• Pregnancy Brain

    Over the past few years I’ve been working with ITV Global. It all started a couple of years back when I was invited to give my Sort Your Brain Out and Neuroscience of Negotiation talks for various members of their senior leadership team, both domestically and worldwide. This year and last the focus shifted to my Science of Creativity talk which I gave for their 100+ leaders across the full breadth of the organisation over the course of six live events. After one of these speaking engagements I was approached by an audience member who’d had a question on her mind since falling pregnant shortly after one of the talks I’d given previously (nothing to do with me!). She had noticed that her usually exceptional memory had gradually eroded as the pregnancy progressed. The burning question was: is the phenomenon of ‘pregnancy brain’ fact or fiction and, more to the point, was there any hope of her getting her previously brilliant memory back again? Had she asked me this question a year earlier I would have had to admit that science hadn’t yet addressed the question properly. As it happens her timing was excellent – a brain imaging study had just been published that might just provide the answer she was hoping for. I promised I’d write a blog about it, so here it is…

    The groundbreaking study by lead author Elseline Hoekzema and colleagues at the Autonomous University of Barcelona and Leiden University was published in the journal Nature Neuroscience. They used Magnetic Resonance Imaging (MRI) to measure the key changes that take place in the female brain as a result of pregnancy. They found that the grey matter consistently shrinks in brain areas commonly associated with social cognition and the greater the degree of volume reduction in these areas, the deeper the mother-child bond. The brain areas in question included in the Superior Temporal Sulcus (STS) and Inferior Frontal Gyrus (IFG) on the outward-facing surface of the left and right hemisphere, and the Precuneus and medial Prefrontal Cortex (mPFC) of the inward-facing surface where left and right hemispheres meet in the middle. Far from reflecting a withering away of brain areas under assault from the tsunami of hormones that regulate gestation (mothers are exposed to progesterone levels over ten times greater than the highest levels of the normal menstrual cycle and more oestrogen during pregnancy than the rest of their lives put together) the changes actually reflect adaptations specialising the brain for maternal attachment.

    Volume reductions were also observed in the hippocampus which could explain the degradation of memory that many women experience during and just after pregnancy. While memory wasn’t rigorously tested (they did a couple of tests but only found a trend towards memory loss) in this particular study, new mothers may take comfort from the observation that while the brain areas involved in social cognition remained two years after completion of the pregnancy, the volume of the left hippocampus had partially recovered (in 11 of the 25 mothers who had not fallen pregnant again). Assuming that the hippocampal volume continues to increase at the same rate, it would fall back into the normal range by around five years after the completion of pregnancy. Given the vital importance of the hippocampus for memory and navigation this seems to be a very promising result.

    This study used MRI to scan the brains of 50 women, of which 25 later fell pregnant for the first time. All were re-scanned after the babies were born, or after a similar period of time had elapsed for those who hadn’t fallen pregnant, so that brain structure could be compared before and after. Those women who did not fall pregnant served as the controls in which no significant structural changes were observed. Changes in brain tissue volume were only observed in those women who did fall pregnant confirming that pregnancy was the likely cause of the changes. They also performed an fMRI study looking for brain areas that were more strongly activated by pictures of each mother’s own baby compared to photos of other people’s babies. As there was considerable overlap between the brain areas more strongly activated by the mother’s own baby and those in which the brain volume reductions occurred, it seems likely that it reflects a process of specialisation for maternal attachment rather than collateral damage.  As these areas are commonly associated with the capacity for Theory of Mind, i.e. the ability to see the world from another’s perspective, these changes presumably reflect a tailoring of the mother’s brain to help them better anticipate the needs of their child.

