Figure 1.

fMRI and EEG evidence for separate neuronal processes underlying attention and consciousness. a) fMRI study showing that, while attention increases neuronal response magnitudes independently of whether a stimulus reached conscious perception, the larger difference in neuronal activity is related to whether a subject was conscious or unconscious of that stimulus (note the difference in units on the y-axis). b) EEG response magnitudes to conscious and unconscious stimuli in the presence or absence of attention, showing a similar effect as a). c) EEG responses to conscious (magenta) vs. unconscious attentional (cyan) cues. Note that even a cue that is not consciously perceived evokes an elevated (albeit somewhat smaller). EEG response, indicating attentional enhancement of neuronal responses.