When you smile, the world smiles with you?

I hear this statistic a lot: "scientists have found that ___% of communication is non-verbal.", with the blank being filled in with a number anywhere from 55 to 95.  So, what is it?  Is non-verbal communication all important (as the 95% number would suggest) or is it somewhat important but we can make up for it through other channels of understanding (as 55% would suggest)? 

As I was looking into this, I found this article that has sparked my interest- Flow of affective information between communicating brains.  Let's discuss, shall we? 

Humans evolved as a social species.  Communication, through both verbal and non-verbal channels has been an important driver for increasing brain size in humans.  In fact, the development of proto-language is thought to have ramped up brain size in human ancestors from 750,000 to 50,000 years ago, with a huge jump in brain size at the 50,000 year mark.  Proto-language is the combination of gestures and one to two words that can be interpreted by others to create action (things like "look there" and "let's go").  But, the key here is to understand the vocalization and the action- the "receiver" must know how to interpret the signals coming from the speaker.  This reception cabability requires us to interpret not just the meaning of the words that are spoken, but the context in which they are presented.  If I say "let's go" and smile, you get a much different meaning than if I say "let's go" and frown.

Here's where things get really cool (and complicated).  When I smile, a series of neurons become active within my brain associated with smiling- both the motor neurons involved in the action of smiling, and the emotional neurons involved in feeling happiness.  When you see me smile, your neural network associated with smiling becomes activated as well through what is called "mirror activation".  This happens because, in your attempt to interpret my emotions, you need to feel those same emotions.  Furthermore, not only are you trying to interpret my emotions, but you're also trying to predict my future actions, and the best way to predict another's actions is to actually feel what they're feeling.  The old saying about "walking a mile in someone else's shoes" really rings true. 

How do we know all of this?  The study above is a really great place to start.  These researchers looked at brain activation in six different couples who had been involved in romantic relationships for at least a year.  The reason they did this with romantically linked couples is because the flow of affective (emotional) information is stronger between couples who are romantically linked than it is between strangers (thoughts on this in just a little bit).  While one partner, the sender, was asked to think about differrent emotions and "emerse in them" (basically not to pose emotions, but recall true emotional states and allow the facial expressions to follow), the other partner, the perceiver, was asked to look at the emotions (by recording) and interpret the emotions felt by the sender.  Both individuals were scanned using fMRI durring their assigned task.  The fMRI scans of the senders were then analysed for emotion-related activity and the perceiver's scans were analysed for activity that reflected the emotion-related activity of the sender.  In addition to looking for reflective activity, the researchers also analysed the scans to discover the time course of the flow of information from the sender's brain to the perceiver's brain. 

What the researchers found was that the emotional state of the sender could be predicted simply by looking at the activity in the perceiver's brain.  More specifically, activity in the parietal, temporal, frontal and insular brain regions specifically reflected the emotional network used by the sender to convey affect.  An even more amazing finding was that early emotional information from the sender was also reflected in the perceiver.  On top of that, there was a time delay at the onset of emotion from the sender to the perceiver (up to 8s.) that reduced with viewing time (down to 0s.).

Ok, so what does all of this mean?  We already "knew" that non-verbal communication is an important part of communication as a whole.  Now we see that, as someone perceives communication they interpret the information with a network of brain structures and that perception evolves over time as the emotion is communicated.  Now, this study did use couples who were romantically linked for a year to four years (the average was two years).  So, granted, these individuals were probably a little more "in tune" with one another than people who are strangers, and many might see this as a fault of the study, but think about it this way- who is the most important person to understand emotionally?  If you can't interpret how your sexual partner is feeling, you're probably not getting any, right?  When we think about how language (specifically proto-language) developed, it wasn't about communicating how to perform technical skills (i.e. hunting, tool making, etc.), our closest evolutionary relatives can do that without language.  Language is about relating to the social group- communicating "who did what to whom" is an important part of social and sexual selection- so of course our neural networks would become tuned to those people who we deem "most important".  A couple of interesting follow-ups for this experiment would be to see how people react to someone they find attractive, but not someone that they have any emotional relationship with, or how people perceive famous actors/actresses as they perform emotions (although, this would require brain scans of the actors/actresses as well...). 

All of this information is great, but really, the most important part of any piece of information is how you use it.  While strangers may perceive your emotions somewhat differently than people you know, strong emotions still cause activation in neural networks of the perceiver.  This is vitally important for people who want to communicate information to another and "have their point heard".  Maybe you're interviewing for a job or presenting information in front of a group of people- this study simply reminds us that HOW we communicate is just as important (if not more important) as WHAT we communicate. 

What is the deal with drummers?

Granted, John Bonham is one of the greatest drummers of all time, but watching any drummer really just amazes me.  Even in the first minute of that performance, John Bonham manages to generate different rhythms with each of his limbs- and he's just getting started there!  My question is, how the hell do they do that?  I've always held a theory that maybe drummers are wired differently- that they are somehow able to disconnect the right and left sides of their brains so that the motor signals don't interfere with one another.  But it's more than just that...take a look at this performance, not only does he have to generate different movements with each of his limbs, each movement with it's own timing and coordination pattern, but he's also got to do that while processing the sensory feedback coming from the drum kit (at some level- maybe it's not conscious processing???).  Ok so I found an article this week that MAY help with this question, I'm not saying that it will answer it completely, but maybe I'll have a clue as to why drummers are motor control freaks.

