Young people have created their own digital social networks, including a shorthand type of language for text messaging, and studies show that fewer young adults read books for pleasure now than in any generation before them. Since 1982, literary reading has declined by 28 percent in eighteen- to thirty-four-year-olds. Professor Thomas Patterson and colleagues at Harvard University reported that only 16 percent of adults age eighteen to thirty read a daily newspaper, compared with 35 percent of those thirty-six and older. Patterson predicts that the future of news will be in the electronic digital media rather than the traditional print or television forms.
These young people are not abandoning the daily newspaper for a stroll in the woods to explore nature. Conservation biologist Oliver Pergams at the University of Illinois recently found a highly significant correlation between how much time people spend with new technology, such as video gaming, Internet surfing, and video watching, and the decline in per capita visits to national parks.
Digital Natives are snapping up the newest electronic gadgets and toys with glee and often putting them to use in the workplace. Their parents’ generation of Digital Immigrants tends to step more reluctantly into the computer age, not because they don’t want to make their lives more efficient through the Internet and portable devices but because these devices may feel unfamiliar and might upset their routine at first.
During this pivotal point in brain evolution, Natives and Immigrants alike can learn the tools they need to take charge of their lives and their brains, while both preserving their humanity and keeping up with the latest technology. We don’t all have to become techno-zombies, nor do we need to trash our computers and go back to writing longhand. Instead, we all should help our brains adapt and succeed in this ever-accelerating technological environment.
>>> it’s all in your head
Every time our brains are exposed to new sensory stimulation or information, they function like camera film when it is exposed to an image. The light from the image passes through the camera lens and causes a chemical reaction that alters the film and creates a photograph.
As you glance at your computer screen or read this book, light impulses from the screen or page will pass through the lens of your eye and trigger chemical and electrical reactions in your retina, the membrane in the back of the eye that receives images from the lens and sends them to the brain through the optic nerve. From the optic nerve, neurotransmitters send their messages through a complex network of neurons, axons, and dendrites until you become consciously aware of the screen or page. All this takes a minuscule fraction of a second.
Perception of the image may stir intense emotional reactions, jog repressed memories, or simply trigger an automatic physical response—like turning the page or scrolling down the computer screen. Our moment-to-moment responses to our environment lead to very particular chemical and electrical sequences that shape who we are and what we feel, think, dream, and do. Although initially transient and instantaneous, enough repetition of any stimulus—whether it’s operating a new technological device or simply making a change in one’s jogging route—will lay down a corresponding set of neural network pathways in the brain, which can become permanent.
Your brain—weighing about three pounds—sits cozily within your skull and is a complex mass of tissue, jam-packed with an estimated hundred billion cells. These billions of cells have central bodies that control them, which constitute the brain’s gray matter, also known as the cortex, an extensive outer layer of cells or neurons. Each cell has extensions, or wires (axons), that make up the brain’s white matter and connect to dendrites, allowing the cells to communicate and receive messages from one another across synapses, or connection sites.
The brain’s gray matter and white matter are responsible for memory, thinking, reasoning, sensation, and muscle movement. Scientists have mapped the various regions of the brain that correspond to different functions and specialized neural circuitry. These regions and circuits manage everything we do and experience, including falling in love, flossing our teeth, reading a novel, recalling fond memories, and snacking on a bag of nuts.
The amount and organizational complexity of these neurons, their wires, and their connections are vast and elaborate. In the average brain, the number of synaptic connection sites has been estimated at 1,000,000,000,000,000, or a million times a billion. After all, it’s taken millions of years for the brain to evolve to this point. The fact that it has taken so long for the human brain to evolve such complexity makes the current single-generation, high-tech brain evolution so phenomenal. We’re talking about significant brain changes happening over mere decades rather than over millennia.
>>> young plastic brains
The process of laying down neural networks in our brains begins in infancy and continues throughout our lives. These networks or pathways provide our brains an organizational framework for incoming data. A young mind is like a new computer with some basic programs built in and plenty of room left on its hard drive for additional information. As more and more data enter the computer’s memory, it develops shortcuts to access that information. E-mail, word processing, and search engine programs learn the user’s preferences and repeated keywords, for which they develop shortcuts, or macros, to complete words and phrases after only one or two keys have been typed. As young malleable brains develop shortcuts to access information, these shortcuts represent new neural pathways being laid down. Young children who have learned their times tables by heart no longer use the more cumbersome neural pathway of figuring out the math problem by counting their fingers or multiplying on paper. Eventually they learn even more effective shortcuts, such as ten times any number simply requires adding a zero, and so on.
