Showing posts with label brain. Show all posts
Showing posts with label brain. Show all posts

Monday, December 29, 2014

Buddhism 101 with Rick Hanson, PhD: The Four Noble Truths and Noble Eightfold Path

Rick Hanson, author of Buddha's Brain (2009), Just One Thing: Developing a Buddha Brain One Simple Practice at a Time (2011), Hardwiring Happiness: The New Brain Science of Contentment, Calm, and Confidence (2013), is a neuropsychologist, Senior Fellow of the Greater Good Science Center at UC Berkeley, and a practicing Buddhist.

Dr. Hanson has been a trustee of Saybrook University and served on the board of Spirit Rock Meditation Center for nine years, where is a regular teacher. 

Over the last couple of months, Dr. Hanson posted a series of articles on the basic premises of Buddhism, the Four Noble Truths. These are those posts, along with an older article on the Noble Eightfold Path.

In essence, this is Buddhism 101, and if we could master just these principles, we would be very successful on our spiritual paths.

The First Noble Truth – The Noble Truth of Suffering

posted on: November 17th, 2014 

Saturday, May 31, 2014

Men Who Watch Porn Have Less Grey Matter in Brain Regions Associated with Motivation and Executive Function


Watch porn and your brain may suffer from the intense stimulation of the reward system. One of the results of this can be a lower top-down modulation of prefrontal cortical areas (i.e., a loss of executive function and the ability to associate behaviors with outcomes). Another outcome is that exposure to porn imagery produced reduced activation in parts of brain associated with motivation - suggesting that porn (like other drugs) reduces the desire to do anything other than look at porn.

The researchers point out, rightly, that they cannot say that porn reduces grey matter - only that those who watch more porn has less grey matter. It may be the later that leads to the former.

By the way, the average porn consumption for the 64 men was 4 hours a week.

Below is a summary of the research from Science Alert, followed by the abstract of the full article (which is sequestered behind a pay wall).

Men who watch porn have less brain grey matter

Porn consumption has been linked to differences in the structure and function of male brains


Felicity Nelson | Saturday, 31 May 2014 

Image: PornHub

Men who watch porn have significantly less grey matter in their brains, a new study shows. MRI brain scans of 64 men between 21 and 45 years of age were taken while participants were shown images of porn and people exercising.

The participants were later requested to provide information about weekly porn consumption via a phone interview. Every person in the study volunteered to answer these questions, even though they were not told that this information would be needed before commencing. The men had a wide range of porn consumption averaging 4 hours a week.

Men with higher porn consumption had lower grey matter volumes. Interestingly, when men were shown sexually explicit material during the MRI scan, the region of the brain associated with motivation showed reduced activity.

"Our findings indicated that grey matter volume of the right caudate of the striatum is smaller with higher pornography use," researchers at the Max Planck Institute for Human Development in Berlin, Germany told ABC Science.

The study could not show that porn caused men's brains to lose grey matter. "Future studies should investigate the effects of pornography longitudinally or expose naive participants to pornography and investigate the causal effects over time", researchers told ABC Science.

This research was published this week in the journal JAMA Psychiatry.

Full Citation:
Kühn, S; Gallinat, J. (2014, May 28). Brain Structure and Functional Connectivity Associated With Pornography Consumption. JAMA Psychiatry. Online First. doi:10.1001/jamapsychiatry.2014.93


Brain Structure and Functional Connectivity Associated With Pornography Consumption

The Brain on Porn ONLINE FIRST

Simone Kühn, PhD; Jürgen Gallinat, PhD

ABSTRACT

Importance Since pornography appeared on the Internet, the accessibility, affordability, and anonymity of consuming visual sexual stimuli have increased and attracted millions of users. Based on the assumption that pornography consumption bears resemblance with reward-seeking behavior, novelty-seeking behavior, and addictive behavior, we hypothesized alterations of the frontostriatal network in frequent users.

Objective To determine whether frequent pornography consumption is associated with the frontostriatal network.

Design, Setting, and Participants Sixty-four healthy male adults with a broad range of pornography consumption at the Max Planck Institute for Human Development in Berlin, Germany, reported hours of pornography consumption per week. Pornography consumption was associated with neural structure, task-related activation, and functional resting-state connectivity.

