Consciousness is gated by attending for action: evidence from hemispatial neglect
Our awareness of the visual environment is limited to only those parts of a scene to which we attend. An emerging view is that stimulus representations compete for processing, and for access to awareness. Neurobiological evidence indicates that attention biases this competition via selective enhancement and attenuation that can begin early in the visual pathway, including primary visual cortex. Nevertheless, there is abundant evidence that unattended information is transmitted to later stages of processing, and that the identity of unattended items is registered outside of our awareness. We asked whether limitations for awareness might arise at the level of representations for action and response. We tested patients with visual extinction on their ability to explicitly detect contralesional visual targets, based on whether responses to the contralesional target were the same or different to that of the ipsilesional one. We found that patients were less likely to detect a contralesional target when it required the same response as an ipsilesional target, suggesting that a competition for response processing determines the contents of awareness.