Calorie restriction and life span extension

We are getting closer to knowing the specific chemical pathways that underlie age extension, at least in nematodes. Similar pathways are found in yeast and higher animals..from the editor's summary in Nature:

Severe calorie restriction extends life-span in mice and other species, but how near-starvation can prolong life remained a mystery. Now at last, specific links between calorie restriction and longevity have been found in that workhorse of ageing research, the nematode C. elegans. Nicholas Bishop and Leonard Guarente find that dietary restriction activates transcription factor SKN-1 in ASI neurons in the head, which signal peripheral tissues to increase metabolic activity, a mechanism suggestive of the involvement of an endocrine system. Panowski et al. report that increased activity of PHA-4, a transcription factor found in the intestine and in a few cells in head and tail, is also essential for diet-restricted longevity. PHA-4 resembles mammalian Foxa transcription factors, which affect development and regulate fasting glucagon and glucose levels. Knowledge of such links raises the prospect of drugs to mimic the benefits of calorie restriction.

From the review by Antebi:

In response to dietary restriction, the activities of SKN-1 and PHA-4 gene-transcription factors increase (black arrows). Neuronal, but not intestinal, SKN-1 mediates longevity in response to reduced dietary intake, where it triggers the release of unidentified hormones (stars) from the pair of ASI neurons to increase mitochondrial activity throughout the body. The PHA-4 transcription factor may also induce hormonal production in the tissues where it is expressed — neurons, intestine and gonad.

Evolution of human and animal personalities

Here is another editor's summary, and a PDF of the review by Bell of the work by Wolf et al. is here.

Although 'personalities' such as boldness, aggressive behaviour and risk avoidance have been shown to exist in more than sixty animal species, from primates to ants, explaining their existence in terms of evolution has been a puzzle. Surely, evolution should not favour the maintenance of different personalities, but rather the convergence towards a single one. In a numerical life-history model, Wolf et al. show that the evolution of animal personalities, defined as consistent sets of behaviours shown in a variety of contexts, is related to an adaptive response to life-history trade-offs. In this model, decisions on trade-offs between current and future reproduction condition the response of individuals to risky situations, and this may be the basis for animal personalities and their maintenance in populations.

In Wolf et al.'s model (from their abstract)

...some individuals put more emphasis on future fitness returns than others. Life-history theory predicts that such differences in fitness expectations should result in systematic differences in risk-taking behaviour. Individuals with high future expectations (who have much to lose) should be more risk-averse than individuals with low expectations. This applies to all kinds of risky situations, so individuals should consistently differ in their behaviour. By means of an evolutionary model we demonstrate that this basic principle results in the evolution of animal personalities. It simultaneously explains the coexistence of behavioural types, the consistency of behaviour through time and the structure of behavioural correlations across contexts. Moreover, it explains the common finding that explorative behaviour and risk-related traits like boldness and aggressiveness are common characteristics of animal personalities.

Apologies to rss, atom feeds for seeing old posts...other details

I may figure out how to stop this from happening (if anyone out there knows how, please let me know), but as I add labels (keywords) to old posts, RSS and atom readers think they are new postings. This will be happening over the next period of time.

The new google search box works like gangbusters, bringing up all posts with the word(s) you enter. The old Technorati search box was useless. The labels on the right will give you an idea of the areas I find interesting and take you to relevant posts. This may be more non-techies want to know, but this blog now completely replaces my existing file systems. A PDF file or link to any article I might want to use is now obtained through the blog, no more storage of paper copies (three file drawers full, used for my book) or copies on my local hard drive apart from backups of the yahoo server that hosts dericbownds.net. My dericbownds.net website stays as it was, with professional and personal stuff, but MindBlog (mindblog.dericbownds.net) has now moved to the blogger servers.

PLEASE NOTE! MindBlog/RSS web URL change

Because I am upgrading my blogger setup to use labels (keywords) I'm having to assign a new URL to MindBlog.

The new URL is http://mindblog.dericbownds.net

If you have bookmarked the blog portion of my site directly, please update your bookmark to the above address.

If you have subscribed directly to my RSS Feed you will need to change the feed URL on your reader.
RSS feed: http://mindblog.dericbownds.net/rss.xml
Atom feed: http://mindblog.dericbownds.net/atom.xml

No changes needed if you have subscribed to my Blog through FeedBurner.

Please allow several days for the changes to my Blog to take full effect while I transition to the new format.