This article was published last year in PLoS One- Excitability of the Motor Cortex Ipsilateral to the Moving Body Side Depends on Spatio-Temporal Task Complexity and Hemispheric Specialization.  Long title, but here's the rundown of what they did.  The subjects in the study were asked to either rest, move their hand (wrist extension/flexion), foot (ankle dorsi/plantar flexion) or both hand and foot at the same time.  When they were asked to move the hand and foot at the same time, they were either required to move in-phase (i.e. wrist flexion and plantar flexion at the same time) or anti-phase (i.e. wrist extension and plantar flexion at the same time).  The researchers measured the activity of the extensors and flexors on both the moving side and the non-moving side- subjects were told to restrict movement to JUST the side that they were asked (i.e. left or right).  So, while the researchers were monitoring the EMG activity of the non-moving side to make sure there wasn't any muscle activation, they were also monitoring the activity on the side of the brain that controls the non-moving side. 

Here's where things get interesting...the results were that there is a significant facilitation effect on the motor cortex for the non-moving side when a complex coordination pattern is used (i.e. hand and foot moving anti-phase). WHAT??? Ok, back it up...basically what they found was that it's harder to keep the non-moving side still when doing a complex movement pattern.  Hmmm, back to the drummer, maybe what's really happening is that they're using this to their advantage and cross patterning movements so that they're getting the maximum subconscious "help" from their brain.  Most people that I've spoken to about this say that as soon as they start thinking about what they're doing on the drum kit, that's when they loose the rhythm.  So conscious processing interferes with the natural facilitation of movement that occurs due to the complexity of the movement pattern.  Rather than disconnection between the two sides of the brain, there's actually a huge amount of cross communication going on and it is exactly that communication that helps them to do what they do!    

On the road to understanding autism (part 3)

This week I'll be taking a look at the chemicals associated with Autism Spectrum Disorder and summing up the article that I've been reading over the past three weeks (if you missed it the first two times, here's the link again!).  Let's jump right in to the discussion of neurochemicals...

One of the great things about looking at neurochemicals and autism is that here we have a real and true theory for what's occuring in ASD- the excitation/inhibition theory postulates that there is a lack of both local inhibition and long distance excitation in the developing brain that leads to the expression of autism.  Based on what we've already seen from exploring the overproduction of gray and white matter, the lack of minicolumnar structures and the changes in the different areas of the brain, this theory makes sense, but it's the underlying chemistry that really pulls everything together here.

The first area that researchers are really concentrating on are the glutamate/GABA chemical pathways.  Glutamate is the most abundant excitatory neurotransmitter in the body while GABA is used for inhibitory connections.  Glutamate is intricately involved in learning and memory through long term potentiation (which is a fancy way of saying that it helps with the "experience dependent plasticity" that I've been talking about for the past two weeks).  In patients with ASD, we see higher than normal concentrations of glutamate production, and decreased GABA receptors.  This partially explains why we see a lack of experience dependent plasticity in the brains of children with ASD.  If there is an abundance of glutamate in the system, then we will see a pattern of local excitation (going back to the excitation/inhibition theory), the local excitation will result in more synapses being upregulated in certain areas, while long distance connections are decreased or inhibited (because the connections in the minicolumns are disorganized due to the excess white matter).  All of this results in local circuits that are highly active and excitable (think repetative behaviors), and disconnection between areas that would normally overrule and inhibit local excitation (executive function of the frontal lobe).  

In addition to glutamate/GABA differences, researchers have also found that about 1/3 of patients diagnosed with ASD have increased levels of serotonin.  In normal development, the amount of serotonin in the system decreases as a child ages, but serotonin levels seem to be independent of age in the patients with ASD who demonstrate high serotonin levels.  Researchers have found that high serotonin levels have an effect on language learning, self-injuring behaviors, and IQ scores, but there has been no direct correlation demonstrated between amount of serotonin and degree of ASD symptoms.

One of the most interesting findings in the neurochemical arena comes not from the patients diagnosed with ASD, but from their families.  Parents and siblings of children diagnosed with ASD also demonstrate higher than normal glutamate and serotonin levels.  This truly shows how complex ASD is, "The Problem" cannot be simply described by looking at neurochemicals, genes, gray matter, white matter, or neuroanatomy.  In order to help people diagnosed with ASD we need to take a wholistic view and understand that it is the interaction of all these factors which result in the expression of ASD symptoms.  In order to effectively treat these symptoms, we need to understand the interaction and address the symptoms from their root cause.  Through exercises (both physical and mental) that directly challenge the functions of frontal and parietal lobes, the amygdala, the anterior cingulate, and the fusiform gyrus we may start to see progress in treating ASD.  Through activation of these areas, I would expect to see experience dependent modification of the gray and white matter both in the areas that are challenged, and those that used to be over active but recieve less stimulation due to the specificity of the challenge presented.  Perhaps the overproduction of glutamate and serotonin cannot be changed, but their effects on the system can be modified through the repetition of the challening stimulus.  In other words, we need to create an "artificially challenging" environment that supports experience dependent plasticity that will override the genetic and structural adaptations that the child with ASD has had in response to his "normal" environment.  THAT BEING SAID, I want to make it clear that I'm not saying that the parents are to blame for a child developing ASD, and I'm not saying that "The Problem" is purely genetic either- the "normal" environment that most kids grow up with is simply not enough, or the right, stimulation to override the natural tendencies of these particular children to develop ASD symptoms. 

Moral of the story...a combination of nature and nurture causes ASD to be expressed and a combination of nature and nurture can help these kids to lead a "normal" life.