In order for us to think, feel, and move, our neurons or brain cells need to communicate with one another. As they mature, neurons sprout abundant branches, or dendrites, that receive signals from the long wires or axons of neighboring brain cells. The amount of cell connections, or synapses, in the human brain reaches its peak early in life. At age two, synapse concentration maxes out in the frontal cortex, when the weight of the toddler’s brain is nearly that of an adult’s. By adolescence, these synapses trim themselves down by about 60 percent and then level off for adulthood. Because there are so many potential neural connections, our brains have evolved to protect themselves from “overwiring” by developing a selectivity and letting in only a small subset of information. Our brains cannot function efficiently with too much information.
The vast number of potentially viable connections accounts for the young brain’s plasticity, its ability to be malleable and ever-changing in response to stimulation and the environment. This plasticity allows an immature brain to learn new skills readily and much more efficiently than the trimmed-down adult brain. One of the best examples is the young brain’s ability to learn language. The fine-tuned and well-pruned adult brain can still take on a new language, but it requires hard work and commitment. Young children are more receptive to the sounds of a new language and much quicker to learn the words and phrases. Linguistic scientists have found that the keen ability of normal infants to distinguish foreign-language sounds begins declining by twelve months of age.
Studies show that our environment molds the shape and function of our brains as well, and it can do so to the point of no return. We know that normal human brain development requires a balance of environmental stimulation and human contact. Deprived of these, neuronal firing and brain cellular connections do not form correctly. A well-known example is visual sensory deprivation. A baby born with cataracts will not be able to see well-defined spatial stimuli in the first six months of life. If left untreated during those six months, the infant may never develop proper spatial vision. Because of ongoing development of visual brain regions early in life, children remain susceptible to the adverse effects of visual deprivation until they are about seven or eight years old. Although exposure to new technology may appear to have a much more subtle impact,
its structural and functional effects are profound, particularly on a young, extremely plastic brain.
Of course, genetics plays a part in our brain development as well, and we often inherit cognitive talents and traits from our parents. There are families in which musical, mathematical, or artistic talents appear in several family members from multiple generations. Even subtle personality traits appear to have genetic determinants. Identical twins who were separated at birth and then reunited as adults have discovered that they hold similar jobs, have given their children the same names, and share many of the same tastes and hobbies, such as collecting rare coins or painting their houses green.
But the human genome—the full collection of genes that produces a human being—cannot run the whole show. The relatively modest number of human genes—estimated at twenty thousand—is tiny compared with the billions of synapses that eventually develop in our brains. Thus, the amount of information in an individual’s genetic code would be insufficient to map out the billions of complex neural connections in the brain without additional environmental input. As a result, the stimulation we expose our minds to every day is critical in determining how our brains work.
>>> natural selection
Evolution essentially means change from a primitive to a more specialized or advanced state. When your teenage daughter learns to upload her new iPod while IM’ing on her laptop, talking on her cell phone, and reviewing her science notes, her brain adapts to a more advanced state by cranking out neurotransmitters, sprouting dendrites, and shaping new synapses. This kind of moment-to-moment, day-in and day-out brain morphing in response to her environment will eventually have an impact on future generations through evolutionary change.
One of the most influential thinkers of the nineteenth century, Charles Darwin, helped explain how our brains and bodies evolve through natural selection, an intricate interaction between our genes and our environment, which Darwin simply defined as a “preservation of favorable variations and the rejection of injurious variations.” Genes, made up of DNA—the blueprint of all living things—define who we are: whether we’ll have blue eyes, brown hair, flexible joints, or perfect pitch. Genes are passed from one generation to the next, but occasionally the DNA of an offspring contains errors or mutations. These errors can lead to differing physical and mental attributes that could give certain offspring an advantage in some environments. For example, the genetic mutation leading to slightly improved visual acuity gave the “fittest” ancestral hunters a necessary advantage to avoid oncoming predators and go on to kill their prey. Darwin’s principle of survival of the fittest helps explain how those with a genetic edge are more likely to survive, thrive, and pass their DNA on to the next generation. These DNA mutations also help explain the tremendous diversity within our species that has developed over time.
Not all brain evolution is about survival. Most of us in developed nations have the survival basics down—a place to live, a grocery store nearby, and the ability to dial 911 in an emergency. Thus, our brains are free to advance in creative and academic ways, achieve higher goals, and, it is hoped, increase our enjoyment of life.
Sometimes an accident of nature can have a profound effect on the trajectory of our species, putting us on a fast-track evolutionary course. According to anthropologist Stanley Ambrose of the University of Illinois, approximately three hundred thousand years ago, a Neanderthal man realized he could pick up a bone with his hand and use it as a primitive hammer. Our primitive ancestors soon learned that this tool was more effective when the other object was steadied with the opposite hand. This led our ancestors to develop right-handedness or left-handedness. As one side of the brain evolved to become stronger at controlling manual dexterity, the opposite side became more specialized in the evolution of language. The area of the modern brain that controls the oral and facial muscle movement necessary for language—Broca’s area—is in the frontal lobe just next to the fine muscle area that controls hand movement.