Children have symbolic arithmetic before formal instruction

The editor's summary of an interesting paper in Nature by Gilmore et al.:

It is commonly assumed that young children need to master the logic of number systems before learning symbolic arithmetic. Now a trial using 5-year-old children suggests that in fact they have symbolic arithmetic knowledge before they have received any arithmetic instruction. The children are capable of solving symbolic addition and subtraction problems with large numbers, provided that only approximate sums and differences must be computed. These findings shed light on the numerical competences that come naturally to children, and suggest ways to enrich children's learning of mathematics.

Some Edward Grieg..

Edward Grieg's "Wedding in Troldhaugen" ....(having just returned from my son's wedding in Mexico.)

Feature Creep...

A brief essay in The New Yorker by James Surowiecki on how technology designed to make our lives easier does just the opposite. Some clips:

Technology is supposed to make our lives easier, allowing us to do things more quickly and efficiently. But too often it seems to make things harder, leaving us with fifty-button remote controls, digital cameras with hundreds of mysterious features and book-length manuals, and cars with dashboard systems worthy of the space shuttle...feature creep is the product of the so-called internal-audience problem: the people who design and sell products are not the ones who buy and use them, and what engineers and marketers think is important is not necessarily what’s best for consumers...although consumers find overloaded gadgets unmanageable, they also find them attractive. It turns out that when we look at a new product in a store we tend to think that the more features there are, the better. It’s only once we get the product home and try to use it that we realize the virtues of simplicity...It seems odd that we don’t anticipate feature fatigue and thus avoid it. But, as numerous studies have shown, people are not, in general, good at predicting what will make them happy in the future. As a result, we will pay more for more features because we systematically overestimate how often we’ll use them. We also overestimate our ability to figure out how a complicated product works.

Anheuser-Busch would never do this

..comments the friend who emailed me this video of a Guiness commercial: Married to a Man

Why don’t we do what we know works better?

I mull frequently about an issue that I’m sure readers of this blog are familiar with. Having assembled a fairly extensive toolkit of techniques to maintain personal poise, sanity, vitality, etc. (tools of the sort mentioned in the essay on my website titled “Mindstuff: a guide for the curious user.”), how is it that I don’t use them more religiously to maintain those desired qualities? Well…. there are some limits intrinsic to the fact that they are constructions of my adult mind, mainly over the past 15—20 years. They require attention and energy for their maintenance, unlike the pandora’s box of less useful older habits and ways-to-be-in-the-world that formed in my youth, and are more hard wired into place. During periods of inattention or low energy, I don’t notice the these older autopilots and temperaments slipping back into place to resume their residency. This, I suppose, is why practitioners of various healthy mind regimes (schools of meditation, cognitive therapies, or whatever) keep saying: “How do you get to Carneige Hall? Practice, practice, practice!”

Joseph LeDoux perhaps puts it better in some recent comments:

One of the things I've learned about the brain is that anxiety and stress breed anxiety and stress. So, it makes sense that we should do things to reduce anxiety and stress in our daily lives, like the sorts of breathing exercises that are used in meditation. These are effective in part because they push the autonomic nervous system toward its parasympathetic side, slowing the driving force of the sympathetic system and reducing the arousal level of the body and the brain. Do I do these exercises? Not as often or as effectively as I probably should. But cardiologists probably don't always eat the right things or exercise as much as they should, either. It's one thing to know what to do, and another to do it. (If we could figure out that discordance, we'd really know something.)

Guide to psychology blogs...

PsyBlog publishes the first part of a two part guide to other psychology blog.

3rd and 1st person narrative in personality change

Benedict Carey writes a piece in the Tuesday NY Times science section (PDF here) reviewing work done by a number of researchers on on how the stories people tell themselves (and others) about themselves do or don't help with making adaptive behavior changes. Third person narratives, in which subjects view themselves from a distance - as actors in their own narrative play - correlate with a higher sense of personal power and ability to make personality changes. First person narratives - in which the subject describes the experience of being immersed in their personal plays - are more likely than third person narratives to correlate with passivity and feeling powerless to effect change. This reminds me of Marc Hauser's distinction of being a moral agent or a moral patient. The third person can be a more metacognitive stance, thinking about oneself in a narrative script while the first person can be a less reflective acting out of the script.

"The Secret" scam....

