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Is Brain Eye connections reversed in all animals or just Humans?

Is Brain Eye connections reversed in all animals or just Humans?


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I know that Brain Eye connections are reversed in Humans,

  • Left Hemisphere controls the Right eye/Right side of the body
  • Right Hemisphere Controls the Left eye/Left side of the body

Is it true in other animals like Birds,Cephalopods and other creatures?

Are the optic nerves physically connected in reverse or is it internally mapped ?


That's not completely true. In mammals, including humans, the left of an image projects to the right of each of your retinae (this is due to the eye working like a camera obscura), and conversely for the right of an image. So you have 2 eyes, each eye receives mostly identical information but one is on the left and one is on the right of your body. You must somehow recombine this information together in the visual cortex. The way this is done is through the optic chiasma, where roughly half the nerves from the nasal parts (the half closer to the center of your body) of each retina cross. Then connect to a relay called Lateral Geniculate Nucleus and then connect to the brain. Below you can see a drawing from Ramón y Cajal, who first proposed this theory, depicting the process.

As you can see the points on each retina that receive information from the same parts of the visual field (here represented by the arrow) project to identical locations in the brain. So there is not a complete decussation (anatomical name for a crossing of nerves) like for muscles, but only a partial decussation of about half in humans.

Although y Cajal was the first to explain exactly why it makes sense to have partial decussation, this phenomenon had been known for a very long time. In facts Newton (hardly an anatomist) discusses that phenomenon in his Optiks and suggested that it might be related to the amount of overlap between the 2 eyes. So the more overlap, the higher the amount of partial decussation. This rule, later called Newton-Muller-Gudden law by Walls, seems to be approximately correct for mammals. However, as noted by Walls, there is no evidence of partial decussation in vertebrates other than mammals. Meaning that the decussation is complete (like muscles). In his Optiks Newton concludes that (I'm paraphrasing) if his theory is right then animals with no binocular overlap should have no decussation, which if he is well-informed is true for chameleons. His theory was indeed right but he was misinformed, chameleons have complete decussation.

Finally non-vertebrates do not have "contra-lateral" brains. They do not have this strange property of having each hemisphere mostly connected to the opposite side of their body. Therefore they have no decussation at all.

So in short: vertebrates-mammals = partial decussation ; vertebrates-non-mammals = total decussation ; non-vertebrates = no decussation.

Although dated, Walls book remain the most complete reference discussing decussation:

Walls, G. L. (1944). The vertebrate eye and its adaptive radiation.


According to Wikipedia, the nerves cross in all the vertebrates:

In vertebrates with a large overlap of the visual fields of the two eyes, i.e., most mammals and birds, but also amphibians, reptilians such as chameleons, the two optic nerves merge in the optic chiasm. Part of the nerve fibres do not cross the midline, but continue towards the optic tract of the same side. The purpose is so that the part of the visual field that is covered by both eyes is joined so that the processing of binocular depth perception by Stereopsis is enabled.

https://en.wikipedia.org/wiki/Optic_chiasm


Hormones and Brain Regions Behind Eye Contact and Empathy

THE BASICS

Just the briefest eye contact can heighten empathetic feelings, giving people a sense of being drawn together. But patients who suffer from autism, even in its most high-functioning forms, often have trouble making this sort of a social connection with other people. Researchers are delving into what’s going on behind the eyes when these moments occur, and the hormones and neural substrates involved may offer hope of helping people with autism in the future. Here are some examples.

We take mental snapshots when we look at people. When you look at someone's face, your eyes may pause or fixate on their eyes, mouth, or nose for only 1/4 to 1/3 second before darting to another point, in a path that can be traced with eye tracking technology. The pauses allow a kind of mental snapshot that we use to get an impression of the other person. But people with Autism Spectrum Disorder, even the high-functioning type also known as Asperger's Syndrome, tend to avoid looking at the eyes.

A hormone can encourage eye contact and empathy. That's why Bonnie Auyung's findings that a dose of oxytocin hormone increased the fraction of time that men with autism looked at an interviewer's eyes, as it did with typical men, could point to future treatment, especially if combined with cognitive-behavioral therapy that encourages practice in gazing directly and empathizing with others.

As James Rilling, a cognitive neuroscientist at Emory University, told me by phone, "The ability of oxytocin to get the men to look at the eye region of the face more is probably very important because we receive so many social cues from the eye region”. “If you’re not attending to those social cues, you miss a lot, and then in turn you miss the opportunity to learn a lot about appropriate social behavior.” If oxytocin could normalize this ability for those with autism, Rilling adds, it would “give more opportunity to work on social skill building.”

The hormone, widely known as Pitocin for its use in childbirth, appears to excite oxytocin receptor sites on neurons in the brain.

Eye contact may normally activate certain "social brain" regions. Even when it occurs, eye contact, or direct gaze, appears to activate certain brain regions in typical people more than in people with autism. With brain scans by functional magnetic resonance imagery (fMRI), Elizabeth von dem Hagen of the UK's Medical Research Council found those regions where the temporal lobe in the side of the brain joins the parietal lobe above it, in front of the region where the visual cortex receives signals from the retina.

Another site identified by von dem Hagen is in the frontal lobe near the midline. These and other regions have been deemed part if a "social brain" network that responds to direct gaze and other social signals.

Direct gaze is a social signal in non-human primates too. When one monkey used a touch screen to present a juice treat to another, it tended to look them in the eye. But when it punished them with a puff of air, it tended to look away. This behavior in nonhuman primates reinforces the idea that eye contact or mutual gaze and empathic actions can be interpreted on both biological and psychological levels.

A behavior that seems so simple and natural to many of us can be a difficult psychosocial event to individuals with autism. But as researchers dig into the neural, hormonal, and behavioral drivers at play behind eye contact, there may be hope that some of the neurological and behavioral symptoms of autism spectrum conditions may someday be alleviated.

THE BASICS

Adapted with permission from an article that appeared in The Scientist, August 2016.


Three Emotion Systems that Complicate Human Life

I believe that three primary, distinct, but interrelated emotion systems in the brain mediate mating, reproduction, and the rearing of young: lust, attraction, and attachment. Each emotion system is correlated with a specific neurobiology in the brain each is associated with a different repertoire of behavior and each evolved to direct a specific aspect of reproduction in birds and mammals.

THE SEX DRIVE (libido or lust) is characterized by the craving for sexual gratification and associated primarily with the hormones (the estrogens and the androgens). The sex drive evolved to motivate individuals to seek sexual union with any appropriate partner.

THE ATTRACTION SYSTEM (in humans termed “passionate love,” “obsessive love,” or “infatuation”) is characterized by increased energy and the focusing of attention on a preferred mating partner. In humans, attraction is also associated with feelings of exhilaration, intrusive thinking about the beloved, and the craving for emotional union. Attraction, I hypothesize, is associated in the brain primarily with high levels of the neurotransmitters dopamine and norepinephrine and with low levels of serotonin. This emotion system evolved chiefly to enable males and females to distinguish among potential mating partners, conserve their mating energy, prefer genetically superior individuals, and pursue these individuals until insemination had been completed.

