Starting with Libet’s work in 1985, a body of evidence has been built up suggesting that actions can be initiated unconsciously and unintentionally. This evidence questions the idea of complete conscious control over behavior, and the philosophical idea of free will.
The idea of ‘free won’t’, however remained. According to some influential theories, unconscious behaviours are the inflexible reproduction of well-learned associations. To understand consciousness we need to discover what processes need consciousness and which don’t. Is consciousness required to inhibit actions?
Experiments seemed to show that subliminal signals could inhibit action. Then the theories on unconscious engagement of inhibition suggests that (a) consciousness is in fact required for inhibitory control in that the stimuli were first consciously associated with inhibition before being used subliminally and (b) willful conscious intent is also required to form a goal or desire to modulate inhibition. Also it was thought that unconscious inhibition might be the result of modulation of motor control processes rather than normal inhibitory control processes.
A recent paper by Hepler and Albarracin (see citation) tackle this question. They found a method of using word primes that suggested action or inaction (as opposed to a specific action) and used the P3 wave strength to gauge the inhibitory processes. The experiments side-step the three possibilities of the arguments against unconscious inhibition of actions.
“This research represents a critical finding in the scientific study of consciousness because it demonstrates that inhibitory self-control mechanisms can operate unconsciously and unintentionally, without prior conscious input – that is, inhibition processes can be engaged by motivationally relevant stimuli that have never been consciously or unconsciously paired with specific, task-relevant responses. Although previous work has demonstrated similar effects on behavior, behavioral inhibition can occur as the result of multiple cognitive processes other than the engagement of inhibitory control mechanisms. Thus, the present research is the first to demonstrate that inhibitory control mechanisms can be modulated completely outside of conscious control. ”
Justin Hepler, & Dolores Albarracin (2013). Complete unconscious control: Using (in)action primes to demonstrate completely unconscious activation of inhibitory control mechanisms Cognition, 128 (3) : 10.1016/j.cognition.2013.04.012