More of Michael Schermer's terrific debunking of popular myth in the June Scientific American... Some clips:

An old yarn about a classic marketing con game on the secret of wealth instructs you to write a book about how to make a lot of money and sell it through the mail. When your marks receive the book, they discover the secret--write a book about how to make a lot of money and sell it through the mail.

A confidence scheme similar to this can be found in The Secret (Simon & Schuster, 2006), a book and DVD by Rhonda Byrne and a cadre of self-help gurus that, thanks to Oprah Winfrey's endorsement, have now sold more than three million copies combined. The secret is the so-called law of attraction. Like attracts like. Positive thoughts sally forth from your body as magnetic energy, then return in the form of whatever it was you were thinking about. Such as money.

A pantheon of shiny, happy people assures viewers that The Secret is grounded in science: "It has been proven scientifically that a positive thought is hundreds of times more powerful than a negative thought." No, it hasn't. "Our physiology creates disease to give us feedback, to let us know we have an imbalanced perspective, and we're not loving and we're not grateful." Those ungrateful cancer patients. "You've got enough power in your body to illuminate a whole city for nearly a week." Sure, if you convert your body's hydrogen into energy through nuclear fission. "Thoughts are sending out that magnetic signal that is drawing the parallel back to you." But in magnets, opposites attract--positive is attracted to negative. "Every thought has a frequency.... If you are thinking that thought over and over again you are emitting that frequency."

The brain does produce electrical activity from the ion currents flowing among neurons during synaptic transmission, and in accordance with Maxwell's equations any electric current produces a magnetic field...The brain's magnetic field... quickly dissipates from the skull and is promptly swamped by other magnetic sources, not to mention the earth's magnetic field ... which overpowers it by 10 orders of magnitude!

Ceteris paribus, it is undoubtedly better to think positive thoughts than negative ones. But in the real world, all other things are never equal, no matter how sanguine your outlook. Just ask the survivors of Auschwitz. If the law of attraction is true, then the Jews--along with the butchered Turkish-Armenians, the raped Nanking Chinese, the massacred Native Americans and the enslaved African-Americans--had it coming.

Oprah, please, withdraw your support of this risible twaddle--as you did when you discovered that James Frey's memoir was a million little lies--and tell your vast following that prosperity comes from a good dollop of hard work and creative thinking, the way you did it.

Neural correlates of social cognition

Vittorio Gallese writes an interesting summary in Proc. Roy. Soc. B titled "Before and below ‘theory of mind’: embodied simulation and the neural correlates of social cognition." (PDF here). His abstract:

The automatic translation of folk psychology into newly formed brain modules specifically dedicated to mind-reading and other social cognitive abilities should be carefully scrutinized. Searching for the brain location of intentions, beliefs and desires—as such—might not be the best epistemic strategy to disclose what social cognition really is. The results of neurocognitive research suggest that in the brain of primates, mirror neurons, and more generally the premotor system, play a major role in several aspects of social cognition, from action and intention understanding to language processing. This evidence is presented and discussed within the theoretical frame of an embodied simulation account of social cognition. Embodied simulation and the mirror neuron system underpinning it provide the means to share communicative intentions, meaning and reference, thus granting the parity requirements of social communication.

Why Americans resist scientific ideas.

Paul Bloom and Deena Skolnick Weisberg offer a fascinating review of the childhood origins of adult resistance to science (PDF here), pointing out that it derives from clinging to incorrect intuitive physics and psychology assumptions that are a normal part of child develpment. They review developmental data that suggests:

...that resistance to science will arise in children when scientific claims clash with early emerging, intuitive expectations. This resistance will persist through adulthood if the scientific claims are contested within a society, and it will be especially strong if there is a nonscientific alternative that is rooted in common sense and championed by people who are thought of as reliable and trustworthy. This is the current situation in the United States, with regard to the central tenets of neuroscience and evolutionary biology. These concepts clash with intuitive beliefs about the immaterial nature of the soul and the purposeful design of humans and other animals, and (in the United States) these beliefs are particularly likely to be endorsed and transmitted by trusted religious and political authorities. Hence, these fields are among the domains where Americans' resistance to science is the strongest.

Adding labels or keywords to MindBlog for indexing... some glitches

I'm going to be adding labels (keywords) to new and older blog posting over the next period of time, and it appears that any change in an old posting makes it appear to some RSS readers as a new posting. Sorry about that.

