I can see both at the same time, and switch between different modes at will. I also tend to be immune to or see much more clearly all kinds of optical illusions and visual effects like this at various at will, or see them all the different possible ways simultaneously, able to see intuitively why things like this works, separately see "colours" like "movement speed" and "local contrast" in a way that intuitively feels like they were sent from the eyes as separate from maps of those properties that have more a feel of concious deduction and are immune to many common optical illusions, am ascribed a good aesthetic sense and artistic talent, tend to move my eyes and scroll on displays in ways that others find disturbing or even painful but I feel constrained and tunnel visioned if I try not to, I have occupationally experienced something reminiscent of blindishgt for short periods of time (remicent in the same sense as a polar opposite is), and am able to "see" things other's can't, and a bunch of other related superpowers.
Hope this is interesting enough as a case study to not come of as bragging. Feel free to run experiments on me since i love this kind of thing.
Summary: Neuroimaging scans and EEG readings comparing nonconscious and conscious stimuli are compared, showing particular patterns in conscious processes. These findings are in line with predictions made by the Global Workspace Theory of consciousness, in which consciousness is closely related to interaction between specialized modules of the brain.
When a bunch of photons hit your eye, it unleashes a long chain of cause and effect that leads to an image being mapped in your brain. When does that image become conscious?
Merikle et al performed experiments in the 80s which helped to resolve this question. In the Stroop task, people are asked to read words written in a different color than the word. Words written in their color (green) are easier to read than those not in their color (also red). Merikle modified the stroop task, using only two colors (red and green), and using the word to prime subjects to describe the color. As was expected, when "green" comes before a green square, subjects respond faster than with no priming.
However, when the situation is regularly reversed and the "red" prime normally comes before a green square (and vice versa) people also respond faster to similar levels. That is to say, subjects are able to notice that the prime and stimulus are incongruent, and act on that information to respond faster to the stimuli.
When the reversed prime ("red" before green) is flashed for such a short time span that people don't report seeing it, they are unable to use this information to react faster to the green stimulus, and the typical Stroop effect is observed -- being subliminally primed with a congruent color speeds up recognition, being subliminally primed with an incongruent color slows it.
The idea that conscious access is related to recurrent processing in the frontoparietal region stands up to experimental verification. Researchers are able to interfere with conscious reports of information independently of stimulus identification simply by applying transcranial magnetic stimulation to the prefrontal cortex, without changing the stimulus.8
Notes
A huge thanks to John Salvatier for getting me a bunch of the papers and editing feedback and putting up with my previous attempts to write an article like this. Also thanks to mtaran, falenas108, and RS (you don't know him) for reading drafts of this article.
Images are from Zeki 2003 and Dehaene 2011, respectively. I'd be very happy if someone helped me format that to show up with the pictures.
1Merikle & Joordens, 1997
2Dehaene, S., & Changeux, J.-P. 2011
3Breitmeyer & Ogmen, 2007
4Moutoussis & Zeki 2002, Image from Zeki 2003
5Tsuchiya & Koch
6Marti et al 2010
7Lamme 2006
8Rounis et al 2010
9Baars 1997
10Metzinger
References
Baars, B. (1997). In the Theatre of Consciousness: The Workplace of the Mind. New York: Oxford University Press. Retrieved from here
Bruno G. Breitmeyer and Haluk Ogmen (2007) Visual masking. Scholarpedia, 2(7):3330
Dehaene, S., & Changeux, J.-P. (2011). Experimental and theoretical approaches to conscious processing. Neuron, 70(2), 200-27. Elsevier Inc. doi:10.1016/j.neuron.2011.03.018
Kouider, S., & Dehaene, S. (2007). Levels of processing during non-conscious perception: a critical review of visual masking. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 362(1481), 857-75. doi:10.1098/rstb.2007.2093
Lamme, V. A. F. (2006). Towards a true neural stance on consciousness. Trends in Cognitive Sciences, 10(11). doi:10.1016/j.tics.2006.09.001
Merikle, P. M., & Joordens, S. (1997). Parallels between perception without attention and perception without awareness.Consciousness and cognition, 6(2-3), 219-36. doi:10.1006/ccog.1997.0310
Lamme, V. A. F. (2006). Towards a true neural stance on consciousness. Trends in Cognitive Sciences, 10(11). doi:10.1016/j.tics.2006.09.001
Lau, H., & Rosenthal, D. (2011). Empirical support for higher-order theories of conscious awareness. Trends in cognitive sciences, 15(8), 365-373. doi:10.1016/j.tics.2011.05.009
Marti, S., Sackur, J., Sigman, M., & Dehaene, S. (2010). Mapping introspection’s blind spot: reconstruction of dual-task phenomenology using quantified introspection. Cognition, 115(2), 303-13. Elsevier B.V. doi:10.1016/j.cognition.2010.01.003
Metzinger, T. (2003). Being No One. Philosophy, 699. MIT Press.
Moutoussis, K., & Zeki, S. (2002). The relationship between cortical activation and perception investigated with invisible stimuli. Proceedings of the National Academy of Sciences, 99(14), 9527. National Acad Sciences. doi:10.1073/pnas.PNAS
Rounis, E., Maniscalco, B., Rothwell, J., Passingham, R., & Lau, H. (2010). Theta-burst transcranial magnetic stimulation to the prefrontal cortex impairs metacognitive visual awareness. Cognitive Neuroscience, 1(3), 165-175. doi:10.1080/17588921003632529
Tsuchiya, N., & Koch, C. (2005). Continuous flash suppression reduces negative afterimages. Nature neuroscience, 8(8), 1096-101. doi:10.1038/nn1500
Zeki, S. (2003). The disunity of consciousness. Trends in Cognitive Sciences, 7(5), 214-218. doi:10.1016/S1364-6613(03)00081-0