Category Archives: Research

Drug addiction is complex

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

Intelligence, creativity and brain function

Do you have to be intelligent to be creative? Can you learn to be more creative? In this episode, we speak with neuropsychologist Rex E. Jung, PhD, who studies intelligence, creativity and brain function. He discusses why – even if it sounds counterintuitive – intelligence and creativity may not have all that much in common.

Transcript of interview with Audrey and Rex Jung from the APA website.

Audrey Hamilton: Do you have to be intelligent to be creative? Can you really learn to be more creative? In this episode, we speak with one neuropsychologist who studies intelligence, creativity and brain function. He talks about why – even if it sounds counterintuitive – intelligence and creativity may not have all that much in common. I’m Audrey Hamilton and this is “Speaking of Psychology.”

Rex Jung is an assistant professor of neurosurgery at the University of New Mexico and a practicing clinical neuropsychologist in Albuquerque. He studies both brain disease and what the brain does well – a field of research known as positive neuroscience. His research is designed to relate behavioral measures, including intelligence, personality and creativity to brain function and structure. He has published research articles across a wide-range of topics including traumatic brain injury, lupus, schizophrenia, intelligence and creativity. Welcome, Dr. Jung.creative-art-brain-300x300

Rex Jung: Thank you, Audrey.

Audrey Hamilton: Could you first of all explain neuroimaging and tell our listeners how it helps researchers understand how people think and act?

Rex Jung: Sure. So, neuroimaging is the tool that we use to measure the brain and there’s lots of different neuroimaging techniques. I use three main neuroimaging techniques – the first that I learned in graduate school was magnetic resonance microscopy, which sounds kind of complicated. But, it is a technique that basically looks at the chemicals in your brain. It’s in a standard MRI machine like you would go to get your knee scanned. But, using some sophisticated techniques you can look at certain chemicals in the brain. Some of those chemicals are very involved in important neuronal processes. And we’ve correlated those with behavior.

A different technique is called diffusion tensor imaging, which allows us to look at water movement in the brain. And this is important because there’s lots of tubes going through your brain like the wires that connect up your computer to the Internet. And these tubes, called axons, are connecting up different processing modules of your brain and those have to be healthy. So, we can look at the health of those axons, those myelinated axons, the fatty sheath like the insulation that surrounds those tubes.

The third technique that we use is just structural magnetic resonance imaging and that allows us to look at the processing modules of the brain – the cortical thickness – the computers that are on the surface of the brain and how much or little of that you have on the surface of the brain. Those are the three main techniques that I use. There’s functional imaging, fMRI, that most people have heard of where you’re looking a blood flow, as well. Those are ways that we measure brain structure and function and this gives us the ability to do scientific measures that then we can correlate to behavioral measures in psychology.

Audrey Hamilton: Does being highly creative mean you’re also more intelligent?

Rex Jung: Not necessarily. There’s a controversy about this in the psychological literature and some people have found correlations between creativity and intelligence. They’re usually pretty low, this association. And some people make a lot of that, this low association. But usually, because this association between creativity and intelligence is low, it means that you don’t necessarily have to be intelligent to be creative. So, I spent over a decade studying intelligence. It’s one of the reasons I started studying creativity because it seemed like something distinctly different and interesting than intelligence, which I have studied. I work with very highly intelligent people in academia and scientists and not all of them are creative. Why is that? If they do go together I would be working with all of the creative people in my city in Albuquerque, but that wasn’t the case so creativity seemed to be something different.

Audrey Hamilton: Can a person learn to become more creative or simply gain intelligence?

Rex Jung: There are some tools and techniques that can help people to be more creative. We’re starting to learn more about creativity and it’s one of the things that I’m excited about in terms of creativity is that there might be ways to increase your creative capacity.

Intelligence unfortunately seems to be much more under tight genetic control. The genetic correlates of intelligence are high, like .75. So, if you have twins – they’re going to be identical twins – their correlation of their intelligence with one another is going to be very, very high. So that implies that the genetic involvement of that capacity is under much more tight control than the environment would be.

With creativity, we don’t have that information and I’m hopeful that you can modulate or modify creative cognition much more than intelligence. There are studies out there that have shown increases in intelligence scores of two, maybe three points on a particular measure, which are not particularly high. But those are also controversial. Some have been replicated. Some haven’t been replicated. And we really don’t see that in terms of intelligence. With creativity, there’s a pitched effort to try to increase creativity scores on some of these measures and we’re seeing some good initial results and I’m very hopeful about that.

Audrey Hamilton: How does the way a person’s brain works and is structured influence how creative or intelligent he or she is?

Rex Jung: The research that we’ve done shows that the brain organization of intelligence and creativity are quite different. So, when you think about those measures that I talked about, those neuroimaging measures, the brain of someone who is intelligent – think of bigger, better, stronger, faster – all the measures are pointing to higher integrity of the brain of someone who has high intelligence. So, the cortical mantle is thicker, the white matter, the wires are more myelinated, the water can travel faster and in a coherent direction, you have more of these certain chemicals that I was talking about.

crAudrey Hamilton: It’s beefed up.

Rex Jung: It’s beefed up, yes. So you can have a better organized brain.

With creativity, the story was different. In different regions of the brain, we were seeing weaker connections, thinner cortex and different levels of these same biochemicals. So, it was really clear from these studies that intelligence and creativity were different because we were seeing different pictures in the measures we were taking of the brain. But I tend to look at creativity and intelligence as two different kinds of reasoning. That creativity is kind of reasoning without all of the information present. So, call it abductive reasoning. But, you have hypothesis testing about how the world could work without all of the information present. So, you have to use abstraction and metaphor and stuff like that about this might look like this or this might be this way.

With intelligence, you’re using deductive reasoning, where it’s rule-based reasoning where a equals b and that’s the way it goes. You have a rule for how this relationship works. So, creativity and intelligence are probably different types of reasoning. Both are very adaptive, but they’re just different for different types of problems that you have to solve out in the world.

Audrey Hamilton: Is real creativity rare? How about genius?

Rex Jung: So, creativity is common and genius is a lot more rare than we would believe. The term genius gets thrown around a lot. But, I think genius is rare because that combination of brain organization where you have high fidelity, beefed up brain in certain regions and then kind of down regulated brain in other regions is really going to be kind of rare where that is present in the same brain. So, to have that back and forth between intelligence and creativity, the ability to do both of those reasoning processes well, where you can do first approximations, hypothesis testing, abstraction and then create a rule, a novel and useful rule out of nothing before is rare and that is true genius.

Audrey Hamilton: Well great. Thank you so much for joining us, Dr. Jung. It’s been very, very interesting.

Rex Jung: Great. Thank you, Audrey.

Dacher Keltner on the Evolutionary Roots of Compassion

Dacher Keltner, UC Berkley psychology professor and faculty director of the Greater Good Science Center, explores the evolutionary roots of compassion and empathy.