Scientists say a part of the brain, smaller than a pea, triggers the instinctive feeling that something bad is about to happen. Writing in the journal PNAS, they suggest the habenula plays a key role in how humans predict, learn from and respond to nasty experiences. And they question whether hyperactivity in this area is responsible for the pessimism seen in depression. They are now investigating whether the structure is involved in the condition.
Money or shock
Animal studies have shown that the habenula fires up when subjects expect or experience adverse events, But in humans this tiny structure (less than 3mm in diameter) has proved difficult to see on scans.
Inventing a technique to pinpoint the area, scientists at University College London put 23 people though MRI scanners to monitor their brain activity.
Participants were shown a range of abstract pictures. A few seconds later, the images were linked to either punishment (painful electric shocks), reward (money) or neutral responses.
For some images, a punishment or reward followed each time but for others this varied - leaving people uncertain whether they were going to feel pain or not.
And when people saw pictures associated with shocks the habenula lit up.
And the more certain they were a picture was going to result in a punishment, the stronger and faster the activity in this area.
Scientists suggests the habenula is involved in helping people learn when it is best to stay away from something and may also signal just how bad a nasty event is likely to be.
'Bad luck' ensured that asteroid impact wiped out dinosaurs
Dinosaurs were wiped out by an asteroid impact when they were at their most vulnerable, according to a new study. Dr Steve Brusatte, of Edinburgh University, said sea level rises and volcanic activity had made many species more susceptible to extinction. They might have survived if the asteroid had hit the Earth a few million years later or earlier, he said, calling it “colossal bad luck”. The assessment has been published in the journal, Biological Reviews. “It was a perfect storm of events that occurred when dinosaurs were at their most vulnerable,” Dr Brusatte told BBC News. The study brought together 11 leading dinosaur experts from the UK, US and Canada to assess the latest research on the extinction of dinosaurs 66 million years ago. There is evidence that some species of dinosaur were dying off shortly before an asteroid hit the Earth. One of the key questions was whether this gradual decline would have led to the extinction of these animals even if the asteroid had not hit. The experts concluded that although some species of plant eaters in North America were dying out in the period leading up to the asteroid impact there was no evidence of a long-term decline. However, the experts believe that rises in sea level and increased volcanic activity made many species more susceptible to extinction just at the point that the asteroid struck. (via BBC News - ‘Bad luck’ ensured that asteroid impact wiped out dinosaurs)
Less than 10% of human DNA has functional role, claim scientists
Large stretches may be no more than biological baggage, say researchers after comparing genome with that of other mammals
More than 90% of human DNA is doing nothing very useful, and large stretches may be no more than biological baggage that has built up over years of evolution, Oxford researchers claim. The scientists arrived at the figure after comparing the human genome with the genetic makeup of other mammals, ranging from dogs and mice to rhinos and horses. The researchers looked for sections of DNA that humans shared with the other animals, which split from our lineage at different points in history. When DNA is shared and conserved across species, it suggests that it does something valuable. Gerton Lunter, a senior scientist on the team, said that based on the comparisons, 8.2% of human DNA was “functional”, meaning that it played an important enough role to be conserved by evolution. “Scientifically speaking, we have no evidence that 92% of our genome is contributing to our biology at all,” Lunter told the Guardian. Researchers have known for some time that only 1% of human DNA is held in genes that are used to make crucial proteins to keep cells – and bodies – alive and healthy. The latest study, reported in the journal Plos Genetics, suggests that a further 7% of human DNA is equally vital, regulating where, when, and how genes are expressed. But if much of our DNA is so worthless, why do we still carry it around? “It’s not true that nature is parsimonious in terms of needing a small genome. Wheat has a much larger genome than we do,” Lunter said. “We haven’t been designed. We’ve evolved and that’s a messy process. This other DNA really is just filler. It’s not garbage. It might come in useful one day. But it’s not a burden.” (via Less than 10% of human DNA has functional role, claim scientists | Science | The Guardian)
Beauty Is Skin-deep—But That’s Where Genetic Engineering Is Going Next
A Korean woman was on the verge of divorce because her husband no longer found her attractive and was having an affair. Nothing worked in her efforts to save the marriage and as a last resort she underwent cosmetic surgery. The result was so dramatic and her son didn’t recognize her when she returned home.
