Thursday, 20 October 2016
Psychologist Scans Own Brain Twice per Week for a Year and a Half
If you use social media, you have probably seen posts where someone has shown photos of themselves taken at regular intervals over a long period. Well, Stanford University psychologist Russell Poldrack has gone them one better: he has scanned his own brain twice per week for a year and a half! But Poldrack’s goal isn’t simply to wow his friends on Facebook. He is using the scans to do something that has never been attempted before: to understand how the connectivity of a normal person’s brain may vary over a period of several months, a span of time in which people with mental disorders often show considerable fluctuations in their psychological functions.
Poldrack calls his study “MyConnnectome”, and he published his initial results in the December 9, 2015 edition of the journal Nature Communications. It might seem surprising that no one had ever gathered such data before. But not many normal subjects would have been willing to do what Poldrack did: get into an MRI machine for a brain scan two mornings each week (one of them on an empty stomach) for a year and a half, have blood samples taken once per week, and write a report on his diet and physical activity every day. It took a scientist who was really motivated to advance the state of knowledge. (more…)
From the Simple to the Complex | Comments Closed
Sunday, 25 September 2016
How Different Parts of the Brain Co-operate
Perhaps one of the hardest things to understand about the brain is the way that it is organized into networks. In this post, I will discuss a 2015 study, on the brain structures involved in delayed gratification, that makes this complex subject a bit easier to grasp. (more…)
Pleasure and Pain | Comments Closed
Wednesday, 7 September 2016
Motor cortex is required for learning but not for executing a motor skill
The motor cortex was long thought to be the part of the brain that controlled the body’s voluntary movements. Given the plasticity of the cortex as a whole, it seemed reasonable to believe that decisive changes in the connectivity of the neurons in the motor cortex might well be associated with motor learning. Although this may indeed be the case, a study published by Risa Kawai and colleagues in the journal Neuron in May 2015 forces us to reconsider the primacy of the motor cortex in learned sequences of movements, at least in rats. (more…)
Body Movement and the Brain | Comments Closed
Monday, 22 August 2016
A good general book on neuroscience
Whenever I give a presentation about the human brain, someone almost always comes up afterward and asks me whether I could recommend a good general book on neuroscience. In fact, there are several such books, but the one that I want to recommend here today offers a special advantage: you can buy a printed copy, but you can also access the entire book on the Internet for free!
The book that I’m talking about is Neuroscience, 2nd edition, edited by Dale Purves et al. and published by Sinauer Associates in 2001. It covers wide areas of modern neuroscience and is chock-full of very informative figures and tables. (more…)
From the Simple to the Complex | Comments Closed
Monday, 8 August 2016
A Nanometric 3D Representation of a Mouse Cortex Cortex
The analogy between a real forest and a “forest of neurons” has been drawn many times, but the images produced most recently by the team of Jeff Lichtman and Narayanan Kasthuri (see the first two links below) make it clear yet again that the complexity of the brain’s connections far surpasses that of the densest forest.
As Lichtman has long said, by going down to the scale of the electron microscope and then reconstructing the slightest contacts between axons, dendrites, and neighbouring glial cells slice by slice, we can detect patterns that escape us at the more “macro” scales previously used to model neuronal connectivity. (more…)
From the Simple to the Complex | Comments Closed
