IamA Danielle Bassett, a physicist/bioengineer (and MacArthur Fellow) analyzing how the brain works. I recently authored a study identifying the neural basis behind multitasking. AMA!

Will we be able to connect our brains to machines and directly access computer storage/memory sometime in next 50 years?

Are there any serious researches in human computer interfaces?

DSB: Indeed, there is very serious research in human computer interfaces. Perhaps the most exciting area is in the use of prosthetics (such as robotic arms) that can be controlled or manipulated based on neural signals acquired from the brain non-invasively (for example using EEG -- electroencephalography). A second exciting area in the field of human computer interfaces is referred to as "neurofeedback". Neurofeedback refers to the process of showing someone their brain activity (or "brain waves" if you like) and asking them to turn down or turn up the activity in a part of their brain. Amazingly, this actually works! And people can learn to control the activity in certain parts of their brain. The hope is that a person could then use this ability to enhance their own cognition: such as their ability to make decisions or to response accurately and swiftly in a changing environment.

Isn't multitasking not real? People can only really focus on one thing at a time right?

DSB: Great question. Multitasking is a colloquial term that encompasses several different functions that the brain performs. If you ask a cognitive neuroscientist about multitasking, they will probably break the concept down into specific cognitive processes including task switching. Task switching is the ability to smoothly transition between two different tasks either at will or in response to our environment. For example, switching from types to speaking, or switching from daydreaming to solving logic problems, or switching from math to playing with kids. Each of us have different task-switching abilities. For some of us, these transitions are quick and for others, these transitions are slow. Part of my research program is focused on explaining what makes us different!

How do you quantify the synapses, given the multi colored data on ct scan or using FRET? how do you relate multitasking to different area of the brain? Does multitasking really improve cognitive skills?

DSB: Fantastic question. In fact, CT scans cannot measure individual synapses because the synapses are too small -- far below the resolution of the image taken. So if we want to understand brain connectivity, we have two options. First, we could look at individual neurons/synapses but we do not have any imaging techniques currently to do this noninvasively, so we would have to wait until someone passes away and donates their body to science, and then study the neurons/synpases postmortem. The second option is to study not individual neurons/synapses, but instead study large bundles of neuronal axons (which link populations of neurons with each other over large distances). To do this, we use a traditional MRI machine (and a specific method of imaging on that machine called "diffusion imaging"). This new type of imaging, which has really only been around for the last 10 years, measure the flow of water molecules in your brain. As it turns out, water molecules bounce around in your brain and hit up again these large bundles of neuronal axons, and so we can infer where the bundles are based on where the water flows. After inferring all of the bundles, we have a map of how different areas of the brain are connected with one another at a very large scale. I think of bundles of neuronal axons (also known as white matter tracts) as the highways of the brain, and I think of individual synapses between neurons as the dirt roads in the countryside in which I grew up.

So which is better: more neurons or longer dendrites? I understand that research is showing that the (length of the) interconnections between neurons is an important factor in intelligence, rather than just the number of neurons. Is this where white matter is showing its importance -- in supporting those connections? How do you simulate this sort of stuff?

DSB: This is a fantastic question! And there are different strands of research that have attempted to address this question from different viewpoints. For example, there is some beautiful work studying the evolution of animals brains (look up "allometric scaling: brain" -- specifically work from Suzana Herculano-Houzel) which offers some insights into what sorts of neural architectures matter for the evolution of higher order cognitive functions (such as those that we find in humans like ourselves). A second line of research examines large-scale white matter tracts, which are bundles of neuronal axons (not single axons themselves). In this case, there is convergent evidence that patters of white matter tracts that are efficient from a network perspective (think: the field of network science which has traditionally been applied to social networks like those in Facebook or Twitter) are found in people with high IQ. Both lines of evidence suggest that the pattern of connections between processing units (neurons or large-scale brain areas) may be a critical driver of human intelligence.

What was it like to receive the MacArthur Fellowship (genius grant)?

DSB: Its a little bit like going under general anesthesia. For a moment, you are fairly sure this can't be real. Kidding aside, receiving the MacArthur Fellowship is an incredible honor that inspires you to change the world.

What will you be focusing on next?

DSB: Much of my recent work has focused on understanding how our brain's change while we learn, and how we can predict how much we will learn based on our brain's network architecture (or "connectome"). What I would really love to do next is to understand how we can use our new knowledge to enhance learning, both in K-12 education and in our undergraduate and graduate populations. What interventions could enhance learning? What environments are most conducive to learning, and how to they change the brain to enable learning to occur?

