Tag Archives: cognitive science

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:

Is thinking conscious or unconscious?

Sherlock Holmes smokes his pipe reclining on cushions and wearing a roomy overcoatThere are two ways to define thinking: each leads to a different answer to the question of whether thinking is conscious or not.

  1. Thinking as a subjective experience. If someone asks you what you are thinking about, you can introspect, and describe your thought process. You can also say that you weren’t really thinking at all.
  2. Thinking as the cause of ideas and thoughts. If you discover a thought, then you can infer that the process that led up to the thought was a form of thinking, even if there was no subjective experience associated with the process.

We can test our preference for definition 1 or definition 2 by considering an example.

Sherlock Holmes was a good chemist. When he found himself stuck while attempting to solve a mystery, he would sometimes distract himself by doing a chemistry experiment. At the end of such an experiment, he often found that a solution simply popped into his head.

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A Clockwork Orange? (A brief musing on the concept of a neural “code”)

I was asked this question on Quora:

Are there many layers of neural codes from the human retina to the optic nerve and the optic nerve to the brain, or are they essentially same signals relayed?

Here’s how I responded:

Here’s a question: in a system composed of clockwork, is there a “code”?

I ask this because I find that the “code” metaphor is often misleading when thinking about biology. Codes are composed of symbols. But it is not clear that neurons communicate using symbols.

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“Are thoughts just a bunch of electrical and chemical signals being tossed around inside the brain, or is there more to it than that?”

“In our world,” said Eustace, “a star is a huge ball of flaming gas.”

“Even in your world, my son, that is not what a star is but only what it is made of…”

The Voyage of the Dawn Treader, CS Lewis

I really like the quote above, which is from the Chronicles of Narnia. It raises a neat little metaphysical question:

Why do we assume that what a thing is made up of is what a thing is?

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Dopamine is not the “feel good” molecule (and the very concept of a feel good molecule is meaningless)

220px-dopamine_3d_ball

Dopamine is not the feel good molecule or the basis of pleasure. The idea that any molecule considered in isolation could be the basis of a subjective experience is basically nonsense.

For people who can’t really reason through this idea, there is plenty of experimental evidence showing the complexity of each and every “celebrity” neurochemical — dopamine, serotonin, oxytocin, and so on.

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In what format is information stored in the brain?

I was asked this question on Quora.

We don’t really know. But as one of my professors once said half-jokingly, “the brain is a bag of tricks”. There is no reason to assume that all brain regions use the same coding scheme.

Here are some basic concepts that guide how neuroscientists think about information in the brain:

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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?

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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.

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Are mental disorders the same as brain disorders? Maybe not!

I am currently reading an excellent paper that will be published in Behavioral and Brain Sciences soon. It raises some very important issues with popular conceptions of mental illness.

Brain disorders? Not really… Why network structures block reductionism in psychopathology research

These two figures capture some of the key points:

Here is the abstract:

“In the past decades, reductionism has dominated both research directions and funding policies in clinical psychology and psychiatry. However, the intense search for the biological basis of mental disorders has not resulted in conclusive reductionist explanations of psychopathology. Recently, network models have been proposed as an alternative framework for the analysis of mental disorders, in which mental disorders arise from the causal interplay between symptoms. In this paper, we show that this conceptualization can help understand why reductionist approaches in psychiatry and clinical psychology are on the wrong track. First, symptom networks preclude the identification of a common cause of symptomatology with a neurobiological condition, because in symptom networks there is no such common cause. Second, symptom network relations depend on the content of mental states and as such feature intentionality. Third, the strength of network relations is highly likely to partially depend on cultural and historical contexts as well as external mechanisms in the environment. Taken together, these properties suggest that, if mental disorders are indeed networks of causally related symptoms, reductionist accounts cannot achieve the level of success associated with reductionist disease models in modern medicine. As an alternative strategy, we propose to interpret network structures in terms of D. C. Dennett’s (1987) notion of real patterns, and suggest that, instead of being reducible to a biological basis, mental disorders feature biological and psychological factors that are deeply intertwined in feedback loops. This suggests that neither psychological nor biological levels can claim causal or explanatory priority, and that a holistic research strategy is necessary for progress in the study of mental disorders.”

Behavioral and Brain Sciences is one of the premier journals for “big thinking” in cognitive science and neuroscience, so it’s great to see these ideas there.

The kind of brain training that actually works!

Just saw this on twitter:

Here’s the link to the (thus far unreviewed!) study:

How much does education improve intelligence? A meta-analysis

“… we found consistent evidence for beneficial effects of education on cognitive abilities, of approximately 1 to 5 IQ points for an additional year of education. Moderator analyses indicated that the effects persisted across the lifespan, and were present on all broad categories of cognitive ability studied. Education appears to be the most consistent, robust, and durable method yet to be identified for raising intelligence.”