A Connectionist Model of Inhibition in Masked Priming (abstract)

A key question that has come to dominate a large body of research on perception to action coupling is the role that consciousness plays in such binding. In fact, there is now considerable evidence that visual stimuli can affect response tendencies even when the stimuli are not consciously perceived. Furthermore, there is also now evidence that subliminally presented stimuli can induce inhibitory effects. It is argued that this inhibitory reversal implements an emergency breaking mechanism - once the evidence for a response is removed (as accrues from mask presentation) the corresponding motor action is suppressed. These results prompt consideration of the computational mechanism that underlies such an inhibitory reversal. Our proposal is that the effect arises from the interplay of response competition (as implemented by lateral inhibition) and a threshold gated direct suppression of strongly activated response nodes. The latter of these is implemented using dedicated opponent processing circuits, Here we present a neural networks-based implementation of these principles, the behaviour of which has a good fit to the available data.