    In addition to these monthly blogs I regularly tweet (@drjacklewis) interesting articles about recent breakthroughs in brain science and do a fortnightly Geek Chic’s Weird Science podcast on strange and wonderful stories from the world of science. Season 2 of my television series Secrets of the Brain starts on Insight TV later this month… so if you are in the UK or Ireland have Sky television you might consider setting your box to record the series on HD channel 564 and if you are elsewhere in Europe you will find it on other satellite/cable providers (check which channel it’s on in your country here). If it’s not available on your TV you can also stream it online via www.insight.tv

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  • Why Do People Litter? by Dr Jack Lewis

    Parks and open spaces improve health and quality of life by incentivising people to get out and take some exercise, which is extremely good for brain health. Just being within eye shot of some greenery can accelerate healing – so even if you can’t get outside, all you need is a room with a view! If it wasn’t for the armies of parkies and council cleaning staff who clean up after members of the public who routinely leave their litter behind, these green spaces would soon become the last place you would want to spend your spare time. The question is: why do people leave their litter behind for somebody else to clear up in the first place?

    All human behaviours are governed, more-or-less, by the brain’s predictions of reward and punishment. We are subconsciously guided towards actions that maximise rewards whilst minimising punishments. The pleasure pathways of the brain, in particular the nucleus accumbens, are involved in attaching a reward prediction to a certain course of action based on past experience. Drinking water when thirsty or eating food when hungry are examples of behaviours hardwired to produce powerful sensations of pleasure because they help to keep us alive. However the sense of pleasure that people get from putting rubbish in the bin is not innate, like drinking and eating, but instead it must be learned.

    Nonetheless, even in the absence of a sense of reward from putting rubbish in the bin, if littering is consistently punished then that too can steer people away from anti-social and towards pro-social behaviours. Whilst most parents are still apt to discipline their children for littering, which provides valuable experience of the punishments that follow such anti-social behaviour, parents aren’t always around. In the past adults felt at liberty to scold, or even physically punish, any child that they happened to see dropping litter, but in the modern climate of political correctness this has become a thing of the past. Young people no longer learn that punishment reliably follows the act of dropping litter and so their brains do not generate the sense of discomfort, anxiety or unease (generated, if you’re interested, by the anterior insula) that would precede acts of anti-social behaviour that they know through experience is likely to be punished. So in the absence of any negative emotions associated with the act of littering, nor positive emotions associated with the act of putting litter in the bin, rubbish ends up being lobbed around willy nilly, even when a bin is conveniently located just a few steps away.

    DontMessWhen children are brought up with a strong sense of social responsibility then in later life they may get sensations of what might be called “righteous” pleasure from doing the “right thing.” The point is that to get a feeling of satisfaction from performing pro-social behaviours you must have been trained over prolonged periods of time by parents, carers, teachers and/or peers in order to get a kick out of it. If society wants to encourage pro-social behaviours we’ve either got to praise young people more for putting litter in the bin, or make them very uncomfortable when they just drop it for someone else to deal with. Or, take a leaf out of the Texan’s book. They had great success in reducing littering on the highway (after many years of failure with several different approaches) by adopting a campaign that would appeal to young men’s sense of pride and bravado (see left).

    A fascinating study, again from the journal Science (Keizer et al, 2008), indicates that evidence of other people’s antisocial behaviour can make others more likely to be antisocial themselves. This would suggest that the problem with litter goes beyond just rubbish on the streets and in our parks. In one of their experiments they demonstrated that environments in which anti-social behaviour was evident, e.g. litter strewn around on the pavement, graffitti sprayed on the walls or fire crackers set off in the background, not only makes people more likely to litter themselves, but also to commit more serious anti-social behaviours like theft. It seems that people modulate their own behaviour according to cues regarding the degree of anti-social behaviours committed by others. So if you really want to stop other people dropping litter, you might consider reducing the evidence of other people’s anti-social behaviour by picking it up yourself!

    I tweet the latest neuro-breakthroughs, hot off the scientific press on a daily basis (and have been doing so for the past 5 years!) so if you’re keen click here to follow me on Twitter.

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  • Dr Jack Lewis on Body Language (part 1 of 2)

    nonverbalBodyPosture

    Last week I gave a talk on body language for post-graduates at Middlesex University. I promised I’d write up a blog about it as a reference for all those lovely people in the audience who listened so attentively and had so many interesting questions for me afterwards (for 2 hours!). So here’s the gist of the main points…

    The brain produces many thoughts during any interaction.
    Every thought generates a feeling.
    Human feelings are spontaneously expressed in body language.