THE ATTACHMENT SYSTEM (termed “companionate love” in humans) is characterized in birds and mammals by behavior that may include defense of a mutual territory, mutual nest building, mutual feeding and grooming, separation anxiety, and shared parental chores. In humans, attachment is also characterized by feelings of calm, security, social comfort, and emotional union. Attachment is associated in the brain primarily with the neuropeptides oxytocin and vasopressin. This emotion system evolved to motivate individuals to sustain their affiliations long enough to complete the parental duties of their species.

For each system, the neural circuits can be expected to vary from one species to the next, among individuals within a species, and over the life of an individual. The three emotion systems also act in concert with one another and with other bodily systems. For example, a person may begin a sexual liaison merely for sexual pleasure, then become romantically involved with this sexual partner. He can become deeply attached to this partner, too, and these enhanced feelings of attachment can be explained biologically. After orgasm, levels of vasopressin rise in men levels of oxytocin rise in women. These hormones are known to cause attachment, and probably contribute to the feelings of closeness after sexual intercourse.

The three emotion systems can act independently, as well. Individuals in approximately 90 percent of bird species form seasonal or lifelong pair bonds, becoming attached and rearing their offspring together. Yet “a lot of birds are having a bit on the side,” reports Jeffrey Black of Cambridge University. 1 In fact, individuals in only 10 percent of the 180 or so species of socially monogamous songbirds are sexually faithful to their mating partners the rest engage in “extra-pair” copulations.

Likewise, men and women can express deep attachment for a long-term spouse or mate at the same time they express attraction for someone else, and also while they feel the sex drive in reaction to situations unrelated to either partner. We are physiologically capable of “loving” more than one person at a time.

The independence of these emotion systems may have evolved among our ancestors to enable males and females to take advantage of several mating strategies simultaneously. With this brain architecture, they could form a pair bond with one partner and practice clandestine adultery too, thereby taking advantage of rare “extra” mating opportunities. They could also practice polygamy if the opportunity arose. But for modern humans, these distinct brain circuits have enormously complicated life, contributing to today’s worldwide patterns of adultery and divorce the high incidence of sexual jealousy, stalking, and spouse battering and the prevalence of homicide, suicide, and clinical depression associated with romantic rejection.

What is the biology of these emotion systems? Why did they evolve in humans? To what extent do they control our lives? How should we use this information in the practice of medicine and the law? I will consider lust, attraction, and attachment separately, and focus my attention on attraction, the least understood of these fundamental emotion systems, the one we have come to call “romantic love.”


The U.S. federal government has awarded more than $28 million to Harvard’s John A. Paulson School of Engineering and Applied Sciences (SEAS), Center for Brain Science (CBS), and Department of Molecular and Cellular Biology to develop advanced machine learning algorithms by pushing the frontiers of neuroscience.

The Intelligence Advanced Research Projects Activity (IARPA) funds large-scale research programs that address the most difficult challenges facing the intelligence community.

Intelligence agencies today are inundated with data — more than they are able to analyze in a reasonable amount of time. Humans, naturally good at recognizing patterns, can’t keep pace with the influx of new information. The pattern-recognition and learning abilities of machines, meanwhile, still pale in comparison to even the simplest mammalian brains.

IARPA’s challenge: figure out why brains are so good at learning, and use that information to design computer systems that can interpret, analyze, and learn information as successfully as humans. To tackle this, Harvard researchers will record activity in the brain’s visual cortex in unprecedented detail, map its connections at a scale never before attempted, and reverse-engineer the data to inspire better computer algorithms for learning.

“This is a moonshot challenge, akin to the Human Genome Project in scope,” said project leader David Cox, assistant professor of molecular and cellular biology and computer science. “The scientific value of recording the activity of so many neurons and mapping their connections alone is enormous, but that is only the first half of the project. As we figure out the fundamental principles governing how the brain learns, it’s not hard to imagine that we’ll eventually be able to design computer systems that can match, or even outperform, humans.”

“This project is not only pushing the boundaries of brain science, it is also pushing the boundaries of what is possible in computer science.” — Hanspeter Pfister

These systems could be designed to detect network invasions, read MRI images, drive cars, or anything in between.

The research team tackling this challenge includes Jeff Lichtman, the Jeremy R. Knowles Professor of Molecular and Cellular Biology Hanspeter Pfister, the An Wang Professor of Computer Science Haim Sompolinsky, the William N. Skirball Professor of Neuroscience and Ryan Adams, assistant professor of computer science as well as collaborators from MIT, Notre Dame, New York University, the University of Chicago, and Rockefeller University.

The multi-stage effort begins in Cox’s lab, where rats will be trained to visually recognize various objects on a computer screen. As the animals are learning, Cox’s team will record the activity of visual neurons using next-generation laser microscopes built for this project with collaborators at Rockefeller, to see how brain activity changes. Then, a substantial portion of the rat’s brain — 1 cubic millimeter in size — will be sent down the hall to Lichtman’s lab, where it will be sliced ultra-thin and imaged under the world’s first multi-beam scanning electron microscope, housed in the Center for Brain Science.

“This is an amazing opportunity to see all the intricate details of a full piece of cerebral cortex,” says Lichtman. “We are very excited to get started but have no illusions that this will be easy.”

This difficult process will generate over a petabyte of data — equivalent to about 1.6 million CDs worth of information. This vast trove of data will then be sent to Pfister, whose algorithms will reconstruct cell boundaries, synapses, and connections, and visualize them in three dimensions.

“This project is not only pushing the boundaries of brain science, it is also pushing the boundaries of what is possible in computer science,” said Pfister. “We will reconstruct neural circuits at an unprecedented scale from petabytes of structural and functional data. This requires us to make new advances in data management, high-performance computing, computer vision, and network analysis.”

If the work stopped here, its scientific impact would already be enormous — but it doesn’t. Once researchers know how visual cortex neurons are connected to each other in three dimensions, the next task will be to figure out how the brain uses those connections to quickly process information and infer patterns from new stimuli. Today, one of the biggest challenges in computer science is the amount of training data that deep-learning systems require. For example, to learn to recognize a car, a computer system needs to see hundreds of thousands of cars. But humans and other mammals don’t need to see an object thousands of times to recognize it — they only need to see it a few times.

In subsequent phases of the project, researchers at Harvard and their collaborators will build computer algorithms for learning and pattern recognition that are inspired and constrained by the connectomics data. These biologically-inspired computer algorithms will outperform current computer systems in their ability to recognize patterns and make inferences from limited data inputs. Among other things, this research could improve the performance of computer vision systems that can help robots see and navigate through new environments.

“We have a huge task ahead of us in this project, but at the end of the day, this research will help us understand what is special about our brains,” Cox said. “One of the most exciting things about this project is that we are working on one of the great remaining achievements for human knowledge — understanding how the brain works at a fundamental level.”


