Looking inside the baby brain

This week, the little one and I were back at Birkbeck Baby Lab to take part in some more experiments. I’ve volunteered us to be part of the control group for the Studying Autism and ADHD Risk in Siblings project, which aims to track the early development of baby brothers and sisters of children with autism spectrum disorders, attention deficit disorders and typical development.

Because it’s a really ambitious, long-term project investigating loads of different factors to do with communication, behaviour and emotion, the researchers have drawn together a whole range of ways to try to get an insight into babies’ brains. Before the visit, I was asked to complete a bunch of questionnaires about my son’s behaviour, preferences and sleep patterns then on the day he was kitted up with some movement and heart rate monitors and recorded playing with various toys and watching short animation sequences (who says television isn’t educational?). During one of these animation sessions, my infant scientist was kitted up with a near infra-red spectroscopy (NIRS) cap.

baby wearing NIRS cap
“I’ll just put on my thinking cap”

This was cool for three reasons. Firstly, it makes my baby look like a cute alien.  Secondly, the first ever infant study using this technique was pioneered by researchers at Birkbeck, so it’s kind of like eating a pizza in Italy. Thirdly, and most importantly, it’s a very clever piece of kit that gives us new insights into what’s happening inside an infant’s brain when they’re engaging with a task – in this case processing emotional and neutral sounds and images.

There are of course lots of other, more well-known ways to measure brain activity. One approach is to measure neuronal signals directly using electroencephalography (EEG). Unfortunately EEG sensors are great at telling us when a signal occurs, but decidedly vague about where. Alternatively, since we know that when a neuron is active it uses up more oxygen and glucose, we can use positron emission tomography (PET) to track where oxygen and/or glucose is being absorbed, and deduce from that the areas that are hardest at work. Unfortunately, PET relies on the use of radioisotopes and overprotective parents like me aren’t so keen on their precious offspring being injected with radioactive substances when not strictly necessary. Alternatively, blood flow can be monitored non-invasively with functional magnetic resonance imaging (fMRI), as long as the participant is completely still whilst completing the relevant task…not something babies are so good at. This leaves us with NIRS.

Anyone who has ever shone a torch against their skin knows that flesh and blood is fairly transparent to light. It turns out that the quality of this light (i.e. the proportions of different wavelengths) varies according to the levels of oxygenation of the blood – so if we record the changes in the light signal at different points around the head, we can deduce which areas are most active. The light will only penetrate the outer layer of the brain, the cortex, but it just so happens that the cortex is involved in all kinds of different activities. So far NIRS-based techniques have been used to identify the specific areas of the infant cortex involved in observing and producing motion, language processing and emotion recognition .

The technology isn’t perfect yet – for instance researchers are still grappling with how to deal with hair, which not only reduces the grip of the headgear but can affect the way light penetrates the scull, leading to unreliable measurements. Nevertheless, if it means we can build up an image of what’s going on inside babies’ brains without immobilizing or irradiating them, then a bias towards bald baby scientists like mine may be a compromise worth making.


Learning time

Baby wearing motion sensors on chest and legs
“I bet Albert Einstein didn’t have to put up with these indignities”

One of the fun things about being a mother interested in psychology is you can enlist your unsuspecting baby into experiments investigating infant cognition, and tell yourself you’re not only contributing to science, but also giving them a new learning experience. Consequently, last week I took my four-month old to the Birkbeck Baby Lab to take part in a study exploring how infants perceive time. Obviously, not being a big talker yet, the researchers needed to find some other way to work out what’s going on my little genius’s brain, so they distributed some sensors around his limbs to pick up muscle twitches, and stuck on a few motion capture pads (the kind worn by actors to get realistic movement in cgi films) for good measure.

Once in the ‘lab’ (a darkened room) the researcher sat in front of my son, said “Ready…go” and after each “go” gently lifted his hands. On the eighth repetition she said “Ready…” but didn’t lift and the sensors detected whether his muscles twitched in anticipation after the same interval as previous lifts – thus indicating that he has a sense of time.