    Thus it is possible to work backwards along this chain of events in the following way:

    A person’s body language can give you an insight into what they are feeling.
    Knowledge of what a person is feeling can be used to infer their thoughts.
    But only if you have given the P. I. C. process careful consideration:

    • PERSPECTIVES – bear context of each situation in mind: crossed arms = feeling defensive? Or just cold?
    • INCONGRUENCE – when words don’t match the voice &/or body language the words will be discounted
    • CLUSTERS – of body language cues are MUCH more reliable than individual ones

    The key thing to bear in mind when thinking about one’s own body language is to try to avoid postures / gestures that raise the suspicion that you are feeling anxious, guilty, uncertain etc. If you know what other people might be looking out for body language-wise then you can take measures to avoid accidentally giving out the wrong message.

    mehrabian-croppedBody Language Is Born

    In 1971 Prof Albert Mehrabian together with colleagues at UCLA published a paper indicating that when we say a word the meaning of that word only accounts for 7% of the information communicated. Visual signals (body posture, facial expressions, eye contact etc) accounted for a whopping 55% of the message and acoustic signals in the voice (volume, tempo, rhythm etc) accounted for 38%. Amazingly, given how unlikely these figures seem when we first hear them, it seems that this idea has more or less stood the test of time.

    Visual > Auditory > Linguistic – In Communication Signals We Trust (most > least)

    Mehrabian et al’s work indicated that if what is being said somehow doesn’t fit with the rhythm, speed, volume of voice and/or facial expressions, eye movements and body posture displayed by the speaker, we become suspicious of the words and tend to ignore them. So if we wish to communicate clearly then we must take measures to ensure that these are all aligned. It is vitally important to ensure that you do not inadvertently send mixed messages into the outside world that might cause people to be confused by, angered by or distrustful of the words we speak. This is particularly important when making a first impression in a job interview, business meeting or on a date.

    Two Way Street

    SmileMagnifiedWhen we feel happy we smile, when we are sad or angry we frown. Not only do these facial expressions helpfully communicate how we’re feeling to others so that they might use this information to guide their behaviour, it also affects the way we feel ourselves (facial feedback hypothesis).

    If you pull a smiling expression, it might feel fake, but it will send a torrent of sensory messages to the brain about the position of your face.  This, in turn, triggers activity in the emotional pathways to create feelings that match the facial expression. The same thing goes for the negative emotions. If you pull a sad face – with bottom lip protruding as if you’re going to start blubbing – eventually you will start to feel melancholy and thoughts of things you really are sad about will start to flit around in your head. People who have had Botox for cosmetic purposes – to remove frown lines in their forehead (making them physically incapable of frowning) – even leads to increased ratings of happiness!

    The critical point of all this is that it’s a two way street:

    • Emotions spontaneously generated by your brain can automatically induce a facial expression
    • Facial expressions commanded voluntarily by your brain can automatically induce an emotion

    When somebody smiles at you, you will instinctively smile back. That is because in our species a smile indicates that the smiling person in question means no harm – it says: I am friendly, you have nothing to fear. If you think about the two way street of facial expressions / emotions in the context of our innate tendency to mimic the facial expressions of the people around us – when you smile at someone it makes them smile, and their own smiling face makes them feel ever so slightly happier. Never underestimate the power of the smile. Your own happiness can be infectious and people like to spend time around people who make them feel good.

    Part two describes body language evolution, leakage and Dr Jack’s A-H of body language, so please CLICK HERE.

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  • Dr Jack on Body Language (part 2 of 2)

    Springing a Leak

    Although we can voluntarily move our faces around at will, pulling whatever facial expressions we want when called upon to do so, there are other automatic physiological responses generated in the body by emotions that we can’t control.

    eye-contactWe betray our true feelings through body language all the time. When we lie, our awareness that we are doing wrong produces feelings of guilt (in most but not all people), which in turn “leak“ out into the outside world through various aspects of body and voice. Whether we are feeling comfortable or stressed. Whether we are feeling confident or timid. Even aspects of our personality are advertised to our immediate environment through our body language.

