Great little video of a historic social psychology experiment about the power of social influence and our desire to conform.
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New CT Scanner from Philips
Philips recently developed a new 64 channel CT scanner that can provide high-resolution 3-D images of the body. The images it can produce are simply fabulous. Philips states that it can have sub-milimeter isotropic resolution and scan the complete human body in less than one minute with 80% less radiation exposure than traditional CT scanners. Numerous articles and pictures are starting to show up on the web. It appears that the main uses of it, at least initially, are focused on the cardiovascular system. I wonder how beneficial or useful it would be for neuroimaging? I’m not an imaging specialist but the speed and resolution of this system could lead to great improvements in neuroimaging. Even with a limited field of view, it seems like it could be beneficial to look at specific regions of the brain. There is no indication if volumetric and quantitative analyses could be performed on the images. Then again, the technology is quite new. Only one hospital in the world is actually using one of these machines.
The reported price of the machine is $2 million, which is quite reasonable. MRI machines can run upwards of $10 million. This is a technology well worth watching as it develops. We are about to enter a golden age of anatomical imaging.
Here are a few links to stories and images:
Images by Philips.
Toshiba also recently unveiled a similar machine: Link here.
MedINRIA MRI Visualization and Processing
I just ran across a site that has a few medical imaging software packages. One of them is MedINRIA.
“MedINRIA aims at providing to clinicians state-of-the-art algorithms dedicated to medical image processing and visualization. Efforts have been made to simplify the user interface, while keeping high-level algorithms. Each application is called a module, and can be loaded dynamically from a single main window. MedINRIA is available for Microsoft Windows XP/Vista, Linux Fedora Core, MacOSX, and is fully multithreaded.”
Link to a description and download.
I have not tried the software yet – my MRI analysis software is FSL – but this software looks promising. Plus it runs natively on Windows, Linux (Fedora Core), and Mac OS X (FSL only runs natively in OS X and Linux – it’s a little tricky to run in Windows). Not that running in Windows is necessarily a perk – our preferred MRI processing workstation is a Mac – but many people are using Windows. If I get around to installing the software, I’ll post a review of it later. I’m always looking to user-friendly ways to analyze MRI data. Best of all, like FSL, it is free. It is based, in part, on the open-source and excellent ITK and VTK packages.
Moral Development
Lawrence Kohlberg developed a theory of moral development in humans that has been quite influential in emotion and moral reasoning developmental psychology. He believed that most adults reason at the 3rd or 4th stage level. A few reach the 5th and very few reach the 6th. However, people can reason at different levels at different times, with someone using stage 5 reasoning one day and stage 3 the next. However, people do tend to reason at one particular level more often than at other levels. The stages of moral development are as follows:
Rules outside oneself
Stage 1: Heteronomous morality
- Punishment-and-obedience orientation
- What is wrong is punished
- What is right is rewarded or not punished
Stage 2: Individualism, instrumental purpose, and exchange
- Naïve hedonism
- Egocentric or needs-based
Continue reading “Moral Development”
Hypothalamic Hamartomas
I saw an interesting case today. It was a child with a hypothalamic hamartoma, a tumor (likely present from birth or shortly thereafter) right on the midline of the brain by the hypothalamus and the third ventricle. These tumors are quite rare and result in some interesting behaviors. A common result of these hamartomas is what is called precocious puberty – very early puberty onset; this early puberty often occurs before age 2. This can occur because the hypothalamus is one of the major brain areas that creates hormones and modulates the endocrine system.
Another common result of these hamartomas is gelastic seizures. Gelastic seizures are laughing seizures. The seizure manifests with the child (or adult) having sudden laughing fits for no apparent reason. They can occur many times a day. Some people also have dacrystic seizures, or crying seizures. Developmental delays are also common in this type of brain disorder as is hyperactive behavior.
Hypothalamic hamartomas are sometimes treatable by resection. This surgery has the possibility of eliminating the seizures and stopping most or all of the hormonal abnormalities.
The beginnings of functional neuroimaging
Angelo Mosso was an Italian physiologist, interested in many things but among them, blood flow and blood pressure in humans. He was born in Turin in 1846 to a father who was a carpenter by trade. Showing great promise in school, Mosso was able to attend the University of Turin and study the natural sciences. Always the consummate and prodigious researcher, over the course of his career he published more than 200 articles and books. Mosso’s work helped lay the foundation for many important (and modern) neuroscientific research methods, such as fMRI and the polygraph.
Mosso demonstrated in the late 1800s an increase in brain blood vessel pulsation as people thought about things. He interpreted this to mean that blood flow increased to the brain when people had thoughts. This particular study was one of the first (documented) functional neuroimaging (of sorts) studies. Both fMRI and PET are based on the idea that increased blood flow to the brain is associated with changes in cognition. It’s doubtful that he could have imagined how influential this research would be.
Visit this site for a longer biography of Mosso.
The neuroscience of aging
I’ll start with the bad news first. The human brain reaches it’s physical peak around the age of 25. After that it’s all downhill. The prefrontal cortex and underlying white matter is the last area of the brain to develop (including myelination); that area is also the first to start the decline. Myelination of the frontal cortex typically isn’t completed until the early to mid 20s. Its slow degradation starts quickly after it finishes development. This slow degradation of the brain correlates with slowed processing speed initially and, later in life, with declines in all areas of cognition. The good news is that cognitive performance in most areas does not typically decline until the mid 50s; many abilities such as verbal continue to increase until the mid 50s or early 60s. While there is often global brain matter loss (slowly over the decades), specific areas of the brain change at different rates (with some areas exhibiting volume increases until the mid 50s or so).
This news can be discouraging for people who are older than 25 (such as myself) – knowing that I am on the downward slope, at least as far as brain volume, myelination, and processing speed are concerned. I wrote about the bad news first so now the good news. Even though cognitive performance starts to decline, on average, in the mid 50s, many domains increase between age 25 and age 55; thus, the declines in late life often merely bring cognitive performance back down to where it was in the mid 20s. Of course processing speed in late life is a lot lower than in the early 20s but verbal memory and abilities, reasoning, and spatial abilities are quite intact in late life. Math abilities tend to decrease significantly over life though. The graph shows cognitive performance as measured by a 35-year longitudinal study (actually a sequential research design – both cross-sectional and longitudinal) (Schaie, K. W. Intellectual Development in Adulthood: The Seattle Longitudinal Study. Cambridge Univ. Press, Cambridge, 1996).
For a comprehensive review of cognitive and neurological changes associated with aging read Trey Hedden and John D. E. Gabrieli’s Nature Review: Neuroscience article published in February 2004. I’ve included a link to a PDF of the article: Aging article.
Another anatomy site
I found a nice but very basic anatomy site (i.e., good for kids). It also has more anatomy than just the brain, with skeletal, heart, and digestive tract anatomy in English and Spanish.
Click on the image to visit the site.
Can we improve our brains?
I thought this was an interesting article. It has a lot of quotes from leading neuroscientists about the possibility of “training” our brains to improve them.
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Cajal claimed in the XX century, “Every man can, if he so desires, become the sculptor his own brain“, may well become reality in the XXI. And influence Education, Health, Training, and Gaming in the process.
Optical Illusions That Make You Fatter and Your Wallet Lighter
“Eat from small plates, drink from taller glasses.” Optical illusions lead us to eat and drink more, as illustrated by the examples in this article. There’s an old saying in cuisine…”the first bite is with the eye.”
Interesting article. I’m not sure if there is empirical data to support it but it does show that our perception of our food can affect how much we eat. Our actions are affected by so many different things, many of which we might not be aware.