How the brain separates relevant from irrelevant information
by Thom Bush
on 02 October 2016
blocking out the external world with brain power

This piece of research intrigues me, because, in one way or another, we can most likely all filter out external distractions and the like, at least to a certain extent. But we also know that some of us are way better at the focusing of our attention than others. How about you; can you focus when you need to . . . . . . . . .

So while this discovery is a huge advancement from the perspective of neuroscience, it seems to raise some very complex questions for those of us who find it so difficult to block out the external clutter or everyday life; even more so when it comes to the internal stuff! I believe that one of the reasons we find it difficult to block out these annoying things that disrupt our lives, is by the way we choose to live; although mostly we are not even aware that we have made this choice!

So what is this choice? Well it's the choice of choosing to live in a "Brain Led way" as opposed to a "Mind Led way." What's the difference? Well, the Brain Led way, allows us to live life, more or less solely, based on previous experience and memory and in some sense, that will almost always have some, small, relevance, even in the Mind Led model. However, with the Mind Led model we make extra-special use of mindfulness and introspection, kind of like micro-managing time, present and future, to predetermine states of mind, attitudes and, onward to that, behaviour.

Hypnotherapy (hypnosis) is an especially effective way to enhance this process because it allows us to experience, neurochemically, what it feels like to have a good experience; in the same way a dream of falling allows to have a fearful one? In both situations, the perceived reality is false but despite that, it is believable. The brains defensive mechanisms will take what it feels is appropriate action and in the case of the falling dream, this could lead to anxiety, chronic stress or depression. Similarly, the empowering uplifting experience in hypnosis, can lead to a boost in confidence, heightened self esteem, more ability to manage your emotions etc. Wouldn't that be nice!

So, if anxiety, stress, depression or any other mind based problem is limiting your life; you know what to do and where to go to do it?

The research: Imagine yourself sitting in a noisy café trying to read. To focus on the book at hand, you need to ignore the surrounding chatter and clattering of cups, with your brain filtering out the irrelevant stimuli coming through your ears and "gating" in the relevant ones in your vision -- words on a page.

In a new paper in the journal Nature Communications, New York University researchers offer a new theory, based on a computational model, on how the brain separates relevant from irrelevant information in these and other circumstances.
"It is critical to our everyday life that our brain processes the most important information out of everything presented to us," explains Xiao-Jing Wang, Global Professor of Neural Science at NYU and NYU Shanghai and the paper's senior author. "Within an extremely complicated neural circuit in the brain, there must be a gating mechanism to route relevant information to the right place at the right time."

The analysis focuses on inhibitory neurons -- the brain's traffic cops that help ensure proper neurological responses to incoming stimuli by suppressing other neurons and working to balance excitatory neurons, which aim to stimulate neuronal activity.

"Our model uses a fundamental element of the brain circuit, involving multiple types of inhibitory neurons, to achieve this goal," Wang adds. "Our computational model shows that inhibitory neurons can enable a neural circuit to gate in specific pathways of information while filtering out the rest."

In their analysis, led by Guangyu Robert Yang, a doctoral candidate in Wang's lab, the researchers devised a model that maps out a more complicated role for inhibitory neurons than had previously been suggested.

Of particular interest to the team was a specific subtype of inhibitory neurons that targets the excitatory neurons' dendrites -- components of a neuron where inputs from other neurons are located. These dendrite-targeting inhibitory neurons are labeled by a biological marker called somatostatin and can be studied selectively by experimentalists. The researchers proposed that they not only control the overall inputs to a neuron, but also the inputs from individual pathways -- for example, the visual or auditory pathways converging onto a neuron.

"This was thought to be difficult because the connections from inhibitory neurons to excitatory neurons appeared dense and unstructured," observes Yang. "Thus a surprising finding from our study is that the precision required for pathway-specific gating can be realized by inhibitory neurons."

The study's authors used computational models to show that even with the seemingly random connections, these dendrite-targeting neurons can gate individual pathways by aligning with excitatory inputs through different pathways. They showed that this alignment can be realized through synaptic plasticity -- a brain mechanism for learning through experience.

Story Source:
Materials provided by New York University. Note: Content may be edited for style and length.

Journal Reference:
1. Guangyu Robert Yang, John D. Murray, Xiao-Jing Wang. A dendritic disinhibitory circuit mechanism for pathway-specific gating. Nature Communications, 2016; 7: 12815 DOI: 10.1038/ncomms12815