Posts Tagged ‘Neuroscience’

Short and long-term impact of meditation on mind and brain

April 27, 2008

Vaughan at Mind Hacks collects and comments on couple of review articles on the neuroscience of meditation:

This month’s Trends in Cognitive Sciences has a fantastic review article on the neuroscience of meditation – focusing on how the contemplative practice alters and sharpens the brain’s attention systems.

The full article is available online as a pdf, and discusses what cognitive science studies have told us about the short and long-term impact of meditation on the mind and brain.

A recent review of ‘mindfulness’ meditation-based therapy found that although research is in its early stages and not all possibilities have been ruled out, there’s good evidence from the existing RCTs that it’s particularly good in preventing relapse in severe depression.

Though Vaughan notes that some of the meditational techniques used in these studies are taken from Buddhist meditation practices (and the role that the interest that the science-savvy Dalai Lama have shown on such scientific studies), such practices are also used in several of the Indian meditational practices and schools — though, to be fair to Buddhists, I think, they are the first ones to secularise meditational practices by noting that any word can be used for meditation and that there is no special power associated with any mantra or special word.

Take a look!

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Jonah Lehrer’s Proust was a neuroscientist

December 24, 2007

I finished reading Jonah Lehrer’s Proust was a neuroscientist. I enjoyed the book. It consists of eight chapters, a prelude and a coda. Each of the chapters discuss an artist or a non-scientist (mostly) — Walt Whitman, George Eliot, Auguste Escoffier, Marcel Proust, Paul Cezanne, Igor Stravinsky, Gertrude Stein and Virginia Woolf.

I think the chapter on Escoffier is the best in the book; an excerpt from that chapter is available here (and, Jenny also thinks that it is the best chapter). I had difficulty in making sense of some parts of the chapter on Gertrude Stein; unsurprisingly, Stein chapter was also the least satisfying of all.

There are a couple of themes that run through the book. One is the plasticity of the brain; all that we enjoy in music, in paintings, and in literature are also modified by what we choose to hear, see or read; by changing the nature of the stimuli, the brain can be trained to see mountains and rocks in clumps of paint, and music in noise. The other is that there is a feed back mechanism that operates with almost all of the activities of the brain — be it memory, self-awareness or perception — which, gives an illusion of continuousness to what is essentially a grainy underlying structure.

Some sections of the book read like it is written by Sacks (and, of course, there are references to Sacks’ the man who mistook his wife for a hat, and a couple of others), which is to say that they are extremely well written and are a pleasure to read. There are also some nuggets of information that I did not know about; for example, though I knew about Maxwell’s demon, I did not know about Laplace’s demon. I also enjoyed the description of musical perception as basically one of a search for pattern:

It is this psychological instinct — this desperate neuronal search for pattern, any pattern — that is the source of music.

Though I enjoyed the book, and I do recommend reading it, I have some serious problems with the premise of the book. PAM Dirac is supposed to have made the following remark (or some words to that effect) about the differences between science and arts to Heisenberg, when he saw the later reading a novel:

In science, we describe the complex in terms of the simple. In the arts, it is the other way around.

Such sentiments, expressed privately, might just be the idiosyncratic notions of an individual. However, when books are written expressing similar notions (Lehrer gives two examples — E O Wilson and Steven Pinker), Lehrer thinks that it is time to fight them with a book; and therein lies the weakness of the book. This is not to say that I agree with such sentiments; this is just to say that, if that is the aim of Lehrer’s book, he fails to make a convincing case.

I think, Greta Munger at Congnitive Daily captures this shortcoming rather nicely in her thumbnail review:

Of course art and science are good for different things, but I think Lehrer is trying to write to a group of folks who may have forgotten (or never knew?) that great art offers us important insights into the world. To my mind, Lehrer overemphasizes what some of the artists might have “known,” but my guess is he does this because he is addressing an art-deprived audience. I enjoy learning about the art of Cézanne and Stravinksy, but I am really not convinced that either man gained special insight from their art about the physiological mechanisms behind early vision (edges are important!) and the flexibility of the auditory cortex. I think it’s great to be able to see the art and recognize its appeal might be related to the first analysis of the visual system; I’m just not sure why it has to be true that Cézanne “knew” that edges were critical to the mechanism.

Without some of the sentences in his prelude, like this one for example,

This book is about artists who anticipated the discoveries of neuroscience. … Their imaginations foretold the facts of the future.

and, several in his coda, like this one, for example,

We now know enough to know that we will never know everything. That is why we need art; it teaches us how to live with mystery.

I think I would have enjoyed the book more. In fact, if Lehrer just took the view point of examining these artists and their creations with the hindsight of what we know about the underlying neuroscience today, it would have made the book less inhomogeneous and more enjoyable. It is all those pretensions about creating a fourth culture (which would be truthful to the original “third culture” ideas of C P Snow) that fail the book.

Some must-read stuff!

