There are two main strategies in cognitive science that pursue the very nature of mental powers. One is seeking the origins of the processes that can be called intelligent. The other is seeking the nature of what one might call mental objects. This article attempts to establish why mental objects are manipulated in the central nervous system, trying to understand one of the most intriguing features of this manipulation, i.e. switching from automatic to conscious modes of operation. In my view cognitive science has a broader view than cognitive systems, while setting the question about the nature of conscious control as opposed to automatic control. A tentative model of automatic to conscious manipulation is presented using the phase-locked-loop approach. Conscious control would be in this way the resulting process that emerges every time an object, here defined as an oscillation of a group of neurons, displays structural instability, i.e. there is a bifurcation point in the parameters space. >