The study is in too early stages to draw any conclusions (other than that my son gets a bit cross if you say “Ready…go” to him too many times) but a previous version of the study, using a videoed version of peek-a-boo in which a teddy bear pops up from behind a screen seven times in a row found that on the eighth time babies’ pupils got wider (indicating surprise) at exactly the moment the bear was supposed to reappear.

What did I learn from this? Firstly, that even young babies have a good sense of time (you only need to watch my son when I sit down on the sofa ready to feed him to know that he’s capable of forming expectations, but it’s interesting to find out just how precise those expectations are). Secondly, that researchers are always looking for innovative ways to test hypotheses: keep an eye on the latest technologies from the movie industry for an idea of what they might come up with next.


In further praise of praise

Last month I blogged about lab-based research showing the benefits of product and process praise over person praise. This week the Journal of Child Development has published a study looking at the relationship between how parents praised their children between the ages two and three, and the same children’s attitudes to success and failure five years later. No prizes for guessing that they found children who were given more process praise as toddlers were most likely to believe as seven-year-olds that people can change (i.e. someone who is naughty once, isn’t necessarily going to misbehave tomorrow) and that difficult tasks provide opportunities to learn.

What was particularly interesting though was that the study looked at what parents actually say rather than what researchers think they ‘should’ say. In my last post I gave an example of process praise as ‘you concentrated really hard’ yet every time I’ve tried to give my toddler a similar comment its felt really contrived and I’ve been half expecting him to retort “stop being so patronising mummy” (he really is a genius you know). In this study, the authors noted that they don’t recall hearing a single utterance like that – instead the process praise utterances they noted were phrases like “good job” or “good running.” Which just goes to show you don’t have to sound like a text book to motivate a toddler.


Clingy baby, clever baby

Right now, my fourteen week old is a big bundle of sunshine. Aside from the odd screaming fit caused by trapped wind, and grouchiness if we don’t put him down for a nap at just the right time, he seems pretty happy with whatever comes his way. However, having been through it once before I know not to get too complacent and that before the month’s out he’s likely to turn into Velcro baby again – yelling in outrage whenever I try to put him down.

First time round I can remember one particularly low week where nothing I did seemed good enough, my son would only sleep with me rocking him, and I was reduced to a sobbing mess contemplating how I could ever get some semblance of a life back if the damn baby wouldn’t give me five minutes peace.  Then someone recommended the book The Wonder Weeks to me, which outlines the 10 great “fussy phases” that all babies go through during their first 20 months. My project manager brain was delighted – suddenly here was a schedule. Albeit not one that I could control, but at least offering some guide to when I might expect a reprieve.

This time round I was prepared. I enlisted extra support for when the new five-week-old refused to settle at night. I shrugged off the eight-week-old grouchiness as ‘just a phase’, and when he screamed down the house at twelve weeks I was almost proud that he was right on schedule. But lately I’ve started wondering if it’s a self-fulfilling prophecy. Now that I know when a fussy phase is due, perhaps I’ve been less motivated to pull out all the stops to soothe him, and consequently he validates my expectations by complaining in the only way he knows how.

A frustrated mother monkey turns to a parenting manual for the answers
A frustrated mother monkey turns to a parenting manual for the answers

So I’ve been doing a little research and have found plenty of evidence that these fussy phases really are universal. For a start, similar patterns have been found in monkeys – who are not known for over reliance on parenting manuals. Horwich noticed way back in 1974 that infant monkeys temporarily increase the amount they suckle on their mothers at similar periods in their development. He concluded that normal behavioural development is a series of stages of progressive growth followed by regressive periods.

