We think about ourselves a lot. We think about our goals in life, about how we feel, and about what others think of us. We also refer to ourselves a lot. We tell others about our thoughts, and if someone tells us about themselves, we immediately relate this to some experience that we have been through. We also remember information better if it is personally relevant.

What is the mechanism behind this constant stream of thoughts about ourselves? Why are we so egocentric? In a recent fMRI study, researchers tried to answer this question. They found that we might actually be primed to think about ourselves when there’s nothing else that demands our attention.

Default network

When we are doing nothing, our brains are far from silent. On the contrary: When we are don’t engage in an active task, a specific network of brain regions is activated. This is called the default network because, as you might guess, these brain regions activate by default.

One important brain region in this default network is the medial prefrontal cortex (MPFC/Brodmann’s area 10). Interestingly, this region is also active when we think about ourselves: The more we reflect on our emotions, think about our personality, and imagine ourselves in the past of future, the more activation in the MPFC.

Might this be the reason that we think about ourselves so readily when we are doing nothing? It might be, but we have to be cautious. Because brain regions are activated in a lot of different tasks and are connected with each other in various ways, the MPFC might have a completely unrelated function within the default network. Thus, whether the default brain activity actually has something to do with thinking about the self has not been tested until now.

Knowing yourself

In this recent study, participants had to judge whether traits (like calm or kind) fitted themselves, someone else, or a physical location. In between, they took breaks. It was found that a the amount of activity in the MPFC during breaks was related to the participants’ performance in trials about the self. In other words: More MPFC activity during rest corresponded with faster reaction times for ‘self trials’, compared to other trials.

The researchers conclude that we have a bias toward thinking about ourselves: The medial prefrontal cortex activates by default when we are not attending to the outside world and this sets self processing in motion. Of course, the medial prefrontal cortex is not the only brain region responsible for our thoughts about ourselves. Almost always it is actually a network of regions that work together, and other default regions have also been related to the self and to social reflection.

Even so, this study is another step toward understanding the mechanisms of our default network. And the idea that we are wired to think about ourselves is actually not surprising at all! We live in a social world, and for our own goal striving and survival it is extremely important to know who we are and what our place is in social networks. Thus, thinking about you is not unhealthy at all! It just helps you to get to know yourself.