Comparisons between computer processors and the brain have been around so long that they’re a conceptual cliché. I’ve been trying to avoid making that comparison for a few hours. One of the problems is that while brains in Blue whales or humans are not computing machines, they do have some things in common. Findings like this make the similarity that much more reasonable. Not at the very abstract thinking level, not at the level that produces inspired areas of inquiry or that create the odd mental chaos of our dreams, but at the level of electrical signals producing certain phenomenon, Brain waves encode rules for behavior
One of the biggest puzzles in neuroscience is how our brains encode thoughts, such as perceptions and memories, at the cellular level. Some evidence suggests that ensembles of neurons represent each unique piece of information, but no one knows just what these ensembles look like, or how they form.
A new study from researchers at MIT and Boston University (BU) sheds light on how neural ensembles form thoughts and support the flexibility to change one’s mind. The research team, led by Earl Miller, the Picower Professor of Neuroscience at MIT, identified groups of neurons that encode specific behavioral rules by oscillating in synchrony with each other.
The results suggest that the nature of conscious thought may be rhythmic, according to the researchers….
One definition of memory in computing is the use of a physical device used to store programs or a series of instructions which can be called upon on a temporary or permanent basis. The physical events that allow that to happen require electric pulses and code. The brain requires electro-chemical pulses and a code.
The researchers identified two neural ensembles in the brains of monkeys trained to respond to objects based on either their color or orientation. This task requires cognitive flexibility — the ability to switch between two distinct sets of rules for behavior.
“Effectively what they’re doing is focusing on some parts of information in the world and ignoring others. Which behavior they’re doing depends on the context,” says Tim Buschman, an MIT postdoc and one of the lead authors of the paper.
As the animals switched between tasks, the researchers measured the brain waves produced in different locations throughout the prefrontal cortex, where most planning and thought takes place. Those waves are generated by rhythmic fluctuations of neurons’ electrical activity.
When the animals responded to objects based on orientation, the researchers found that certain neurons oscillated at high frequencies that produce so-called beta waves. When color was the required rule, a different ensemble of neurons oscillated in the beta frequency. Some neurons overlapped, belonging to more than one group, but each ensemble had its own distinctive pattern.
Interestingly, the researchers also saw oscillations in the low-frequency alpha range among neurons that make up the orientation rule ensemble, but only when the color rule was being applied. The researchers believe that the alpha waves, which have been associated with suppression of brain activity, help to quiet the neurons that trigger the orientation rule.
“What this suggests is that orientation was dominant, and color was weaker. The brain was throwing this blast of alpha at the orientation ensemble to shut it up, so the animal could use the weaker ensemble,” Miller says.
The findings could explain how the brain can create any appropriate behavioral response to the countless possible combinations of stimuli, rules and required actions, says Pascal Fries, director of the Ernst Strungmann Institute for Neuroscience in Frankfurt, Germany.
“We likely compose the appropriate neuronal assembly on the fly through synchronization,” says Fries, who was not part of the research team. “The number of combinatorial possibilities is enormous, just like the number of possible 10-digit telephone numbers is.”
How are the orientation rules or the neurons that handle those rules coordinating with the ensemble of cells to handle recognition and response. Good question. That is one of the big mysteries of cognitive ability. If some neurons make some permanent or semi-permanent changes to remember how to respond to the shape of an object first, and then evaluate color, what deeper mechanism is signaling them to do so – the core of our hard-drive.
Ruth Marcus really needs to find some honest work, Is Paula Broadwell’s wardrobe fair game?
Some readers — some female readers, to be precise — chided me for sexism. “Why is it okay to imply that a woman who wears a halter top to show off her guns on ‘The Daily Show’ must be a seductress?” asked one e-mailer. “That is dangerously close to the mind-set that suggests women who are raped are somehow responsible because of the way they dress. Shame on you.”
