The default network is a network of brain regions that are active when the individual is not focused on the outside world and the brain is at wakeful rest. Also called the default mode network (DMN), default state network, or task-negative network (TNN), it is characterized by coherent neuronal oscillations at a rate lower than 0.1 Hz (one every ten seconds). During goal-oriented activity, the DMN is deactivated and another network, the task-positive network (TPN) is activated. It is thought that the default network corresponds to task-independent introspection, or self-referential thought, while the TPN corresponds to action, and that perhaps the TNN and TPN may be "considered elements of a single default network with anti-correlated components".
Hvad hvis man kaldte det noget mere positivt? Det fantaserende og erindrende netværk!
The default network is an interconnected and anatomically defined brain system that preferentially activates when individuals focus on internal tasks such as daydreaming, envisioning the future, retrieving memories, and gauging others' perspectives. It is negatively correlated with brain systems that focus on external visual signals. Its subsystems include part of the medial temporal lobe for memory, part of the medial prefrontal cortex for theory of mind, and the posterior cingulate cortex for integration, along with the adjacent precuneus and the medial, lateral and inferior parietal cortex.In the infant brain, there is limited evidence of the default network, but default network connectivity is more consistent in children aged 9–12 years, suggesting that the default network undergoes developmental change. In humans, the default network has been hypothesized to generate spontaneous thoughts during mind-wandering and to be an essential component of creativity.
- tænkning der indebærer fremdragning af autobiografiske erindringer
- tænkning der involverer projektion af jeget ud i fremtiden,
- tænkning igennem imaginære fortællinger og forestillinger om andre universer,
- tænkning der involverer hypotetisk moralsk stillingtagen,
- tænkning der indebærer at man sætter sig i en andens sted,
- tænkning om hvem jeg selv er - i forhold til andre (det der kaldes "theory of mind")
Og som - siger teorien - gør det muligt for os at aflæse andre menneskers intentioner og følelser der ligger under og bag de bevægelser, den mimik og de handlinger vi ser de udfører.
We have attempted to outline a common thread linking aspects of the self across the domains of time, space, physical embodiment and the social world as may be accomplished through a simulation mechanism. In our interpretation of the process of simulation, the self uses available knowledge as a template for processing, representing and understanding new information. Whether simulation involves self-projection in time for the purposes of planning the future, or projection of a perceived image onto the self-image during self-other differentiation; at their core, mental time travel, perspective taking, self-representation and mentalizing are all cogitations that in the broadest sense appear to involve a simulation mechanism. These high-level functions rely on a distributed network of brain structures, including the medial prefrontal cortex, medial temporal lobe, parietal regions and the temporo-parietal junction forming the core of the default mode network, and the posterior inferior frontal gyrus and inferior parietal lobule forming the core of the human mirror neuron system.
På den ene side må han/hun bruge sine erindringer, sine fantasier om mulige verdener, sin teori om identiteten af eget sind med andres, etc. - og på den anden side må han/hun trække på de mentale spor som spejlneuronerne har lagret i hans visuelle hukommelse om hvordan ydre, synlig og hørbare, konkrete handlinger og bevægelser hænger sammen med indre intentioner og følelser.
We speculate that the CMS might support evaluative simulation in the same way that the MNS supports motor simulation. This distinction serves as a practical division of labor between two networks that are specialized for two related processes that are crucial to navigating the social world. The mirror neuron system provides the essential physical other-to-self mapping that is necessary for comprehending physical actions of intentional agents, whereas cortical midline structures maintain and support processes that are related to understanding complex psychological aspects of others, such as attitudes, perhaps by simulation of one’s own attitudes .Because the MNS and CMS both seem to be involved in self–other representations, it seems only natural that they interact. The existence of direct connections between the precuneus (a major node of the CMS) and the inferior parietal lobule (the posterior component of the MNS)  suggests that this is one pathway by which such interactions might occur. Indeed, it has been suggested that, owing to its strong cortical and subcortical connections, the precuneus is likely to be involved in elaborating highly integrated and associative information, rather than directly processing external stimuli .Additionally, there are direct connections between mesial frontal areas and the inferior frontal gyrus . Thus, the anterior and posterior nodes of the CMS and MNS are in direct communication. Although the exact nature of the interactions between these two networks is unknown, it is likely that the direct connections between them facilitate integration of information that is necessary for maintaining self–other representations across multiple domains. One intermediate representational domain in which both neural systems might cooperate is the domain of imagination (Box 3).
Box 3. Imagining self and other
Imagination is an important mental function for social behavior. Rather than actually having to witness events that directly involve ourselves or others, we can mentally project these events and simulate outcomes.
In terms of self and other, imagining actions performed by the self or the other activates shared midline and frontoparietal structures . This suggests that imagination is a common representational domain between CMS and MNS, as far as self–other relationships are concerned. Indeed, some of these regions seem concerned with a variety of imaginative processes that involve self and other, from feelings in socially relevant situations , to pain  and perspective taking 
Self- and other- representations are crucial to social functioning. Although most animals can distinguish, on some level, the self from others, such separation is more reﬁned in the non-human primates that possess self-recognition, self-awareness and basic theory-of-mind skills. The right frontoparietal MNS and the CMS seem to support these abilities, albeit in different ways. Here, we propose that the MNS enables physical other-to-self mapping, whereas the CMS underscores mental state and evaluative simulation. Both processes are crucial to understanding other social beings. Although the distinctions are not fully understood, both neural systems contribute to the ability to move beyond simple motor imitation to more complex forms of social learning and understanding.By providing both the neural basis of the co-representation and the distinction of self and other, these two systems integrate with the brain as a whole to enable successful navigation of the social world.