Archive for the ‘Behavioral science’ Category

Hearing voices? You might just be primed for it

August 27th, 2017

Enlarge (credit: flickr user: David Wood)

Hallucinations tend to be associated with psychosis, but the reality is more complicated than that. Some people who hear voices don’t suffer from other mental health problems, and the voices they hear aren’t distressing. These “non-clinical voice-hearers” provide an important opportunity to understand hallucinations without the complications of mental illness or medication.

A preliminary study published this week in the journal Brain reports that non-clinical voice-hearers were more likely to detect language in a recording of distorted speech. Voice-hearers also showed some different patterns in brain activation as they listened. The results could help to explain why some people are more likely to hear voices, as well as help to direct future research on the topic.

Hearing meaning in noise

Ben Alderson-Day, the lead author on the paper, is a psychologist at Durham University whose research focuses on auditory hallucinations. To investigate differences of perception in voice-hearers, Alderson-Day and his colleagues used sine-wave speech, which strips out some of the most vital acoustic properties of speech and leaves something that sounds kind of like a series of clicks and whistles. It’s possible to understand it—once you already know what it says, or once you’ve listened to quite a bit of sine-wave speech. (Listen to some examples here.)

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Meta-analysis shows psychotherapy leads to long-term personality change

August 23rd, 2017

Enlarge / Even Lego clowns need therapy sometimes. (credit: Pascal / Flickr)

If you’ve ever wondered whether psychotherapy achieves meaningful, long-term change in a person’s life, wonder no more: combined evidence from multiple studies suggest that it does. A meta-analysis published recently in Psychological Bulletin reports that a variety of different therapeutic techniques results in positive changes to personality, especially when it comes to neuroticism, that last over a considerable period of time.

Personality is, as your intuition might tell you, relatively stable—people who start out gregarious and adventurous tend to stay gregarious and adventurous throughout their lives. Assessments of people’s personality traits taken at different times tend to agree pretty well with each other. But that doesn’t mean personality is static: personal growth, life experiences, and age all play their part, and people’s personalities do change somewhat throughout their lives—usually for the better.

An OCEAN of change

But it can be tricky to work out precisely what is being evaluated in measures of personality like the “Big Five” of Openness to experience, Conscientiousness, Extraversion, Agreeableness, and Neuroticism (“OCEAN”). Any personality questionnaire will come up with metrics that capture both someone’s stable, long-term tendencies (their traits), as well as how they are feeling in a given moment or phase in their life (their state). So, it’s not enough to find that therapy brings about personality changes—it’s also necessary to figure out how deep those changes go.

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Tracking the spread of culture through folktales

August 13th, 2017

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There’s a reason why the premise of American Gods is so alluring: the US is home to a wild and glorious mishmash of gods, folktales, and cultural heritage. One by one, groups from around the world picked up and landed on a new shore, bringing their stories with them.

The mere existence of certain tales can be revealing. They develop and mutate as they get passed from one group to the next, and the best stories are passed on more readily. Understanding the spread of folktales can help us understand cultural evolution more generally, and a paper in this week’s PNAS does just that by combining data on folktales with genetic, geographic, and linguistic information.

Researchers studying cultural evolution use biological evolution as a starting point for their ideas, but they also point out that clear and important differences separate the two types of evolution. The timescales, for instance, are often very different—cultural units can be transmitted between people of the same generation, while powerful ideas (like religions) can spread incredibly quickly and easily. A lot of work in cultural evolution is dedicated to trying to divine the mechanisms that underlie the spread of cultural ideas. How do people choose which ideas to adopt? And how does the spread of ideas compare to the spread of genes?

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Humans were in Indonesia more than 63,000 years ago

August 11th, 2017

Enlarge / Lida Ajer modern human tooth (left top) with its corresponding scanned image (left bottom) compared to an orangutan tooth (right) (credit: Tanya Smith and Rokus Awe Due)

In the Padang Highlands of western Sumatra, a large island in Indonesia, there is a small cave called Lida Ajer that has long offered up clues about human history. Dutch paleoanthropologist Eugene Dubois first excavated the cave before 1890, and Lida Ajer has turned up plenty of preserved animal remains since, including teeth that were identified as human in 1948.

It’s only now that the cave has been carefully and thoroughly dated, providing a new line of evidence that our species was in the region more than 60,000 years ago. That’s 20,000 years older than the previous oldest skeletal evidence of humans in the area. But these new dates line up with existing genetic evidence, as well as with reconstructions of the climate and sea levels at the time.

In a paper published in Nature this week, Kira Westaway of Macquarie University in Australia and her colleagues report what they found when they revisited the discoveries of Lida Ajer. They re-examined the teeth, pointing to all the evidence that the teeth did indeed belong to anatomically modern humans rather than orangutans or other primates. And they carefully dated the cave site to establish how old the teeth were likely to be.

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There’s a debate raging in science about what should count as “significant”

August 4th, 2017

Enlarge (credit: flickr user: Artiom Gorgan)

Psychology and many related fields are in the midst of what can be viewed as a coming-of-age crisis. Following a stream of depressing revelations about a lack of reliability in the field, lots of researchers are dedicating themselves to improving the discipline’s rigor.

The latest proposal to up that rigor is a big one: 72 researchers from a range of disciplines have drafted a manuscript arguing that the threshold for claiming “statistical significance” should become much stricter. There’s often a fair amount of consensus on how science could be improved, but this suggestion has stimulated some intense debate.

Statistical significance in a very small nutshell

Statistical significance is a concept underlying a huge amount of science—not just psychology or social sciences, but medicine, life sciences, and physical sciences, too. “Significance” used in this way doesn’t mean the importance or size of a finding, rather it’s the probability of that finding showing up in your data even though your hypothesis turns out to be wrong.

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There’s a debate raging in science about what should count as “significant”

August 4th, 2017

Enlarge (credit: flickr user: Artiom Gorgan)

Psychology and many related fields are in the midst of what can be viewed as a coming-of-age crisis. Following a stream of depressing revelations about a lack of reliability in the field, lots of researchers are dedicating themselves to improving the discipline’s rigor.

The latest proposal to up that rigor is a big one: 72 researchers from a range of disciplines have drafted a manuscript arguing that the threshold for claiming “statistical significance” should become much stricter. There’s often a fair amount of consensus on how science could be improved, but this suggestion has stimulated some intense debate.

Statistical significance in a very small nutshell

Statistical significance is a concept underlying a huge amount of science—not just psychology or social sciences, but medicine, life sciences, and physical sciences, too. “Significance” used in this way doesn’t mean the importance or size of a finding, rather it’s the probability of that finding showing up in your data even though your hypothesis turns out to be wrong.

Read 14 remaining paragraphs | Comments

Posted in Behavioral science, Biology, science, statistics | Comments (0)