Even more dramatic was her husband’s attitude towards his new “goddess”: no more mention of divorce, and he was now willing staying at home all the time! This seems to be a true story as the woman appeared on a TV show. Unfortunately the show is in Korean, but you can see many amazing “before-and-after” faces on this short video. The Korean plastic surgery industry has been a huge success in tapping into this fundamental human desire. And who does not love beauty? But of course the “beauty cure” is transitory. A popular joke is: How can a Korean groom know the real face of his bride? Answer: wait till the baby is born. On the other hand, the joke won’t work anymore if such “beauty” modifications begin to occur at the genetic level. Then it will be truly a long-term investment, avoiding the cost and possible surgical pain if future generations get the same idea as the Korean woman, and then turn to fundamental genetic alteration that will effect their progeny too! People who object to this may argue that we should learn to love what we have, or what we are born with. Indeed we should. But the natural attraction to beauty is universal and undeniable. How we look not only matters for marriage, but also for one’s job and social life. Academic studies have found that we are more likely to earn more and make more friends with good looks, especially for females.
So the market for good looks, or willingness to pay, has huge potential. As I argue in Chapter 9 of my book, the posthuman future should and will be driven, at least initially, by our most basic animal-like desires,simply because they are the strongest driver for most people. Since the divergence of skin color and facial features is a very recent phenomenon, we may look different but will be essentially the same person; thus, this step should be relatively easy and low risk, i.e., relatively free of unintended consequences.
But once we learn how to democratize movie-star looks through genetic engineering, will we be satisfied? Most likely not. As looks become less of a differentiator, we will appreciate other personal characteristics more, such as kindness and intelligence.
Now interventions to achieve those attributes is serious genetic engineering. And furthermore, at what I call the second stage of conscious evolution, we should even be able to modify our innate desires and preferences themselves, including aesthetic values. At that point, another concern about cosmetic genetic engineering will be addressed: we will no longer be satisfied with the same movie star looks. Humanity will diversify and flourish, sometimes beyond our recognition.
A Circle In Vienna
Logical Positivism was a theory developed in the 1920s by the ‘Vienna Circle’, a group of philosophers centred (unsurprisingly) in Vienna. Its formulation was entirely driven by Wittgenstein’s Tractatus, which dominated analytical philosophy in the 1920s and 30s. The Circle itself owed its existence primarily to Moritz Schlick, who came to Vienna in 1922 as Professor in the Philosophy of Inductive Science; besides Schlick, the Circle included Rudolph Carnap, Otto Neurath, Friedrich Waismann and other very able thinkers – but not Wittgenstein himself, who could not be persuaded to attend their meetings. The Circle had a programme of research and a journal, Erkenntnis, to publish its results. Waismann defined the hallmark of Logical Positivism – namely ‘the principle of verification’. As Waismann explained this principle: “If there is no way of telling when a proposition is true, then the proposition has no sense whatever; for the sense of a proposition is its method of verification. In fact whoever utters a proposition must know under what conditions he will call the proposition true or false; if he cannot tell this, then he does not know what he has said” [My italics] (from ‘A Logical Analysis of the Concept of Probability’, Erktenntis 1, 1930-1). So the principle of verification was supposed to be a criterion to determine whether or not a sentence is literally meaningful: and the criterion was that the user must know the conditions under which the sentence’s assertions are verifiable.
This doctrine drew a line of demarcation between science and what the Circle’s members pejoratively called ‘metaphysics’ – a word they used as a synonym for ‘nonsense’. Their principle of verification meant that only propositions concerned with matters of empirically-verifiable fact (‘It is still raining’), or the logical relationship between concepts (‘A downpour is heavier than a shower’) are meaningful. Propositions that fall into neither of these camps fail to satisfy the principle, they argued, and consequently lack sense. It follows, therefore, that the propositions of ethics, aesthetics, and religion, are meaningless nonsense. The same would be said for any proposition that expressed a judgement of value as distinct from propositions solely concerned with facts.
One Englishman attended meetings of the Vienna Circle: A. J. Ayer, who in 1936, at the age of twenty-six, published a book called Language, Truth and Logic. This brought the ideas of the Vienna Circle to the attention of the English-speaking world. The title of the first chapter of this dogmatic, even arrogant, book, is ‘The Elimination of Metaphysics’. Here’s how to do it, according to Ayer:
“We may define a metaphysical sentence as a sentence which purports to express a genuine proposition, but does, in fact, express neither a tautology nor an empirical hypothesis. And as tautologies and empirical hypotheses form the entire class of significant propositions, we are justified in concluding that all metaphysical assertions are nonsensical.”
Poor Immanuel Kant – all those years of effort on metaphysical analysis wasted! His analysis of the concept of free will, for example: meaningless! For the sentence ‘I chose freely’ is neither a tautology nor an empirical hypothesis (for it is incapable of being either proved or disproved empirically); therefore it must be nonsense. Isn’t that shocking?
It never seemed to occur to the Vienna Circle that the proposition ‘the sense of a proposition is its method of verification’ is itself a metaphysical assertion that cannot be verified by its own test: their doctrine is self-contradictory, and therefore must be false.
Does the language you speak influence how you think?
Studies show that our language affects how we experience the world, playing a role in everything from how we save for retirement to the colors we see.