This may account, scientists say, for the fact that there are many more male mathematicians, airplane pilots, bush guides, mechanical engineers, architects and race car drivers than female ones.

On the other hand, women are better than men in human relations, recognizing emotional overtones in others and in language, emotional and artistic expressiveness, esthetic appreciation, verbal language and carrying out detailed and pre-planned tasks.

The “father” of sociobiology, Edward O. Wilson, of Harvard University, said that human females tend to be higher than male in empathy, verbal skills, social skills and security-seeking, among other things, while men tend to be higher in independence, dominance, spatial, and mathematical skills, rank-related aggression, and other characteristics.

When all these investigations began, scientists were skeptical about the role of genes and of biological differences, because cultural learning is very powerful and influential among humans. Are girls more prone to play with dolls and cooperate among themselves than boys, because they are taught to be so by parents, teachers and social peers, or is it the reverse order?

However, gender differences are already apparent from just a few months after birth, when social influence is still small. For example, Anne Moir and David Jessel, in their remarkable and controversial book “Brain Sex”, offer explanations for these very early differences in children. “These discernible, measurable differences in behaviour have been imprinted long before external influences have had a chance to get to work. They reflect a basic difference in the newborn brain which we already know about – the superior male efficiency in spatial ability, the greater female skill in speech.”

According to the Society for Neuroscience, the largest professional organization in this area, evolution is the reason for these gender differences in structure and function. “In ancient times, each sex had a very defined role that helped ensure the survival of the species. Cave men hunted. Cave women gathered food near the home and cared for the children. Brain areas may have been sharpened to enable each sex to carry out their jobs.” Prof. David Geary, at the University of Missouri, USA, a researcher in the area of gender differences, thinks that “in evolutionary terms, developing superior navigation skills may have enabled men to become better suited to the role of hunter, while the development by females of a preference for landmarks may have enabled them to fulfill the task of gathering food closer to home.” The advantages of women regarding verbal skills also make evolutionary sense. While men have the bodily strength to complete with other men, women use language to gain social advantage, such as by argumentation and persuasion.

In another research, a group from the University of Cincinnati, USA, Canada, presented morphological evidence that while men have more neurons in the cerebral cortex, women have the space between cell bodies, which contain synapses, dendrites and axons, and allows for communication among neurons. This research may explain why women are more prone to dementia than men, because although both may lose the same number of neurons due to the disease, “in males, the functional reserve may be greater as a larger number of nerve cells are present, which could prevent some of the functional losses.”

Other researchers, from the Yale University School of Medicine, discovered that the brain of women processes verbal language simultaneously in the two sides of the front brain, while men tend to process it in the left side only. They performed a functional planar magnetic resonance tomographic imaging of the brains of 38 right-handed subjects (19 males and 19 females). The difference was demonstrated in a test that asked subjects to read a list of nonsense words and determine if they rhyme. Curiously, oriental people who use pictographic written language tend to use both sides of the brain, regardless of gender.

Do these differences mean a superiority/inferiority relationship between men and women? “No”, says Dr.Pearlson. “To say this means that men are automatically better at some things than women is a simplification. It’s easy to find women who are fantastic at math and physics and men who excel in language skills. Only when we look at very large populations and look for slight but significant trends we do see the generalizations. There are plenty of exceptions, but there’s also a grain of truth, revealed through the brain structure, that we think underlies some of the ways people characterize the sexes.”

 

Text 2

Memory’s Mind Games

 

When it comes to memory problems, forgetting is only the tip of the iceberg. The failure and failing of memory run much deeper than an inability to recall your neighbor’s name, the capital of Illinois or the location of your keys. Much recent memory research has focused on why we forget, shedding light on tragedies like Alzheimer’s as well as puzzles like why we often know the first letter of a name or word we are trying to remember, but not the rest of it. But unlike absent-mindedness and other ‘sins of omission”, – as psychologist Daniel Schacter of Harvard University calls them in his new book, “The Seven Sins of Memory”, memory’s “sins of commission” shape – and often distort – our view of reality and relationships. Some of the sins:

Blocking. Somewhere between remembering and forgetting lies blocking. You know that the word for an oration at a funeral begins with a vowel, maybe even a “u” … but it just won’t spring into consciousness. You know the name of the longtime neighbor who us approaching as you talk to the new people next door, but as the seconds tick down until you will have to make the introduction, the best you can come up with is that his name begins with an “R”. Proper names are blocked more than any other words, memory researchers find, and more in old people than young. The problem with names is that they are (in Western cultures, at least) completely arbitrary: that guy looks no more like a Richard than he does a Paul. Also, the sound of a word is encoded in the brain in a different place from its meaning. If the links from concept (the context in which you know a person) to visual representation (aha, that face belongs to my neighbor!) to the word itself (Paulie Walnuts) are weak, then we can’t get to the word even though we can remember everything about it. You may tick neurons here, but the reverberations never reach those deeper in the circuit.