Neuroscientists reveal how the brain can enhance connections

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When the brain forms memories or learns a new task, it encodes the new information by tuning connections between neurons. MIT neuroscientists have discovered a novel mechanism that contributes to the strengthening of these connections, also called synapses.

At each synapse, a presynaptic neuron sends chemical signals to one or more postsynaptic receiving cells. In most previous studies of how these connections evolve, scientists have focused on the role of the postsynaptic neurons. However, the MIT team has found that presynaptic neurons also influence connection strength.

“This mechanism that we’ve uncovered on the presynaptic side adds to a toolkit that we have for understanding how synapses can change,” says Troy Littleton, a professor in the departments of Biology and Brain and Cognitive Sciences at MIT, a member of MIT’s Picower Institute for Learning and Memory, and the senior author of the study, which appears in the Nov. 18 issue of Neuron.

Learning more about how synapses change their connections could help scientists better understand neurodevelopmental disorders such as autism, since many of the genetic alterations linked to autism are found in genes that code for synaptic proteins.

Richard Cho, a research scientist at the Picower Institute, is the paper’s lead author.

Rewiring the brain

One of the biggest questions in the field of neuroscience is how the brain rewires itself in response to changing behavioral conditions — an ability known as plasticity. This is particularly important during early development but continues throughout life as the brain learns and forms new memories.

Over the past 30 years, scientists have found that strong input to a postsynaptic cell causes it to traffic more receptors for neurotransmitters to its surface, amplifying the signal it receives from the presynaptic cell. This phenomenon, known as long-term potentiation (LTP), occurs following persistent, high-frequency stimulation of the synapse. Long-term depression (LTD), a weakening of the postsynaptic response caused by very low-frequency stimulation, can occur when these receptors are removed.

Scientists have focused less on the presynaptic neuron’s role in plasticity, in part because it is more difficult to study, Littleton says.

His lab has spent several years working out the mechanism for how presynaptic cells release neurotransmitter in response to spikes of electrical activity known as action potentials. When the presynaptic neuron registers an influx of calcium ions, carrying the electrical surge of the action potential, vesicles that store neurotransmitters fuse to the cell’s membrane and spill their contents outside the cell, where they bind to receptors on the postsynaptic neuron.

The presynaptic neuron also releases neurotransmitter in the absence of action potentials, in a process called spontaneous release. These “minis” have previously been thought to represent noise occurring in the brain. However, Littleton and Cho found that minis could be regulated to drive synaptic structural plasticity.

To investigate how synapses are strengthened, Littleton and Cho studied a type of synapse known as neuromuscular junctions, in fruit flies. The researchers stimulated the presynaptic neurons with a rapid series of action potentials over a short period of time. As expected, these cells released neurotransmitter synchronously with action potentials. However, to their surprise, the researchers found that mini events were greatly enhanced well after the electrical stimulation had ended.

“Every synapse in the brain is releasing these mini events, but people have largely ignored them because they only induce a very small amount of activity in the postsynaptic cell,” Littleton says. “When we gave a strong activity pulse to these neurons, these mini events, which are normally very low-frequency, suddenly ramped up and they stayed elevated for several minutes before going down.”

Synaptic growth

The enhancement of minis appears to provoke the postsynaptic neuron to release a signaling factor, still unidentified, that goes back to the presynaptic cell and activates an enzyme called PKA. This enzyme interacts with a vesicle protein called complexin, which normally acts as a brake, clamping vesicles to prevent release neurotransmitter until it’s needed. Stimulation by PKA modifies complexin so that it releases its grip on the neurotransmitter vesicles, producing mini events.

When these small packets of neurotransmitter are released at elevated rates, they help stimulate growth of new connections, known as boutons, between the presynaptic and postsynaptic neurons. This makes the postsynaptic neuron even more responsive to any future communication from the presynaptic neuron.

“Typically you have 70 or so of these boutons per cell, but if you stimulate the presynaptic cell you can grow new boutons very acutely. It will double the number of synapses that are formed,” Littleton says.

The researchers observed this process throughout the flies’ larval development, which lasts three to five days. However, Littleton and Cho demonstrated that acute changes in synaptic function could also lead to synaptic structural plasticity during development.

“Machinery in the presynaptic terminal can be modified in a very acute manner to drive certain forms of plasticity, which could be really important not only in development, but also in more mature states where synaptic changes can occur during behavioral processes like learning and memory,” Cho says.

The study is significant because it is among the first to reveal how presynaptic neurons contribute to plasticity, says Maria Bykhovskaia, a professor of neurology at Wayne State University School of Medicine who was not involved in the research.

“It was known that the growth of neural connections was determined by activity, but specifically what was going on was not very clear,” Bykhovskaia says. “They beautifully used Drosophila to determine the molecular pathway.”

Littleton’s lab is now trying to figure out more of the mechanistic details of how complexin controls vesicle release.


Researchers question the cooperative eye hypothesis

Credit: Pixabay/CC0 Public Domain

The sclera of the eye is devoid of pigment, which is why humans can easily follow where counterparts are looking. Researchers have long believed this facilitates glance-based communication. A team of zoologists based at the University of Duisburg-Essen (UDE) and the Anthropological Institute in Zurich is now challenging this traditional view in a new study. The researchers looked at communicative behavior and eye color in apes and question the proposed connection between the two phenomena. The results have just been published in Scientific Reports.

"Part of this hypothesis is based on the idea that among primates, only humans have white sclerae," says study leader Kai Caspar (UDE). "However, only few comparative data have been available to back up this claim. Therefore, we assessed scleral pigmentation and measured eye contrast values in photos of more than 380 hominoids from 15 species. These included humans, great apes such as chimpanzees and orangutans, and gibbons, the small apes."

Although all hominoids are closely related, they communicate by different means. UDE zoologist Caspar says, "Different from us humans, glances play only a subordinate role in great ape communication, and for the gibbons they seem to have no communicative significance at all. So if the traditional assumption were true, differences in pigmentation should comply to differences in communicative behavior: the lighter the sclera, the more are the eyes used to convey information."

But this is not the case, as the study was able to show. Neither is the white of the human eye unique, nor can a connection be made between scleral color and communicative demands. "The expression of contrast in our eyes is not significantly different from that in some great apes, such as the Sumatran orangutan. Interestingly, however, scleral pigmentation can sometimes be highly variable within the same ape species. In humans, there is only plain white. This uniformity is a quite unusual extreme."

The zoologists around Kai Caspar fully reject the common assumption that the lightening of our sclera arose for the purpose of effective communication. Instead, they suspect other evolutionary mechanisms such as genetic drift or sexual selection to be at play: "These may have altered the appearance of our eyes in comparison to that of our closest living relatives."


How Does Human Sleep Compare With the Sleep of Other Animals?

It’s not only the required amount of sleep that varies among humans and other animals. Sleep cycles and processes that take place during sleep can also differ. These differences in sleep habits and needs are caused by many factors, including brain size, diet, body mass index (BMI), and social hierarchy. Predatory animals usually sleep in longer uninterrupted periods that are diurnal—primarily at night, like humans—or nocturnal—primarily during the daytime, like tigers.

