However, what is the value of processing important information if it does not lead to specific changes in observers' attentional states and preparation for action? For example, if highly attractive, aversive, or threatening information comes from one side of the visual field and it subsequently activates emotional brain systems without awareness, will this lead to a reorienting of spatial attention? Activation of the amygdala may or may not carry specific spatial information. One natural question is whether activation of the emotional system also directs observers' attention to the stimulus in the absence of awareness. Emotionally salient information was also shown to receive enhanced processing under limited attention, such as during the attentional blink, with the amygdala playing a critical role ( 6).
Recent studies have shown that subliminal presentation of emotional stimuli can modulate activity of the amygdala ( 4, 5), a subcortical nucleus that is centrally involved in emotional information processing. However, it makes ecological and evolutionary sense if important events can influence observers' spatial attention even before the observer becomes aware of the event. Intuitively, in order for a “cue” to attract visual spatial attention, the “cue” needs to be perceived by the observer. Salient events in a visual scene can attract visual attention and subsequently enhance information processing at the attended location ( 1 – 3).