Category Archives: Research

Drug addiction is complex

14 Wednesday Oct 2020

Posted by in Addiction, Research

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We’re told studies have proven that drugs like heroin and cocaine instantly hook a user. But it isn’t that simple – little-known experiments over 30 years ago tell a very different tale.

Drugs are scary. The words “heroin” and “cocaine” make people flinch. It’s not just the associations with crime and harmful health effects, but also the notion that these substances can undermine the identities of those who take them. One try, we’re told, is enough to get us hooked. This, it would seem, is confirmed by animal experiments. 0312ILIN03-web.jpg

Many studies have shown rats and monkeys will neglect food and drink in favour of pressing levers to obtain morphine (the lab form of heroin). With the right experimental set up, some rats will self-administer drugs until they die. At first glance it looks like a simple case of the laboratory animals losing control of their actions to the drugs they need. It’s easy to see in this a frightening scientific fable about the power of these drugs to rob us of our free will.

But there is more to the real scientific story, even if it isn’t widely talked about. The results of a set of little-known experiments carried out more than 30 years ago paint a very different picture, and illustrate how easy it is for neuroscience to be twisted to pander to popular anxieties. The vital missing evidence is a series of studies carried out in the late 1970s in what has become known as “Rat Park”. Canadian psychologist Bruce Alexander, at the Simon Fraser University in British Columbia, Canada, suspected that the preference of rats to morphine over water in previous experiments might be affected by their housing conditions.

To test his hypothesis he built an enclosure measuring 95 square feet (8.8 square metres) for a colony of rats of both sexes. Not only was this around 200 times the area of standard rodent cages, but Rat Park had decorated walls, running wheels and nesting areas. Inhabitants had access to a plentiful supply of food, perhaps most importantly the rats lived in it together.

Rats are smart, social creatures. Living in a small cage on their own is a form of sensory deprivation. Rat Park was what neuroscientists would call an enriched environment, or – if you prefer to look at it this way – a non-deprived one. In Alexander’s tests, rats reared in cages drank as much as 20 times more morphine than those brought up in Rat Park. 

Inhabitants of Rat Park could be induced to drink more of the morphine if it was mixed with sugar, but a control experiment suggested that this was because they liked the sugar, rather than because the sugar allowed them to ignore the bitter taste of the morphine long enough to get addicted. When naloxone, which blocks the effects of morphine, was added to the morphine-sugar mix, the rats’ consumption didn’t drop. In fact, their consumption increased, suggesting they were actively trying to avoid the effects of morphine, but would put up with it in order to get sugar.

‘Woefully incomplete’

The results are catastrophic for the simplistic idea that one use of a drug inevitably hooks the user by rewiring their brain. When Alexander’s rats were given something better to do than sit in a bare cage they turned their noses up at morphine because they preferred playing with their friends and exploring their surroundings to getting high.

Further support for his emphasis on living conditions came from another set of tests his team carried out in which rats brought up in ordinary cages were forced to consume morphine for 57 days in a row. If anything should create the conditions for chemical rewiring of their brains, this should be it. But once these rats were moved to Rat Park they chose water over morphine when given the choice, although they did exhibit some minor withdrawal symptoms.

You can read more about Rat Park in the original scientific report. A good summary is in this comic by Stuart McMillen. The results aren’t widely cited in the scientific literature, and the studies were discontinued after a few years because they couldn’t attract funding. There have been criticisms of the study’s design and the few attempts that have been made to replicate the results have been mixed.

Nonetheless the research does demonstrate that the standard “exposure model” of addiction is woefully incomplete. It takes far more than the simple experience of a drug – even drugs as powerful as cocaine and heroin – to make you an addict. The alternatives you have to drug use, which will be influenced by your social and physical environment, play important roles as well as the brute pleasure delivered via the chemical assault on your reward circuits

It suggests that even addictions can be thought of using the same theories we use to think about other choices, there isn’t a special exception for drug-related choices. Rat Park also suggests that when stories about the effects of drugs on the brain are promoted to the neglect of the discussion of the personal and social contexts of addiction, science is servicing our collective anxieties rather than informing us

Self-Control Can Drain Your Memory

27 Thursday Aug 2020

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The human body has a finite amount of resources, and scientists are always discovering more about how these resources are shared, depleted, and replenished. Now a new study suggests that the areas in your brain responsible for self-control and forming memories are closely linked – in other words, if you’re concentrating hard on staying disciplined, you’re probably becoming less adept at remembering what’s happening.