REM Sleep in Humans and Animals

What happens while humans sleep? During sleep, our bodies cycle through four stages. Physical changes take place during each stage, such as decreased temperature and heart rate. Different types of brain activity also occur during each stage, with more activity taking place during the fourth stage, called rapid-eye movement (REM) sleep. In addition to the fluttering eyes behind eyelids, this sleep phase is also characterized by muscle twitching and waking-like electrical brain patterns (electroencephalogram or EEG). Although humans can dream during any phase of sleep, they are most likely to during REM sleep.

Do all animals have REM sleep? Many terrestrial mammals, including primates, and some reptiles, birds, and aquatic invertebrates experience REM sleep. The amount of REM sleep varies widely depending on the species. Because elephants sleep so little, REM sleep doesn’t happen daily for them. In contrast, house cats can spend up to 8 hours a day in REM sleep.

Some animals, such as dolphins and whales, do not show typical behaviors associated with REM sleep. However, whales do exhibit some muscle jerking that might be representative of REM sleep.

The cycles of REM sleep vary across species, too. Humans experience REM sleep approximately every 90–120 minutes during sleep, while mice experience REM sleep every 10–15 minutes.

The Brain During Sleep in Humans and Animals

Animals obtain their sleep and rest in a multitude of ways. In contrast to humans, some animals only have one hemisphere of the brain sleep at a time. For example, in dolphins, it appears that only one half of the brain exhibits sleep characteristics while the other exhibits wakeful characteristics. This allows them to swim to the water’s surface to breathe in while sleeping.

Lack of Sleep in Humans and Animals

Without enough sleep, humans are susceptible to changes in mood, impaired memory, illness, and even death. These risks are true for many animals as well, such as rats. Rats that are sleep-deprived quickly lose weight and develop infections. After just a few weeks without proper sleep, rats die.

How Does Human Sleep Compare To Other Primate Sleep?

In a study of 30 types of primates, humans slept the least over a 24-hour period. One hypothesis explaining why humans sleep less than other primates is that in the past, humans faced increased pressures of survival, risks of being preyed upon, and benefits of social interaction. These experiences likely impacted current sleep practices. Today, humans have shorter, deeper sleep with more REM cycles than other primates. Human sleep is described as “more efficient” than the sleep of primates.

One clear commonality among primates is nest making, or, in the case of humans, bed making. Nest building is present across great ape species, though shapes, sizes, and locations of nests vary. Because of the prevalence of nest building, it is hypothesized that the last common ancestor between humans and other primates was a nest builder. While primate nests may have once been used primarily for feeding, they evolved into spaces of rest that promote better sleep. It’s also hypothesized that ground sleeping made human ancestors more vulnerable, so sleeping periods had to become shorter.


Disorders of Development

Damage during development affects the brain in a qualitatively different manner than does damage during adulthood. Adult brain injury often results in severe and selective cognitive impairments, with loss of ability in one function against a background of otherwise spared cognition. Examples include amnesia (selective impairment in forming new memories), aphasia (selective loss of the ability to understand or express speech), and agnosia (inability to recognize and identify familiar objects or people). In contrast, cognitive impairments due to brain damage sustained during development are typically less severe but more general, affecting a wider range of cognition. One possibility for these differences is that focal damage sustained early in life can impact the function of other brain regions that are connected with the damaged area during the processes of maturation. However, we don’t currently have a full understanding of all of the factors that contribute to the differential effects on cognition of damage acquired at different points during development. The nonhuman primate model is critical for advancing our understanding of developmental disorders because it allows prospective and longitudinal studies in a system—unlike the mouse—where the course and specificity of cortical development is much the same as it is in humans.

The articles in this section highlight the contribution of the nonhuman primate model to our current understanding of developmental disorders of cognition. The clinical perspective by Cacucci and Vargha-Khadem (5) provides a theoretical and clinical framework for understanding the cognitive effects of brain injury in children. The article by Bachevalier (6) describes a series of developmental studies in monkeys that have informed our understanding of the development of the hippocampus and its unique role in the primate memory system. The hippocampus is particularly vulnerable to periods of low oxygen, and early damage to the hippocampus is observed in children who have experienced hypoxic or ischemic events, epilepsy, and even stress. The studies using the nonhuman primate model have provided important information about the time course of the emergence of hippocampal-dependent cognitive functions, how memory is affected with early damage to the hippocampus, and the clinical implications of damage to this part of the brain in developmental neuropsychiatric disorders. None of this information can be obtained from work with other models, such as the mouse. The article by Kiorpes (7) describes the childhood developmental disorder of amblyopia, which disrupts vision in a large population of children around the world. Kiorpes describes work with the nonhuman primate model that recapitulates the human disease in ways that other models like the mouse do not. This model has provided insight into the brain mechanisms that underlie amblyopia, as well as new understanding of its origins and sensitive periods. This research has led to important changes in clinical practice both by enhancing understanding of the importance of early interventions in children with conditions that predispose them to amblyopia, and also in guiding novel therapies for affected children based on monkey experiments on brain plasticity. Experiments in nonhuman primate models of brain damage sustained early in life has been, and will continue to be, critical for advancing our understanding of the potential for compensatory processes and reorganization of function. These studies are instrumental to the goal of developing novel therapeutic interventions to improve human health and outcomes for children, adolescents, and adults affected by developmental disorders.


Why our brains love the ocean: Science explains what draws humans to the sea

By Wallace J. Nichols
Published July 19, 2014 9:00PM (EDT)

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I’m standing on a pier at the Outer Banks of North Carolina, fifty feet above the Atlantic. To the left and right, forward, back, and below, all I can see is ocean. I’m wearing a light blue hat that looks like a bejeweled swim cap, and a heavy black cable snakes down my back like a ponytail. Even though I look like an extra from an Esther Williams movie who wandered into Woody Allen’s Sleeper by mistake, in truth I’m a human lab rat, here to measure my brain’s response to the ocean.

The cap is the nerve center of a mobile electroencephalogram (EEG) unit, invented by Dr. Stephen Sands, biomedical science expert and chief science officer of Sands Research. Steve’s a big, burly, balding guy of the sort that could be mistaken for the local high school science teacher who’s also the football coach, or perhaps the captain of one of the deep-sea fishing boats that call the Outer Banks home. An El Paso (a city on the San Antonio River) resident by way of Long Beach, California, and Houston, Texas, Steve spent years in academia as a professor, using brain imaging to research Alzheimer’s disease. In 1998 he established Neuroscan, which became the largest supplier of EEG equipment and software for use in neurological research. In 2008 Steve founded Sands Research, a company that does neuromarketing, a new field using behavioral and neurophysiological data to track the brain’s response to advertising. “People’s responses to any kind of stimulus, including advertising, include conscious activity—things we can verbalize—and subconscious activity,” he once wrote. “But the subconscious responses can’t be tracked through traditional market research methods.” When groups of neurons are activated in the brain by any kind of stimulus — a picture, a sound, a smell, touch, taste, pain, pleasure, or emotion—a small electrical charge is generated, which indicates that neurological functions such as memory, attention, language processing, and emotion are taking place in the cortex. By scrutinizing where those electrical charges occur in the brain, Steve’s sixty-eight-channel, full-spectrum EEG machine can measure everything from overall engagement to cognition, attention, the level of visual or auditory stimulation, whether the subject’s motor skills are involved, and how well the recognition and memory circuits are being stimulated. “When you combine EEG scans with eyemovement tracking, you get unique, entirely nonverbal data on how someone is processing the media or the real-world environment, moment by moment,” Steve says.

