On Perception (And Pancakes): How The Brain Keeps Vision Stable

By Alexandra Morris
CommonHealth Intern

You probably didn’t think Julia Roberts could teach you much about subtle, yet critical, brain functions.

But, it turns out, she can. Recall Roberts in her iconic film “Pretty Woman.” In one scene, she is eating a croissant. But as the camera pans back to her, the croissant turned into a pancake.

It’s likely that many of us missed that blooper, and now we know why. Scientists have discovered a brain mechanism that smooths our field of vision so that we don’t notice certain subtle visual changes — such as a croissant becoming a pancake in an otherwise identical scene.

In a paper published last month in Nature Neuroscience, researchers from the University of California, Berkeley have identified a brain mechanism that helps to stabilize our field of vision. They call it, a “continuity field” — a process the brain uses to merge similar objects seen within a 15-second timeframe.

“It seems like a very odd thing the brain is doing that could make us less accurate,” said the study’s lead author, Jason Fischer, who is now a postdoctoral fellow in the Department of Brain and Cognitive Sciences at MIT. “But in fact there is this huge benefit to it — and that is stabilizing perception over time.”

To measure this process, researchers showed study participants an image with alternating light and dark bars, or “gratings,” at a random angle every five seconds. The participants were then asked to move a white bar to match the tilt of the grating that had been shown.

Here’s the video:

Researchers found that while the white bars generally aligned with the image, there were subtle differences that were biased toward the previous three or so images. These differences could be attributed to the continuity field.

Imagine, now, for example, you are driving down a highway in the pouring rain and you’re trying to read a road sign. The windshield wipers are moving; the raindrops are hitting your windshield. As you’re looking at the sign, you’re experiencing constant interruptions in your visual stream. In that case, the changes that the continuity field is causing us to miss are the raindrops and windshield wipers — you may even fail to notice them after a while. The continuity field, for the most part, is beneficial — it blocks the stuff we don’t want to see. Continue reading

Psychobiotics: Can Stomach Bacteria Change Your Brain?

The plot keeps thickening when it comes to the connection between your gut and your brain.

A new review article links probiotics to changes in mood and mental health, suggesting these “good” bacteria might have potential as a treatment for depression and other psychiatric maladies. In the study, published in the journal Biological Psychiatry, researchers define the term “psychobiotic” as “a live organism that, when ingested in adequate amounts, produces a health benefit in patients suffering from psychiatric illness.”



These organisms act on what researchers call the “brain-gut axis,” a biological network connecting the intestinal and endocrine systems to the spinal cord and regions in the brain that process stress, such as the HPA-axis.

Is all this plausible? Perhaps. Ghrelin, known as the “hunger hormone” and produced in the intestines, was recently found to play a role in the development of chronic stress. And stress in turn has been found to alter our microbiota. There’s growing evidence that there’s a special connection between the gut and the brain, and as one MGH psychiatrist said recently: “There is a neural feedback from the gut to the brain so chronic gastrointestinal distress can exacerbate anxiety or depression.”

Thomas Insel, Director of the National Institute of Mental Health, stated last December that how “differences in our microbial world influence the development of brain and behavior will be one of the great frontiers of clinical neuroscience in the next decade.”

Dr. Timothy Dinan of University College Cork in Ireland and the psychobiotic study’s lead author says that although the research conducted on humans is sparse, “the animal studies indicate that certain psychobiotics can change brain chemistry.”

Continue reading

Your Brain On Poverty: Low-Income Childhood Linked To Smaller Brain

Young children living in poverty appear to have smaller brain volumes in critical areas, according to researchers at Washington University School of Medicine. But poverty’s detrimental impact on brain development may be mediated by basic early interventions like compassionate parenting and caregiving, the report says.

(Digital Shotgun/flickr)

(Digital Shotgun/flickr)

Growing up poor is already known to be associated with a higher risk of “poor cognitive outcomes” and school performance, the researchers note. But what’s fairly new here is how outside economic forces play out in the development of a child’s brain. According to the study, published in JAMA Pediatrics Monday:

Poverty was associated with smaller white and cortical gray matter and hippocampal and amygdala volumes. The effects of poverty on hippocampal volume were mediated by caregiving support/hostility on the left and right, as well as stressful life events on the left.

