The 24th edition of psychology and neuroscience writing carnival Encephalon has just been published at psychology blog The Phineas Gage Fan Club.
A couple of my favourites include a post on deep brain electrode recordings from the human nucleus accumbens and a post on a psychological sex differences study run on 200,000 participants (wow).
For more articles, on everything from law to neural information storage, follow the link below for the full edition.
Link to Encephalon 24.
The Washington Post published an interesting article last week on research suggesting that human traits like generosity and altruism may be innate.
It describes a number of experiments which are tackling the relatively new field of ‘moral neuroscience’, which aims to understand how the brain is involved in moral decision-making.
What is interesting is that some of the brain areas found to be associated with this form of reasoning are those thought to be quite ‘old’ in evolutionary terms.
In one 2004 brain-imaging experiment [pdf], Greene asked volunteers to imagine that they were hiding in a cellar of a village as enemy soldiers came looking to kill all the inhabitants. If a baby was crying in the cellar, Greene asked, was it right to smother the child to keep the soldiers from discovering the cellar and killing everyone?
The reason people are slow to answer such an awful question, the study indicated, is that emotion-linked circuits automatically signaling that killing a baby is wrong clash with areas of the brain that involve cooler aspects of cognition. One brain region activated when people process such difficult choices is the inferior parietal lobe, which has been shown to be active in more impersonal decision-making. This part of the brain, in essence, was “arguing” with brain networks that reacted with visceral horror.
Such studies point to a pattern, Greene said, showing “competing forces that may have come online at different points in our evolutionary history. A basic emotional response is probably much older than the ability to evaluate costs and benefits.”
Link to Washington Post article.
pdf of paper mentioned in excerpt.
Despair Inc has this fantastic parody of the t-shirts worn by private security firms at concerts, gigs and public events. So now you can wear the t-shirt and advertise yourself as a member of the insecurity team.
The company makes some fantastic parodies of corporate motivational merchandise, including a great range of demotivating posters.
Link to Despair Inc’s ‘Insecuritee’.
A recently published study has found that females show greater brain activation to uncertain rewards during the most fertile stage of the menstrual cycle, perhaps explaining why women dress more attractively and have altered sexual preferences during this time.
The dopamine system is known to be involved in reward processing, and one of the current theories is that it is particularly involved in reward prediction – that is, it signals when we might expect to find something gratifying.
The key female sex hormone estrogen is known to alter dopamine function, so it was thought that females might show changes in how they experience rewards when estrogen levels fluctuate during the menstrual cycle.
The most direct dopamine-related rewards are drugs like cocaine and amphetamine, and studies have found that the same dose feels stronger during the fertile follicular phase of the cycle.
Research, largely conducted with straight women, has found that females dress more attractively during this phase and have altered sexual preferences so that they experience more masculine looking, assertive males as more attractive.
This new study by Dr Jean-Claude Dreher and colleagues fMRI brain-scanned men and women during a gambling task, and looked at between-sex differences and within-cycle differences in brain activity.
They found that women have a greater response to rewards than men in the amygdala and hippocampus, both key emotion areas.
They also found that during the most fertile follicular phase of the menstrual cycle, women show more activity when predicting rewards, particularly in the amygdala and another key emotion and reward area, the orbitofrontal cortex.
When the reward was delivered (a win in the gambling task), women showed stronger response in a number of reward-related areas during the fertile phase, including the striatum, a dopamine-rich deep brain area.
It seems that the hormone cycle makes brain areas related to the prediction and experience of rewards become more active when women are more fertile. This might explain why the menstrual cycle can alter women’s sexual preferences and behaviour.
If you want more details of the study, the full paper is available at the link below.
Link to PubMed entry for the scientific paper.
pdf of full-text scientific paper.
Simultanagnosia is where a person can’t perceive more than one object at a time. They literally cannot see the wood for the trees. There are two main types that differ depending on the location of the brain injury which has caused the syndrome.
Damage to the dorsal stream can cause dorsal simultanagnosia, where the patient cannot see two or more objects at the same time.