Given current perplexity about the value of promotional efforts, Steve’s data are increasingly sought after. Sands Research does advertising impact studies for some of the largest corporations in the world it’s perhaps best known for an “Annual Super Bowl Ad Neuro Ranking,” which evaluates viewers’ neurological responses to those $3.8-million-per-thirty-second spots. (Among those that Steve’s team measured were the well known ads that featured people sitting on a beach, backs to the camera as they gazed at white sand and blue water, Corona beers on the table between them, and only the lapping of the sea as a soundtrack. That campaign made the brewer famous, forever associated with tropical ocean leisure.)

In the months prior to my trip to the Outer Banks, I’d been contacted by Sands Research’s director of business development, Brett Fitzgerald. Brett’s an “outside” kind of guy with a history of working with bears in Montana. He’d heard about my work combining water science with neuroscience and contacted me to see if we could do some sort of project together. Before I knew it, he was on a plane to California, and we met along the coast north of my home to talk “brain on ocean.” Not long after, I was on a plane heading to North Carolina.

Today Brett has fitted me with a version of the Sands Research EEG scanning apparatus that can detect human brain activity with the same level of precision as an fMRI (functional magnetic resonance imaging). The data from the electrodes in this ornamented swim cap are sampled 256 times per second and, when amplified for analysis, will allow neuroscientists to see in real time which areas of the brain are being stimulated. Typically such data are used to track shoppers’ responses in stores like Walmart as they stop to look at new products on a shelf. In this case, however, the sixty-eight electrodes plugged into the cap on my head are for measuring my every neurological up and down as I plunge into the ocean. It’s the first time equipment like this has been considered for use at (or in) the water, and I’m a little anxious about both the current incompatibility (no pun intended) between the technology and the ocean, but also about what we might learn. So is Brett—the cap and accompanying scanning device aren’t cheap. In the future such a kit will be made waterproof and used underwater, or while someone is surfing. But for today, we’re just hoping that neither the equipment nor I will be the worse for wear after our testing and scheming at the salt-sprayed pier.

It’s only recently that technology has enabled us to delve into the depths of the human brain and into the depths of the ocean. With those advancements our ability to study and understand the human mind has expanded to include a stream of new ideas about perception, emotions, empathy, creativity, health and healing, and our relationship with water. Several years ago I came up with a name for this human–water connection: Blue Mind, a mildly meditative state characterized by calm, peacefulness, unity, and a sense of general happiness and satisfaction with life in the moment. It is inspired by water and elements associated with water, from the color blue to the words we use to describe the sensations associated with immersion. It takes advantage of neurological connections formed over millennia, many such brain patterns and preferences being discovered only now, thanks to innovative scientists and cutting-edge technology.

In recent years, the notion of “mindfulness” has edged closer and closer to the mainstream. What was once thought of as a fringe quest for Eastern vacancy has now been recognized as having widespread benefits. Today the search for the sort of focus and awareness that characterizes Blue Mind extends from the classroom to the boardroom to the battlefield, from the doctor’s office to the concert hall to the world’s shorelines. The stress produced in our overwhelmed lives makes that search more urgent.

Water’s amazing influence does not mean that it displaces other concerted efforts to reach a mindful state rather, it adds to, enhances, and expands. Yet this book is not a field guide to meditation, nor a detailed examination of other means toward a more mindful existence. To use a water-based metaphor, it offers you a compass, a craft, some sails, and a wind chart. In an age when we’re anchored by stress, technology, exile from the natural world, professional suffocation, personal anxiety, and hospital bills, and at a loss for true privacy, casting off is wonderful. Indeed, John Jerome wrote in his book "Blue Rooms" that “the thing about the ritual morning plunge, the entry into water that provides the small existential moment, is its total privacy. Swimming is between me and the water, nothing else. The moment the water encloses me, I am, gratefully, alone.” Open your Blue Mind and the ports of call will become visible.

To properly navigate these depths, over the past several years I’ve brought together an eclectic group of scientists, psychologists, researchers, educators, athletes, explorers, businesspeople, and artists to consider a fundamental question: what happens when our most complex organ—the brain— meets the planet’s largest feature — water?

As a marine biologist as familiar with the water as I am with land, I believe that oceans, lakes, rivers, pools, even fountains can irresistibly affect our minds. Reflexively we know this: there’s a good reason why Corona chose a beach and not, say, a stockyard. And there are logical explanations for our tendency to go to the water’s edge for some of the most significant moments of our lives. But why?

I look out from the pier at the vast Atlantic and imagine all the ways that the sight, sound, and smell of the water are influencing my brain. I take a moment to notice the feelings that are arising. For some, I know, the ocean creates fear and stress but for me it produces awe and a profound, immersive, and invigorating peace. I take a deep breath and imagine the leap, cables trailing behind me as I plunge into the waves surging around the pier. The EEG readings would reflect both my fear and exhilaration as I hit the water feet first. I imagine Dr. Sands peering at a monitor as data come streaming in.

Water fills the light, the sound, the air — and my mind.

Our (Evolving) Relationship to Water

Thousands have lived without love, not one without water.
— W. H. Auden

There’s something about water that draws and fascinates us. No wonder: it’s the most omnipresent substance on Earth and, along with air, the primary ingredient for supporting life as we know it. For starters, ocean plankton provides more than half of our planet’s oxygen. There are approximately 332.5 million cubic miles of water on Earth—96 percent of it saline. (A cubic mile of water contains more than 1.1 trillion gallons.) Water covers more than 70 percent of Earth’s surface 95 percent of those waters have yet to be explored.

From one million miles away our planet resembles a small blue marble from one hundred million miles it’s a tiny, pale blue dot. “How inappropriate to call this planet Earth when it is quite clearly Ocean,” author Arthur C. Clarke once astutely commented.

That simple blue marble metaphor is a powerful reminder that ours is an aqueous planet. “Water is the sine qua non of life and seems to be all over the universe and so it’s reasonable for NASA to use a ‘follow the water’ strategy as a first cut or shorthand in our quest to locate other life in the universe,” Lynn Rothschild, an astrobiologist at the NASA Ames Research Center in Mountain View, California, told me. “While it may not be the only solvent for life, it certainly makes a great one since it is abundant, it’s liquid over a broad temperature range, it floats when solid, allowing for ice-covered lakes and moons, and it’s what we use here on Earth.”