Main Outcomes and Measures Gray matter volume of the brain was measured by voxel-based morphometry and resting state functional connectivity was measured on 3-T magnetic resonance imaging scans.

Results We found a significant negative association between reported pornography hours per week and gray matter volume in the right caudate (P < .001, corrected for multiple comparisons) as well as with functional activity during a sexual cue–reactivity paradigm in the left putamen (P< .001). Functional connectivity of the right caudate to the left dorsolateral prefrontal cortex was negatively associated with hours of pornography consumption.

Conclusions and Relevance The negative association of self-reported pornography consumption with the right striatum (caudate) volume, left striatum (putamen) activation during cue reactivity, and lower functional connectivity of the right caudate to the left dorsolateral prefrontal cortex could reflect change in neural plasticity as a consequence of an intense stimulation of the reward system, together with a lower top-down modulation of prefrontal cortical areas. Alternatively, it could be a precondition that makes pornography consumption more rewarding.

Monday, March 24, 2014

Dr. Sarah McKay - How Finding Your Purpose Protects Your Brain: A Neuroscientist Explains

Do you know what your purpose is in life? Why you are here? Is there a set of values or beliefs around which you organize.

How Finding Your Purpose Protects Your Brain: A Neuroscientist Explains

By Dr. Sarah McKay
March 23, 2014


What is your purpose in life? Your passion. Your bliss. Your calling … Whatever you call it, we’re all searching for it to some extent. Mastin Kipp’s words sum it up for me: “Your bliss and your purpose are the same thing.”

If finding your north star is an elusive task, then perhaps taking a scientific approach to defining and measuring "purpose" might work as a discovery strategy.

Patricia Boyle, a neuropsychologist who specializes in Alzheimer's research defines "purpose in life" as: “the psychological tendency to derive meaning from life’s experiences and to possess a sense of intentionality and goal directedness that guides behavior.”

To measure purpose in life, researchers from the Rush University Medical Center in Chicago asked over 900 older folks living in residential communities to rate their level of agreement from 1 to 5, to each of the following statements:
  • I feel good when I think of what I have done in the past and what I hope to do in the future.
  • I live life one day at a time and do not really think about the future.
  • I tend to focus on the present because the future nearly always brings me problems.
  • I have a sense of direction and purpose in life.
  • My daily activities often seem trivial and unimportant to me.
  • I used to set goals for myself, but that now seems like a waste of time.
  • I enjoy making plans for the future and working them to a reality.
  • I am an active person in carrying out the plans I set for myself.
  • Some people wander aimlessly through life, but I am not one of them.
  • I sometimes feel as if I have done all there is to do in life.
The researchers found that a high purpose in life score was linked to many positive health outcomes including:
  • Better mental health
  • Less depression
  • Happiness
  • Satisfaction
  • Personal growth, self-acceptance
  • Better sleep
  • Longevity
Startlingly, in the seven years of the study, 155 of 951 people developed Alzheimer’s disease. A more detailed analysis showed that those folks with high purpose in life scores had:
  • Reduced risk of Alzheimer’s disease
  • Less mild cognitive impairment
  • Slower rate of cognitive decline in old age
Explaining her findings to Science Daily, Patricia Boyle explained: "Somehow, having a purpose allows people to cope with the physical signs of Alzheimer's disease."

So what might be is the biological basis linking purpose and passion with brain health?

The researchers in this study weren’t 100% sure, but neuroscience tells us that a lack of purpose in life is associated with the follower indicators of poor health:
  • High levels of the stress hormone cortisol
  • Markers of inflammation
  • Low high-density lipoprotein cholesterol levels (the "good" cholesterol)
  • Abdominal fat
We know these factors probably combine to diminish the brain’s resilience to degeneration and aging. Brain resilience is also referred to as "brain reserve"—its ability to cope with increasing damage while still functioning adequately. So, if you’re still searching, neuroscience might just be able provide some pretty compelling evidence about why you should foster your purpose and passions. And maybe thinking about the questions posed to the older folks might just guide you to your north star.

If you're totally lost when it comes to your purpose, this piece may offer some pointers.

Photo Credit: Shutterstock.com

Monday, March 17, 2014

Robert Sapolsky - Metaphors Are Us (from Nautilus)

This is an old article (from April 2013) by Stanford professor of biology and neurology Robert Sapolsky, the author of many books, including Why Zebras Don't Get Ulcers (Third Edition) (1994/2004), Monkeyluv: And Other Essays on Our Lives as Animals (2005), and A Primate's Memoir: A Neuroscientist's Unconventional Life Among the Baboons (2001).

