Videos on computational neuroscience – by me!

I haven’t been blogging much, and that is partly because I have been organizing weekly meetings devoted to computational neuroscience. Between January and July, my friends and I did a series on dynamical systems theory in neuroscience. I created a YouTube channel for the videos.

Here’s the playlist for the dynamical systems series:

This month we started talking about Stephen Grossberg’s new book, ‘Conscious Mind, Resonant Brain’. Grossberg set up the department where I did my PhD, and his ideas suffuse how I think about mind and brain. I’m uploading the videos as they happen. Here’ the playlist:

On the neuroscience of creativity

I was asked the following question on Quora recently:

What part of the brain is responsible for linear thinking? What part of the brain is responsible for creativity?

Thinking [1] [2] is very poorly understood, but broadly speaking in seems to involve the prefrontal cortex (PFC), with a special role for the dorsolateral PFC. Other important areas include the hippocampus and parietal cortex. Ultimately, thinking involves many brain regions, and cannot be localized to one place. Thinking is a distributed process that can incorporate many different parts of the brain. And the specific content of the thoughts will influence which brain areas are involved. If you are thinking about images, visual areas will be involved. If you are thinking about movement, motor areas will be involved.

In my opinion, the distinction between “linear” and “creative” thinking is somewhat vague. At this point, the most important thing to note is that the idea that the “left brain is rational/logical and the right brain is creative/artistic/emotional” is totally wrong [3] . Both hemispheres contribute to logic as well as creativity. Moreover, the use of logic can itself be a creative activity.

Continue reading →

On sleep and creativity

800px-francisco_josc3a9_de_goya_y_lucientes_-_the_sleep_of_reason_produces_monsters_28no-_43292c_from_los_caprichos_-_google_art_project Just came across a nice little article by Ed Yong on how the two major phases of sleep — REM and slow-wave sleep — might contribute to creativity. These ideas have been floating around for a while, but it’s nice to see them in a pop sci article.

A New Theory Linking Sleep and Creativity

Continue reading →

Why human memory is not a bit like a computer’s

(This is a cross-post of a 3 Quarks Daily article I wrote last year.)

A few months ago I attended a rather peculiar seminar at MIT’s Department of Brain and Cognitive Sciences. A neuroscientist colleague of mine named Robert Ajemian had invited an unusual speaker: a man named Jim Karol, who was billed as having the world’s best memory. According to his website, his abilities include “knowing over 80,000 zip codes, thousands of digits of Pi, the Scrabble dictionary, sports almanacs, MEDICAL journals, and thousands of other facts.” He has memorized the day of the week for every date stretching back to 1AD. And his abilities are not simply matter of superhuman willingness to spend hours memorizing lists. He can add new items to his memory rapidly, on the fly. After a quick look at a deck of cards, he can recall perfectly the order in which they were shuffled. I witnessed him do this last ‘trick’, as well as a few others, so I can testify that his abilities are truly extraordinary [1].

Continue reading →

What is neuroplasticity?

I was asked this question on Quora:

Can you explain to a layman what neuroplasticity entails?

Neuroplasticity is the umbrella term for all of the brain’s mechanisms for learning and memory.

Since the average layperson already knows about learning and memory, I’m not sure whether there are any interesting implications.

Unless of course you are surprised that the brain is involved in learning and memory. Then the implications are vast. 🙂

Continue reading →

Is a memory a bunch of atoms? And does this mean we can transfer exact memories?

I was asked the following question on Quora.

“Are specific memories just arrangements of atoms in our brains? Could you put certain molecules in someones head and give them an exact memory that you had?“

Short answer: No.

Modern science has shown that every thing is an arrangement of atoms: neurons, apples, tables, rockets, asteroids, aardvarks… they are all made up of atoms.

The question now is this: is a memory a thing?

Continue reading →

No New Neurons? No Problem!

This answer was written in response to the following Quora question:

New research has found no neurogenesis in human adults, could this mean there is none or could it mean that neural stem cells are undetectable with the used techniques? What are your thoughts on this?

It’s good that you’re thinking of such things, since that is exactly what researchers themselves have to do, and what reviewers do. In order to show that the method works, there have to be adequate controls as part of the experiment.

And this is in fact the case. The paper would not have been published without controls.

Continue reading →

Perhaps neurogenesis doesn’t happen in adult humans?

A new study suggests that new neurons are not born very often in human adults.

Birth of New Neurons in the Human Hippocampus Ends in Childhood

“The lab’s new research, based on careful analysis of 59 samples of human hippocampus from UCSF and collaborators around the world, suggests new neurons may not be born in the adult human brain at all. The findings present a challenge to a large body of research which has proposed that boosting the birth of new neurons could help to treat brain diseases such as Alzheimer’s disease and depression. But the authors said it also opens the door to exciting new questions about how the human brain learns and adapts without a supply of new neurons, as in seen in mice and other animals.”

My labmates are all monkey neuroanatomists, and for years they have been skeptical about the neurogenesis narrative, particularly in primates. Another famous dissenter is Pasko Rakic. Read about his complaints in this Guardian article from 2012:

Does your brain produce new cells?

Why human memory is not a bit like a computer’s

My latest 3QD essay is about the mystery of human memory, and why it is not at all like computer memory. I discuss the quirks of human memory formation and recall, and the concept of “content-addressable memory”.

3quarksdaily: Why human memory is not a bit like a computer’s