Whether searching the universe or roaming here at home humans have always sought to be by or near water. It’s estimated that 80 percent of the world’s population lives within sixty miles of the coastline of an ocean, lake, or river. Over half a billion people owe their livelihoods directly to water, and two-thirds of the global economy is derived from activities that involve water in some form. Approximately a billion people worldwide rely primarily on water-based sources for protein. (It’s very possible that increased consumption of omega-3 oils from eating fish and shellfish played a crucial role in the evolution of the human brain. And, as we’ll discuss later in the book, the seafood market is now global in a manner that could never have been imagined even a few decades ago.) We use water for drinking, cleansing, working, recreating, and traveling. According to the U.S. Geological Survey, each person in the United States uses eighty to one hundred gallons of water every day for what we consider our “basic needs.” In 2010 the General Assembly of the United Nations declared, “Safe and clean drinking water is a human right essential to the full enjoyment of life.”

Our innate relationship to water goes far deeper than economics, food, or proximity, however. Our ancient ancestors came out of the water and evolved from swimming to crawling to walking. Human fetuses still have “gill-slit” structures in their early stages of development, and we spend our first nine months of life immersed in the “watery” environment of our mother’s womb. When we’re born, our bodies are approximately 78 percent water. As we age, that number drops to below 60 percent — but the brain continues to be made of 80 percent water. The human body as a whole is almost the same density as water, which allows us to float. In its mineral composition, the water in our cells is comparable to that found in the sea. Science writer Loren Eiseley once described human beings as “a way that water has of going about, beyond the reach of rivers.”

We are inspired by water — hearing it, smelling it in the air, playing in it, walking next to it, painting it, surfing, swimming or fishing in it, writing about it, photographing it, and creating lasting memories along its edge. Indeed, throughout history, you see our deep connection to water described in art, literature, and poetry. “In the water I am beautiful,” admitted Kurt Vonnegut. Water can give us energy, whether it’s hydraulic, hydration, the tonic effect of cold water splashed on the face, or the mental refreshment that comes from the gentle, rhythmic sensation of hearing waves lapping a shore. Immersion in warm water has been used for millennia to restore the body as well as the mind. Water drives many of our decisions — from the seafood we eat, to our most romantic moments, and from where we live, to the sports we enjoy, and the ways we vacation and relax. “Water is something that humanity has cherished since the beginning of history, and it means something different to everyone,” writes archeologist Brian Fagan. We know instinctively that being by water makes us healthier, happier, reduces stress, and brings us peace.

In 1984 Edward O. Wilson, a Harvard University biologist, naturalist, and entomologist, coined the term “biophilia” to describe his hypothesis that humans have “ingrained” in our genes an instinctive bond with nature and the living organisms we share our planet with. He theorized that because we have spent most of our evolutionary history—three million years and 100,000 generations or more — in nature (before we started forming communities or building cities), we have an innate love of natural settings. Like a child depends upon its mother, humans have always depended upon nature for our survival. And just as we intuitively love our mothers, we are linked to nature physically, cognitively, and emotionally.

You didn’t come into this world. You came out of it, like a wave from the ocean. You are not a stranger here.
— Alan Watts

This preference for our mother nature has a profound aesthetic impact. The late Denis Dutton, a philosopher who focused on the intersection of art and evolution, believed that what we consider “beautiful” is a result of our ingrained linkage to the kind of natural landscape that ensured our survival as a species. During a 2010 TED talk, “A Darwinian Theory of Beauty,” Dutton described findings based on both evolutionary psychology and a 1997 survey of contemporary preference in art. When people were asked to describe a “beautiful” landscape, he observed, the elements were universally the same: open spaces, covered with low grass, interspersed with trees. And if you add water to the scene — either directly in view, or as a distant bluish cast that the eye takes as an indication of water — the desirability of that landscape skyrockets. Dutton theorized that this “universal landscape” contains all the elements needed for human survival: grasses and trees for food (and to attract edible animal life) the ability to see approaching danger (human or animal) before it arrives trees to climb if you need to escape predators and the presence of an accessible source of water nearby. In 2010 researchers at Plymouth University in the United Kingdom asked forty adults to rate over one hundred pictures of different natural and urban environments. Respondents gave higher ratings for positive mood, preference, and perceived restorativeness to any picture containing water, whether it was in a natural landscape or an urban setting, as opposed to those photos without water.

Marcus Eriksen, a science educator who once sailed a raft made entirely of plastic bottles from the U.S. Pacific coast to Hawaii, expanded upon Dutton’s hypothesis to include seacoasts, lakeshores, or riverbanks. In the same way the savannah allowed us to see danger a long way off, he theorized, coastal dwellers could see predators or enemies as they came across the water. Better, land-based predators rarely came from the water, and most marine-based predators couldn’t emerge from the water or survive on land. Even better than that: the number of food and material resources provided in or near the water often trumped what could be found on land. The supply of plant-based and animal food sources may vanish in the winter, Eriksen observed, but our ancestors could fish or harvest shellfish year-round. And because the nature of water is to move and flow, instead of having to travel miles to forage, our ancestors could walk along a shore or riverbank and see what water had brought to them or what came to the water’s edge.

While humans were developing an evolutionary preference for a certain type of water-containing landscape, the human brain was also being shaped by environmental demands. Indeed, according to molecular biologist John Medina, the human brain evolved to “solve problems related to surviving in an unstable outdoor environment, and to do so in nearly constant motion.” Imagine that you are one of our distant Homo sapiens ancestors, living in that ideal savannah landscape more than 200,000 years ago. Even if you and your family have inhabited this particular spot for a while, you still must be alert for any significant threats or potential sources of food. Every day brings new conditions—weather, animals, fruits, and other edible plants. Use up some sources of food and you have to look for more, which means constant exploration of your environment to learn more about where you are and what other sources of food and water are available for you and your family. Perhaps you encounter new plants or animals, some of which are edible—some not. You learn from your mistakes what to gather and what to avoid. And while you and your children learn, your brains are being shaped and changed by multiple forces: your individual experiences, your social and cultural interactions, and your physical environment. Should you survive and reproduce, some of that rewiring will be passed on to your descendants in the form of a more complex brain. Additional information for survival will be socially encoded in vivid stories and songs.

