Category-selective attention interacts with partial awareness processes in a continuous manner: An fMRI study

Recently, our team found that category-selective attention could modulate tool processing at the partial awareness level and unconscious face processing in the middle occipital gyrus (MOG). However, the modulation effects in MOG were in opposite directions across the masked tool and masked face conditions in that study: MOG activation decreased in the masked faces condition but increased in the masked tools condition under the consistent compared with the inconsistent cue-selective-attentional modulation. In the present study, in order to confirm that the opposite effects were due to the changed contours of the tools, using the same tool pictures and fMRI technique, we devised another two conditions: variant mirror tool picture condition and invariant tool picture condition. The results showed that, during the variant mirror tool picture condition, activation in the MOG decreased under tool-selective attention compared with face-selective attention. Interestingly, however, during the invariant tool picture condition, activation in the MOG revealed neither positive nor negative changes. Combined with the result of increased MOG activity in the changed different tool condition, the three different effects demonstrated not only that the unconscious component of partial awareness processing (no knowledge of the identity of the tool) could be modulated by the category-selective attention in the earlier visual cortex but also that the modulation effect could further interact with the conscious component of partial awareness processing (consciousness of the changing contour of the tool) in a continuous manner.