(An image the human brain’s Default Mode Network, Credit: Marcus Raichle, Washington University)
The Default Mode Network plays a key part in our sense of self, attachment style and mood. This article explains where it is located in the brain and why it is so important.
What is the DMN?
The Default Mode Network (DMN) in the brain, is active when we stop doing something (and we are not in the task mode network, TMN). When the brain is not focused on a challenging or attention-grabbing task, we are no longer paying attention to the external world and the parts of the brain associated with this network light up. Our brain automatically brings together memory and thought and integrates both of these with our sense of self. Some scientists have said that the DMN is where the ‘self’ is located; it is the “me myself and I” network. It is self referential, self-other referential, future referential and past referential. It is universal to all humans and it is active immediately, as soon as we stop focusing on externals. It is not only the part of the brain where we “mind wander”; we use the DMN intentionally too. We do this when we are reaching for autobiographical memory, thinking about the future, using our imagination or empathising with someone. It can be active from the moment we wake up; it is the background of our days and is with us continually, even under anaesthesia as well as when we fall asleep at night. It is said to be the night garden in which our night dreams grow. It changes during the day as we integrate the day’s events, and this may be why the way we feel when we wake up can be so different from how we feel when we fall asleep. Interestingly, studies have shown that the two main activities where the DMN is completely switch off is when we play video games or when we smoke.
Scientists are still trying to find out exactly which parts and regions of the brain are involved most often. What is most important to know is that the parts of the brain that we use for this automatic integration of self and social connections are almost entirely different from the parts we use when we are concentrating on getting things done in the external world. For example, when we learn to do something new and are not therefore using procedural memory, the DMN goes offline as focused attention comes online. As the task becomes more automatic, the DMN starts to become active again. We could say that familiarity or boredom can be one of the prompting factors to the DMN coming into use.
(Figure of the seven different major networks and way the brain uses itself depending on what we are doing taken from Your Resonant Self by Sarah Peyton). Notice how different the DMN is form the others. Especially notice the DAN (Dorsal Attention Network). This is the network that most completely turns off the DMN; it come online when we are doing new or absorbing things like video games
DMN: Social Attachments & Predictions
Our social world as humans has become so incredibly complex. Our DMN is always trying to help us to stay afloat socially and keep our important attachments. It is trying to support our wellbeing. Memories don’t just help us to remember things; our DMN seems to use them to make predictions about what is going to happen next and what people are likely to be intending or thinking that helps us grow and move within our families and social groups. It also helps us, from when we are very young, ensure that we got our basic needs met, most especially attachments to important figures in our lives (when we were younger, our parents).
The DMN: Anxiety, Depression & Trauma
Many things change the way our DMN interacts with our externally focused brain including anxiety, trauma and depression. A ‘healthy’ DMN, which helps the brain integrate the experiences of life, requires that all regions of the DMN be interconnected and functional. When these interconnections between the DMN regions are disrupted (which can happen due to trauma, anxiety, depression and other illnesses that disrupt brain and neurotransmitter function), we can expect the brain to start spinning “negative” and self-debilitating thoughts whenever it is trying to rest. With early childhood trauma, the DMN can default to self-blame and self abuse rather than neutrality. People can be in the habit of walking around unconsciously berating themselves (or blaming others). If people feel badly about themselves, then this emotional tone can run through their automatic thoughts, can come like a knife in the dark whenever consciously directed activity stops.
The DMN: When it Becomes Toxic and Savage
The main problem with such a savage DMN is connectivity. When certain brain regions are not corrected as they should be, negative thoughts and interpretations of life and the sense of self can grow. The more emotional pain and neglect a person has survived, the more likely it is for the DMN to be toxic and savage and for a harsh inner critic to take over. What is needed to correct these faulty connections and change the tone of a ruthless DMN is warm, responsive nurturing. It is often not what has happened to us, it is how it has been reacted to by those around us. If we receive a warm and nurturing response, we are more likely not to experience such disconnection and disintegration in the brain and nervous system. When people are in the grip of their own savage self-dislike, they can’t believe that they cared for by others, so they cant reach out to people and isolation is more likely. Changing the tone of the automatic way people speak to themselves is essential to making the mind and body a safer space to inhabit.
It is possible that part of the ongoing stream of distraction in our world helps people to manage the traumatised and unkind self-talk that starts as soon as they are quiet. This can happen unconsciously, which is why it is important to learn about and understand the DMN.
The DMN: Compassion & Meditation
The life that we live when we have integrated self compassion (when we can be gentle and warm with ourselves and others) feels very different from one lived inside a savage DMN.
It is important to know that, though mindfulness meditation is supposed to integrate the brain, the network used for meditation and the DMN can remain distinct. It can explain how somebody with years of meditation practice can still have a savage DMN that comes into play when they come off the cushion and why it is important to focus on both these aspects of the brain to heal a toxic and savage DMN.
Even If that inner critic is still trying to convince you that it is selfish to start caring for yourself, consider this: the ongoing self attack of living with a savage DMN is a sign that we may be living with PTSD. Research is showing that the different names we give to anxiety, social anxiety, general anxiety, PTSD, OCD and panic each have their own way of taking over our DMN and giving us a hard time.
The important thing to remember is that our brains don’t develop easily when we are not able to see and treat ourselves with affection. If no one we know has ever really held themselves with warmth, then we don’t have a model of how to do this. However, no matter how old we are, we can turn our compassion for others back towards ourselves and follow the invitation to self-care.