Another reader, in a letter to the editor, wondered, “Are black silk halter tops the mark of some sort of vindictive, national security-threatening evildoer? Or was Marcus resorting to stereotypes?” Her conclusion: “Dumping on Broadwell because of how she dresses does a disservice to all women.”
These are reasonable points, reasonably made. So let me explain why my response is to double down on the halter comments.
I’ve read this argument in many forms over the years. Men have a uniform – suits, law enforcement or military uniforms. Women do not so they need to be very careful about not appearing to look sluttish. How can someone be so aware of social norms and not understand them. If men started wearing dresses and lip-gloss and women all stared wearing loose jeans with their shirt tales out would that change the truth or falsehood of what they say. No. What they say has merits or it does not, regardless of externalities. because we’re human and have perceptual biases does not mean that the truth changes. Women have more freedom in some ways, less in others – they can wear dresses or suits. So people like Ruth will have to do some mental work – like setting aside socially ingrained perceptions and seeing the substance of the person first and their fashion choices down the line. This is not about defending certain behaviors that M’s Broadwell has engaged in, that is another issue, only not to judge her by how she decided to dress. Marcus, perhaps unknowingly is making the pro burka argument. let’s cover all women up so sex can supposedly be removed from the viewers mind -male or female. The problem with a woman dressed in a sack or cardboard box is that once a man knows it’s a woman, his brain is going to go into female perception mode. While the prejudices invoked are slightly different, the same is true of women judging other women.
Of course Petraeus is responsible for his misconduct; my point was that he should have looked at her and known better. But she should have known better, too. No woman is responsible for being raped, no matter what’s she’s wearing. We are responsible, however, for the way in which we present ourselves publicly. We are asking for sexist treatment when we dress like sex objects.
No they’re not. While some people can be tremendously shallow and judgmental about fashion, how you judge someone is based frequently based on learned societal norms, not an essential reality. I somehow doubt that Marcus goes weeks without bathing and wears a baggy sweatsuit and old sneakers into the office. Some related history, When Did Girls Start Wearing Pink?
Little Franklin Delano Roosevelt sits primly on a stool, his white skirt spread smoothly over his lap, his hands clasping a hat trimmed with a marabou feather. Shoulder-length hair and patent leather party shoes complete the ensemble.
We find the look unsettling today, yet social convention of 1884, when FDR was photographed at age 2 1/2, dictated that boys wore dresses until age 6 or 7, also the time of their first haircut. Franklin’s outfit was considered gender-neutral.
But nowadays people just have to know the sex of a baby or young child at first glance, says Jo B. Paoletti, a historian at the University of Maryland and author of Pink and Blue: Telling the Girls From the Boys in America, to be published later this year. Thus we see, for example, a pink headband encircling the bald head of an infant girl.
Why have young children’s clothing styles changed so dramatically? How did we end up with two “teams”—boys in blue and girls in pink?
Art deco facade of Penn Way Drug Store, Miami, Florida. I’m not sure when the store was originally built, but the photo was taken in 1980. Those levered windows are a south Florida trademark.
Art deco center area looking from the south. Rockaway Point, NY. Again, not sure about the build date. The photo was done in 1990 by Jack E. Boucher. I’m ambivalent about a lot of art deco bric-a-brac, but the architecture has a wonderful timeless quality about it. It is so timeless that it ends up in a lot of science fiction films. Gattica is a very good example.
This is just one of the wonderful photo collections at this blog, Vintage Guitars
Sorry, but you’ll have to put up with some ads to watch this video. H/T to here and a review, Reviewed: Sing the Delta by Iris Dement
Religion is another reoccurring theme throughout Dement’s music (she’s the youngest of fourteen children raised in a conservative, tight-knit Pentecostal family). On Sing the Delta Dement examines her lapsed faith while still managing to find solace in the world around her. In “There’s a Whole Lotta Heaven” she sings, “We don’t have a prophet to tell us what our future holds / We’ve only got each other and the love we carry in our souls.”
Some how I got into a southern soulful mood this week, don’t worry I’ll snap at least partly out of it soon.