Rijt-Plooij and Plooij (who went on to write The Wonder Weeks) found similar patterns with chimpanzees before moving on to humans, where they found a common consensus on the ages when mothers experienced their infants as ‘difficult’. These difficult periods were mainly characterized by an increase in crying and a decrease in independence and amount of sleep. Their observations (of Dutch families) have since been replicated by other researchers in Spain, Britain and Sweden, with one study indicating that regression periods also coincide with peaks in illness and sudden infant death (SID).

So, what’s going on? The clue appears to be in what happens soon after the fussy period. Each phase is swiftly followed by a transition period of development where the baby can be observed mastering new skills or seeming to achieve new levels of understanding – ranging from the first social smile at 6 weeks, beginning to make vocalisations and join in ‘proto-conversations’ at 9 weeks, to the use of yes/no and the beginning of symbolic play at 55 weeks.

No one is quite sure yet just why these milestones are preceded by fussiness but Plooij and others suggest that it may be because an increased awareness of the world puts stress on the infant. Alternatively, attachment theorists suggest that the increased parental attention instigated by fussiness is essential for encouraging the baby to seek new forms of knowledge. Either way, the next time my baby is clingy I’ll take comfort in the fact that its one more step in the development of his amazing baby brain.


Connected via the funny bone

Baby smiling
The elusive baby smile

Every parent knows that the first true smile (by which we mean one that isn’t directly followed by a fart) is a huge milestone in their relationship with their child. For me the first smiles were a sign that I was more than just a source of milk for my babies – an indication that we had a special bond. And it turns out that swapping smiles may be an important part of developing secure attachments.

Researchers have recently found that trait humour (how often a baby smiles/laughs in different situations, according to their parent) predicted attachment security at six months… but in the opposite direction to that expected: 6-month-olds who scored lower in ‘good humour’ scored higher as 12-month-olds on attachment security. The researchers suggest that this may be because parents will work as hard as necessary to make their babies smile, so if the baby isn’t a natural grinner it means the parent has to put in more emotional legwork to get them to crack a smile.

A study by Sostek and Anders back in 1977 found a similar relationship between infant temperament and cognitive ability, with the explanation being that parents talk more to infants of difficult temperament in an effort to cheer them up, which has a side effect of boosting their cognitive skills.

Whilst the trait humour researchers admit that their sample was comprised of parents who self-selected into a study on the emotional development of their babies and were therefore more likely to be invested in developing a secure attachment with their child, it does give me pause for thought. My older (genius) son, who was more of a looker/thinker than a smiler has always been incredibly cuddly and reluctant to leave his mummy. So far, at 12 weeks, his younger brother seems a lot more quick to smile, and also happier to kick about by himself for small stretches of time. If I’m to give him a chance to be as securely attached and clever as his big brother, perhaps I need to crack open that joke book again.


In (partial) praise of praise

I’ve previously blogged about the negative effects of rewards on inherent positive behaviours, but is it possible that some kinds of praise could also be damaging?

Certainly many educators believe in the phrase ‘praise the deed and not the doer’. This philosophy seems to be based largely on the work of Mueller & Dweck, which demonstrated that praise for intelligence had more negative consequences for 10-11 year-olds’ achievement motivation than praise for effort. After failure, children previously praised for intelligence displayed less task persistence, less task enjoyment, more low-ability attributions, and worse task performance than children praised for effort.

Its suggested that such ‘person praise’ fosters a detrimental sense of contingent self-worth; praising children for their personal attributes rather than specific aspects of their performance may teach them that they’re only as good as their last performance: all very well whilst they’re successful, but when they do experience failure they may come to believe that they are incompetent, bad, or unworthy. My personal experience seems to support this. I can vividly remember the pressure that came with being told by teachers I was clever, and the lingering worry that if I wasn’t able to maintain high grades I’d be letting my teachers down.