Sometimes we get to the first sound in the word but no further: the phonemes of words are apparently encoded separately, too, and coming up with that “eu-” sound doesn’t guarantee that will move on to “-lo.” Words we use infrequently are especially subject to this tip-of-the-tongue phenomenon. If you need to remember which medicine to take for a common ailment, you will probably come up easily with “aspirin” for a headache or “antacid” for a stomach upset. But you might well struggle before remembering what’s needed to treat a sudden allergic reaction: “antihistamine”.

Misattribution. The EL AL cargo flight had smashed into an apartment building outside Amsterdam killing 39 residents and all four crew members in a fiery explosion. Ten months after the 1992 disaster, Dutch psychologists quizzed colleagues about how well they remembered television footage of the crash. Most remembered it so well that they could describe whether the fuselage was aflame before it hit, where the plane fell after impact and other details. But there was no such footage: people attributed to video what they had inferred from newspapers, discussions with friends and other sources.

In misattribution, people unconsciously transfer a memory from one mental category to another – from imagination to reality, from this time and place to that one, from hearsay to personal experience. The brain has made what psychologists call a “binding error,” incorrectly linking the content of a memory with its context. The fault may lie in the hippocampus, a seahorse-shaped structure deep in the brain’s temporal lobe, whose job includes binding together all facets of a memory. When the hippocampus is damaged, patients are more prone to binding errors. So next time you believe that you experienced something you only imagined, or that you mentioned your impending business trip to your wife when in fact you told only your secretary, blame a hiccup in your hippocampus.

Suggestibility. In this memory error, people confuse personal recollection with outside sources of information. Suggestibility is therefore a form of misattribution, but an especially pernicious one. “Leading questions or even encouraging feedback can result in ‘memories’ of events that never happened,” says Schacter. In one recent case, Korean War veteran Edward Daly became convinced that he participated in the horrific massacre of civilians at No Gun Ri. Military records show he was nowhere near the site at the time, suggesting that he had confused hearing rumors of the massacre with witnessing it. (Some reporters, though, believe he was outright lying). But that wasn’t the end of it. As Delt talked to vets who were present at the massacre, “reminding” them about his deeds that day, several became convinced, as one told The New York Times, that “Daly was there. I know that. I know that.”

Suggestibility can lead to false eyewitness IDs because even seemingly innocuous feedback can distort recall. In one study, psychologist Gary Wells of Iowa State University and colleagues showed volunteers a security video of a man entering a Target Store. Moments later, Well told them, the man murdered a guard. He then showed them photos and asked them to identify the gunman (who actually appeared in none of the snapshots). Good, you identified the actual suspect, the scientists told some of the volunteers. Those who received this encouragement later told Wells they were more confident in their recall and had had a better view of the man on the video than those who did not get a verbal pat on the back for their “correct” ID. Certainty and your assurance that you got a good look at the suspect are the kinds of details a jury uses when weighing eyewitness testimony. Positive feedback seems to cement memory and even erase any original uncertainty.

Persistence. Memories that refuse to fade tend to involve regret, trauma and other potent negative emotions. All emotions strengthen a memory, but negative ones seem to write on the brain in indelible ink, Schacter finds. That’s especially true if the memory reinforces your self-image: if you think of yourself as a crew-up, you’ll have hard time erasing the memory of the time you spilled wine all over your boss. Blame your amyglada. When you experience a threatening event like the approach of a menacing stranger, the level of activity in this clutch of brain neurons predicts how well you will remember the experience. Stress hormones seem to strengthen the neuronal circuit that embodies a traumatic memory.

Bias. It is a cliche that couples in love recall their courtship as a time of bliss, while unhappy pairs recall that “I never really loved him (or her).” But the cliche is true. “We rewrite our memories of the past to fit our present views and needs,” says Schacter. That may be an outgrowth of forgetting: we can’t recall how we felt in the past, so we assume it must be how we feel today. But often bias arises when more powerful mental systemsbully poor little memory.

Stereotyping can also bias memory. Researchers at Yale University asked students which names on a list they recalled as those of criminals recently in the news. The students were twice as likely to “remember” the stereotypically black names as they were the stereotypically white ones. None of the names had been in the news as criminal suspects or anything else, the scientists reported in 1999. When memory conflicts with what you’re convinced is true, it often comes out on the losing end. And that can make forgetting where you put your keys seem trivial indeed.

Text 3

 

Купите мозги

 

Молодой человек, решивший поглумиться над своей супругой, а заодно поупражняться в остроумии, выставил на Интернет-аукционе ее мозги.

