I just came across an article published last month in the Proceedings of the National Academy of Sciences, US. It turns out that shifting of the circadian clock – the natural light/dark and sleep cycle represented in mammalian hypothalamic suprachiasmatic nuclei – is probably not good for you. If lack of sleep in the modern era isn’t bad enough, the daily deviation from the natural synchronous rhythms of activity and light, brought about mainly with the advent of electric lighting, affects us as well (rather than just the absolute amount of sleep).
Researchers at Rockefeller University in New York bounced mice off the normal 24hr light cycle they (and, of course, we) evolved in response to, and found devastating effects:
Housing in these conditions results in accelerated weight gain and obesity, as well as changes in metabolic hormones. In the brain, circadian-disrupted mice exhibit a loss of dendritic length and decreased complexity of neurons in the prelimbic prefrontal cortex, a brain region important in executive function and emotional control. Disrupted animals show decreases in cognitive flexibility and changes in emotionality consistent with the changes seen in neural architecture.
Maybe this means we should start going to work at 5:30 in the morning, get home at 2:00pm, and turn off the lights at 6:00.
Oh yea, and no more transoceanic flights, night shifts, or midnight screenings….and last call is now at 8:00pm.
New research out of the University of North Carolina at Chapel Hill shows that the immensely complicated, accurate, and dangerous migration of hatchling loggerhead sea turtles in the open ocean is acheived using an amazing sixth sense: the ability to sense the earth’s magnetic fields.
The turtles measure both angle and intensity of the planet’s natural magnetic field created billions of years ago. The Loggerhead’s abililties are especially interesting, as the turtles are turning a relatively small amount of data into a superlative ability to locate a single breeding site. As one of the reserachers, Nathan Putman, says, “although it is true that an animal capable of detecting only inclination or only intensity would have a hard time determining longitude, loggerhead sea turtles detect both magnetic parameters…This means that they can extract more information from the Earth’s field than is initially apparent.”
Little is known regarding the neuroscience behind this amazing sensory feat, but it’s sure to be interesting.
And I wonder what the sensation of sensing the earth’s magnetic fields would be like…itchy? warm? tasty? completely subconscious? Hmmmm…..
Lab site: http://www.unc.edu/depts/geomag/
We’ve got an exciting new feature on BB:
The Beautiful Brain now has an official Blog! It’s called the “BBBlog” and will provide a constant stream of interesting news and thought from the neuroscience and art worlds we like to cover. The blog sits over in the right column of the main page and also has its own site (see below). Expect a broad range of posts on a broad range of topics, and please share and comment on the posts!
Remember when when Gap tried to change their iconic logo and the immediate backlash from consumers? No? Well it happened. And as luck has it, neuroscientists were consulted for advice on why their new logo failed. Some advice:
-When a word overlaps with an image, the brain tends to ignore the word in favor of the image
-The sharp edge behind the letter “p” can invoke negative subconscious feelings.
-The old logo had a slightly odd font, which our brains prefer and remember better.
-High contrast is good. The new logo’s “p” is lost in front of the blue box.
-The capital “G” followed by lowercase letters makes our brains think of “Gap” as a word rather than a logo.
Some would argue that these are principles that every designer knows, regardless of lacking a neuroscience background. But it’s nice to know the neural reasoning for things we take for granted, like design.
via PR Newswire
Using a reverse-engineering method similar to that of the Blue Brain Project, Jenn-Kang Hwang and her team at the National Tsing Hua University in Taiwan have engineered a computer-simulated fruit fly brain with single-cell precision.
The researchers stained (using green-fluorescent protein) and imaged tens of thousands of neurons in the fly brain and used complex gene-marking procedures to find out which cells interacted with one another.
These methods helped them elucidate the architecture of specific networks of cells, and that information allowed for a reconstruction of the pathways of functional brain regions, and ultimately the full structure of the brain. The authors compare their model of interacting neurons to a city highway system, writing:
Each unit is like a city containing local intersected streets and avenues linked to other cities through multi-lane highways without cross-traffic. Sometimes, several geographically closed units form a family working together for a specific function requiring intensive information processing.
The researchers also address the age-old brain/computer comparison, pithily stating:
It seems that a fly brain is smarter and more complicated than any computer built thus far.
However, their work by no means represents a full understanding of the workings of the fruit fly brain and the translation of neural network to behavior (that level of understanding is a ways away); rather, it’s a useful visual tool for testing hypotheses about specific neural interactions in the fruit fly brain, and locating neurons of interest. It’s akin to navigating on a road trip – why use a glove compartment full of small, unconnected state maps when you can use a nice, big road atlas?
The Hwang team has published the results of their brain-mapping project online for free and open access, just like the Human Genome Project did in 2003. To see the exciting images and videos, go here.
Carl Zimmer recently reviewed studies by Dr. Niedenthal in the New York Times. In it, he reports a new theory on how a person detects different types of smiles. When we see someone smile, we tend to mimic the smile. This act of mimicry lights up different parts of our brain for different types of smiles (genuine, happy, fake, etc). Dr. Niedenthal’s model suggests we decode other’s smiles by analyzing our own brain activity when we mimic.
When subjects were shown fake and genuine smiles under two conditions, with and without pencils in their mouths, those who had their smile-muscles occupied by a pencil had a significantly harder time distinguishing the test smiles. It is good support for the model, but this is still a budding field.
via The New York Times
Which is genuine?