Neural modulations of interference control over conscious perception

The relation between attention and consciousness is a highly debated topic in Cognitive Neuroscience. Although there is an agreement about their relationship at the functional level, there is still no consensus about how these two cognitive processes interact at the neural level. According to the gateway hypothesis (Posner, 1994), attention filters the information accessing to consciousness, resulting in both neural and functional modulations. Contrary to this idea, the cumulative influence hypothesis (Tallon-Baudry, 2012) proposes that both attention and consciousness independently impact decision processes about the perception of stimuli. Accordingly, we could observe an interaction between attention and consciousness at the behavioral level, but not at the neural level. Previous studies have shown that alerting and orienting networks of attention modulate participants' ability to verbally report near-threshold visual stimuli both at behavioral and neural levels, supporting the gateway hypothesis over the cumulative influence hypothesis. The impact of the executive control network of attention on conscious perception, however, has only been explored behaviorally (Colás et al., 2017). In the present study, we employed high-density encephalography to investigate the neural basis of the interaction between executive attention and conscious perception. We presented a classical Stroop task concurrently with a detection task of near-threshold stimuli. In two separate sessions, we manipulated the proportion of congruent and incongruent Stroop stimuli. We found that the Stroop-evoked N2 potential (usually associated to conflict detection and localized in the anterior cingulate cortex) was modulated by both conflict detection and conscious perception processes. These results suggest that the relation between executive control and conscious perception lies in frontal lobe regions associated to conflict detection, supporting the gateway hypothesis over the cumulative influence hypothesis.