I hope then to figure out how to install one of the widgets that lets you click on a keyword in the list of keywords or labels and see a list of all the relevant blog postings. If any of you are expert at this and could point me in the right direction I would be grateful.

The New Synthesis in Moral Psychology

The article of this title by Haidt is worth passing on to those of you who are interested in this area (PDF here). Here is the abstract:

People are selfish, yet morally motivated. Morality is universal, yet culturally variable. Such apparent contradictions are dissolving as research from many disciplines converges on a few shared principles, including the importance of moral intuitions, the socially functional (rather than truth-seeking) nature of moral thinking, and the coevolution of moral minds with cultural practices and institutions that create diverse moral communities. I propose a fourth principle to guide future research: Morality is about more than harm and fairness. More research is needed on the collective and religious parts of the moral domain, such as loyalty, authority, and spiritual purity.

Embodying emotion

This is the title of an interesting review by Niedenthal (PDF here) on how manipulations of facial expression and posture in the laboratory can influence how emotions are processed. Whether we are similing or frowning, or hunched over or upright, can profoundly influence our emotional reactions to positive or negative input. Here is the abstract:

Recent theories of embodied cognition suggest new ways to look at how we process emotional information. The theories suggest that perceiving and thinking about emotion involve perceptual, somatovisceral, and motoric reexperiencing (collectively referred to as "embodiment") of the relevant emotion in one's self. The embodiment of emotion, when induced in human participants by manipulations of facial expression and posture in the laboratory, causally affects how emotional information is processed. Congruence between the recipient's bodily expression of emotion and the sender's emotional tone of language, for instance, facilitates comprehension of the communication, whereas incongruence can impair comprehension. Taken all together, recent findings provide a scientific account of the familiar contention that "when you're smiling, the whole world smiles with you."

Two ways in which facial expression has been manipulated in behavioral experiments. (Top) In order to manipulate contraction of the brow muscle in a simulation of negative affect, researchers have affixed golf tees to the inside of participants' eyebrows. Participants in whom negative emotion was induced were instructed to bring the ends of the golf tees together, as in the right panel. [Photo credit: Psychology Press]. (Bottom) In other research, participants either held a pen between the lips to inhibit smiling, as in the left panel, or else held the pen between the teeth to facilitate smiling.

A Wedding in Mexico

Pictures: Deric and his son Jonathan in exile while the women are getting ready; the ceremony; Jonathan and Shana in the sunset.

A neural link between hand muscle excitability and numerical counting

Sato et al. do an interesting experiment showing that excitability of our hand muscles changes when we perform a visual (non-numerical) counting task, reinforcing the idea that finger counting represents an basic embodied strategy for number learning. (PDF here.) Their abstract:

Developmental and cross-cultural studies show that finger counting represents one of the basic number learning strategies. However, despite the ubiquity of such an embodied strategy, the issue of whether there is a neural link between numbers and fingers in adult, literate individuals remains debated. Here, we used transcranial magnetic stimulation to study changes of excitability of hand muscles of individuals performing a visual parity judgment task, a task not requiring counting, on Arabic numerals from 1 to 9. Although no modulation was observed for the left hand muscles, an increase in amplitude of motor-evoked potentials was found for the right hand muscles. This increase was specific for smaller numbers (1 to 4) as compared to larger numbers (6 to 9). These findings indicate a close relationship between hand/finger and numerical representations.

Gene crucial to learning and memory unique in humans

Zu et al report that a human-specific gene mutation (not seen in other primates) leads to the origin of a novel splice form of neuropsin (KLK8), a protein involved in learning and memory. This may be one of the genes that have been positively selected during human evolution Their abstract:

Neuropsin (kallikrein 8, KLK8) is a secreted-type serine protease preferentially expressed in the central nervous system and involved in learning and memory. Its splicing pattern is different in human and mouse, with the longer form (type II) only expressed in human. Sequence analysis suggested a recent origin of type II during primate evolution. Here we demonstrate that the type II form is absent in nonhuman primates, and is thus a human-specific splice form. With the use of an in vitro splicing assay, we show that a human-specific T to A mutation (c.71-127T>A) triggers the change of splicing pattern, leading to the origin of a novel splice form in the human brain. Using mutation assay, we prove that this mutation is not only necessary but also sufficient for type II expression. Our results demonstrate a molecular mechanism for the creation of novel proteins through alternative splicing in the central nervous system during human evolution.