This paper examines three properties of attentional inhibition mechanisms. First, previous research has suggested that the inhibitory mechanism of selective attention has a central locus between perception and action. We attempt to confirm the locus of this inhibition. Second, the processing of an unattended stimulus has been observed via the effects of the stimulus on a concurrent target (interference), and on a subsequent target (negative priming). The former effect demonstrates that distractors interfere with the processing of the target, and the latter negative priming effect implies that distractors are inhibited during selection. We demonstrate that these two measures of unattended processing can be dissociated. Third, we reveal that inhibition appears to be a stable mechanism of selection, in that effects do not decline after a large number of experimental trials.