Monday, February 27, 2012

Fear of spiders makes you believe creepy crawlies are bigger

The more you fear a spider the bigger it will appear to be, according to new research.

A portrait of a jumping spider by Dusan Beno
A jumping spider Photo: BARCROFT/DUSAN BENO
A study of arachnophobes found the worse their condition the larger they estimated the creepy crawlie's size.
The irrational fear of spiders is believed to affect as many as half of women and girls, and up to one in six males.
And the latest findings explain why many sufferers hold out their arms shrieking "it was that big" when the reality of the situation turns out to be much less scary.
A better grasp of how a phobia affects perception of feared objects can help doctors design more effective remedies, the Journal of Anxiety Disorders reports.
Psychologist Professor Michael Vasey, of Ohio State University, said: "If one is afraid of spiders, and by virtue of being afraid of spiders one tends to perceive spiders as bigger than they really are, that may feed the fear, foster that fear, and make it difficult to overcome."
His team recruited 57 participants with a spider phobia who were asked to undergo five encounters with live tarantulas in uncovered glass tanks and then provide size estimates.
The more afraid they rated in anxiety scores the bigger they described the hairy beasts, which spanned between one and six inches.
Prof Vasey said: "When it comes to phobias, it is all about avoidance as a primary means of keeping oneself safe.
"As long as you avoid, you cannot discover you are wrong. And you are stuck.
"So to the extent that perceiving spiders as bigger than they really are fosters fear and avoidance, it then potentially is part of this cycle that feeds the phobia that leads to its persistence.
"We are trying to understand why phobias persist so we can better target treatments to change those reasons they persist."
The volunteers, who were studied over a period of eight weeks, began their encounters 12 feet from the tank and were asked to approach the spider.
Once they were standing next to it, they had to guide the spider around by touching it with an 8-inch probe, and then with a shorter one.
Throughout their ordeal they reported how afraid they were feeling on a scale of 0-100 according to an index of subjective units of distress.
Afterwards they completed additional self-report measures of their specific fear of spiders, any panic symptoms they experienced and thoughts about fear reduction and future spider encounters.
Finally, they estimated the size of the spiders - while no longer being able to see them - by drawing a single line on an index card indicating the length between the tips of its front and back legs.
Prof Vasey said: "It would appear fear is driving or altering the perception of the feared object, in this case a spider.
"We already knew fear and anxiety alter thoughts about the feared thing. For example, the feared outcome is interpreted as being more likely than it really is.
"But this study shows even perception is altered by fear. In this case, the feared spider is seen as being bigger. And that may serve as a maintaining factor for the fear."
The approach tasks with the spiders are a classic example of exposure therapy, a common treatment for people with phobias.
Although this therapy is known to be effective, scientists still do not fully understand why it works.
And for some, the effects do not last - but it is difficult to predict who will have a relapse of fear, said Prof Vasey.
He and colleagues are studying these biased perceptions as well as attitudes with hopes that the new knowledge will enhance treatment for people with various phobias.
The work suggests that fear not only alters one's perception of the feared thing, but also can influence a person's automatic attitude toward an object.
Those who have developed an automatic negative attitude toward a feared object might have a harder time overcoming their fear.
Although individuals with arachnophobia are unlikely to seek treatment, the use of spiders in this research was a convenient way to study the complex effects of fear on visual perception and how those effects might cause fear to persist, Prof Vasey noted.
He added: "Ultimately, we are interested in identifying predictors of relapse so we can better measure when a person is done with treatment."

Tuesday, February 7, 2012

'Oldest living thing on earth' discovered

Ancient patches of a giant seagrass in the Mediterranean Sea are now considered the oldest living organism on Earth after scientists dated them as up to 200,000 years old.

Scientists say a patch of ancient seagrass in the Mediterranean is up to 200,000 years and could be the oldest known living thing on Earth. Australian researchers, who genetically sampled the seagrass covering  40 sites from Spain to Cyprus, say it is one of the world's most resilient organisms - but it has now begun to decline due to global warming. Scientists say a patch of ancient seagrass in the Mediterranean is up to 200,000 years old Photo: Getty Images

Australian scientists sequenced the DNA of samples of the giant seagrass, Posidonia oceanic, from 40 underwater meadows in an area spanning more than 2,000 miles, from Spain to Cyprus.

The analysis, published in the journal PLos ONE, found the seagrass was between 12,000 and 200,000 years old and was most likely to be at least 100,000 years old. This is far older than the current known oldest species, a Tasmanian plant that is believed to be 43,000 years old.

Prof Carlos Duarte, from the University of Western Australia, said the seagrass has been able to reach such old age because it can reproduce asexually and generate clones of itself. Organisms that can only reproduce sexually are inevitably lost at each generation, he added.

"They are continually producing new branches," he told The Daily Telegraph. "They spread very slowly and cover a very large area giving them more area to mine resources. They can then store nutrients within their very large branches during bad conditions for growth."

The separate patches of seagrass in the Mediterranean span almost 10 miles and weigh more than 6,000 tons.

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Thursday, February 2, 2012

Rare dragonfly spotted at Thenmala

The rare lesser blue wing dragonfly sighted at the
Thenmala Butterfly Safari Park in Kollam district.
The rare lesser blue wing dragonfly sighted at the Thenmala Butterfly Safari Park in Kollam district. 
The lesser blue wing dragonfly (Rhyothemis triangular) considered a rare dragonfly in South India has been spotted and photographed at the Thenmala Butterfly Safari Park in Kollam district. 

This feast for the eyes sighting was made on January 14 by the butterfly and bird enthusiasts, C. Sushanth and M.S. Akhil during the monthly butterfly and dragonfly monitoring exercise. 

The slow-flying lesser blue wing is a medium-sized elusive dragonfly with metallic blue markings on the base of its wings. Ponds and marshes are the favourite spots of these dragonflies since they love perching near water bodies. This could be because it breeds in marshes and similar habitats. 

But in the southern part of the country they are rarely sighted. The previous recorded sighting of this dragonfly was some last year by wildlife photographer and dragonfly enthusiast T. Dragon fly close to a wetland in Vithura of Thiruvananthapuram district. 

Mr. Sushanth said that one of the fascinating aspects of the lesser blue wing is that it can float in the air for long periods without flapping the wings. Both Sushanth and Akhil recorded sighting rare dragonflies and damselflies within and around the Thenmala butterfly park.