A recent paper
by Jack et al showed that the Default Mode Network
(DMN) is opposed and anti-correlated to the Task Positive Network (TPN) and that while DMN sub serves a cognitive
style marked by emphasis on conscious agents, the TPN is activated when cognition involves inanimate objects and invariant laws and principles of physics.
The authors show evidence, using fMRI, that there exists two modes of cognition- physical cognition: reasoning about the causal/mechanical properties of inanimate objects – and – social cognition: reasoning about the mental states of other persons; and that these modes of cognition respectively engage TPN and DMN.
TPN, as per them, can be broken into two related, but separate, networks: the Dorsal Attention Network (DAN) and the Fronto-pareital control Network (FPCN). The DAN is more anti-correlated and deactivated when people indulge in mentalistic cognition; and FPCN is not implicated to the same extent.
The authors also invoke Dennett’s and Robbins & Jack’s concept of ‘stances’ indirectly and relate them to these three networks.
To recap, Dennett’s stances are like this:
- Physical stance: the domain of physics and chemistry: focus is on causal/mechanical explanation informed by universal laws. Determinism prevails. Spatial cognition and perception is important.
- Intentional stance: the domain of psychology and sociology: focus is on internal states (beliefs, desires, intentions etc) of agents that inform their behaviour. Free will for self and others is assumed. Mindreading, mentalizing, ToM are important underlying abilities.
- Design stance: the domain of biology, engineering and economics: focus is on functional use or utility of an object/ feature. Objective utility rules. Planning and executive control directed towards utilizing and using the objects is important.
And the 4th stance added by Robbins
- Phenomenal stance: the domain of morality and humanity: focus is on self-similar experiential qualities of other peers (qualia or what–it-is-like-to-be). Conscious experience or qualia is in focus. Empathy and compassion directed towards relating to another person is important.
To be clear, the world we inhibit is made up of two types: inanimate objects and conscious persons. Both require different stances and activate different brain networks. Thinking about inanimate objects activates TPN while thinking about conscious persons activate DMN.
However, conscious persons or entities are typically represented as having two properties: Agency and Experience. Considering that conscious persons have agency and are intentional means taking an intentional stance towards them. Considering that conscious persons are experiential and there is something it means to be like them, one needs to take a phenomenal stance towards them.
The distinction between Agency and Experience is also reflected in Competence and Warmth dimensions of personality by which people judge leaders etc. when indulging in folk-psychology. Thus, this suggests a bifurcation of DMN such that one DMN sub-part is more concerned with Experience while the other with Agency.
Buckner et al propose exactly such a division of DMN with the DMN sub-network consisting of dMPFC being more concerned with mental simulation and computing agency; while the DMN sub part concentrated around hippocampal formation more concerned with episodic experience and memory and how that may guide empathising with others.
It is instructive to note here that autistics have selective deficit in Intentional part of DMN (dMPFC), rather than Phenomenal part; while Psychopaths have the reverse profile (deficits in DMN around Hippocapmal Formation (HF+)).
It is also instructive to note that just like conscious persons have two different dimensions: Agency and Experience; inanimate objects too have two dimensions: Structure and Function of that object.
When focusing on structure or what it is made of, we can take a psychical stance towards the object. When focusing on function or what it is made for, we can take a design stance towards the object.
Taking the physical stance maps to activating the DAN: you need to pay attention to what is happening focally in the world out there, to predict and make sense. Taking the design stance maps to activating the FPCN: you need to figure the utility of the object (what it is for) and thus plan or control your actions to make full use of opportunities that object provides.
Thus I would suggest that there are four stances one can take with respect to people and objects out there and these different stances activate different resting state networks or ICN’s.
- Physical stance: DAN: attention (Affective/sensory in nature as per ABCD model)
- Intentional stance: DMN-dMPFC: consciousness (Behavioural/motor in nature)
- Phenomenal stance: DMN-HF+ : memory (desire/dynamics part of ABCD)
- Design stance: FPCN: planning and control (cognitive part of ABCD)
One can see many dissociations and oppositions above: it has been shown that attention and consciousness dissociate; so too executive control/working memory dissociate from episodic memory. The above model makes much stronger predictions than the broader DMN-EAN opposition model. For eg., if physical and intentional stance subsume mechanistic and mentalistic reasoning, then anti-correlations should be seen between only DAN and DMN-dMPFC in tasks as employed by Jack et al. However, if as is well known economic and moral reasoning work at cross-purposes and if as hypothesized, design and phenomenal stances are behind that, then taks that emply differences in that area will differentially and dissociably recruit FPCN and DMN-HF+.
The above can be validated using good experiments and will provide a better framework with which to look at the fundamental brain networks and fundamental stances one can take.