    At the same time that we are constantly leaking information into the outside world through body language, information that subtly betrays our true feelings, there are many body positions that we assume and actions that we perform which have nothing to do with our current feelings whatsoever.

    Beware Lone Rangers

    Sometimes we scratch our nose just because it is itchy, and it has nothing to do with whether or not we are lying. Just a spurious coincidence. Sometimes we put our hand to our mouth simply because we’re stifling an unfortunately-timed belch, any apparent relevance to the words just uttered entirely coincidental. The point here is critical – there is lots of noise in the body language signal. The secret to decoding the signals properly is to keep the P.I.C. in mind and never allow a lone indicator to skew your thinking.

    Dr Jack’s A-H of Body Language

    Here’s my A-H of Body Language signals (with guidance for avoiding giving confused signals in parentheses) :

    A – Appendages (uncross arms & legs, plant feet squarely on floor, keep your hands in view / suppress urge to fidget)

    B – Body Posture / Tension (sit up straight, alert, edge of your seat to open diaphragm, breathe deep to reduce stress)

    nod1C – Contact (beware the limp hand shake – grasp palm to palm)

    D – Dress (what you wear speaks volumes about you, invest wisely in a suitable outfit that blends in to the particular work environment)

    E – Eyes (listen with eyes; professional triangle of gaze: eye, forehead, eye; don’t look away too much; not looking = not listening)

    F – Face (pulling a smile = friendliness, frown = hostility; smile to show you are friendly and mean no harm, but don’t over do it!)

    G – Gestures (amplify your words with firm gestures. Get in the Goldilocks Zone: not too much, not too little, but just right)

    H – Head (Active listening involves plenty of eye contact but also nodding [slow→fast] to show you: are following → agree → want to speak)

    Over the next few weeks look for these critical sites of body language in the people around you whilst traveling, in restaurants, pubs, bars, offices, meeting rooms and in your home. The more you study it the more aware you will become of the feelings of the people around you. The more you increase your awareness of how body language betrays true feelings in others, the more you will start noticing yourself betraying your true feelings to others. As your awareness of your own body language and that of others increases you will not only get better at detecting deception in others but you will be able to communicate more effectively yourself by ensuring that the visual, auditory and linguistic components line up so that you come across as confident, competent and trustworthy.

    Origins of Body Language

    The human brain became much, much larger than our primate cousins as we began living in larger and larger groups. And over these many thousands of years certain areas of this expanded brain real estate became specialised to improve our abilities to communicate with each other. We now have brain networks specialised for creating and understanding speech, but also others that discern eye gaze direction and movements, another territory for perceiving faces, yet another involved in registering body parts and even several involved in trying to deduce what a person is really thinking.

    More effective communication would likely have been the foundation for stronger, broader allegiances which in turn enabled pre-human species to enjoy a greater ability to read between the lines. This probably increased likelihood of survival amongst these creatures leaving the less sophisticated communicators in their wake. In this way the human brain would have evolved according to a selection pressure on communication abilities to equip the human race with increasingly sophisticated social skills whilst competitors without the ability to read true intentions from voice and body language perished.

    In addition to these monthly brain blogs you can also follow me on Twitter for daily news about discoveries in neuroscience, psychology and psychiatry…

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  • Social networking, Politics and the Amygdala by Dr Jack Lewis

    The amygdala is a cluster of nuclei deep within the brain’s temporal pole

    If you take a quick peak in most neuroscience textbooks you will most likely be informed that the amygdala is a critical part of the emotion-generating limbic system, that it’s activation makes events more memorable and that it’s primary role is to trigger the fear response. However during the few days between Christmas and New Year I found myself writing two separate #braintweets that described a pair of recent studies that identified a positive correlation between the size of a person’s amygdalae and high-level brain functions that, on the face of it, have nothing to do with fear whatsoever: 1) a larger social network and 2) a conservative political persuation. Here I investigate how these seemingly incompatible findings about the amygdala all fit together. I argue that, tempting as it is to draw the facile conclusion that people with large amygdalae are more fearful in general, which makes them more likely to vote conservative and to nurture a large group of allies to protect themselves , in all likelihood this is probably not the case.