A nervous system is the part of an animal that coordinates activity by transmitting signals about what’s happening both inside and outside the body. It’s made up of special types of cells called neurons, and ranges in size and complexity from just a few hundred nerve cells in the simplest worms, to some 20,000 neurons in the California sea hare, Aplysia californica (a very cool mollusk whose large, sometimes gigantic, neurons have made it the darling of neurobiologists for the past fifty years), to as many as 100 billion in humans. We’ll be looking in detail at the human brain and DNA in later chapters, but there’s an important point to be made before we leave our ancestors on the distant savannah: just as the human brain changed and evolved over the millennia, our individual brain changes and evolves from the day we are born until we die. Critical studies starting in the 1970s and 1980s demonstrated that our brains are in a state of constant evolution — neurons growing, connecting, and then dying off. Both the brain’s physical structure and its functional organization are plastic, changing throughout our lives depending on need, attention, sensory input, reinforcement, emotion, and many other factors. The brain’s neuroplasticity (its ability to continually create new neural networks, reshape existing ones, and eliminate networks that are no longer used due to changes in behavior, environment, and neural processes) is what allows us to learn, form memories throughout our lifetimes, recover function after a stroke or loss of sight or hearing, overcome destructive habits and become better versions of ourselves. Neuroplasticity accounts for the fact that, compared to most of us, a disproportionate amount of physical space in a violinist’s brain is devoted to controlling the fingers of his or her fingering hand, and that studying for exams can actually increase the amount of cortical space devoted to a particular subject (more complex functions generally require more brain matter). As we’ll see later, it also accounts for certain negative behaviors, like obsessive-compulsive disorder.

You will hear the term neuroplasticity a lot in this book, because it exemplifies one of the fundamental premises of Blue Mind: the fact that our brains — these magnificent, three-pound masses of tissue that are almost 80 percent water — are shaped, for good or ill, by a multitude of factors that include our perceptions, our emotions, our biology, our culture — and our environment.

You’ll also hear a lot about happiness. While the “pursuit of happiness” has been a focus of humankind since almost before we could put a name to the feeling, from ancient times onward philosophers have argued about the causes and uses of happiness, and composers, writers, and poets have filled our heads with stories of happiness lost and found. In the twenty-first century, however, the pursuit of happiness has become one of the most important means of judging our quality of life. “Happiness is an aspiration of every human being,” write John F. Helliwell, Richard Layard, and Jeffrey D. Sachs in the United Nations’ World Happiness Report 2013, which ranks 156 countries by the level of happiness of their citizens. It’s a vital goal: “People who are emotionally happier, who have more satisfying lives, and who live in happier communities, are more likely both now and later to be healthy, productive, and socially connected. These benefits in turn flow more broadly to their families, workplaces, and communities, to the advantage of all.”

“The purpose of our lives is to be happy,” says the Dalai Lama—and with all the many benefits of happiness, who would disagree? As a result, today we are bombarded with books on happiness, studies (and stories) about happiness, and happiness research of every kind. We’ll walk through some of the studies later, and discuss why water provides the most profound shortcut to happiness, but suffice it to say, greater individual happiness has been shown to make our relationships better help us be more creative, productive, and effective at work (thereby bringing us higher incomes) give us greater self-control and ability to cope make us more charitable, cooperative, and empathetic boost our immune, endocrine, and cardiovascular systems lower cortisol and heart rate, decrease inflammation, slow disease progression, and increase longevity. Research shows that the amount of happiness we experience spreads outward, affecting not just the people we know but also the friends of their friends as well (or three degrees of the famous six degrees of separation). Happy people demonstrate better cognition and attention, make better decisions, take better care of themselves, and are better friends, colleagues, neighbors, spouses, parents, and citizens. Blue Mind isn’t just about smiling when you’re near the water it’s about smiling everywhere.

Water and Our Emotions

Some people love the ocean. Some people fear it. I love it, hate it, fear it, respect it, resent it, cherish it, loathe it, and frequently curse it. It brings out the best in me and sometimes the worst.
— Roz Savage

Beyond our evolutionary linkage to water, humans have deep emotional ties to being in its presence. Water delights us and inspires us (Pablo Neruda: “I need the sea because it teaches me”). It consoles us and intimidates us (Vincent van Gogh: “The fishermen know that the sea is dangerous and the storm terrible, but they have never found these dangers sufficient reason for remaining ashore”). It creates feelings of awe, peace, and joy (The Beach Boys: “Catch a wave, and you’re sitting on top of the world”). But in almost all cases, when humans think of water — or hear water, or see water, or get in water, even taste and smell water — they feel something. These “instinctual and emotional responses . . . occur separately from rational and cognitive responses,” wrote Steven C. Bourassa, a professor of urban planning, in a seminal 1990 article in Environment and Behavior. These emotional responses to our environment arise from the oldest parts of our brain, and in fact can occur before any cognitive response arises. Therefore, to understand our relationship to the environment, we must understand both our cognitive and our emotional interactions with it.

This makes sense to me, as I’ve always been drawn to the stories and science of why we love the water. However, as a doctoral student studying evolutionary biology, wildlife ecology, and environmental economics, when I tried to weave emotion into my dissertation on the relationship between sea turtle ecology and coastal communities, I learned that academia had little room for feelings of any kind. “Keep that fuzzy stuff out of your science, young man,” my advisors counseled. Emotion wasn’t rational. It wasn’t quantifiable. It wasn’t science.

Talk about a “sea change”: today cognitive neuroscientists have begun to understand how our emotions drive virtually every decision we make, from our morning cereal choice, to who we sit next to at a dinner party, to how sight, smell, and sound affect our mood. Today we are at the forefront of a wave of neuroscience that seeks to discover the biological bases of everything, from our political choices to our color preferences. They’re using tools like EEGs, MRIs, and those fMRIs to observe the brain on music, the brain and art, the chemistry of prejudice, love, and meditation, and more. Daily these cutting-edge scientists are discovering why human beings interact with the world in the ways we do. And a few of them are now starting to examine the brain processes that underlie our connection to water. This research is not just to satisfy some intellectual curiosity. The study of our love for water has significant, real-world applications—for health, travel, real estate, creativity, childhood development, urban planning, the treatment of addiction and trauma, conservation, business, politics, religion, architecture, and more. Most of all, it can lead to a deeper understanding of who we are and how our minds and emotions are shaped by our interaction with the most prevalent substance on our planet.

The journey in search of people and scientists who were eager to explore these questions has taken me from the sea turtles’ habitats on the coasts of Baja California, to the halls of the medical schools at Stanford, Harvard, and the University of Exeter in the United Kingdom, to surfing and fishing and kayaking camps run for PTSD-afflicted veterans in Texas and California, to lakes and rivers and even swimming pools around the world. And everywhere I went, even on the airplanes connecting these locations, people would share their stories about water. Their eyes sparkled when they described the first time they visited a lake, or ran through a sprinkler in the front yard, caught a turtle or a frog in the creek, held a fishing rod, or walked along a shore with a parent or boyfriend or girlfriend. I came to believe that such stories were critical to science, because they help us make sense of the facts and put them in a context we can understand. It’s time to drop the old notions of separation between emotion and science— for ourselves and our future. Just as rivers join on their way to the ocean, to understand Blue Mind we need to draw together separate streams: analysis and affection elation and experimentation head and heart.

The Tohono O’odham (which means “desert people”) are Native Americans who reside primarily in the Sonoran Desert of southeastern Arizona and northwest Mexico. When I was a graduate student at the University of Arizona, I used to take young teens from the Tohono O’odham Nation across the border to the Sea of Cortez (the Gulf of California). Many of them had never seen the ocean before, and most were completely unprepared for the experience, both emotionally and in terms of having the right gear. On one field trip several of the kids didn’t bring swim trunks or shorts—they simply didn’t own any. So we all sat down on the beach next to the tide pools of Puerto Peñasco, I pulled out a knife, and we all cut the legs off our pants, right then and there.