September 27, 2007

Avian Grandmas

A few months back, I wrote a post titled In praise of grandparents; the post lead to some interesting discussions, where, I also wrote about how birds cope with child rearing:

As far child rearing, it is interesting to see how other species cope with the burden–in some bird species, for example, when the mother gets children, it is the elder sons who are forced to help the mother; in fact, the father will actively stop the sons from setting up their own nests! All this is explained in this rather nice article (pdf) (and in this book too, called Survival Strategies by Raghavendra Gadagkar).

However, I am afraid I was too quick to conclude that there are no avian grandparents. In a very readable post, Grrlscientist explains some recent research along these lines:

When talking about evolution, some people have wondered aloud about why grandmothers exist in human society since they clearly are no longer able to reproduce. However, these people are conveniently overlooking the fact that grandmothers perform a valuable service; they help their relatives, often their own children, raise their offspring — offspring that are genetically related to them. But curiously, grandmother helpers have not been documented to occur in birds, where most of our research into cooperative breeding systems occurs, so this makes the question even more intriguing: Why are there no avian grandmothers? Further, since cooperatively breeding birds are relatively long-lived, grandparental care should indeed be identifiable, especially if cooperatively-breeding bird societies are observed long enough.

(…)

This is the first time that grandparent helping has been documented in birds, although there are several other species where kin-directed helping behavior has been observed.

However, it is important to note that in other avian helping species, “all individuals attempt to breed independently each year and only move to helping if their nest fails. Consequently, this behavior would be very different to that of individuals that forgo independent breeding and become subordinate grandparent helpers.

A very interesting piece!

Oxytocin and childbirth

A couple of years ago, if I had seen a blog post on oxytocin and childbirth, I would have moved on without paying close attention; however, all the child care classes that we attended as well as my staying with my wife during our daughter’s birth has made me more aware; so, it is with great interest that I read Coturnix’s post on the issue — true, there seems to be more questions than explanations — but that is what makes is all the more interesting. Take a look!

A researcher’s nightmare(s)

It had happened to almost all the researchers I know; it happened to me recently when, one of my collaborators, who was trying to use my code reported that he is not able to reproduce some of the results that I report in my thesis; the nightmare lasted a couple of days before we could sort everything out, and thankfully, my results were indeed reproducible.

Highly Allochthonous writes about a similar horrifying experience that he went through recently; and, again, thankfully, it turns out that what he thought to be the mistake, actually wasn’t:

It was at about this point that an entire PhD’s worth of stress hormones decided to dump themselves into my bloodstream. It looked like all the cool and exciting conclusions from my PhD research were built on an exceedingly unsafe foundation. Also, if I was honest with myself, such a glaring mistake galloped far beyond the unfortunate, deep into the realm of the toweringly incompetent. Writing and publishing the necessary corrections and retractions would be equivalent to standing up in a room packed with everyone who might ever hire me and yelling “Hey! I’m a dumbass!”

It was a good job, then, that I turned out to be mistaken – although it took me until Monday to realise it. My salvation lay in the fact that samples were not placed in my old magnetometer in the ‘right’ orientation: what the machine measured as the x-axis was in fact the z-axis of the sample. This substitution meant that when the correction software rotated what it thought was the x-axis, it was actually rotating the z-axis of the sample, which meant that I was supplying the right direction and everything had ended up in the appropriate reference frame. ‘Phew’ is an understatement.

It is important to note though, that it is not always that such stories have such a happy ending. On another occasion, a week before my submitting an important document, I found a bug in my code. As Chris Rowan mentions, that is the time I realised how much of research reporting is based on trust. I am happy to say that I had enough courage to tell my adviser (who was more cool in that, instead of getting upset about my carelessness, he said “Guru, it is better that we noticed it before the referees did; throw away all the tainted results, run the code once more and let us see”). Fortunately, the changes in the results were more quantitative than qualitative. Again, for me too, “Phew” was an understatement.

Apart from these, there is another nightmare that some of us face–especially in the early stages of research–when you open a journal and see a paper which ostensibly solves the exact problem that you are trying to solve. But, as one of my experiences colleagues pointed out to me when I faced one such situation long ago, it is never that two groups would independently solve the same problem, using same techniques and arrive at identical results. So, most of the times, something of your efforts can be salvaged. But, it still is a nightmare when it happens.

A strongly recommended book

Recently, Jonah Lehrer recommended Body has a mind of its own (as we noted here); it is Grrlscientist’s turn now:

As a biologist who reads both widely and deeply about a number of scientific topics, it is very rare when I read a popular book that adds depth and nuance to my understanding of a biological phenomenon, but The Body Has a Mind of Its Own By Sandra Blakeslee and Matthew Blakeslee (NYC: Random House; 2007) is that book. This quiet but well-written book explores the interconnection between the environment, the body and the brain; discusses that the body is more just than a container for the brain and a vehicle that moves it around; and reveals how the brain depends upon sensory feedback from the environment in order to develop properly.

Looks like a must-read book. Take a look!

Happy reading!