The finding that exposure to poverty in early childhood materially impacts brain development at school age further underscores the importance of attention to the well-established deleterious effects of poverty on child development. Continue reading

Nature: Recipe For A (Primitive Precursor Of A) Human Brain In A Jar


So delicious! No, I don’t mean vat-grown brain pickles. I mean the delicious frisson I get every time real-life science news seems to echo long-beloved science fiction in uncanny ways.

So to today’s very serious report in the prestigious journal Nature: Researchers have found a way to build a sort of a human proto-brain in the lab. (Of course, their work, striking as it is, falls miles short of the classic cinematic depictions of brains in jars, but let’s just take a moment here to recall Steve Martin’s true love in “The Man With Two Brains,” and the ancient black-and-white sci-fi flicks featuring disembodied brains. “Brain in a jar” even has a whole page on

Now to 2013 reality: The scientists, based mainly at the Institute of Molecular Biotechnology in Vienna, used stem cells to engineer a three-dimensional precursor of a human brain, about the size of a pea. They say this miniature proto-brain could help illuminate how the human brain develops — and what can go wrong as it does.

They grew the stem cells into a brain-like structure at about the level of a nine-week-old human embryo’s brain. And they showed that this primitive mini-brain could cast light on a specific disorder: microcephaly, a rare birth defect in which the brain doesn’t grow nearly as big as it should.

The work is still in very early stages, but the researchers say they hope it can also be used to help treat more common brain diseases that begin early in life, including schizophrenia and autism.

They began with human stem cells from adults, and helped them grow and self-organize into a primitive but strikingly brain-like structure, which they call a cerebral organoid. An organoid is a structure like an organ — so this isn’t a full-fledged brain, but if you consider that the human brain is known as the most complex organ in the animal kingdom, it’s still pretty impressive.

So what exactly is the recipe for whipping up a human brain? Continue reading

10 Facts You May Not Know About ADHD

By Karen Weintraub
Guest Contributor

When you think about ADHD, what do you imagine? If you’re like most people, it’s probably a stereotypical image of a young boy bouncing off the walls, buzzing with pent-up, unfocused energy.

But many people with ADHD aren’t hyperactive at all, and by the time they reach adulthood, most hyperactive people have calmed down — at least on the outside. This helps explain why Attention Deficit Hyperactivity Disorder, which used to be considered a childhood condition, is now being diagnosed in adults as well.

There are some who dismiss the condition as massively over-diagnosed, perhaps as a ploy by drug companies to boost business. And maybe there’s some truth to that on the margins. Not everyone who’s got ideas racing through their head should be medicated. (Just ask most of the faculty at MIT.)

But there are large numbers of people — studies suggest it’s as many as 4 percent of adults – who are profoundly affected by the symptoms of ADHD. Many can’t hold a job or stick with a relationship. They’re chronically late or forgetful. They jump into jobs and purchases and relationships without thinking them through, only to regret their impulsive actions later. They get stuck in self-destructive patterns, fall prey to addiction and depression. And they can’t figure out why they struggle so much more than everyone else.

For this population, a diagnosis can be a huge relief, explaining why they’ve always felt out of step with the world.

Here are a few other things you might not have known about ADHD, drawn from a new book I co-write, Fast Minds, How to Thrive if You Have ADHD (Or Think You Might) published by Berkley Books:

Medication Can’t Fix ADHD
Treating ADHD in adults with medication can be helpful – and it’s often the first suggestion a diagnosing doctor will make. But it’s not enough. Adults with ADHD often need help getting and staying organized, even with their own priorities in life. They may need help at critical moments, making a constructive choice, rather than a destructive one. And they need emotional support to counteract all the negative messages they’ve received all their lives when their actions didn’t meet other people’s expectations.

Not Everyone Who’s High Energy Has ADHD
Our images of ADHD come from celebrities who talk about having it, like singer Adam Levine or actor and game show host Howie Mandel. But many people with the condition struggle to get up off the couch. They were the quiet ones in class who always seemed like they were in their own world. As adults, they may be unsure of what to do, or want to do so many things that they paralyze themselves. On the other hand, there are plenty of people who have some of the traits of ADHD without being impaired by the condition. Some of the same organizational and self-control strategies may help.

