Autopilot: Scientists find important role for daydreaming network

on 31 October 2017
Default mode network

Could scientists be on the verge of explaining what we call the subconscious? It seems the default mode network takes over when we perform routine tasks, BUT . . . . . . . . 

What does that actually mean? For example many of the things we do not want to do could fall into this category, smoking, grinding teeth, brushing teeth, fears, phobias etc. The one commonality in all these tasks, is, that somewhere in the brain there is a record (memory) of these events. For things we like and enjoy, these may be recorded in the brain's pleasure centre and for fear related things, its fear centres.

THis is very good news for us hypnotists because it kind of validates what we already know. So what do we know? Well, we know that a client can come in with a particular issue and after hypnosis; leave without it. The only thing we have to work with, is the client's mind and how it works. How it, the individual's mind, works is very different from the generic view of the mind. Knowing how your mind works is of far more value to you than knowing how someone else's does! 

It is already known that the brain areas involved in language cause a corresponding response in selective areas, related to the words we use, e.g. when we hear or say the word lavender, the olfactory lobes light up. In hypnosis, it is the knowledge of this that allows us to effectively rewrite the neural code that elicits the removal of unwanted habits or the creation of wanted behaviours! Every day people make decisions to make changes in their life and are often successful. However, specific behaviours, that we do not want, are wanted at some level of mind and that is simply because there is a perceived benefit. For example it is known that most people who smoke are aware of the dangers they face to their health; yet they continue to smoke. The reason, psychologically, is that the brain derives some kind of payoff from smoking; and that is what keeps you smoking. Hypnosis is what allows you to interrupt this pattern of brain activity and make the changes you want. Whilst the example given is for smoking, the same principle applies across all forms of human behaviour; albeit some are more challenging to deal with!

The Research:  A brain network previously associated with daydreaming has been found to play an important role in allowing us to perform tasks on autopilot. Scientists at the University of Cambridge showed that far from being just 'background activity', the so-called 'default mode network' may be essential to helping us perform routine tasks.

When we are performing tasks, specific regions of the brain become more active -- for example, if we are moving, the motor cortex is engaged, while if we are looking at a picture, the visual cortex will be active. But what happens when we are apparently doing nothing?

In 2001, scientists at the Washington University School of Medicine found that a collection of brain regions appeared to be more active during such states of rest. This network was named the 'default mode network' (DMN). While it has since been linked to, among other things, daydreaming, thinking about the past, planning for the future, and creativity, its precise function is unclear.

Abnormal activity in the DMN has been linked to an array of disorders including Alzheimer's disease, schizophrenia, attention-deficit/hyperactivity disorder (ADHD) and disorders of consciousness. However, scientists have been unable to show a definitive role in human cognition.

Now, in research published today in the Proceedings of National Academy of Sciences, scientists at the University of Cambridge have shown that the DMN plays an important role in allowing us to switch to 'autopilot' once we are familiar with a task.

In the study, 28 volunteers took part in a task while lying inside a magnetic resonance imaging (MRI) scanner. Functional MRI (fMRI) measures changes in brain oxygen levels as a proxy for neural activity. In the task, participants were shown four cards and asked to match a target card (for example, two red diamonds) to one of these cards. There were three possible rules -- matching by colour, shape or number. Volunteers were not told the rule, but rather had to work it out for themselves through trial and error.

The most interesting differences in brain activity occurred when comparing the two stages of the task -- acquisition (where the participants were learning the rules by trial and error) and application (where the participants had learned the rule and were now applying it). During the acquisition stage, the dorsal attention network, which has been associated with the processing of attention-demanding information, was more active. However, in the application stage, where participants utilised learned rules from memory, the DMN was more active.

Crucially, during the application stage, the stronger the relationship between activity in the DMN and in regions of the brain associated with memory, such as the hippocampus, the faster and more accurately the volunteer was able to perform the task. This suggested that during the application stage, the participants could efficiently respond to the task using the rule from memory.

"Rather than waiting passively for things to happen to us, we are constantly trying to predict the environment around us," says Dr Deniz Vatansever, who carried out the study as part of his PhD at the University of Cambridge and who is now based at the University of York. "Our evidence suggests it is the default mode network that enables us do this. It is essentially like an autopilot that helps us make fast decisions when we know what the rules of the environment are. So for example, when you're driving to work in the morning along a familiar route, the default mode network will be active, enabling us to perform our task without having to invest lots of time and energy into every decision."

"The old way of interpreting what's happening in these tasks was that because we know the rules, we can daydream about what we're going to have for dinner later and the DMN kicks in," adds senior author Dr Emmanuel Stamatakis from the Division of Anaesthesia at the University Of Cambridge. "In fact, we showed that the DMN is not a bystander in these tasks: it plays an integral role in helping us perform them."

This new study supports an idea expounded upon by Daniel Kahneman, Nobel Memorial Prize in Economics laureate 2002, in his book Thinking, Fast and Slow, that there are two systems that help us make decisions: a rational system that helps us reach calculated decisions, and a fast system that allows us to make intuitive decisions -- the new research suggests this latter system may be linked with the DMN.

The researchers believe their findings have relevance to brain injury, particularly following traumatic brain injury, where problems with memory and impulsivity can substantially compromise social reintegration. They say the findings may also have relevance for mental health disorders, such as addiction, depression and obsessive compulsive disorder, where particular thought patterns drive repeated behaviours, and the mechanisms of anaesthetic agents and other drugs on the brain.


Story Source:

Materials provided by University of Cambridge. The original story is licensed under a Creative Commons LicenseNote: Content may be edited for style and length.

Journal Reference:

  1. Deniz Vatansever, David K. Menon, Emmanuel A. Stamatakis. Default mode contributions to automated information processingProceedings of the National Academy of Sciences, 2017; 201710521 DOI: 10.1073/pnas.1710521114