Nine out often people are right-handed, and their Broca’s area, located in the left hemisphere of their brain, controls the right side of their body. Left-handers generally have their Broca’s area in the right hemisphere of their brain. Some of us are ambidextrous, but our handedness preference for the right or the left tends to emerge when we write or use any handheld tool that requires a precision grip.
In addition to handedness, the coevolution of language and toolmaking led to other brain alterations. To create more advanced tools, prehuman Neanderthals had to have a goal in mind and the planning skills to reach that goal. For example, ensuring that a primitive spear or knife could be gripped well and kill prey involved planning a sequence of actions, such as cutting and shaping the tool and collecting its binding material. Similar complex planning was also necessary for the development of grammatical language, including stringing together words and phrases and coordinating the fine motor lingual and facial muscles, which are thought to have further accelerated frontal lobe development.
In fact, when neuroscientists perform functional magnetic resonance imaging (MRI) studies while volunteers imagine a goal and carry out secondary tasks to achieve that goal, the scientists can pinpoint areas of activation in the most anterior, or forward, part of the frontal lobe. This frontal lobe region probably developed at the same time that language and tools evolved, advancing our human ancestors’ ability to hold in mind a main goal while exploring secondary ones—the fundamental components of our human ability to plan and reason.
Brain evolution and advancement of language continue today in the digital age. In addition to the shorthand that has emerged through e-mail and instant messaging, a whole new lexicon has developed through text messaging, based on limiting the number of words and letters used when communicating on handheld devices. Punctuation marks and letters are combined in creative ways to indicate emotions, such as LOL = laugh out loud, and :-) = happy or good feelings. Whether our communications involve talking, written words, or even just emoticons, different brain regions control and react to the various types of communications. Language—either spoken or written—is processed in Broca’s area in our frontal lobes. However, neuroscientists at Tokyo Denki University in Japan found that when volunteers viewed emoticons during functional MRI scanning, the emoticons activated the right inferior frontal gyrus, a region that controls nonverbal communication skills.
>>> honey, does my brain look fat?
Natural selection has literally enlarged our brains. The human brain has grown in intricacy and size over the past few hundred thousand years to accommodate the complexity of our behaviors. Whether we’re painting, talking, hammering a nail or answering e-mail, these activities require elaborate planning skills, which are controlled in the front part of the brain.
As Early Man’s language and toolmaking skills gradually advanced, brain size and specialization accelerated. Our ancestors who learned to use language began to work together in hunting groups, which helped them survive drought and famine. Sex-specific social roles evolved further as well. Males specialized in hunting, and those males with better visual and spatial abilities (favoring the right brain) had the hunting advantage. Our female ancestors took on the role of caring for offspring, and those with more developed language skills (left brain) were probably more nurturing to their offspring, so those offspring were more likely to survive. Even now, women tend to be more social and talk more about their feelings, while men, no longer hunters, retain their highly evolved right-brain visual-spatial skills, thus often refusing to use the GPS navigation systems in their cars to get directions.
The printing press, electricity, telephone, automobile, and air travel were all major technological innovations that greatly affected our lifestyles and our brains in the twentieth century. Medical discoveries have brought us advances that would have been considered science fiction just decades ago. However, today’s technological and digital progress is likely causing our brains to evolve at an unprecedented pace....
&n
bsp; >>> your brain, on google
We know that the brain’s neural circuitry responds every moment to whatever sensory input it gets, and that the many hours people spend in front of the computer—doing various activities, including trolling the Internet, exchanging e-mail, videoconferencing, IM’ing, and e-shopping—expose their brains to constant digital stimulation. Our UCLA research team wanted to look at how much impact this extended computer time was having on the brain’s neural circuitry, how quickly it could build up new pathways, and whether or not we could observe and measure these changes as they occurred.
I enlisted the help of Drs. Susan Bookheimer and Teena Moody, UCLA experts in neuropsychology and neuroimaging. We hypothesized that computer searches and other online activities cause measurable and rapid alterations to brain neural circuitry, particularly in people without previous computer experience.
To test our hypotheses, we planned to use functional MRI scanning to measure the brain’s neural pathways during a common Internet computer task: searching Google for accurate information. We first needed to find people who were relatively inexperienced and naive to the computer. Because the Pew Internet project surveys had reported that about 90 percent of young adults are frequent Internet users compared with less than 50 percent of older people, we knew that people naive to the computer did exist and that they tended to be older.
After initial difficulty finding people who had not yet used computers, we were able to recruit three volunteers in their midfifties and sixties who were new to computer technology yet willing to give it a try. To compare the brain activity of these three computer-naive volunteers, we also recruited three computer-savvy volunteers of comparable age, gender, and socioeconomic background. For our experimental activity, we chose searching on Google for specific and accurate information on a variety of topics, ranging from the health benefits of eating chocolate to planning a trip to the Galápagos.
The Digital Divide Page 9