A few weeks ago I was having a discussion about mathematical models for the prediction of the movements of the stock market. The question was whether there was any use to developing complex algorithms trying to predict these fluctuations. My friend (an economist) argued that while he admits the market value isn’t truly random, incorporating random variables may be the best model we have for it. It turns out that many mathematicians (and quants, economists who analyze market fluctuations using algorithms) have been using “random” models for their predictions. These range from sequences randomly drawn from log-normal distributions, to chaotic systems that may allow for the prediction of market crashes and other rare large movements. I was fascinated by the idea of randomness as a model for complex systems. It seemed particularly interesting to explore this in the context of biological processes, especially when the laws of thermodynamics have described that all physical phenomena drift towards the chaotic state of maximum entropy. Could randomness be a model for circuit wiring and function in the brain?
Posted by Jasmine Reggiani on August 21, 2016
During these hot summer days, lying in the shadow puffing and sweating, my arms and legs pulling down like bags of sand, it is sometimes difficult to believe that my brain is still functioning fine. How do we manage to keep our head cool, even on hot days like these?
Posted by vivianhemmelder on July 26, 2016
We make decisions every day. Decision-making is a way by which we exert control over our behavior, mood and even the course of our lives. One key element in decision-making is self-control. This is often seen when we have to make that extremely difficult decision between another double cheeseburger and a healthier salad. While that may seem difficult enough on its own, many decisions, such as having to choose which graduate program to join or which answer to circle on an exam, come with substantial amounts of stress. This stress can guide or compromise the decisions we make. So, how do stress and self-control come together during decision-making? What is the neurobiological basis underlying this convergence?
Posted by Sivapratha Nagappan on June 21, 2016
Our sense of touch has an innate connection with our emotions. Gentle touches are soothing for not only us but also other animals. For example, classic experiments by psychologist Harry Harlow in the 1950s found that an infant monkey raised with two robots, one providing food and the other wearing soft cloth, spends more time cuddling with the cloth robot1. When scared, the infant monkey also goes to the cloth robot for protection. Clearly, there is a special pathway that guides touch sensation to the depths of animal instincts. Working out this pathway requires knowledge about the neural circuitry processing touch sensation.
Posted by Stephen X. Zhang on June 14, 2016
A peek into the unconscious brain under anesthesia
In our everyday lives we are aware of ourselves, our behavior, and the sensory perception of our environment. This awareness during awake states is known as consciousness. As much as it is central to our brain activity, it has also been one of the greater mysteries of neuroscience. In our lifetimes we all experience changes in our state of consciousness, particularly in the alternation between sleep and wake states. We may also experience changes in consciousness state when fainting, during an epileptic seizure, and through the effects of psychoactive drugs. What is happening in our brains when our conscious selves are not present?
Posted by Jasmine Reggiani on May 31, 2016
I recently had the opportunity to write a post for Nautilus on a subject that is dear to me – the use of crows and other intelligent members of the corvid family for neuroscience research. Corvid intelligence has been noticed by humans for millennia, and more recently by ethologists and psychologists. The fascinating thing about these animals is that like all birds, they do not have a neocortex – the part of the mammalian brain that has countless times been implicated in intelligence. Now, there is just one lab in the world – Andreas Nieder at the University of Tübingen – that has started peering into the brains of these fascinating creatures to try to understand how crows’ cortex-less brains enable them to perform amazing cognitive feats. You can read the full story on Nautilus.
The post received moderate praise (thanks, mom!), but some of the comments on Nautilus struck me because they focused not on the ideas or experiments I proposed, but on the treatment of animals in research. Ricky, for example, wrote: Read the full post »
Posted by Grigori Guitchounts on May 17, 2016
Today, let’s throwback to the multiple comparisons problem and relate it to something new: Open Science.
Gold Diggers in Australia (Edwin Stocqueler, 1855)
Read the full post »
Posted by vivianhemmelder on May 12, 2016
A few weeks ago, Vivian wrote a post about prion disease, discussing how understanding the mechanisms of Kuru could help us design treatments for other neurodegenerative disorders characterized by protein aggregations. The accumulation of protein as a pathological process has also been investigted outside the brain. Aging and degeneration are complex system-wide phenomena and studies like the one by Demontis and Perrimon (2011) show that by looking outside the brain we can unveil new whole-body regulatory mechanisms for neurodegeneration. Read the full post »
Posted by Jasmine Reggiani on May 5, 2016
This week I’m re-visiting adult human neurogenesis: the seminal neuroscience finding that new neuronal cells are born in adult human brains after the normal developmental period in which neurons are generated. This remarkable discovery was made by Peter Eriksson and colleagues in the lab of Fred Gage at The Salk Institute for Biological Studies. Prior consensus in the field was that once neurons died (a hallmark of neurodegenerative diseases such as Alzheimer’s and Parkinson’s) there was no regeneration of neurons. The view was that brains generated a finite number of neurons for the life of the organism, and these neurons networked to handle all learning of new knowledge and the making of new memories and associations—quite an incredible feat! However, the Gage group questioned the current model and found that there was neurogenesis in specific areas of rodent brains, a huge finding in and of itself. But this generated some controversy— another group published that neurogenesis was not taking place in marmosets (a higher mammal than rodents) and therefore it was likely not happening in other primates, i.e., humans. Therefore, the publication of “Neurogenesis in the Adult Human Hippocampus” in Nature (Eriksson et al., 1998) helped to resolve what had become a contentious issue and definitively showed that indeed, new neurons are being born and incorporated into the hippocampal region of adult brains.
Posted by Kathryn on April 28, 2016
If you aren’t asleep when the clock strikes three in the early morning, your eyelids get heavy and your brain feels like mush. You still have that paper to finish writing and you want to stay awake but staying awake is a struggle, a fight against our own brain. We have all been there (especially during finals week). With today’s post, lets look at how our brain regulates sleep and why we spend our days alternating between sleep and wakefulness?
Posted by Sivapratha Nagappan on April 26, 2016