Tuesday, 27 January 2015
Functions of the amygdala : more diverse than previously thought
Science in general, and neuroscience in particular, are constantly evolving. So even though our knowledge of a given brain structure may not have undergone a scientific revolution or a paradigm shift at any given time, when we compare what we know about it now with what we knew, say, 10 years ago, we may find that things have changed a lot. That’s certainly the case for the amygdala, a small but very important piece of the brain. And since we first described the amygdala on this website just about 10 years ago, we’d like to give you a little update now. (more…)
Tuesday, 6 January 2015
Literary Activity and the Default Mode Network
In every human culture, much of life revolves around the stories that we tell—about the world around us, about other people, and about ourselves. When you come right down to it, just like traditional oral storytelling, that is all that modern literature and film do today. There must be something in the brain that resonates especially strongly with the narrative process.
That something might well resemble what neuroscientists call the the brain’s default mode network: the particular set of brain structures whose activity increases by default, when someone is doing absolutely nothing. (more…)
Tuesday, 16 December 2014
The Infinitely Large, Infinitely Small, and Infinitely Complex
This week, we’re going to talk about nothing less than the place that the human brain occupies in the known universe. Let’s begin by recalling that, as stated often elsewhere on The Brain from Top to Bottom, the brain that each of us possesses is one of the most complex objects in that universe, which is already saying a lot.
The complexity of the human brain is one of the reasons that this website is organized the way it is. (more…)
Monday, 24 November 2014
Persistence of social signatures in human communication
No need to be impressed anymore by people who have 600 or 1400 “friends” on Facebook. Just like you and I, they are not really discussing their true feelings or anything else important with more than one or two dozen people at most. And for every individual, the size of this limited “hard core” of relationships seems to persist over time, even though the friends who compose it may change. These fascinating cognitive data come from a study entitled “Persistence of social signatures in human communication”, published in the journal Proceedings of the National Academy of Sciences of the United States of America in January 2014. (more…)
Wednesday, 5 November 2014
A Brain Circuit That Links Two Events in Time
If you’re out in a storm and you see a bolt of lightning streak across the sky, you tend to pull your head down between your shoulders for the next few seconds, fearing the big thunderclap that you expect to come next. This kind of association between a stimulus and a potential danger is something that the human brain retains easily, because it has always had an obvious importance for our survival.
A study co-ordinated by MIT professor Susumu Tonegawa and published in the journal Science in January 2014 reveals the neuronal bases of this association between a stimulus and the timing of a potential danger, about which relatively little was previously known compared with the association with the other essential property of a danger: its location. In the latter case, the hippocampus, the key brain structure for encoding memories, makes use of place cells, which are activated when you are in or are remembering a specific location. (more…)