В описании к лоту Кевин Долейк указывает, что предлагаемые мозги абсолютно новенькие и ранее никогда не использовались. К объявлению прилагается фотопортрет его жены Верены с припиской, что мозги “пока находятся в этой коробке”.

За размещение объявления на сайт Кевин заплатил 2,5 доллара. В обращении к потенциальным покупателям он говорит, что мозги этой голове абсолютно не нужны и что он с удовольствием избавится от них за любую сумму. В течение первой недели объявление прочитали около 200 человек, но только четверо предложили цену, причем самая высокая составила 4,5 долларов.
“Жена постоянно твердит, что у нее с головой не в порядке, если она согласилась выйти за меня замуж. Вот я и решил отомстить ей. Впредь я буду припоминать ей, что мало кто заинтересовался ее мозгами”, – говорит Кевин. Но Верена нисколько не обескуражена такими результатами и добавляет, что если поставить на продажу мозги Кевина, то ими вообще вряд ли кто заинтересуется, даже психиатры.

 

Text 4

Подзаряди свой мозг

Посещение ментального курорта, примерно 2015 год. Терапевтические процедуры начинаются с нескольких тестов – от визуальных головоломок и упражнений на проверку памяти до игр для замера времени реакции. После оценки результатов на вас надевают легкий шлем, в который вмонтированы электромагнитные катушки. Пока вы расслабляетесь, аттестованный «нейротренер» изучает трехмерное изображение вашего мозга с целью регулирования установочных параметров шлема. Вы ощущаете необычный прилив энергии по мере того, как устройство безболезненно обрабатывает ваше серое вещество.

Такой сценарий не так далек от реальности, как представляется на первый взгляд. В работе, спонсируемой Агентством передовых исследований в области обороны (ААИО), ученый-невролог Марк Джордж и его коллеги по Медицинскому университету (шт. Южная Каролина) разработали легковесную электромагнитную катушку, которую в будущем можно будет устанавливать в шлем летчика для снятия усталости. При помощи устройства транскраниальной магнитной стимуляции (ТМС) микросекундные импульсы энергии проникают в мозг испытуемого на глубину нескольких сантиметров, стимулируя тем самым электрическую активность клеток мозга. Исследования показали, что подача магнитного импульса непосредственно перед тем как испытуемый должен будет нажать кнопку в ответ на звуковой сигнал повышает время реакции на 5-10% «так, как будто эта часть мозга была подготовлена к действию», – говорит Джордж. В сочетании с отображением функционального магнитного резонанса (ОФМР), дающего трехмерное изображение активности мозга, ТМС получает способность нацеливаться на определенный участок нейронов. Группа Джорджа показала, что еженедельная ритмическая стимуляция прифронтальной коры головного мозга, т.е. той части мозга, в которой замечены нарушения у многих пациентов, страдающих депрессией, может облегчить их симптомы. Исследователи, занимающиеся ТМС, также надеются разработать технику проникновения в кору головного мозга, что может позволить найти способы лечения таких нарушений, как болезнь Паркинсона. Более того, Джордж надеется, что когда-нибудь эта методика может быть использована для стимулирования центров удовольствия мозга.

Тем временем Helicon Therapeutics и другие лаборатории разрабатывают соединения, призванные повысить когнитивную эффективность и расширить возможности памяти, из них будут состоять напитки в меню бара ментального курорта. Объектом нового лекарства является белок, отвечающий за способность памяти реагировать на возникающие ситуации, т.е. молекула, способствующая формированию долгосрочной памяти. В основе лекарства, предложенного лабораторией Helicon, лежало исследование, которое Тим Тулли, профессор лаборатории Cold Spring Harbor и его соавтор Джерри Ин, который в настоящее время работаете университете шт. Висконсин, провели в 1995 году. Генетически модифицируя плодовых мушек с целью увеличения объема белка в их мозгах, ученые вывели насекомых с эквивалентом фотографической памяти. Генетически модифицированные мушки смогли это делать уже после первой тренировки. «Мы показали на подопытных мушках, что лекарство, разработанное в Helicon, сокращает время наработки, необходимое для совершения чего-то такого, что требует активации долговременной памяти», – говорит Тулли.

Если мозговые курорты когда-либо появятся, то первыми клиентами, скорее всего, будут люди с нарушениями работы мозга, вызванными старением и болезнями. По мнению Тулли, пройдет целое десятилетие или больше, прежде чем мозговая терапия будет применяться к здоровым людям, потому что потенциальные риски, связанные с манипулированием мозгом, выходят далеко за рамки обычных побочных эффектов. «Не исключено, например, что при помощи мозговой терапии вы сможете стать высококлассным водителем, но при этом в вашем мозгу произойдут такие изменения, что через несколько лет он уже просто не сможет воспринять ничего другого», – считает Дэвид Песковитц.

 

UNIT 2

ADDICTIONS

Text 1