Damage to the ventral stream can cause ventral simultanagnosia, where the patient can see multiple objects, but can only identify one at a time.
The following is from p61 of the 1970 book Brain Damage and the Mind (ISBN 0140801405) by Moyra Williams, who describes a gentleman with dorsal simultanagnosia:
A sixty-eight-year old patient studied by the author had difficulty finding his way around because “he couldn’t see properly”. It was found that if two objects (e.g. pencils) were held up in front of him at the same time, he could see only one of them, whether they were held side by side, one above the other, or one behind the other.
Further testing showed that single stimuli representing objects or faces could be could be identified correctly and even recognized when shown again, whether simple or complex… If the stimuli included more than one object, only one would be identified at one time, though the other would sometimes “come into focus” as the first one went out…
If long sentences were presented, only the rightmost word could be read… If a single word covered as large a visual area as a sentence which could not be read, the single word was read in its entirety… If the patient was shown a page of drawings, the contents of which overlapped (i.e. objects were drawn on top of one another), he tended to pick out one and deny that he could see any others.
Recent evidence has suggested that although the unseen objects may not be consciously available, carefully designed psychological tests can detect they have been registered at some unconscious level.
The book Visual Agnosia by Prof Martha Farah covers a number of curious object perception disorders that occur after brain injury, including simultanagnosia.
The book’s webpage has a table of contents and some sample chapters freely available online.
Link to webpage for Visual Agnosia.
A poem from the book Uncut Confetti by the brilliant John Hegley:
For Therapeutic Purposes
I have not been quite right in the head
Like a balding tyre, I’ve been losing my grip
I have been given various medications
to help me cope
anti-depressants
anti-psychotics
And my brother has given me
a skipping rope.
Hegley’s poems move effortlessly between the comic and the achingly poignant, and often touch upon the more curious aspects of human nature.
The New York Times is reporting that James Watson, co-discover of DNA, will have the whole of his DNA sequence made publicly available, with the exception of one gene known as apolipoprotein E.
Watson doesn’t want to know which version of the gene he has, as it is one of the strongest predictors for the development of Alzheimer’s disease.
In fact, it’s the only gene which has specifically been shown to increase risk for the brain disorder.
The gene for apolipoprotein E, or ApoE as it is more widely known, comes in three main forms or alleles called ApoE ε2, ε3 and ε4.
Studies have consistently shown that the more ApoE Œµ4 alleles you have, the higher the chances of developing Alzheimer’s disease and the younger the age it will begin to take effect.
In fact, having two ApoE Œµ4 alleles virtually guarantees you’ll have Alzheimer’s by the age of 80 and if you do get Alzheimer’s disease, the presence of this allele seems to make it more likely that you’ll experience delusions and psychosis.
The gene codes for the apolipoprotein which combines with fats (such as cholesterol) in the body and transports them to various places, including the liver, where they are broken down.
Alzheimer’s disease is linked to the accumulation of ‘amyloid plaques’ and ‘neurofibrillary tangles’ in the brain, both of which are abnormal clumps of protein.
The presence of the ApoE ε4 allele makes these protein clumps more likely, even in people who have not developed the disorder.
However, the exact link between ApoE and fat processing, protein clumps and Alzheimer’s disease is still not fully understood.
What Watson does understand, however, is that he could work out how likely he is to develop Alzheimer’s disease from the versions of the gene he carries, and it seems he’d rather not live with the knowledge.
This is not an uncommon situation, as people with genetic disorders, or people whose close family have genetic disorders, often have to decide whether they want to know the chances of them or their children developing a potentially life-threatening disease.
Genetic counselling is a service that assists the the person in understanding the risks and possible outcomes based on the science of genetics, as well as dealing with the emotional impact of the sometimes difficult process of discovery and decision-making.
Link to NYT article ‘Genome of DNA Discoverer Is Deciphered’.
The San Francisco Chronicle has an article on neurotech industry consultant Zack Lynch, who you might know from the blog Brain Waves.
Lynch is executive director of the Neurotechnology Industry Organization, an umbrella organisation for the commercial neuroscience sector, and managing director of NeuroInsights, a business intelligence service.