People With ADHD Don’t Have Trouble Paying Attention Continue reading

Rethinking Autism As A ‘Whole Body’ Condition

We often think of autism as a disorder of the brain. And it certainly is. But a new book, “The Autism Revolution,” (Random House) by Dr. Martha Herbert, an autism expert and pediatric neurologist at Massachusetts General Hospital, and CommonHealth writer Karen Weintraub asserts a more comprehensive and wholistic view in which autism is really a condition of the whole body and should be treated with that in mind.

Here is an excerpt from the book:

Chapter 1: Go for the Extraordinary

Caleb tore himself away from a game with his sisters, bounced into the kitchen and asked his mom what she was making for dinner. It was one of his favorites: gluten-free pasta and ground beef.

He started to turn back to the girls, but paused. “Mom,” he said, as casually as if he were commenting on the weather, “my autism is gone.”

“How do you know?” his astonished mother managed to ask.

“It’s easy to be with people now,” the 10-year-old said matter-of-factly, and then headed back to his younger sisters.

Joy Petersen stared, dumbfounded for a few seconds in the middle of the kitchen. It wasn’t until two months later that she realized he was right.

Caleb has his father’s bright blue eyes, his mother’s dark hair and a complexion that reflects his mixed Dominican-American heritage. He is still looking up at 5 feet, and his voice remains a little boy’s for now. He wants to be a zoologist when he grows up, and is already talking about going away to college, although he understands that his parents will be sad to see him go.

She recently took him to a new doctor, a specialist in treating children with autism and other special needs. Caleb noticed the photographs covering the doctor’s wall, and asked why the doctor was holding a gun in one of them. After talking to Caleb and his parents for a while, the doctor announced that Caleb didn’t fit the criteria for autism anymore. “Yeah!” Caleb said, jumping up and pumping his arms. His mother began to sob uncontrollably.

Joy used to dream of the day someone would say her son was no longer autistic. Of the day he’d come up to her, say he loved her and really mean it.

That day was unimaginable when Caleb was 4, still had no language, and was so afraid that he would wail and cry when anyone other than his parents came within 5 feet. Joy said she would put her fingertips on his body and he would scream as if somebody had hit him. Taking care of Caleb was so overwhelming that she would often find herself in tears. There were times when she was so afraid of hurting him in her anger and stress, that she’d put him down, walk into her bedroom, shut herself in her closet and collapse on the floor, crying.

The doctors and therapists told her she had to be realistic. Your son will probably be like this forever, Continue reading

Brain Decline Seen ‘As Early As Age 45,’ But Not To Worry (Yet)

“I knew it — I’m getting stupider,” was my first response when I saw the major new study on “cognitive decline” just out in the BMJ (formerly known as the British Medical Journal.)

“Cognitive decline can begin as early as age 45, warn experts,” was the headline of the press release. It began: “The brain’s capacity for memory, reasoning and comprehension skills (cognitive function) can start to deteriorate from age 45, finds research published on today. Previous research suggests that cognitive decline does not begin before the age of 60, but this view is not universally accepted.”

Not a pleasant prospect — early senility. But I feel much better now that I’ve spoken with Dr. Francine Grodstein, an associate professor of medicine at Brigham and Women’s Hospital who studies aging. She wrote a BMJ editorial that accompanied the study, and I turned to her for a reality check. Tell me it ain’t so, I begged; is there real cognitive decline in our forties?

‘The translation in a day-to-day message for people in their forties is, ‘Start living healthy now, because if you put it off for 40 years, it may be too late.’

“It depends on what ‘real’ means,” she replied. “They did demonstrate in this study that there was ‘measurable’ cognitive decline in people in their mid-40s. So ‘measurable’ is probably a better word than real. But it still was quite a small amount and though it’s not data-driven, I would say those 40-year-olds who had measurable cognitive decline aren’t feeling anything. So it’s probably a small enough amount that in terms of their day-to-day life, it does not mean very much in the present.

The bigger question is really whether a small amount of measurable decline that the [BMJ] Whitehall study could see in the forties does predict dementia 20-30-40 years down the line. And if it does, then the translation in a day-to-day message for people in their forties is, ‘Start living healthy now, because if you put it off for 40 years, it may be too late.'”