Once in the shallow water we put on masks and snorkels (we’d brought enough for everyone), had a quick lesson on how to breathe through a snorkel, and then set out to have a look around. After a while I asked one young man how it was going. “I can’t see anything,” he said. Turns out he’d been keeping his eyes closed underwater. I told him that he could safely open his eyes even though his head was beneath the surface. He put his face under and started to look around. Suddenly he popped up, pulled off his mask, and started shouting about all the fish. He was laughing and crying at the same time as he shouted, “My planet is beautiful!” Then he slid his mask back over his eyes, put his head back into the water, and didn’t speak again for an hour.

My memory of that day, everything about it, is crystal clear. I don’t know for sure, but I’ll bet it is for him, too. Our love of water had made an indelible stamp on us. His first time in the ocean felt like mine, all over again.

The Beginnings of Blue Mind

In 2011, in San Francisco—a city surrounded by water on three sides—I gathered a group of neuroscientists, cognitive psychologists, marine biologists, artists, conservationists, doctors, economists, athletes, urban planners, real estate agents, and chefs to explore the ways our brains, bodies, and psyches are enhanced by water. I had realized that there was a constellation of innovative thinkers who had been trying to put the pieces together regarding the powerful effects of water, but they had mostly been isolated from one another. Since then, the Blue Mind gathering has become an annual conference that taps into a growing quantity of new mind/body/environment research and continues to produce new and startling insights on how humanity interacts with our watery planet. Both the brain and the ocean are deep, complex, and subtle realms — scarcely explored and poorly understood. However, we are on the cusp of an age when both the brain and the ocean are giving up more and more of their secrets to dedicated scientists and explorers. As more researchers from varied disciplines apply their expertise to the relation between water and humanity, the insights from their collaborations are illuminating the biological, neurological, and sociological benefits of humanity’s Blue Mind.

Every year more experts of all kinds are connecting the dots between brain science and our watery world. This isn’t touchy-feely “let’s save the dolphins” conservation: we’re talking prefrontal cortex, amygdala, evolutionary biology, neuroimaging, and neuron functioning that shows exactly why humans seem to value being near, in, on, or under the water. And this new science has real-world implications for education, public policy, health care, coastal planning, travel, real estate, and business — not to mention our happiness and general well-being. But it’s science with a personal face science practiced by real people, with opinions, biases, breakthroughs, and insights.

At subsequent Blue Mind conferences on the shores of the Atlantic and Pacific, scientists, practitioners, and students have continued to share their research and life’s work, huddling together to discuss, create, and think deeply. We’ve produced documents describing “what we think we know” (facts), “what we want to explore” (hypotheses), and “what we want to share” (teachings). At Blue Mind 2013, held on Block Island, we discussed topics like dopaminergic pathways, microplastics and persistent organic pollutants, auditory cortex physiology, and ocean acidification, but for those of us drawn to the waves, no discussion of water is without joy and celebration. At dawn we sang together, overlooking the sparkling blue Atlantic Ocean, and in the evening we drank wine, those waters now black and sparkling, and listened to former Rhode Island poet laureate Lisa Starr.

“Listen, dear one,” it whispers.
“You only think you have
forgotten the impossible.

“Go now, to that marsh beyond
Fresh Pond and consider how the red
burgeons into crimson
go see how it’s been preparing forever
for today.”

This is poetry, this is science this is science, this is poetry. So, too, are oceans and seas, rivers and ponds, swimming pools and hot springs — all of us could use a little more poetry in our lives.

We could use a lot more, too — and, in some cases, a lot less. Too many of us live overwhelmed—suffocated by work, personal conflicts, the intrusion of technology and media. Trying to do everything, we end up stressed about almost anything. We check our voice mail at midnight, our e-mail at dawn, and spend the time in between bouncing from website to website, viral video to viral video. Perpetually exhausted, we make bad decisions at work, at home, on the playing field, and behind the wheel. We get flabby because we decide we don’t have the time to take care of ourselves, a decision ratified by the fact that those “extra” hours are filled with e-mailing, doing reports, attending meetings, updating systems to stay current, repairing what’s broken. We’re constantly trying to quit one habit just to start another. We say the wrong things to people we love, and love the wrong things because expediency and proximity make it easier to embrace what’s passing right in front of us. We make excuses about making excuses, but we still can’t seem to stop the avalanche. All of this has a significant economic cost as “stress and its related comorbid diseases are responsible for a large proportion of disability worldwide.”

It doesn’t have to be that way. The surfers, scientists, veterans, fishers, poets, artists, and children whose stories fill this book know that being in, on, under, or near water makes your life better. They’re waiting for you to get your Blue Mind on too.

Excerpted from “Blue Mind: The Surprising Science That Shows How Being Near, In, On, or Under Water Can Make You Happier, Healthier, More Connected, and Better at What You Do” by Wallace J. Nichols. Copyright © 2014 by Wallace J. Nichols. Reprinted by arrangement with Little, Brown. All rights reserved.


Summary

The human brain consists of billions of neurons that are interconnected via neuronal synapses. Cells other than neurons called the glial cells are also present to proivide support to the neurons.

A neuron consists of a cell body and cellular process.

The cell body contains the nucleus in the center and other organelles for the synthetic needs of the cell. The complex system of rough endoplasmic reticulum and polyribosomes is also present called the Nissl granules. They are exclusive to the cell body of neurons.

Dendrites are the slender processes that show abundant branching and carry nerve impulses to the cell body of neurons. Dendritic spines are the sites for synapse formation on dendrites.

Axons are the cylindrical processes that carry nerve impulses away from the cell body of neurons. They do not show branching and have a constant diameter throughout their length. They are the myelinated nerve fibers.

Neurons can be divided into sensory, motor, and interneurons. Most of the neurons present in the brain are interneurons.

The neurons in the brain are arranged into gray matter and white matter.

These neurons communicate via chemical synapses.

In a chemical synapse, neurotransmitters are released by the pre-synaptic cells that diffuse through the synaptic cleft and excite the post-synaptic neuron.

The synapses present in the brain might be axoaxonic, axosomatic, or axodendritic.

Glial cells replace the connective tissue in the brain. They provide support, nutrition, and protection to the neurons. They are involved in myelin sheath synthesis, providing metabolic support, regulating the flow of CSF providing protection from pathogens.


Watch the video: Streunender Welpe folgt einem Polizisten und was dann geschah, wird dein Herz schmelzen (September 2022).


Comments:

  1. Gerald

    I apologize, but this option was not suitable for me.

  2. Lad

    Wacker, it seems to me, it is a brilliant phrase

  3. Vunris

    It can't be!

  4. Onille

    no, why can you dream about the unreal at your leisure!

  5. Nashicage

    Fascinating question

  6. Kinris

    A good answer, bravo :)



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