The San Francisco Chronicle article looks at Lynch’s aims and work, in partnership with his wife, neurobiologist Casey Lynch, as well as giving an insight into how the neurotech industry is becoming an increasingly important force in the marketplace and in policy making.
Lynch is an interesting guy to watch. He’ll always pitch for industry, but his job relies on him having a balanced view of what’s likely to work out in the marketplace.
Interestingly, the article also notes he’s written a book on the neurotech industry that’s recently found a publisher:
The first neurotechnology project Lynch took on in 2001, a book titled “Brain Waves,” just landed a publisher. The book allows Lynch to take his favored “200-year view,” speculating on how business, politics and culture will evolve in a future era of neurotech inventions that might change the way people think and communicate. Lynch is fascinated by the ethical and social dilemmas that might emerge. If drugs can enhance memory, for example, would college entrance exams still be fair? “Who’s going to be able to afford this?” Lynch asks.
Link to article ‘Brainstorming about the brain’.
The latest edition of Scientific American Mind has just been published, and as is customary, two of the feature articles are freely available online.
The first is on the psychology of teams and how science is attempting to understand what makes a successful and productive working party.
The article describes effective team learning strategies and how emotions help groups bond during work.
These researchers trained college students to assemble transistor radios either alone or in groups of three. A week later the subjects were tested with their original group or, for people who received solo training, in newly formed groups. Members of groups that had trained together remembered more details, built better-quality radios and showed greater trust in fellow members’ expertise. People in newly formed groups were less likely to have the right mix of skills to complete the task efficiently and knew less about one another’s strengths.
The second article looks at the controversial topic of prescribing psychiatric drugs to children and evidence that the use of psychiatric drugs alters the growing brain.
This is weighed up against the evidence that in children with serious mental illness, an untreated disorder may alter the growing brain.
It’s a difficult topic because it often boils down to picking the lesser of two evils, although, because of lack of research, it’s often not easy to tell which will have the least negative effect for any given child.
It’s a fascinating article on one of the major issues facing psychiatry today.
There are also articles on expertise and the role of mirror neurons in stroke recovery in the full edition, as well as all the regular features.
Link to article ‘The Science of Team Success’.
Link to article ‘Kids on Meds — Trouble Ahead’.
Polymath physician Dr Ray Tallis has written an optimistic article in the latest edition of Philosophy Now magazine arguing that human technological enhancement is over-hyped but no reason for fear.
Tallis is a professor of geriatric medicine, so it’s no surprise that he sees some of the most applicable benefits of technological advances for diseases like Alzheimer’s and Parkinson’s.
Critics have suggested that using technology to enhance human abilities, whether by drugs, implants or genetics, will lead to an erosion of our sense of identity.
Tallis looks back on past promises and argues that this is unlikely to be the case:
The most often repeated claim is that we are on the verge of technological breakthroughs – in genetic engineering, in pharmacotherapy and in the replacement of biological tissues (either by cultured tissues or by electronic prostheses) – which will dramatically transform our sense of what we are and will thereby threaten our humanity. A little bit of history may be all that is necessary to pour cooling water on fevered imaginations.
In 1960, leading computer scientists, headed by the mighty Marvin Minsky, predicted that by 1990 we would have developed computers so smart that they would not even treat us with the respect due to household pets. Our status would be consequently diminished. Anyone seen any of those? Smart drugs that would transform our consciousness have been expected for 50 years, but nothing yet has matched the impact of alcohol, peyote, cocaine, opiates, or amphetamines, which have been round a rather long time.
As well as making some telling philosophical points, the article is quite funny in places, as Tallis uses some of his literary skills to good effect.
Link to Philosophy Now article ‘Enhancing Humanity’.
American TV discussion host Charlie Rose has a series of programmes available online where some of the world’s leading researchers discuss Freud, neurobiology and the latest in psychological treatments for mental illness.
The first programme is a discussion of the legacy of Freud, with neurobiologist Eric Kandel, Freudian psychotherapist Peter Fonagy, inventor of cognitive therapy Aaron Beck and psychiatrist Charlie Roose.