It’s good to hear the early decline is slight, but I still find it depressing…

It’s not depressing! The amount of decline that was measured here was tiny. It doesn’t mean you’re demented when you’re 50. This is a long, long way from anything that has clinical relevance. People are more sensitive about memory, but it’s no different from other things: cancer, cardiovascular disease — the same thing is true: These are very long-term processes and the fact that you have some early signs of it in mid-life shouldn’t be something that depresses you, it should be something that inspires you. It should get you to say, ‘If I want to prevent something bad from happening in 30 years, I need to start doing more healthy things today.’ These findings in no way mean that at 50, there are more people with dementia than we previously thought.”

But doesn’t it imply that we’re getting stupider? Continue reading

Why To Exercise Today: Even Weight-Lifting May Make You Smarter

Yeah, this guy doesn’t look like the brightest bulb. We tend to stereotype weight-lifters as heavier on brawn than brains.

But recent research in animals, and a bit in humans as well, suggests that weight-lifting may improve brain function, just as aerobic workouts are known to do. This New York Times blog entry reports on recent studies in rodents and adds:

Whether the same mechanisms occur in humans who undertake resistance training of one kind or another is not yet fully clear, but “the data look promising,” said Teresa Liu-Ambrose, a principal investigator at the Brain Research Center at the University of British Columbia. In results from her lab, older women who lifted weights performed significantly better on various tests of cognitive functioning than women who completed toning classes. Ms. Liu-Ambrose has also done brain scans of people who lifted weights to determine whether neurogenesis is occurring in their brains, and the results, still unpublished, are encouraging, she said.

(Of course, we can’t ignore one commenter’s point: “I have two words that disprove this theory: Jersey Shore.”)

Zap! You’re Better at Math! Brain Stimulation May Improve Skills

Sign me up.

A small study published online today in the journal Current Biology reports that non-invasive electrical stimulation of the right side of 15 healthy adults’ brains made them better at math tasks — and the effect was still there six months later.

Researchers have shown in previous studies that non-invasive stimulation — magnetic, rather than electrical — can make a subject’s performance in math worse. But this is the first time, the study’s authors say, that it has been shown that non-invasive stimulation “can also enhance numerical abilities with remarkable longevity.”

They speculate that eventually, brain stimulation could help the 20 percent of the population with “numerical disabilities,” and the 6.5% of the population so bad with numbers that they even get a diagnosis, “developmental dyscalculia.” I may joke about being somewhat “innumerate” myself sometimes, but it’s not funny at all to be unable to count your change or run a checkbook.

Before we get into the study’s details, let’s have the huge grain of salt that is clearly called for. reports here:

One American researcher said the findings were encouraging, but a lot more study is needed.

“Like many good studies, it opens a raft of fertile questions, including ‘Will this work in children?’ and ‘Is it safe to use in children?'” said Dr. Edwin M. Robertson, associate director of the Berenson-Allen Center for Noninvasive Brain Stimulation at Beth Israel Deaconess Medical Center in Boston.

“It is certainly possible that undergoing this procedure will affect brain function in children and so cause either neurological or psychiatric problems in the future, and so good follow-up studies are required to examine this issue,” said Robertson, who is also an assistant professor of neurology at Harvard Medical School. “The concern is greater for children whose brains are still developing, as opposed to the adult population of volunteers who took part in the current study.”

In other words, no, kids should not yet get some juice to the head before the SATs, and accountants need not order their zap-helmets yet.
Back to the study: According to the study’s press release — Continue reading

From MIT: Why You Shower, Then Brush (Or Vice Versa)

By Marielle Segarra, WBUR intern

This week, when you woke up, you checked your e-mail, brushed your teeth, ate some oatmeal, and then took a shower. Maybe last week, when you woke up, you showered, brushed your teeth, ate, and then checked your e-mail.

A new Massachusetts Institute of Technology study suggests that your routines and habits may be changing constantly until your brain finds the most efficient way to finish a task or set of tasks, even if you don’t notice the minor alterations.

The new study by MIT professor and neuroscientist Ann Graybiel and graduate student Theresa Desrochers suggests that your routines and habits may be a way your brain seeks a reward that isn’t immediately obvious to other people, or even to you. The reward in this example, and in the study, is saving time.
Continue reading