The Stimulating World We Live In

I can recall being in the classrooms of my youth in the Midwest. During the winter, the only things to keep the school warm were large furnaces in each room.  These were truly large and obnoxious things.  The furnaces, covered in tin, had internal fans that created a horrendous buzzing that elevated the noise of the room twofold.  An odd thing happens when you sit around these things for hours at a time though; you forget they are even there.  In fact, often the only time I would find them irritating is after they cycled off.  The new-found silence that fell upon the classroom was so dramatic that I often found myself shifting my attention away from the lesson and onto the emptiness that now filled my ears. That is to say that I often found the absence of the sound more distracting than the sound itself.

Where Has All The Stimulus Gone?

Surely you have been in a loud room, party, or restaurant where you were able to focus on the conversation you were having with the person in front of you while ignoring all other conversations in the room.  Have you ever wondered how you are able to focus on the conversation your having at a party or a busy restaurant when there are literally hundreds of other conversations occurring within ear shot?  It turns out, our brain is pretty good at filtering out unwanted stimuli.  While it is possible to manually shift our attention to one (or several) stimuli, for the most part this all occurs without any conscious effort.  Although perhaps obvious, studies indicate that this filtration of external stimuli requires a lot of brainpower.  Specifically, it seems that focused attention (which requires the filtering of stimuli not being attended to), uses a broad network of brain pathways.  This is very likely why a common characteristic of brain damage (regardless of where the brain damage occurs) is a reduced ability to filter unwanted stimuli.

The Over-Stimulation of Today’s Brains

If you’re reading this post on an iPhone or iPad, that’s really cool because frankly I don’t have a mobile following yet.  It’s also a real sign of the times.  Here is a fun task: Go to a public place and do some people watching. Airports are probably the best example while restaurants may be more depressing.   In either case, it is not uncommon to find the majority of people filling their empty time texting, browsing facebook or catching up on the day’s news.  For the millennial’s, this is just life.  The ease of sharing information has become so profound in the last two decades across various platforms (both software and hardware) that we have become accustom to constantly seeking it out and feeding the perceived need to “know”.  In short, our brains are not only being stimulated by environmental stimuli, such as the sound of other people talking, the sensation of air moving across our skin, the feeling of the chair we are sitting in but additionally with information such as news on our iPad, music on our iPod and texts on our iPhone (if you own and carry all three of these devices at once, I suppose you are rather silly).

The effects of this over-stimulation should not be ignored and recent studies indicate that there can be some significant long-term ramifications.  It may come as little surprise that there is a strong correlation between internet addiction and ADHD in children.  A responsible question to ask: Does the ADHD lead to internet addiction or does the internet addiction lead to ADHD? The difference may seem minor but is in fact rather significant.  It is very possible that the speed of today’s internet makes it very tolerable, and in fact enjoyable, for children suffering from ADHD to bounce from topic to topic with ease.  It is, of course, also very possible that this nature of the internet also facilitates the development of ADHD.

Unfortunately, the body of academia seems to indicate the former more than the latter.  For example, children exposed to television at an early age seem to demonstrate less attention span than peers not exposed to television. Additionally, children who spend more than an hour per day playing video games have more severe  cases of ADHD than those that do not play video games. It is therefore not surprising to learn that ADHD rates are increasing from year to year, and have been for the past several decades.  This coincides with the growth of cable television, video games, the internet, and mobile technology (whether it is in the form of a cellphone or a PSP).

ADHD and Brain Size

Advances in brain imaging in the past two decades have allowed researches to dig deeper into the pathology of mental disorders.  In the past 10 years, many efforts have been made to pinpoint the cause(s) of ADHD and one, perhaps unsurprising, finding is that the brain development is delayed in children with ADHD.  In fact, individuals with ADHD have smaller brains than those who do not.  And while the delayed development is thought to take the same path as the healthy brain, this difference in gray matter volume persists into adulthood.

The reasons for these differences remain unknown and as with most psychological disorders, it is likely a combination of biology and environment.  That is to say that there may be a genetic predisposition that may be reinforced by environmental stimuli.  Is the recent spike in ADHD diagnoses related to the proliferation of environmental stimuli across our culture? It use to be the case that while sitting at a restaurant waiting for our food that we would speak to those we are with.  Increasingly, this time is spent reading LaymanPsych.com on our iPhones.

