Created: September 29, 2021
Modified: February 25, 2022
Modified: February 25, 2022
default mode network
This page is from my personal notes, and has not been specifically reviewed for public consumption. It might be incomplete, wrong, outdated, or stupid. Caveat lector.- A set of connected brain regions that are active when you're 'at rest', not focused on the external world. This includes mental states such as ruminating, remembering, planning, simulating our interactions with other people, and their thoughts and feelings.
- An operational definition of a default mode network is that it constitutes the thoughts that intrude on your consciousness. Some qualia are strong enough to drown out intruding thoughts: if you're being chased by a tiger, you'll mostly be thinking about running away. But in absence of external stimuli, or of a specific goal to pursue, the brain has a process to generate new thoughts all on its own. Maybe it would be better to say, to let thoughts break through into your consciousness. These thoughts that break through are your 'default' thoughts; the thoughts you think if no other thoughts are more pressing.
- The neurological reality of the default mode network is not universally accepted.
- Studies suggest that psychedelics and meditation can both suppress the activity of the default mode network.
- This suggests a connection to prior beliefs and reality tunnels. Thinking-at-rest involves some combination of model-building, amortizing inference, and model-based planning (building a model and planning in it are conceptually different activities, but in real cognition they're closely tied because an important criterion for whether an abstraction is useful is whether we can use it to plan). We search for concepts that explain and compress things that we've seen, and these concepts form the conceptual scaffolding that determines how we see the world.
- Surprisingly (?), suppressing the default mode network seems to suppress the scaffolding itself, not just the process that produces it. The walls of the reality tunnel disappear.
- This suggests a connection to prior beliefs and reality tunnels. Thinking-at-rest involves some combination of model-building, amortizing inference, and model-based planning (building a model and planning in it are conceptually different activities, but in real cognition they're closely tied because an important criterion for whether an abstraction is useful is whether we can use it to plan). We search for concepts that explain and compress things that we've seen, and these concepts form the conceptual scaffolding that determines how we see the world.
- TODO, there is a relationship to attention. What is it?