Children given product or process praise spent almost twice as long subsequently engaging with puzzles as those given person praise
Amount of time 4-5 year olds (girls and boys) spent with puzzles during subsequent classroom observation, by feedback condition

But perhaps that’s because I’m a girl. Henderlong Corpus and Lepper investigated the role of age and gender in the effect of three different types of praise: person (‘you’re such a great artist’); product (‘what a lovely picture’); and process (‘you concentrated really hard’). They asked children aged 4-5 and 9-11 to complete puzzles of varying difficulties and found that while all types of praise had beneficial effects on motivation for the younger children, process and product praise had particularly beneficial effects. Meanwhile, the older girls showed enhanced intrinsic motivation when given product and process praise, but dampened motivation when given person praise. There were few effects of praise on subsequent motivation for older boys.

The researchers aren’t sure why this should be the case, but suggest that maybe girls become socialised to focus more on dependence and interpersonal relationships than boys, leading them to rely more on external evaluations for feelings of self-worth. Since I’m the mother of two sons, it would seem then that I can get away with praising frequently and generically (aside from the risk of sounding like an overly smug parent in the playground). However, just to be on the safe side, I’ll try to stick to product and process praise… after all, they might turn out like their mother, and I wouldn’t want them thinking that’s a bad thing.


The risk of rewards

My partner and I have been thinking recently about our approach to encouraging good behaviour in our toddler. Fortunately, he seems to have a naturally gentle and easygoing disposition but, like most two year olds he’s beginning to test boundaries and assert his own opinions. We decided early on that we’d avoid punishment wherever possible, opting instead for modelling and encouragement to reinforce positive behaviours. So far we’ve been relying on praise, plus giving him stickers for successful toilet visits (that’s another story…), but are more material rewards ever appropriate?

One of my favourite parenting sites Aha parenting argues that rewarding a child for a behaviour implicitly communicates that the behaviour must be unpleasant and that it’s more effective in the long term to point out the inherent rewards of the activity itself (you shared your toys…  that makes your friend happy – that kind of thing). A little digging reveals this does seem to be backed up by research: 

Researchers at the Max Planck Institute found that giving 20 month olds a toy when they helped the experimenter reach something they’d dropped actually decreased this spontaneous helping behaviour over time, compared with when the toddlers were given social praise or no reward at all. They conclude that extrinsic rewards can actually undermine inherent positive behaviours such as altruistic tendencies.

A young girl drawing
Drawing is its own reward for most
pre-schoolers… until you reward them.
© Evan Long via Flickr

This so-called overjustification principle also seems to apply to inherent interest: Lepper, Greene and Nisbett divided 3- to 5-year-olds observed to enjoy drawing into three groups. The first group were asked to do a drawing to receive a reward (a certificate), the second group were surprised with the reward at the end, whilst the third group neither expected or received the award. A couple of weeks later the same children were engaged in another drawing activity and the children in the expected reward group were observed to show significantly less interest in drawing, and to produce drawings of lower quality.

I was pretty convinced by this, and excitedly explained to my partner why I thought we should keep rewards to a minimum for now. His response? “So, when he’s 14 and we can’t keep him off his game console, we just need to offer him a tenner each time he plays?”

Anyone with a teenager want to volunteer for that bit of research?


Iodine and the baby brain

A new study published in the Lancet has found low maternal iodine levels during early pregnancy to be linked to poor cognitive outcomes in their children. Being in my final weeks of pregnancy at the moment, my first reaction to this study was to panic wonder whether I was likely to have low iodine levels and if so if it’s too late to do anything about it.

Plate of seafood
Seafood is a natural source of iodine
© Edgeplot via Flickr

As a non-fish eating vegetarian it would seem at first that my diet puts me firmly in the at risk category, although this may have been mitigated by the ridiculous amounts of chocolate milkshake and bowls of cereal I consumed in my first trimester, since milk is apparently another key source of iodine. Even more reassuring was the fact that the (mainstream pregnancy) supplements I’ve been taking since planning the pregnancy contain 90% of the European RDA for iodine… so perhaps this study isn’t the radical insight into nutritional requirements it first seems to be.