    Why we think the amygdala does fear

    It has been known for several decades that the amygdala, an almond-shaped cluster of highly interconnected brain cell nuclei deep within the inward facing part of the left and right temporal lobes, are very important in the generation of fear. Ever since fairly barbaric surgical procedures carried out in the 1930’s to see what happens when the temporal poles were removed (including the amygdalae) the most obvious consequence was that the animals lost their fear of the human experimenters. They also over-reacted to all stimuli, showed an increased propensity to exploring objects with their mouths, and became hypersexual, as well as becoming incapable of producing the standard usual responses to danger, such as freezing, increased heart rate, hair standing on end etc, that usually occur in response to an overpowering and unexpected occurance such as a loud bang.

    Since then many brain imaging studies have gone on to demonstrate that the amygdala is also highly responsive to fearful facial expressions (Sato et al, 2010, for a recently published example). Presumably this is because if another human is scared, it is advantageous for us to also generate feelings of fear, thus encourage behaviours that might also help us to evade the fearsome agent. Interestingly the neural mechanisms involved in making you feel scared when you lay eyes on the face of a petrified individual implies a multi-step process that includes: 1) accurately identification the emotion that they are experiencing AND then 2) generating this emotion in your own mind. This quite possibly invokes the dual phenomena of expression mimickry and the facial feedback hypothesis: we all have a curious tendency to copy the facial expressions of the people around us and the proprioceptive detection of this facial expression is thought to then trigger the feelings and potentially life-saving behaviours associated with fear. A similar sequence of mechanisms is involved when you see a smiling face – you tend to smile yourself and the smile makes you feel happy.

    Beyond fear – what else does the amygdala do?

    An fMRI experiment I did during my PhD studies investigated which human brain areas were sensitive to the relative synchrony between visual and auditory stimuli. Despite there being nothing particularly emotional (and certainly not fearsome) about a pair of visual stimuli that each rotated synchronously with a different characteristic sound, to my surprise I discovered that this multisensory synchrony produced strong activation of the amygdala (unpublished observation). Reading deeper into the  amygdala literature I soon discovered that far from being a single functional unit it is in fact a cluster of several different brain nuclei, each highly interconnected with a different groups of brain regions and also highly interconnected with each other. Meta-analyses of many different brain imaging studies revealed that the amygdala is activated in response to faces displaying a whole range of different emotions including positive emotions and not just negative emotions such as fear (Phan et al., 2002).

    A recent publication has demonstrated a positive correlation between the size and complexity of a person’s social network and the size of their amygdalae (Bickart et al, 2010). The suggested explanation for this correlation is that “a larger amygdala might enable us to more effectively identify, learn about and recognize socioemotional cues”. No suggestion that, of the 58 people whose brains were scanned in this study, those with the larger amygdala were the biggest scaredy cats. The question of which of them were the most timid simply wasn’t asked.

    Geraint Rees, Director of UCL’s Institute of Cognitive Neuroscience, speaking on a recent BBC radio show, described an experiment due to be published next year (assuming it passes the peer-review process) that observed a positive correlation between amygdalar volume and conservative political views. This would be a step forward from a recently published paper that indicated increased activation of the amygdala when politically-interested participants read statements that agreed with their own political views  (Gozzi et al, 2010).

    It is difficult to see how the results of all these different studies might fit together in terms of a universal theory of amygdala function but the most parsimonious explanation is that different amygdalar nuclei each fulfil different functional roles. Some nuclei directly influence the hypothalamus to orchestrate the increased heart rate, breathing rate and freezing behaviour characteristic of the fear response. Other nuclei well connected with visual and auditory brain areas may direct attention to multisensory phenomena that change simultaneously. And yet further subdivisions of this complex brain structure may be involved in learning and using the critical social cues that help us to form allegiances with other humans, both on a personal and political level.

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