It is a great guide to the differences between Freudian and cognitive approaches to psychotherapy, as well as how it relates to brain function and modern neuroscience.
A second programme looks at a similar topic, but expands the discussion to include cognitive psychological research and also includes psychologists Nancy Kanwisher, Nora Volkow, Rebecca Saxe and Liz Phelps.
Finally, one is a special interview with Eric Kandel, which is guest hosted by fellow Novel Prize winner Harold Varmus, who, incidentally co-founded PLoS – the organisation behind some of the world’s finest open-access science journals.
Quick links from the past week in mind and brain news:
A disquieting feeling of strangeness?: Just found this great 2001 paper on the ‘the art of the mentally ill’ on PubMedCentral.
Brain scan can predict response to antidepressants, reports New Scientist.
Neurophilosophy has an excellent article on famous amnesia case HM.
Pesticides ‘up Parkinson’s risk‘ according to BBC News.
Scientific American reports that Scottish scientists uncover a striking link between genes for brain size and tonality in spoken language.
Developing Intelligence investigates the neuroscience of imagination.
Forbes profile a cognitive scientist. Still no word from Hello magazine.
The rate of diagnosed clinical depression among retired American football players is strongly correlated with the number of concussions they sustained, reports The New York Times.
Pure Pedantry looks at research on storing computer information in biological neurons.
Young children can crudely add and subtract numbers before they have learned the rules of arithmetic, reports Scientific American.
Brain Ethics highlight a new book by the widely liked and respected neuroscientist, Chris Frith.
The BPS Research Digest covers a simple yet fascinating study on the power on lightly touching someone’s arm when trying to persuade them.
In this case, the psychology study involved a man asking women to dance or for their phone numbers.
A good-looking man approached 120 women in a night club over a period of three weeks, and asked them to dance. It was in the name of science – the man was an assistant to the psychologist Nicolas Guegen. Remarkably, of the 60 women who he touched lightly on the arm, 65 per cent agreed to a dance, compared with just 43 per cent of the 60 women who he asked without making any physical contact.
A second study involved three male research assistants approaching 240 women in the street and asking them for their phone numbers. Among those 120 women who the researchers touched lightly on the arm, 19 per cent agreed to share their number, compared with 10 per cent of the women with whom no physical contact was made.
Christian has a fantastic talent for finding really intriguing studies and this is a particularly good example.
Have a look at his article for more on why this effect might occur.
Link to BPSRD on ‘The power of a light touch on the arm’.
An article in Time magazine discusses how an understanding of the psychology of disgust is being applied to selling products and the arrangement of items in supermarkets.
One key finding has been that disgust is heavily linked to ideas of contamination and this holds even when there’s no risk – just the idea is enough.
For example, people are less likely to want to put a plastic spoon in their mouth that has touched fake plastic vomit, despite the fact that it is no more risky than putting a spoon in your mouth that has touched other plastic spoons in the packet.
Psychologists Andrea Morales and Gavan Fitzsimons has discovered that this principle applies to consumer products that are linked to things that can trigger disgust – rubbish bags, nappies, toilet paper and so on.
Crucially, the contamination principal works here, so people view things less favourably that have been near these products.
Strong preferences were just what the subjects exhibited. Any food that touched something perceived to be disgusting became immediately less desirable itself, though all of the products were in their original wrapping. The appeal of the food fell even if the two products were merely close together; an inch seemed to be the critical distance. “It makes no sense if you think about it,” says Fitzsimons. More irrationally still, the subjects were less comfortable with a transparent package than an opaque one, as if it somehow had greater power to leak contamination. Whatever the severity of the taint, the result was predictable…
“More and more stores organize products by category,” says Morales, “so you have a baby aisle, for example, with diapers and wipes and baby food all together.” Supermarkets might want to rethink that arrangement.
Link to Time article ‘The Science of Disgust’.
In a study investigating how the brain generates paranormal experiences and psychotic states, researchers used strong electromagnets to alter brain function and found they could reduce the number of times healthy volunteers saw spontaneously experienced false perceptions.
