Network 3

In N3 we discover the physiology of the central seat of imagination, memory and learning.

Q: Where is it?

A: N3 is right in the very middle of your brain towards the rear. Here’s a picture of the brain spread out, so that we can see N3 in a bit more detail:

Removed from its surrounding hemispheres, the central part of N3 looks rather bizarrely like a lobster! Here it is on its own below:

N3 includes the most important departments for imagination & memory –the thalamus, the hippocampus and the amygdala. The amygdala (amy) and hippocampus (hippo) are important NH areas and we will look at them more closely in the next tutorial. You will probably want to learn a little about them, especially if you want to use mind machines.

Q: What does it do?

A: Network 3 does loads of things, so in this tutorial we’re just going to explore what it does in relation to imagination. You’ll notice that its central part is symmetrical, and that it has two of several bits –two amygdalae, two hippocampi, two caudate nuclei and so on. Each side handles different parts of the same tasks. The thalamus, hippo and amy do a variety of tasks, so again we’re focusing mainly on their roles in imagination and perception. Because it’s right here where perception takes form and where most learning, memory processing and formation happen. We'll be looking more closely at these three parts in the next tutorial; for now, just get used to where they are; this will help you understand how TMS etc targets these areas.

Network 3 is the place where information incoming from all our senses is collected together and given meaning by imagination as parts of the whole experience we call ‘perception’. From this experience, we decide what's happening, what to do about it, what to explore further and what not to, what needs to be remembered and what isn’t important. So the accuracy of imagination is very important as in facilitating perception it provides our basic onboard picture of what’s going on “out there”.

DO IT NOW

 Hack your own perception as the brain picks up different information from the same input:

Take a look at the pictures below. It looks like an angry face on the left, and a neutral woman on the right, yeh?

Now, get up and walk away from your computer a few feet. If you wear long-distance glasses, put them on. Walk forward until you can see the images clearly on the screen. What do you see when you look at the faces now? As you move towards the screen, how do the faces change?

These are 'hybrid' images. Hybrid images change in interpretation as a function of viewing distance. They combine the low spatial frequencies of one image with the high-spatial frequencies of another, producing a result that your brain interprets differently depending on how close you are. Thay can portray different moods and even sexes as you move closer or further away.

All you have done, to give the brain totally different information from the same input, is alter that one single variable -distance. You merely moved your head closer to the object (the human version of zoom). Maybe now you are beginning to see how fragile perception really is, so now consider that perception is not just about visuals.

All of your sensory input about everything is turned into percepts, and all of it is subject to being misinterpreted just like this. Brains need a certain critical mass of information before we can imagine accurately what is going on. In this case, you can only get all the information by adopting two or more different points of view. Remember this, when we start exploring empathy!

Alice through the looking glass - Mirror Neurons

The inner model that imagination projects images onto includes a large population of mirror neurons.

Mirror neurons or 'mirror cells' are a type of neuron discovered in the 1980s and were so named because, by firing both when an animal performs a behavior and when it simply watches the same behavior, they appear to "mirror" movement, using the same brain pathways as though the observer themselves were performing the behavior.

With fMRI came the ability to examine the entire brain at once, revealing a much wider network of brain areas showing mirror properties in humans than was previously thought.

Detailed human fMRI analyses suggest activity compatible with the presence of mirror neurons in areas of N2, N3 & N6 and they were thought to make the observer feel what it feels like to move in the observed way. More recent experiments have shown that even at the level of single participants, scanned using fMRI, large areas containing multiple fMRI voxels increase their activity both during the observation and execution of actions.[4]

Mirror neurons provide the real life 3-D ‘mind's eye’ in N3.

The initial images and sounds coming in are percepts, so imagination starts to process them, accessing N3's main memory database which contains the imagery for core concepts. The percept images from input are projected onto the inner model and compared against (also projected) known concept images, to see what they most closely match up to. Whatever imagination associates them with most, they will be categorized accordingly and any differences examined. The differences will later determine their exact location on the inner model.

Mirror neurons project images of any percept including specific behaviors like 'raising arm' or 'sticking out tongue', whether the behavior is performed by ourselves or another individual.[5] Other neurons have anti-mirror properties, that is, they respond when the participant sees an interaction but are inhibited when the participant performs that action, and this is how we are able to tell the difference.

This is the main way in which mirror neurons assist our perception, but in the past few years researchers have newly defined different types of mirror neurons and shown how finely tuned these subsets of mirror neurons can be [1].

Mirror Neurons and Empathy

Mirror neurons play a critical role in how and why we understand other people’s behavior. There are many different physical interactions, like Bruce Lee doing Kung Fu, or Jimi Hendrix playing guitar, that many of us can’t do, but we understand those interactions anyway because when the mirror neurons portray them on the model the percepts are close enough to known concepts to be understood. Doing them physically ourselves isn’t required for understanding; we can imagine how they are done. In fact, neuroimaging data demonstrate that the behaviors we ourselves have the most experience doing — the actions we are best at doing and understand best — actually show less mirror neuron activity because they are so well known they have become 'automatic' and require less imaging when others do them.

Researchers have since shown that, in humans, apes and monkeys, the mirror system also responds to the sounds of interactions.[6]

A large number of experiments using functional MRI, EEG and MEG have now shown that mirror neuron brain regions are active when people experience an emotion (disgust, happiness, sorrow, lust etc.) and when they see another person experiencing a recognized emotion.[7]

More recently, researchers have shown that people who are more empathic have stronger activations both in the mirror system for sensorimotor behavior and the mirror system for emotions,[8] providing more direct evidence that the mirror system is linked to empathy. A notable example of sensorimotor empathy is yawning, which mirror neurons often manage to kick off in ourselves if we see someone else yawn.

But mirror neurons do a great deal more than just help us understand others. Mirror neurons provide a mechanism for action-understanding, imitation-learning, and the simulation of other people's behavior.[9] This enables modeling, a widespread animal behavior that puts the 'M' in COMP.

Mirror Neurons & Modeling

Mirror neurons are present in many other creatures including infant monkeys. In the 1980s the first abstract appeared reporting that surface electrodes had recorded mirroring in monkeys one- to seven-days old as they watched humans stick out their tongues and smack their lips. This was the first evidence that infants have a mirror mechanism at birth that responds to facial gestures.

Without any experience of stimulation, they are able to focus their attention on the most relevant stimuli and respond. The days-old monkeys stuck out their tongues when they saw the human tongue.

Researchers propose that automatic imitation is mediated by the mirror neuron system and that it is the laboratory equivalent of the motor mimicry observed in naturalistic social contexts.[10]

The inner projection system enables us to copy things[17]. The mind can remember and replay a memory of someone else doing something, compare our current performance at the same task against the memory, look at the differences between the two, and fine tune our performance just as adeptly as if we had a real live tutor demonstrating in front of us.

Mirroring abilities increase with experience, and practice increases the acuity of mirror neurons. In humans, for example, more mirroring activity occurs when dancers see other dancers perform routines they know well. Mirroring in blind people is more active in response to more familiar action sounds. More importantly, as we develop we adapt the mirror system to copy not just physical concrete movements (say, for learning to ride a bike) but also abstract concepts like how someone else is able to think (say, for learning nuclear physics or calculus). That's why the mirror system is so important to learning.