What is left of responsibility when we take decisions together with the machines? 

What is left is that aspect of responsibility that refers to our interaction with the machines themselves. I say "our", in the sense of us, humans. This responsibility refers to two levels in particular: it's, for example, the responsibility of the coders, constructors, testers etc of the AI machines and systems. It is the especially responsibility of those who make business with these machines and systems. And then, there is each of us' responsibility, as users of such machines. Actually, each one of us, by activating certain processes with our own prompts, with certain daily usage, directs the machines and programmes in a certain way and produces certain consequences in the environment where we live.

How does trust change when a growing number of decisions is delegated to algorithms?

Trust is an approach that is today extended to programmes and machines as well. Consider that many times we trust Google Maps more than our own eyes. In many cases, in this extension of trust, we are not aware how certain systems work and the difference in the way they work with respect to the way people behave.

Instead, the anthropomorphisation of machines prevails. And thus, by our own ignorance, we finish by not relating to them in the right manner. We take advantage of the opportunities, without understanding the risks. Yet, when it comes to human beings, or at least to some of them, we have learnt to be vigilant.  

The history of man can be read as a progressive delegation of functions? 

It can be seen as a double process: for the repeated delegation of some functions, there has always been a correspondence with the acquisition of other functions. A deskilling is hence a reskilling. For example, when we gave up the central place of memory as oral culture disappeared, it became necessary to learn to read and write in order to transmit knowledge. The risk today is that for a massive loss of skills, we don't have the corresponding reskilling needed, or at least not to the degree required, which is as much and even more massive.

Who is responsible when no one decides alone?

The person guiding the decisions is responsible. And it's responsible he who lets himself guided by the others.