Here is Clark, (2008):
Now, it is certainly true (and this, I think, is one important fact to which Adams and Aizawa's argument quite properly draws the reader's attention) that not just any old kind of coupling will achieve this result. But as far as I am aware, nobody in the literature has ever claimed otherwise. It is not the mere presence of a coupling that matters but the effect of the coupling-the way it poises (or fails to poise) information for a certain kind of use within a specific kind of problem-solving routine. (p. 87).Wilson & Clark, (2009) also present the weakening as part of a reply to A&A here:
One key failure of the arguments supporting the extended-mind story, they suggest (this volume), is the failure of those arguments to distinguish mere causal influence from constitution. Now merely coupling a resource to an agent does not, of course, make it part of the agent. But this does not show the nature and degree of intercomponential coupling to be irrelevant to the question of constitution. What makes my hippocampus part of my cognitive system, it seems fair to say, has a great deal to do with how it is informationally integrated with the rest of my cognitive system. We can imagine a case in which, despite being firmly located in my head, there is zero integration and hence the onboard hippocampus fails to form part of my active cognitive system. Contrariwise, we can imagine a hippocampus in a distant vat whose activity is so well integrated as to unproblematically count as part of my cognitive apparatus (see, e.g., Dennett, 1978 - a classic treatment titled "Where Am I?"). Coupling, we conclude, does not in and of itself render a tool or resource part of the agent's cognitive apparatus. But the right kind of coupling (one resulting in deep functional integration) is a major part of what determines the scope and bounds of an agent's cognitive apparatus. (p. 68)
Clark, A. (2008). Supersizing the mind: Embodiment, action, and cognitive extension. New York: Oxford University Press, USA.
Wilson, R. A., & Clark, A. (2009). How to situate cognition: Letting nature take its course. In P. Robbins & M. Aydede (Eds.), The Cambridge Handbook of Situated Cognition (pp. 55-77). New York: Cambridge University Press.