Researchers Yu-Chin Chiu and Tobias Egner from Duke University in the US asked a group of volunteers to recognise a series of faces, both with and without the inclusion of a self-control test in the middle. They found that having to exercise self-control had a negative impact on the participants’ ability to recall which pictures they’d previously seen. The same experiment was then repeated with a new set of volunteers and brain-scanning fMRI (functional magnetic resonance imaging) equipment on hand. Brain-0008.jpg

The pair discovered that one area of the brain – the ventrolateral prefrontal cortex – was activated frequently during the self-control test and predicted the strength of the volunteers’ memory later on. The findings suggest that self-control and memory compete for the same resources inside the brain, and support the theory that inhibiting ourselves can also cause us to forget more easily.

“The control demands of response inhibition divert attention away from stimulus encoding, thereby weakening memory traces for inhibitory cues,” the researchers conclude in The Journal of Neurosience. “These findings shed new light on the relation between the control process of response inhibition and the cognitive domains of perception, attention, and memory.”

The self-control test used was a traditional Go/No-Go task: these tasks work by asking participants to view a series of items and push a button only when certain criteria are met – in the case of this experiment, when the face shown is male rather than female. The theory is that those who are able to hold back from a button push when necessary are those with the strongest self-control (or “response inhibition”, as neuroscientists like to call it). The participants were not told in advance that they would need to remember the faces they were shown.

“The scans revealed that responding to a cue and inhibiting a response produced overlapping activation patterns in brain regions within the right frontal and parietal lobes, a network that has previously been implicated in response inhibition,” Mo Costrandi reports for The Guardian. “Crucially, ‘no-go’ trials produced greater activation of this network than ‘Go’ trials, and activity in one specific brain region (the ventrolateral prefrontal cortex) predicted the strength of the participants’ memory, such that the greater the observed network activation, the more likely the participants were to forget that face later on.”

The researchers admit their theory is still “speculative” for now, but if further study confirms the link, they believe their discovery could be used to treat people who have problems with self-control: those suffering from ADHD (Attention Deficit Hyperactivity Disorder), for example, or some form of addiction.

One scenario put forward by the pair is having to suddenly cancel a lane change on the motorway because a car is already in the spot you want to move into. If they’re right, the act of having to control and inhibit your actions would make it less likely that you would remember the details of the incident – such as the make and model of the car that was blocking your path.

American Views on China: A Pew Research Center Survey

25 Tuesday Aug 2020

Posted by in China, Research, Social Science

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The Pew Research Center has been polling American adults on their perceptions of China since 2005. The latest report, based on interviews conducted in March 2020, shows that growing numbers of Americans have become increasingly negative about China. For the first time, more than half of Americans between the ages of 18 and 29 held unfavorable views of China. Almost nine in ten Americans see China’s power and influence in the world as a threat, with 62% saying that it is a “major threat.”

Popular fairy tales and folk stories are ancient

14 Friday Aug 2020

Posted by in culture, discovery, Research

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They have been told as bedtime stories by generations of parents, but fairy tales such as Little Red Riding Hood may be even older than was previously thought.

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Dr Jamie Tehrani, a cultural anthropologist at Durham University, studied 35 versions of Little Red Riding Hood from around the world

A study by anthropologists has explored the origins of folk tales and traced the relationship between varients of the stories recounted by cultures around the world.

The researchers adopted techniques used by biologists to create the taxonomic tree of life, which shows how every species comes from a common ancestor.

Dr Jamie Tehrani, a cultural anthropologist at Durham University, studied 35 versions of Little Red Riding Hood from around the world.

Whilst the European version tells the story of a little girl who is tricked by a wolf masquerading as her grandmother, in the Chinese version a tiger replaces the wolf.

In Iran, where it would be considered odd for a young girl to roam alone, the story features a little boy.

Contrary to the view that the tale originated in France shortly before Charles Perrault produced the first written version in the 17th century, Dr Tehrani found that the varients shared a common ancestor dating back more than 2,600 years.

He said: “Over time these folk tales have been subtly changed and have evolved just like an biological organism. Because many of them were not written down until much later, they have been misremembered or reinvented through hundreds of generations.

“By looking at how these folk tales have spread and changed it tells us something about human psychology and what sort of things we find memorable.

“The oldest tale we found was an Aesopic fable that dated from about the sixth century BC, so the last common ancestor of all these tales certainly predated this. We are looking at a very ancient tale that evolved over time.”

Dr Tehrani, who will present his work on Tuesday at the British Science Festival in Guildford, Surrey, identified 70 variables in plot and characters between different versions of Little Red Riding Hood.

He found that the stories could be grouped into distinct families according to how they evolved over time.

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The original ancestor is thought to be similar to another tale, The Wolf and the Kids, in which a wolf pretends to be a nanny goat to gain entry to a house full of young goats.