In this excellent article from Nautilus, Sapolsky examines the use of metaphor in humans, perhaps the last vestige of human exceptionalism not yet demonstrated in other animals.

The topic of metaphors is rich territory for digging deep and going down the rabbit hole. Two excellent books, both by George Lakoff and Mark Johnson, are Metaphors We Live By (1980/2003) and Philosophy in the Flesh: the Embodied Mind & its Challenge to Western Thought (1999). The latter book deals with how body-based metaphors permeate our language and our understanding of the world around us. After all, the first tool of measurement we had was a foot, and taking a leap of faith is not dissimilar to jumping off a cliff (physically).

Metaphors Are Us

War, murder, music, art. We would have none without metaphor.

By Robert Sapolsky
Illustration by John Hendrix April 29, 2013

THE OTHER DAY I fixed something—a rarity for me. The flotation device in the toilet water tank was rubbing against the side, getting stuck halfway up so that the tank didn’t fill completely. I own a hammer and know how to operate it. But I couldn’t fit it into the tank to whack the device back into place. Ditto for owning and using a wrench. It wouldn’t fit either. But fortunately I also own a plunger and I used its handle to push the floating thing back the other way, using the side of the tank as a fulcrum. It worked, although the device got bent so that the top of the tank didn’t quite fit. That overwhelmed me, so I called it a good day’s work.

I was proud of myself. “There,” I thought smugly. “It’s not just chimps who can use tools.”

Humans used to be unique in lots of ways. We were the only species who made tools, murdered each other, passed on culture. And each of those supposed defining features has now been demonstrated in other species. We’re not so special after all. But there are still ways that humans appear to stand alone. One of those is hugely important: the human capacity to think symbolically. Metaphors, similes, parables, figures of speech—they exert enormous power over us. We kill for symbols, die for them. Yet symbols generate one of the most magnificent human inventions: art.

In recent years scientists from leading universities, including UCLA, University College London, and Yale, have made remarkable insights into the neurobiology of symbols. A major finding from their work is that the brain is not very good at distinguishing between the metaphorical and literal. In fact, as scientists have shown us, symbols and metaphors, and the morality they engender, are the product of clunky processes in our brains.

Symbols serve as a simplifying stand-in for something complex. (A rectangle of cloth with stars and stripes represents all of American history and values.) And this is very useful. To see why, start by considering basic language—communication without a lot of symbolic content. Suppose you are being menaced by something terrifying and so scream your head off. Someone listening can’t tell if the blood-curdling “Aiiiii!” means an approaching comet, right-wing death squad, or Komodo dragon. It just means that things are majorly not right, a generic scream where the message is the meaning. This present-tense emotionality is what communication by animals is mostly about.

Symbolic language brought huge evolutionary advantages. This can be seen even in the baby steps of symbolism of other species. When vervet monkeys, for instance, spot a predator, they don’t just generically scream. They use distinct vocalizations, different “proto-words,” where one means, “Aiiiiii!, predator on the ground, run up the tree,” and the other means, “Aiiiiii!, predator in the air, run down the tree.” It’s mighty useful to have evolved the cognitive capacity to make that distinction. Who would want to guess wrong and dash up to the top of a tree when the problem is a raptor swooping down?

Language pries apart a message from its meaning, and as our hominid ancestors kept getting better at this separation, great individual and social advantages accrued. We became capable of representing emotions in the past and possible emotions in the future, as well as things that have nothing to do with emotion. We evolved a uniquely dramatic means of separating message from meaning and intent: lying. And we invented asthetic symbolism; after all, those 30,000-year-old paintings of horses in Chauvet cave are not really horses.

Our early use of symbols helped forge powerful bonds and rules of cooperation, as human societies grew increasingly complex and competitive. A recent study by Ara Norenzayan of the University of British Columbia and Azim Shariff of the University of Oregon revealed that, across 186 societies, the larger the typical social group, the more likely it was the culture created a god who monitored and judged human morality—perhaps the ultimate symbol of rule enforcement.


