Archive for July, 2014

Positive attention from fathers is associated with successful development of the frontal lobes.

Monday, July 28th, 2014

Just read this study, published in 2010 by Kosuke Narita and colleagues from Japan’s Gunma University. In it they investigated the relationships between parenting styles and brain development. The authors recruited a sample of young adults, all of whom completed the Parental Bonding Instrument (PBI), a retrospective questionnaire in which adults describe the behavior of their parents toward them up until age 16. (If you’d like to have a look at the PBI to get a feel for what they were measuring, take a look here.) The PBI has two major factors, that is, subsets of items that tend to be endorsed in the same direction by the same people. One of the factors measures “care”, and includes behavior such as smiling, treating the child warmly, and so on. The other factor measures “overprotection”, which really is just like it sounds. Everyone who completed the questionnaire was also scanned in an MRI scanner, which computed the volume of grey matter in a couple of regions of interest, specifically the dorsolateral prefrontal cortex (DLPFC) and some other frontal sites.

What the authors found was quite interesting. First, they found that scores on the paternal “care” factor (i.e., scores reflecting loving treatment by the father) correlated positively with grey matter volume in the left dorsolateral prefrontal cortex (DLPFC), the right ventromedial prefrontal cortex, and the right orbitolateral prefrontal cortex. The left DLPFC is important for concentration, planning, and memory, while the other two sites are involved in emotion regulation. On the contrary, there was a negative correlation between paternal “overprotection” and left DLPFC grey matter, meaning that the more overprotective or smothering the fathers were, the less successfully the left DLPFCs of their children developed. Interestingly, there were no correlations between grey matter volume at any site and maternal care or maternal overprotection, although on some other analyses maternal overprotection was also negatively associated with grey matter volume at the left DLPFC. That is, the amount of maternal care the person experienced was generally unrelated to his subsequent grey matter volume in adulthood.

If these findings can be replicated, it will mean that fathers have a particularly important role in shaping the brain development of their children, influencing not only their cognitive capacity, but also their propensity toward things like anxiety and depression.  The way fathers can bring about the most positive results is by being a steady, warm, loving presence in the lives of their children, but at the same time allowing the children to take risks and explore their world. Mothers’ care, it seems, exerts other, apparently unrelated effects, but mothers also need to be careful not to stifle and overprotect their children if they want their children’s frontal lobes to develop well.

All of this highlights the absolutely vital importance of fathers in children’s lives. Nowadays we tend to think of adult “parental figures” as basically interchangeable units. We assume that as long as there is some well-intentioned adult or combination of adults in the home, it doesn’t matter what sex they are, or if they are biologically related to the children. Indeed, this assumption has underlain unprecedented experimentation with different combinations and permutations of adults in the home in the last generation or two, a marked departure from the way families have been structured everywhere, throughout (nearly) all of human history. The Narita study (and other studies as well, like this one) suggests that all of this social experimentation may be ill-advised. Fathers matter. Mothers matter. Children have a right to be raised by both, and to have their parents love them and accept them, while giving them enough space to allow them to learn to be independent. These are the conditions under which their brains will develop the best.

So. Let me introduce you to my friend LORETA.

Monday, July 21st, 2014

It’s not what you think. Although I do know a really nice woman named Loreta. A colleague from a ways back. But I digress. What I’m talking about is LORETA, with capitals. It’s poised to transform the field of neurofeedback completely.

LORETA stands for Low Resolution Electromagnetic Tomography – I know, the acronym doesn’t really work, but “LORETA” is way nicer than “LRET”. I mean, c’mon, you can’t even pronounce “LRET”. LORETA is what is known mathematically as an “inverse solution”. That is, it’s a means of mathematically reconstructing the source or sources of scalp-recorded EEG patterns, deep within the three-dimensional space inside the skull. That is, inverse solutions aim at identifying where in the brain the stuff is happening that is being picked up as electrical fields on the surface of the head. I’ll explain:

EEG in its raw form looks like this. Each electrode picks up a complex, oscillating signal from the brain tissue underneath it, and the oscillations are plotted across time, like this:

This is the EEG that neurologists read. Now, for the purposes of neurofeedback, we analyse the EEG waves into their component oscillating frequencies and compare the size (amplitude) and scalp distribution of those oscillations to a normative database. For the gentleman depicted here, who is in his thirties, the EEG waves contained an abundance of activity (relative to other people his age) in the range between about 12 and 14 cycles per second, or 12 to 14 Hz. In the database output, that looked like this:

The yellow and orange areas are where, on my client’s scalp, the brain waves at these particular frequencies exceeded the amplitude that is considered normal compared to the EEG of other people his age. Notice how there seems to be something going on in the back half his head, maybe a little more on the right side than the left.

Now, that already provides us with a lot of information—especially given accumulated clinical wisdom that says an overabundance of activity in this frequency range in the back of the head is associated with anxiety (this guy was very anxious). But it doesn’t tell us where exactly in the brain all that 12 to 14 Hz activity is really coming from.

That’s where LORETA comes in. The invention of a neuroscientist at the University of Zurich named Roberto Pascual-Marqui, LORETA is a mathematical solution that estimates—as it turns out with a high degree of accuracy—exactly where, in three dimensions deep within the brain, the source of the activity measured on the scalp is. So, in the case of my client, here’s a depiction of which part of the brain was producing the most deviant of activity at 13 Hz:

The LORETA analysis superimposes the estimated locations of activity onto a standard image of the brain, and allows us to spot the location of the abnormal activity with remarkable accuracy. The images shown here are likes slices made by a big saw (not to be all macabre about it): one horizontal, one vertical along the long axis of the brain (perpendicular to a line drawn between the ears) and one vertical, crossing the long axis of the brain at ninety degrees (parallel to a line drawn between the ears). This three-dimensional “slicing” of the brain is the way all imaging techniques work. It is, in fact, where the word tomography comes from; literally from the ancient Greek, “slice-writing”. Here’s what the same information looks like on an image of a whole, intact brain:

What LORETA allows us to do, then, is to identify with increased spatial accuracy where the patterns of brain activity observable as scalp EEG originate. Rather than looking at a smeared map of activity spread across a wide area of scalp, we can see in three dimensions where that activity actually originates in the brain. From there we can make connections to our knowledge about what locations and networks in the brain are involved in what sorts of functions. In this case, the area producing the most aberrant 13-Hz activity is the right temporoparietal junction (TPJ), which is known to be involved in responding to stimuli that are unexpected, but that have special behavioral importance or salience to the individual. Taking this information, along with the symptoms and complaints with which the individual comes to us, we can identify the structures and networks most likely to be contributing to their problems.

So, LORETA allows us to see with more precision where the sources of scalp-recorded EEG really are in the brain, even if they’re buried quite deep in the cranial vault. Want to know something even cooler? Stay tuned…