In Haggard, Patrick. "Human volition: towards a neuroscience of will." Nature Reviews Neuroscience 9.12 (2008): 934., the author states in the caption of Figure 1 (pg. 4):
The primary motor cortex (M1) receives two broad classes of inputs. One key input (left-hand panel) reaches M1 from the supplementary motor area (SMA) and the pre-supplementary motor area (preSMA), which in turn receives inputs from the basal ganglia and the prefrontal cortex.
I'm failing to disambiguate the ending phrase (emphasis mine)
basal ganglia and the prefrontal cortex
Is the "and" meant to be interpreted as a logical AND or logical OR? In other words, does a readiness potential in the pre-supplementary motor area (preSMA) require an active input from both the basal ganglia AND the prefrontal cortex concurrently or is a sufficiently strong signal from either region alone sufficient?
My guess is that the latter is the case. For example, on the very same caption of Figure 1 part b, the author indicates that the signal from the frontopolar cortex starts a chain that ends with voluntary action of the right hand. This indicates that executive control from the frontopolar cortex alone can trigger an eventual movement. Since this is only a hunch, I still want to clarify the point of confusion.
I'm asking this question because I want to figure out a situation at the behavioral level, namely if people can trigger movements purely by executive function and independently of primal urges/apprehensions.
It may be difficult to give a direct and bulletproof answer to the question without a deliberate experiment (see comment). However, I find it acceptable to have a lower standard for potential answer post - for example, conjectures based on indirect evidence.