Personal agenda dealt with, I could then look closer at the study. Overall, it was impressive in its control of potential confounders, ranging from maternal age and education to stressful life-events scores and ethnicity. However, it ignored the educational background of the children themselves – which seems remiss in a study using reading ability as a measure of cognitive function. Is it not possible that the children found to have poor reading ability at age nine were exposed to poor teaching, or had a disrupted educational experience for reasons outside the controlled-for socio-economic factors? The researchers do acknowledge that there may have been residual confounding by non-considered factors but argue that adjustment for the 21 variables they did consider made little difference to overall effect sizes – seemingly ignoring the possibility that the factors they missed may have been more important.

More worrying is the fact that cognitive development is equated so simplistically with just two measures: IQ at age eight years and reading at age nine. Not only is IQ a contested measure of cognitive ability but reading age is an even cruder measure – ignoring important factors such as memory, awareness, problem-solving, motor skills and analytical abilities.

The researchers (and the mainstream press) conclude that maternal iodine deficiency in pregnancy might have been overlooked as a preventable cause of developmental delay in UK children. Whilst I support their relatively restrained recommendations that more research is conducted and that in the meantime pregnant women should consider ways to safely achieve the World Heath Organisation’s recommended intake for pregnant women of 250mcg of iodine per day (without resorting to seaweed or kelp supplements which can provide excessive quantities of iodine, that may in turn be damaging), I’d challenge the idea that one aspect of nutrition, which correlates with one or two limited measures of cognition, can be a ‘cause’ of developmental delay. I have just poured myself another glass of milk though…


The myth of baby brain

For my first pregnancy I was working full time in a fairly stressful, fairly senior role. I was determined that my expanding belly wouldn’t affect my job, yet the closer I got to my due date, the more colleagues started jokingly talking about ‘baby brain’. Perhaps I was paranoid, but it seemed as if any momentary lapse in memory or concentration was automatically added to the evidence pile that I was losing touch. Coupled with numerous variations of the phrase “of course, you don’t care – you’ll be knee deep in nappies by the time this comes into effect” such comments seemed like an unfair way of diminishing my input into any serious conversation. But, unpalatable as they were, were they truly unjustified?

Tests of delayed recall showed no significant differences in cognitive change from Waves 1 to 2 between those who were pregnant and those who were not.
Tests of delayed recall showed no significant differences in cognitive change at each test point between those who were pregnant and those who were not.

A systematic review of 14 recent studies into women’s performance on memory tasks found that pregnant women and new mothers are significantly impaired on some specific aspects of memory, such as processing of working memory. However, researchers at The  Australian National University noticed that most of these studies used small, unrepresentative samples, and none examined data on participants’ cognitive performance prior to pregnancy. They aimed to rectify this by using a huge sample of over 1000 women in their early twenties, and testing them at three four-year intervals, thereby capturing large numbers (70+) of women at each phase who were pregnant or new mothers. At each phase they tested the participants in cognitive speed, working memory, delayed recall and immediate recall and found no significant differences in performance for those who were pregnant or new mums. But if pregnancy really doesn’t affect cognitive ability, why are so many people (mothers included) convinced ‘baby brain’ exists? Lead researcher Helen Christensen told the BBC: “Part of the problem is that pregnancy manuals tell women they are likely to experience memory and concentration problems – so women and their partners are primed to attribute any memory lapse to the ‘hard to miss’ physical sign of pregnancy.” And memory lapses do occur of course. Certainly, in my second pregnancy I did seem more forgetful, whilst my already poor sense of direction became so atrocious I repeatedly lost my way to places that I’d been to twenty times before. But then I realised that pregnancy insomnia, coupled with a teething toddler, was meaning I was averaging about five hours sleep per night. A few more daytime naps and the ‘baby brain’ was miraculously cured. I still get lost on the way to the doctors though.