Method at a glance
- Modality: visual (interocular suppression)
- Measures: How long a stimulus stays out of conscious awareness — a proxy for conscious access / unconscious visual processing
- Procedure: A high-contrast, rapidly changing pattern (‘Mondrian’ masks, typically ~10 Hz) is shown to one eye while a static or slowly-introduced target is shown to the other. Interocular competition renders the target invisible; the target is ramped up (or held) until it ‘breaks through’ into awareness, and the time-to-emergence (breaking-CFS time) is recorded. Shorter breakthrough = weaker suppression = privileged access.
- Also called: CFS, breaking CFS, b-CFS
Strengths
- Produces long, controllable periods of invisibility (seconds), far longer than binocular rivalry or masking — enough to run an fMRI trial on a stimulus the participant never consciously sees.
- Breaking-time is a graded, continuous dependent measure sensitive to stimulus properties (emotional content, familiarity, congruence) that modulate access to awareness.
Limitations
- Breaking-CFS time as a proxy for ‘conscious access’ has been criticized (Stein et al. 2011; Yang et al. 2014): differences in breakthrough time can reflect low-level detectability or post-perceptual processes rather than a genuine difference in unconscious processing.
- Requires dichoptic presentation (mirror stereoscope, prisms, or HMD) and depends on eye dominance; needs control conditions (e.g. non-suppression ‘blended’ presentation) to rule out response/detection bias.
Connections
- Key studies: Salomon et al. (2016)
- Related methods: Visual crowding, Heartbeat detection task
A visual-psychophysics technique for rendering a stimulus invisible for a sustained period, used to study what the brain processes outside of awareness. A rapidly changing high-contrast pattern (“Mondrians”) is flashed to the dominant eye; a target presented to the other eye is suppressed from consciousness by the interocular competition. Because the suppression lasts seconds — much longer than binocular rivalry or backward masking — CFS is the workhorse for asking whether invisible stimuli are still processed, and how fast different stimuli “break through.”
Breaking CFS (b-CFS) uses the time to emergence as the dependent measure: a stimulus that reaches awareness faster is treated as having privileged access. Emotional faces, one’s own name, and semantically congruent images all break suppression faster than their controls.
In this wiki
- Salomon et al. (2016) used b-CFS to show that a visual target flashed synchronously with the viewer’s own heartbeat takes longer to break suppression than an asynchronous one — interoceptive timing suppressing exteroceptive awareness. Crucially, they also ran a full-suppression fMRI version (the target never becomes visible) to localize the effect in the anterior insula independent of time-to-emergence, and a classic non-suppression CFS control (target blended into both eyes) to rule out a response/detection bias.
Caveats the wiki cares about
The breaking-CFS measure is contested: a “faster breakthrough” can be a difference in low-level detectability or in post-perceptual decision rather than in genuine unconscious processing (Stein et al. 2011; Yang et al. 2014). Studies that lean on it are stronger when — as in Salomon et al. — they pair it with a full-suppression measure and a converging paradigm that does not use time-to-emergence (there, Visual crowding).