Inattentional blindness versus inattentional amnesia for fixated but ignored words.

People often are unable to report the content of ignored information, but it is unknown whether this reflects a complete failure to perceive it (inattentional blindness) or merely that it is rapidly forgotten (inattentional amnesia). Here functional imaging is used to address this issue by measuring brain activity for unattended words. When attention is fully engaged with other material, the brain no longer differentiates between meaningful words and random letters, even when they are looked at directly. These results demonstrate true inattentional blindness for words and show that visual recognition wholly depends on attention even for highly familiar and meaningful stimuli at the center of gaze.