Dotov, Nie, and Chemero on Extended Cognitive Systems

Tony Chemero sent me a link to his paper in PLoS.

Their theory of cognitive systems jumped out at me:

Hammers and other tools that are ready-to-hand are literally part of the cognitive system. When a tool malfunctions, however, and becomes unready-to-hand, it becomes the object of primary concern; it is no longer part of the extended cognitive system, rather it is the thing that that the cognitive system is concerned with.

This seems to raise some questions.

I. When I get a piece of dust in my eye and it becomes an object of primary concern, then my eye is no longer part of my cognitive system?  Or, I have a nervous system breakdown or brain tumor that draws attention to the nervous system, that makes my nervous system not a part of my cognitive system?

II. By this account, the general moral is that one cannot pay attention to one's own cognitive system. Is this a desired result?

III. This account seems to conflict with van Gelder's theory of what a dynamical systems cognitive system is:

In this vision, the cognitive system is not just the encapsulated brain; rather, since the nervous system, body, and environment are all constantly changing and simultaneously influencing each other, the true cognitive system is a single unified system embracing all three.  The cognitive system does not interact with the body and the external world by means of the occasional static symbolic inputs and outputs; rather, interaction between the inner and the outer is best thought of as a matter of coupling, such that both sets of processes continually influencing [sic] each other’s direction of change (van Gelder, 1995, p. 373).

I don't buy van Gelder's account, but the conflict would go something like this.  You might be constantly influencing your injured, malfunctioning eye and your injured, malfunctioning eye is constantly influencing you, so that by the van Gelder standard, your injured, malfunctioning eye is part of your cognitive system.  But, by the Heiddeggerian standard, since your injured, malfunctioning eye is a subject of your attention, it is not part of your cognitive system.  Is this a desired result?