Isolation Tanks

Isolation Tanks were created to test the effects of sensory deprivation, and they do a very good job at depriving the brain of outside stimulation.  Ideally, an isolation tank cuts off all sound, light, and the subject floats in a mixture of saltwater kept at the same temperature as your skin. Thus, a proper isolation tank leaves the subject seeing nothing, hearing nothing, and feeling nothing.  The tank leaves the subject to float and let their brain meander through its own thoughts, completely uninterrupted by outside stimuli (ignoring taste and smell).   This dramatic shift in environment has been said to produce dramatic effects for participants.  One of the most visible proponents in recent years, Joe Rogan claims there is a hallucinogenic effect.  Recent study indicates that the isolation tanks can reduce anxiety, depression, hostility, and fatigue while increasing creativity.  With the sheer amount of brainpower dedicated filtering out unneeded stimuli, it seems logical that sensory deprivation would have dramatic effects by allowing more brain power to be dedicated to other tasks or brain development.

Filtering, Over-stimulation, ADHD, What is The Connection?

Let us pause for a moment.  The first half of this article outlined an (unqualified)* argument that perhaps the reason the attention span of society in recent years is dropping, ADHD is on the rise, as a result of the increase in information and pure stimulation that our brains must filter out in order to function properly.  This filtering takes a massive amount of brainpower and yet because it happens without any conscious effort, it is taken for granted.  A newborns brain is roughly 1/4 of the size of its adult form and grows massively into the teen years.  Somewhere between the ages of 10 and 18, the brain begins to shrink.  This is a natural process as unused pathways are pruned out.  The differences are (subjectively) small, changing no more than 10% over the course of an individual’s life (from peak brain volume to death) and unrelenting.  Once the shrinking starts, it does not stop.

And at long-lost, this is where the study at hand comes into play.

Long-term sensory deprivation prevents dendritic spine loss in primary somatosensory cortex

The sky may not be falling, but our brains certainly are shrinking.  This is a fact and it is unavoidable. In all mammals, brains peak in size shortly after birth (this is relative, in humans it is around the age of 15 plus or minus a few years) and the number of synapses continue to decrease until death.  But can the shrinkage be slowed?

Yi zuo, Guang Yang, Elaine Kown & Wen-Biao Gan of the New York University School of Medicine sought to find out by playing a prank on mice…sort of.

The role of whiskers in those lucky mammals that have them

Whiskers are an important feature of those fury little creatures that have them: cats, dogs, mice, etc.  Whiskers are simply specialized hairs that provide tactical feedback.  Cats, for example, use their whiskers to gauge the size of an opening to determine if they can fit through it or not.  Whiskers exist to provide feedback, they are in every sense of the word…stimulating.

So Zuo and his fellow researchers used this fact to help study the effects of sensory deprivation on mice by cutting the whiskers off of several mice and looking at the effects of their brains.  The whiskers were trimmed daily of the experimental group of mice while a control group was left alone. Otherwise, the two groups of mice lived the same existence over the course of the experiment.

What they found

In short, the removal of the whiskers slowed down dendritic spine loss ( the part of a neuron that receives information a synapse).  Over the course of the study, this meant that the volume of the mice who underwent the whisker-trimming had larger brains than the control group. It should be pointed out that this was not because of new dendritic spine formation but rather a slowing down of loss of dendritic spines.   Additionally, while these findings held true regardless of the age of the mice, the results were more dramatic in adolescent mice than in adult mice.

Putting it all together: What can we take from this?

Here are some facts

1. Brains shrink as we get older
2. Our society is becoming more and more stimulated as we become more and more plugged in
3. ADHD, a disorder that predominately surfaces in adolescence, is on the rise
4. Individuals with ADHD have less brain volume than healthy counterparts
5. Isolation Chambers seem to have positive benefits
6. Sensory deprivation appears to reduce the rate of natural brain loss, this is more profound in children
7. If sensory deprivation reduces brain loss, one can reason that over-stimulation can promote it

In today’s ever-stimulating world, getting some rest and tuning out is becoming rare.  It only makes sense that we are probably frying our brains away on our iPods and video games.  Perhaps it’s time that we all just take a moment and listen to nature, unplug, and hike the Appalachian trail.  Ok, that may be a tad extreme, but you may want to reconsider that end-of-the-night facebook binge before you go to bed.  It’s not that computers are bad, certainly the benefits to today’s youth far outweighs the fact that many children have internet addictions and our taste and diversity in music is strongly related to the fact that it is so easy to listen to anything with a few passes of our thumb.  No, technology is not evil, but it probably shouldn’t run our lives unchecked.

*LaymanPsych never pretends to be authoritative and thus such arguments are to be taken with a grain of salt. Feel free to disagree with any arguments made here but please post comments below if you do!

%RELATEDPOSTS%