1) I've often heard that women are better at multitasking than men. Is there any merit behind this claim?

2) In layman's terms, how would you describe the results you've discovered through your research?

Thanks for doing this AMA!

DSB: (1) This is of course a difficult question, largely because notions of gender are scientifically fluid concepts. Most of us are far from stereotypical examples of one gender or another, and we each have very different abilities in terms of multitasking as well as many other cognitive functions characteristic of humans. One of the questions I find particularly fascinating is how these individual differences between us can be related to differences in our brain network architecture: that is, how the connections or wires between different parts of our brain are organized. Far from a spaghetti like mess, the connections between different parts of our brain are fairly organized, but by a rule that none of us have been able to define. We would have loved the answer to be simple: That brain regions connect to other brain regions that are close by (similar to what might happen in grade school when you become friends with kids in your own school more so than with kids in the school district next door). But interestingly, the brain shows long-distance connections as well. How does the pattern of local versus long-distance connections make us who we are, and relate to how well we can multitask? Stay tuned!! (2) In lay terms, we are trying to understand how the patterns of connections between areas of your brain relate to how you think and how you behave.

Hi, can you talk about how different people's brains are wired differently? E.g. a nuclear physicist vs. a salesman vs. a football player. Would they be more similar than different?

DSB: This is a very interesting question, and one that is the topic of a growing number of studies. The answer is that people's brains are definitely wired differently, but we cannot explain all of those differences. For example, when we note that one person has 1 wire that is different than another person, it is not always understood what impact that 1 wire has on cognition or ability. What is better understood is how our brain wiring can change when we change our behavior. For example, if you learn how to juggle, and practice extensively over the course of about 6 months, wires from your motor cortex to the rest of the brain will be enhanced. Similarly, if you learn a new language, there will be appreciable changes in your brain wiring in language-related areas. These studies give us the first inklings that there is a direct relationship between wiring and abilities, but we have much more to do to flesh out exactly what that relationship looks like in people who have wildly different types of expertise (such as the nuclear physicist and football player).

Any differences between brains of artists, musicians and other creative types vs those who aren't involved in creative activities?

DSB: I wish I knew! In fact, prior to entering an undergraduate program in physics, my plan was to enter conservatory for piano performance. Unfortunately, 11hr/day practice sessions led to stress fractures and tendinitis, so I had to move to plan B. But, to get back to your question, someone who is doing really fantastic work in this area is Scott Kauffman from the Imagination Institute, who is quantifying creativity and determining which regions of the brain drive the creative process. I think a very exciting direction that this type of research could take would be to understand how we can enhance creativity and the creative process -- not just in the arts and music, but also in scientific fields where principles of design, out-of-the-box thinking, and imaginative solutions are absolutely critical to the scientific enterprise (the natural world is far from predictable!) and to the development and engineering of new technologies.

Is it possible that our understanding of addiction is wrong?

DSB: I would love to hear more about what motivated this question. Is there a particular feature of addition that you are thinking of?

What number am I thinking of?

DSB: If you are anything like me, you are thinking of a very long prime number of course! :)

What region of the brain is active during multitasking?

DSB: Many areas of the brain are active during multitasking. In fact, growing evidence suggests that the notion that brain regions are ever truly "off" is probably inaccurate. The exciting fact that we observed is that during tasks that require multitasking, or switching between different tasks, there is an area in the front of your brain (known as frontal cortex) that changes its connections with other brain regions swiftly. I think about this area a bit like sun sparkling on snow or glistening on the surface of a river: its an area whose role in information manipulation and transmission is constantly changing. And people whose frontal cortex shows more of that change are better at task-switching than people whose frontal cortex shows less of that change.

Is there any evidence that our ability to multitask changes as you age?

DSB: Indeed. Multitasking is a part of a whole class of human characteristics called "executive functions". Executive functions include making difficult decisions, or stopping yourself from doing something inappropriate or wrong. A person's executive function capabilities change pretty drastically over their lifetime, and in fact are one of the latest functions to develop to their fullest (which usually occurs after our teenage years). There are some very interesting theories about why this might be. For example, one theory posits that executive function hinders some types of learning, and therefore evolution has staved off the development of executive functions until later in the child's life to provide protected time early in development when learning can occur relatively unhindered.