4 ms·

Not ELI5 exactly, but the article does a pretty good job of explaining in the first paragraph: > The default mode network (DMN) is an internally directed syste

Not ELI5 exactly, but the article does a pretty good job of explaining in the first paragraph: > The default mode network (DMN) is an internally directed system that correlates with consciousness of self, and the dorsal attention network (DAT) is an externally directed system that correlates with consciousness of the environment... the DMN and DAT appear to be in a reciprocal relationship with each other such that they are not simultaneously active, i.e., they are “anticorrelated.” The "temporal circuit" the paper describes is the neural architecture that facilitates the transitions between these two networks.

abvdasker 7y ago
Totally fascinating. It makes me wonder what kind of dysfunction would result from both the DMN and DAT being active at the same time, and especially what my subjective experience of that would be if it were happening to me.
- lifty 7y ago
  I am not sure if this is accurate but intuitively, in strong psychedelic experiences it feels that both the DMN and DAT are active at the same time, which leads to, among many other things, a clearheaded view of mental processes that are hard to observe otherwise. One example would be observing emotions and how they affect your state of mind, while at the same time being totally detached from them. Some studies [1] propose that this happens because of an increase in connectivity between various parts of the brain, which could also be the thing that leads to ego dissolution. [1] https://www.cell.com/current-biology/fulltext/S0960-9822(16)30062-8 https://www.cell.com/current-biology/fulltext/S0960-9822(16)...
- Mithriil 7y ago
  I may have found a partial answer to that, or at least a track to explore. I read some research articles from Robin Carhart-Harris on psylocibin/psylocin ("magic mushrooms") last year. The effect of psylocibin on the Default-Mode Network (DMN) seemed to be a critical part of his research, and so I searched if there was also some observations on the antiphasic nature of the DMN and the Dorsal Attention Network (DAN), and I found something rather interesting [1]: "The following example may help to illustrate what is meant by competition between conscious states—and the loss of it in primary consciousness. Functional brain imaging has identified distinct brain networks that subserve distinct psychological functions. For example, the DMN is associated with introspective thought and a dorsal frontoparietal attention network (DAN) is associated with visuospatial attention and is a classic example of a “task positive network” (TPN)—i.e., a network of regions that are consistently activated during goal-directed cognition. If the brain was to be sampled during a primary state (such as a psychedelic state) we would predict that the rules that normally apply to normal waking consciousness will become less robust. Indeed, we recently found this to be so when analysing the degree of orthogonality or “anti-correlation” between the DMN and TPN post-psilocybin. Post-drug there was a significant reduction in the DMN-TPN anticorrelation, consistent with these networks becoming less different or more similar (i.e., a flattening of the attractor landscape). The same decrease in DMN-TPN anticorrelation has been found in experienced meditators during rest (Brewer et al., 2011) and meditation (Froeliger et al., 2012). Moreover, decreased DMN-TPN inverse coupling is especially marked during a particular style of meditation referred to as “non-dual awareness” (Josipovic et al., 2011). This is interesting because this style of meditation promotes the same collapse of dualities that was identified by Stace (and Freud) as constituting the core of the spiritual experience. The DMN is closely associated with self-reflection, subjectivity and introspection, and task positive networks are associated with the inverse of these things, i.e., focus-on and scrutiny of the external world (Raichle et al., 2001). Thus, it follows that DMN and TPN activity must be competitive or orthogonal in order to avoid confusion over what constitutes self, subject and internal on the one hand, and other, object and external on the other. It is important to highlight that disturbance in one's sense of self, and particularly one's sense of existing apart from one's environment, is a hallmark of the spiritual (Stace, 1961) and psychedelic experience (Carhart-Harris et al., 2012b)." [1] https://www.frontiersin.org/articles/10.3389/fnhum.2014.00020/full https://www.frontiersin.org/articles/10.3389/fnhum.2014.0002...
TeMPOraL 7y ago
Your description parsed back into electronics-land sound to me like: "temporal circuit" is a clock signal, DMN ticks on raising edge, DAT ticks on falling edge.

abvdasker 7y ago

Totally fascinating. It makes me wonder what kind of dysfunction would result from both the DMN and DAT being active at the same time, and especially what my subjective experience of that would be if it were happening to me.

lifty 7y ago
I am not sure if this is accurate but intuitively, in strong psychedelic experiences it feels that both the DMN and DAT are active at the same time, which leads to, among many other things, a clearheaded view of mental processes that are hard to observe otherwise. One example would be observing emotions and how they affect your state of mind, while at the same time being totally detached from them. Some studies [1] propose that this happens because of an increase in connectivity between various parts of the brain, which could also be the thing that leads to ego dissolution. [1] https://www.cell.com/current-biology/fulltext/S0960-9822(16)30062-8 https://www.cell.com/current-biology/fulltext/S0960-9822(16)...
Mithriil 7y ago
I may have found a partial answer to that, or at least a track to explore. I read some research articles from Robin Carhart-Harris on psylocibin/psylocin ("magic mushrooms") last year. The effect of psylocibin on the Default-Mode Network (DMN) seemed to be a critical part of his research, and so I searched if there was also some observations on the antiphasic nature of the DMN and the Dorsal Attention Network (DAN), and I found something rather interesting [1]: "The following example may help to illustrate what is meant by competition between conscious states—and the loss of it in primary consciousness. Functional brain imaging has identified distinct brain networks that subserve distinct psychological functions. For example, the DMN is associated with introspective thought and a dorsal frontoparietal attention network (DAN) is associated with visuospatial attention and is a classic example of a “task positive network” (TPN)—i.e., a network of regions that are consistently activated during goal-directed cognition. If the brain was to be sampled during a primary state (such as a psychedelic state) we would predict that the rules that normally apply to normal waking consciousness will become less robust. Indeed, we recently found this to be so when analysing the degree of orthogonality or “anti-correlation” between the DMN and TPN post-psilocybin. Post-drug there was a significant reduction in the DMN-TPN anticorrelation, consistent with these networks becoming less different or more similar (i.e., a flattening of the attractor landscape). The same decrease in DMN-TPN anticorrelation has been found in experienced meditators during rest (Brewer et al., 2011) and meditation (Froeliger et al., 2012). Moreover, decreased DMN-TPN inverse coupling is especially marked during a particular style of meditation referred to as “non-dual awareness” (Josipovic et al., 2011). This is interesting because this style of meditation promotes the same collapse of dualities that was identified by Stace (and Freud) as constituting the core of the spiritual experience. The DMN is closely associated with self-reflection, subjectivity and introspection, and task positive networks are associated with the inverse of these things, i.e., focus-on and scrutiny of the external world (Raichle et al., 2001). Thus, it follows that DMN and TPN activity must be competitive or orthogonal in order to avoid confusion over what constitutes self, subject and internal on the one hand, and other, object and external on the other. It is important to highlight that disturbance in one's sense of self, and particularly one's sense of existing apart from one's environment, is a hallmark of the spiritual (Stace, 1961) and psychedelic experience (Carhart-Harris et al., 2012b)." [1] https://www.frontiersin.org/articles/10.3389/fnhum.2014.00020/full https://www.frontiersin.org/articles/10.3389/fnhum.2014.0002...

TeMPOraL 7y ago

Your description parsed back into electronics-land sound to me like: "temporal circuit" is a clock signal, DMN ticks on raising edge, DAT ticks on falling edge.