Stories in Africa are closely related to this original tale, whilst stories from Japan, Korea, China and Burma form a sister group. Tales told in Iran and Nigeria were the closest relations of the modern European version.

Perrault’s French version was retold by the Brothers Grimm in the 19th century. Dr Tehrani said: “We don’t know very much about the processes of transmission of these stories from culture to culture, but it is possible that they may being passed along trade routes or with the movement of people.”

Professor Jack Zipes, a retired professor of German at the University of Minnesota who is an expert on fairy tales and their origins, described the work as “exciting”. He believes folk tales may have helped people to pass on tips for survival to new generations.

He said: “Little Red Riding Hood is about violation or rape, and I suspect that humans were just as violent in 600BC as they are today, so they will have exchanged tales about all types of violent acts.

“I have tried to show that tales relevant to our adaptation to the environment and survival are stored in our brains and we consistently use them for all kinds of reference points.”

sailing stones of Death Valley

05 Wednesday Aug 2020

Posted by in discovery, Environment, Japanese Textile Designs, Research, Science

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The sailing stones of the Racetrack Playa, a dry lakebed in Death Valley, have been the subject of a mystery since the 1940s. The playa is dotted with stones, some as large as 700 pounds (320kg), with long tracks behind them, as though they have been performing a synchronised dance.

Although there have been many theories about how the rocks might be moving on their own — including dust devils, hurricane-force winds, films of slippery algae or thick sheets of ice — none had ever been confirmed, nor had any human seen the rocks actually moving.DSC00220-sm

Until now, that is. A team of researchers from the Scripps Institution of Oceanography at UC San Diego decided they were going to solve the mystery once and for all. In the winter of 2011, they brought in a high-resolution weather station to measure wind at one-second intervals, and brought in 15 rocks fitted with GPS devices (since the National Parks Service would not allow them to use the native rocks).

Read More Here.

Moral determination

02 Thursday Jul 2020

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When people witness a hurtful action they make a moral determination based on whether it is intentional or accidental instantly, according to a new paper.

The paper says the brain is hard-wired to recognize when another person is being intentionally harmed. It also provides new insights into how such recognition is connected with emotion and morality, according to lead author Jean Decety, Professor of Psychology and Psychiatry at U of Chicago.

The researchers studied adults who watched videos of people who suffered accidental harm (such as being hit with a golf club) and intentional harm (such as being struck with a baseball bat). While watching the videos, brain activity 12balwas collected with equipment that accurately maps responses in different regions of the brain and importantly, the timing between these regions. The technique is known as high-density, event-related potentials technology.

The intentional harm sequence produced a response in the brain almost instantly. The study showed that within 60 milliseconds, the right posterior superior temporal sulcus (also known as TPJ area), located in the back of the brain, was first activated, with different activity depending on whether the harm was intentional or accidental. It was followed in quick succession by the amygdala, often linked with emotion, and the ventromedial prefrontal cortex (180 milliseconds), the portion of the brain that plays a critical role in moral decision-making.

There was no such response in the amygdala and ventromedial prefrontal cortex when the harm was accidental.

“Our data strongly support the notion that determining intentionality is the first step in moral computations,” said Decety, who conducted research on the topic with Stephanie Cacioppo, a research associate (assistant professor) in psychology at U of Chicago.

Other studies with functional MRI scans, including those in Decety’s lab, have shown that those areas of the brain become activated when people see others intentionally harmed, but those studies have been unable to separate or time the way the various parts of the brain may work together.

“High-density ERPs can identify spatio-temporal patterns of communication between regions that contrast analyses (such as fMRI) with low temporal resolution may not detect, and such methods are necessary to advance knowledge of neuroscience of morality,” said Cacioppo.

The ability to recognize and respond emotionally to the intentional infliction of harm is a critical source of morality that is universal across cultures, researchers believe. “It is part of humans’ evolutionary heritage,” Decety said. “The long history of mammalian evolution has shaped our brains to be sensitive to signs of suffering of others. And this constitutes a natural foundation for morality and sensitivity to justice.”

Philosophers have debated the origins of this moral response for ages. Some maintain that moral judgments begin with an immediate aversive reaction to perceived or imagined harm to victims, though the full moral judgment may form only after the fact. Other philosophers maintain that moral principals develop from reason alone and are not connected to emotion.

The new research suggests that emotion and the perception of intentionality, rather than deliberate reasoning, comprise the vital first component of moral responses—at least for responses that stem from care for others Decety said.

The research may help inform other areas of neurodevelopment research, including studies of the moral responses of psychopaths and of children who lack empathy for others, displaying what are called callous-unemotional traits.

Published in the Journal of Neurophysiology. See article here.