Features of inattentional blindness:
(1) The person fails to perceive a stimulus.
(2) The person's attention is focused elsewhere:
(2a) visual fixation on an external object
(2b) inward focus (daydream, deep thought, etc.)
(2c) highly complex task
(2d) mixed activity with limited attentional resources (driving and talking, other multi-tasking)
(3) The stimulus may be perceived if the person's attention is not focused elsewhere.
The risk of inattentional blindness to an alarm can be reduced by:
(1) making the alarm multi-modal (sound, flashing light, changing colors, etc.)
(2) inserting the warning into the task being performed
(3) training and education
Differential diagnosis:
(1) color blindness
(2) low signal frequency (stimulus occurs at a rate low enough to be missed by an observer taking intermittent readings)
(3) inability to understand message (foreign language, term unknown)
(4) intentional disregard of the warning