The researchers altered the function of the temporal lobes with a method called transcranial magnetic stimulation or TMS while participants were asked to detect supposedly ‘hidden’ images in what were actually completely random dot patterns.
When compared to a control area at the top of the head, reducing left temporal lobe function significantly reduced the number of false perceptions.
During the procedure, participants were asked to look at a series of quickly presented dot patterns and told to indicate which had images ‘hidden’ within them.
Crucially, they were told not to guess and only to press a button when they genuinely detected a ‘hidden’ image. In actual fact, all the dot patterns were completely random and none contained ‘hidden’ images, so every ‘detect’ response was a false perception of meaningful information.
Just before each dot pattern was presented, the brain was stimulated with a pulse of TMS, either to the left or right temporal lobe, or a control spot at the top of the head known as the vertex.
TMS uses magnetic pulses to safely ‘switch off’ a small area of brain for a several hundred milliseconds.
When compared to the control area, temporarily ‘switching off’ an area on the left temporal lobe significantly reduced the number of false perceptions, suggesting that this brain area is likely to be involved in making meaningful connections, even when there’s no meaning to be found.
Seeing meaningful information in random data is known as ‘apophenia’ and statistically is known as a false positive or a Type I error.
Previous research has shown that this tendency is known to be enhanced in people who report high levels of paranormal experience, and to a greater extent, in people who experience psychosis – the mental state involving delusions and / or hallucinations that is most commonly linked to schizophrenia.
Other evidence suggests that differences in temporal lobe function are common in people diagnosed with schizophrenia.
The paper is published in the May edition of Cortex, but a pre-print is available at the link below if you don’t have access to the journal.
pdf of full-text paper.
Disclaimer: This study is from my own research group
Neurophilosopher has a great article on a brain scanning study showing that people with synaesthesia have different patterns of brain connections compared to non-synaesthetes.
You read a lot of articles on the brain that use phrases like “wired differently”, suggesting that the connections in the brain are altered.
As the connections in our brain are changing all the time at the dendrite level, often this is just a meaningless way of saying “there’s a difference”.
Perhaps these sort of phrases are best applied to white matter which is the nearest you’ll find to genuine wires in the brain.
White matter fibres run in bundles, they carry electrical signals, and they are insulated by a fatty covering called myelin.
The connections of white matter have been quite hard to study in living people until the development of diffusion tensor imaging (DTI), a brain scanning technology that can specifically pick out the white matter fibres and create maps like the one in the picture.
Rarely when articles talk about “different brain wiring” do they actually mean detectable differences in white matter though.
In the DTI study covered by Neurophilosopher this is exactly what was studied, and it does indeed seem to be different in people who experience synaesthesia, a condition where some of the senses are crossed so, for example, numbers might be also experienced as colours.
DTI is a type of magnetic resonance imaging (fMRI) that measures the diffusion of water molecules. In the brain, water diffuses randomly, but tends to diffuse easier along the axons that are wrapped in myelin, the fatty protein that insulates nerve fibres. Diffusion tensor imaging can therefore be used to infer the size and direction of the bundles (or “fascicles”) of white matter tracts that connect different regions of the brain (above).
The Dutch researchers show that synaesthetes have more connections between the two adjacent areas in the fusiform gyrus than non-synaesthetes. They report their findings in the June issue of Nature Neuroscience.
As well as showing these differences between synaesthetes and non-synaesthetes, the authors also show that there are also differences in connectivity between synaesthetes who differ in the intensity of their sense-mixing experiences.
In other words, the researchers found people with synaesthesia had white matter ‘wiring’ between sensory areas that others don’t have, and that this wiring differed depending on how much synaesthesia the participants experience.
Just from the fantastically straight-forward explanation of DTI imaging given above, you can see that it’s a wonderfully written article.
Have a look at the full piece for more on this fascinating study.
Link to Neurophilospher on ‘Imaging of connectivity in the synaesthetic brain’.
Link to abstract of scientific study.
Mind Hacks 