Familiar and recognizable stimuli enjoy an advantage of predominance during binocular rivalry, and this advantage is usually attributed to their enhanced processing during the dominant phase. However, do familiar and recognizable stimuli have an advantage in breaking suppression? Test images were gradually introduced to one eye to compete against a standard high-contrast dynamic noise pattern presented to the other eye. Results showed that an upright face took less time than an upside-down face to gain dominance against the identical suppression noise. Results also showed that for Chinese readers, Chinese characters were faster to gain dominance than Hebrew words, whereas for Hebrew readers, the reverse was true. These results suggest that familiar and recognizable information, even when suppressed and invisible, is processed differently from unfamiliar information. Apparently, high-level information about visual form does contribute to the strength of a stimulus during its suppressed phase.

Human observers are constantly bombarded with a vast amount of information. Selective attention helps us to quickly process what is important while ignoring the irrelevant. In this study, we demonstrate that information that has not entered observers' consciousness, such as interocularly suppressed (invisible) erotic pictures, can direct the distribution of spatial attention. Furthermore, invisible erotic information can either attract or repel observers' spatial attention depending on their gender and sexual orientation. While unaware of the suppressed pictures, heterosexual males' attention was attracted to invisible female nudes, heterosexual females' attention was attracted to invisible male nudes, gay males behaved similarly to heterosexual females, and gay͞bisexual females performed in-between heterosexual males and females.awareness ͉ interocular suppression ͉ attention S alient events in a visual scene can attract visual attention and subsequently enhance information processing at the attended location (1-3). Intuitively, in order for a ''cue'' to attract visual spatial attention, the ''cue'' needs to be perceived by the observer. However, it makes ecological and evolutionary sense if important events can influence observers' spatial attention even before the observer becomes aware of the event. 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. 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). One natural question is whether activation of the emotional system also directs observers' attention to the stimulus in the absence of awareness. 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. 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?To investigate the ability of invisible information to guide spatial attention, we combined two paradigms: interocular suppression to render stimuli invisible (5, 7, 8) and a modified version of the Posner cuing paradigm to test the effect of spatially directed attention (1-3). In the interocular suppression paradigm, a pair of highcontrast dynamic noise patches are presented to both sides of a fixation point in one eye, and a test picture and its scrambled control are presented to the fellow eye in spatial locations corresponding to the noise patches. Because of strong interocular suppression, the intact meaningful image and its scrambled control remain invisible for the period they are presented. If the suppr...

In general, stimuli that are familiar and recognizable have an advantage of predominance during binocular rivalry. Recent research has demonstrated that familiar and recognizable stimuli such as upright faces and words in a native language could break interocular suppression faster than their matched controls. In this study, a visible word prime was presented binocularly then replaced by a high-contrast dynamic noise pattern presented to one eye and either a semantically related or unrelated word was introduced to the other eye. We measured how long it took for target words to break from suppression. To investigate word-parts priming, a second experiment also included word pairs that had overlapping subword fragments. Results from both experiments consistently show that semantically related words and words that shared subword fragments were faster to gain dominance compared to unrelated words, suggesting that words, even when interocularly suppressed and invisible, can benefit from semantic and subword priming.

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