HOW DID OUR BRAINS evolve to mediate this complexity? In an awkward way. As has been said, evolution is not an inventor, it’s a tinkerer, making do with the pieces at hand. While a squid can’t swim as fast as many fish, it swims pretty fast for something that evolved from mollusks. Similarly, while the human brain turns out to handle symbols and metaphors in an inelegant way, it still does a pretty good job for something that evolved from brains that only processed the literal. The best way to shine a light on this unwieldy process is through metaphors for two feelings critical to survival: pain and disgust.

Consider the following: you stub your toe. Pain receptors there send messages to the spine and on up to the brain, where various regions kick into action. Some of these areas tell you about location, intensity, and quality. Is it your left toe or right ear that hurts? Was your toe stubbed or crushed by a tractor-trailer? This is the meat-and-potatoes of pain processing, found in every mammal.

But there are fancier, more recently evolved parts of the brain in the frontal cortex that assess the meaning of the pain. Maybe it’s bad news: your stubbed toe signals the start of some unlikely disease. Or maybe it’s good news: you’re going to get your firewalker diploma because the hot coals made your toes throb. Much of this assessing occurs in a frontal cortical region called the anterior cingulate. This structure is heavily involved in “error detection,” noting discrepancies between what is anticipated and what occurs. And pain from out of nowhere surely represents a discrepancy between the pain-free setting that you anticipate versus the painful reality.

Now let’s go a little deeper, based on work by Naomi Eisenberger at UCLA. While lying in a brain scanner, you play a game of virtual catch, where you and two people in another room toss a cyberball around on a computer screen. (In reality, there aren’t two other people, only a computer program.) In the control condition, you’re informed mid-play that there’s a computer glitch and you’re temporarily off-line. You watch the virtual ball get tossed between those two people. Now in the experimental setting, you’re playing with the other two and suddenly they start ignoring you and only toss the ball between them. Hey, how come they don’t want to play with me anymore? Junior high all over again. And the brain scanner shows that the neurons in your anterior cingulate activate.

In other words, rejection hurts. “Well, yeah,” you might say. “But that’s not like stubbing your toe.” It is to your anterior cingulate. Both abstract social and literal pain impact the same cingulate neurons.

We take things a step further with work by Tania Singer and Chris Frith at University College London. While in a brain scanner, you’re administered a mild shock, delivered through electrodes on your fingers. All the usual brain regions activate, including the anterior cingulate. Now you watch your beloved get shocked in the same way. The brain regions that ask, “Is it my finger or toe that hurts?” remain silent. It’s not their problem. But your anterior cingulate activates, and as far as it’s concerned, “feeling someone’s pain” isn’t just a figure of speech. You seem to feel the pain too. As evolution continued to tinker, it did something remarkable with humans. It duct-taped (metaphorically, of course) the anterior cingulate’s role in giving context to pain into a profound capacity for empathy.

We’re not the only empathic species. Chimps show empathy when, for example, they become more likely to groom someone who has been unfairly thrashed by an aggressive jerk of a chimp. And we’re not the only species with an anterior cingulate. But studies show the human anterior cingulate is more complex than in other species, with more connections to abstract, associational parts of the cortex, regions that can call your attention to the pains of the world, rather than the pain in your big toe.

And we feel someone else’s pain like no other species. We extend it over distance to help a refugee child on another continent. We extend it over time, feeling the terror of what are now mere human remains at Pompeii. We feel it embodied in words, as we contemplate George’s sadness that Lennie is never going to get his rabbits. (That part of Of Mice and Men never failed to leave me a sopping, tearful mess when I’d reread it obsessively as a kid.) We even feel empathic pain prompted by symbols encompassed in pixels. “Oh no, the poor Na’vi!” we cry, when Home Tree is destroyed in Avatar. Because the anterior cingulate has trouble remembering “it’s only a figure of speech,” it functions as if your heart is literally being torn out.


LET'S CONSIDER another domain where our brains’ shaky management of symbols adds tremendous power to a unique human quality: morality.

You’re in a brain scanner and because of the scientist’s weirdly persuasive request, you bite into some rotten food. Something rancid and fetid and skanky. This activates another part of the frontal cortex, the insula, which, among other functions, processes gustatory and olfactory disgust. It sends neuronal signals to face muscles that reflexively spit out that bite, and to your stomach muscles that make you puke. All mammals have an insula that processes gustatory disgust. After all, no animal wants to consume poison.

