Dear Alex and colleagues,

Thanks for the opportunity to ad a few lines on signaling matters. I would not discard any organizational aspect of signaling pathways. I have put below a diagram that approaches the dynamics of some major ones.Your analogy with mobile phones would be right, provided that conversations were mixed, that a number of receivers were just random, and that a component of "experience information" would be entered too --I think it can apply to the dynamics of second messengers, where multitudes of microevents and pathways may be integrated via lots of feedbacks (See the box in the figure below). Symmetry is a big word concerning the organization of pathways in the construction of multicellular development... opposed paths, tipping points, collective (populational) symmetry breakings, massive feedbacks, etc.

By the way, when we commented days ago on Tononi's phi, both from John Collier and myself, the idea was to consider it as applied to the closure of meaning episodes in language. How "getting" the meaning of some linguistic episode (eg, a joke) provokes a sudden change of transient connectivity between areas...

Apart from meaning, it may also be interesting that there seems to be a strong asymmetry in between the incoming / outgoing information flows--the "social info loops" around. In most human organizations, the ratio is in between 3 and 4. It means that you and me are ordered by upper levels in around 80 % of our exchanges, while what we send upwards becomes a meager 20 %. It is from a statistics on business communication metrics. The generalization is far from direct, but maybe it would occur in the cells too--amazingly there is very little literature on cellular "signal emission".

Anyhow, how the whole ascending and descending info flows give raise to all the varieties of organizational complexity is a fascinating problem,

All the  best--Pedro

*Figure 6: Prototypical signaling pathways of multicellularity.*From left to right, a stimulus in the intercellular space binds to a transmembrane receptor (sensor) on its extracellular domain. Upon binding, the receptor undergoes a transient modification of its cytoplasmic domain; this effect triggers a transient modification of a series of proteins in the cell, each one acting as an intermediate in the signal transduction pathway (signal processing), with characteristic hierarchies of protein kinases and second messengers. The last components are actuators or effectors that activate or inhibit proteins and channels that control several cellular functions, notably gene expression by means of transcriptional switches that may interact with several coactivator partners. The whole biochemical changes produced in the cell represent the response to the received signal —its /molecular meaning/.

 El 26/04/2016 a las 10:10, Alex Hankey escribió:
Dear Pedro,

Thank you for the comments on my presentation, and particularly for reminding us all that life transmits information of many different kinds by very specific and selective processes in chemical signally molecules.

I must confess that I had assumed that such kinds of signals could be considered special cases of digital information analogous to the codes transmitted by a digital signalling tower in a mobile telephone network, where the initial code has to name the device that the rest of that message section is meant to receive.

In mobile phone systems, individual devices are sent information by identifiers. If we have a nervous system working with several neurotransmitters, or a cell signalling system working with a number of cytokines, each with a specific regulatory influence / purpose, are these individual items not performing in ways that are covered by the usual combination of Wiener and Shannon, and therefore in principle understood, and AS YOU SPECIFICALLY POINT OUT, with no particular "experience" component.

I wonder whether the material I transmitted made the following point succinctly / precisely enough: David Chalmers specifically hypothesized that 'experience information' (my terminology) mst have a double aspect, and that the 'loop' arising from criticality specifically fulfils his hypothesis in a new and potent way. (The material contains so many points that this, to my mind, really significant one may have got buried.)

Thank you also for appreciating the amplification of Tononi's contribution (Tononi, I personally regard as of real significance). The internal loop creates the internal coherence that is required to form the 'integrated information'.

I have a suspicion that the following propositions are probably correct:
a. any information structure that is truly 'non-reductive'
(Chalmers requirement 3) must possess long range coherence.
b. any information structure with long-range coherence will be a form of integrated information.
c. Hence Chalmers requirement 3 in fact specifies integrative information.
This sequence a, b, c simplifies what those writing in the 1990's were saying: they were in fact setting equivalent requirements on the form of 'experience information' (though Tononi undoubtedly thought he was saying something different, as did those who followed up on his work, and Chalmers did not realize that Tononi's proposal was equivaent to the point that he had proposed.

Anyone's thoughts on this would be very much appreciated,
All best wishes,


Pedro C. Marijuán
Grupo de Bioinformación / Bioinformation Group
Instituto Aragonés de Ciencias de la Salud
Centro de Investigación Biomédica de Aragón (CIBA)
Avda. San Juan Bosco, 13, planta X
50009 Zaragoza, Spain
Tfno. +34 976 71 3526 (& 6818)

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