But we are the only animal where that process serves something more abstract. Think about eating something disgusting. Think about a mouthful of centipedes, chewing and swallowing them as they struggle, wiping off the little legs that you’ve drooled onto your lips. Whammo goes the insula, leaping into action, sending out its usual messages of disgust. Now think about something awful you once did, something deeply shameful. The insula activates. It has been co-opted into processing that human invention: moral disgust.

Is it a surprise that the human insula is involved in processing moral disgust along with gustatory disgust? Not when human behaviors can make us feel sick to our stomachs, can leave bad tastes in our mouths, can stink. When I heard about the massacre at Newtown, “feeling sick to my stomach” wasn’t just some symbolic figure-of-speech way of saying that I felt distressed. I felt nauseous. The insula not only prompts the stomach to purge itself of toxic food; it prompts our stomach to purge the reality of that nightmarish event. The distance between the symbolic message and the meaning shrinks.

As shown by Chen-Bo Zhong of the University of Toronto and Katie Liljenquist of Brigham Young University, if you’re forced to ruminate on a moral transgression of yours, you’re more likely to clean your hands afterward. And the scientists showed something even more provocative. They ask you to ruminate on your moral failings; afterward, you’re put in a position where you can respond to someone’s request for help. Wallow in your moral turpitude and you’re more likely to help. Unless you had a chance to wash post-wallowing. Then that urge to compensate for your transgression is gone; you’ve washed away your sins and gotten that damn spot out. Pontius Pilate and Lady Macbeth could lecture at scientific conferences about this one.

Remarkably, the way our brains use symbols to discern disgust and morality also contributes to political ideology. Work by scientists such as Kevin Smith of the University of Nebraska reveals that on the average conservatives have a lower threshold for visceral disgust than do liberals. Look at pictures of excrement or open sores undulating with maggots, and if your insula goes atypically berserk, chances are that you’re a conservative—but only about social issues, say, gay marriage, if you’re heterosexual. And if your insula just takes those maggots in stride, chances are you’re a liberal. In a study by Yoel Inbar of Tilburg University, David Pizarro of Cornell and Paul Bloom of Yale, participants, placed in a room with a wastebasket marinated in a stink spray (note to self: never do research in that lab) “showed less warmth toward gay men relative to heterosexual men.” In a control room, without the stink, participants evaluated gay and heterosexual men equally. In a nutty, smart, real world example, Tea Party candidate Carl Paladino mailed out campaign flyers impregnated with the smell of garbage during his GOP primary campaign for New York governor in 2010. His campaign trumpeted, “Something really stinks in Albany.” Paladino won his primary. (He stunk, however, in the general election, losing by a large margin to Andrew Cuomo.)

Our wobbly, symbol-dependent brains are molded by personal ideology and culture, shaping our perceptions, emotions, and convictions. We use symbols to demonize our enemies and wage war. The Hutu of Rwanda portrayed the enemy Tutsi as cockroaches. In Nazi propaganda posters, Jews were rats who carried dangerous microbes. Many cultures inculcate their members into acquiring symbols that repel, doing so by strengthening specific neural pathways from the cortex to the insula, pathways that you’d never find in another species. Depending on who you are, those pathways could be activated by the sight of a swastika or of two men kissing. Or perhaps by the thoughts of an abortion, or of a 10-year-old Yemeni girl forced to marry an old man. Our stomachs lurch, and we feel the visceral certainty of what is wrong. And we belong.

The same brain apparatus is behind symbols that move us to our most empathic, inclusive, and embracing. It is often art that does this most powerfully. We see the artistry of a skillful photojournalist—a photo of a child whose home was devastated by a natural disaster— and we reach for our wallets. If it is 1937, we don’t look at Picasso’s “Guernica” and see a menagerie of anatomically deformed mammals. Instead we see the devastation and feel the pain of a defenseless Basque village immolated during the Spanish Civil War. We feel moved to act against the Fascists and Nazis who conducted the aerial attack. Today we can feel moved to care about the fate of animals when we look at the simple artistic symbol, like a panda logo, of an environmental group.

Our metaphor-making brains are unique in the animal kingdom. But clearly we are dealing with a double-edged sword. We can dull the edge that demonizes, and sharpen the one that urges us to good acts.