Is consciousness a continuous flow of awareness without intervals or is it something that emerges continually at discrete points in a cascade of microbits?
The Buddhist answer has always been the latter.
The Buddha’s five skandha explanation of perception and consciousness says that there are four discrete steps that are the basis of consciousness.
The five skandhas are form, sensation, perception, activity, consciousness. A form can arise in the mind or outside of the mind. This form gives rise to a sensation, which gives rise to perception, followed by activity (mental or physical), and lastly consciousness. In the Buddha’s explanation, the five skandhas occur one after the other, very rapidly. They are not a continuous stream but rather a series of discrete or discernible moments. A form arises or appears, then there is a sensation, then perception, then activity, then consciousness. (The five skandhas and modern science)
The first four skandhas are normally unconscious. Buddhist mindfulness and meditation training are importantly designed to help us become conscious of each of the five skandhas as they actually function in real-time.
A study from 2014—Amygdala Responsivity to High-Level Social Information from Unseen Faces—supports the five skandha explanation. From that study:
The findings demonstrate that the amygdala can be influenced by even high-level facial information before that information is consciously perceived, suggesting that the amygdala’s processing of social cues in the absence of awareness may be more extensive than previously described. (emphasis added)
A few days ago, a new model of how consciousness arises was proposed. This model is being called a “two-stage” model, but it is based on research and conclusions derived from that research that support the Buddha’s five skandha explanation of consciousness.
The study abstract:
We experience the world as a seamless stream of percepts. However, intriguing illusions and recent experiments suggest that the world is not continuously translated into conscious perception. Instead, perception seems to operate in a discrete manner, just like movies appear continuous although they consist of discrete images. To explain how the temporal resolution of human vision can be fast compared to sluggish conscious perception, we propose a novel conceptual framework in which features of objects, such as their color, are quasi-continuously and unconsciously analyzed with high temporal resolution. Like other features, temporal features, such as duration, are coded as quantitative labels. When unconscious processing is “completed,” all features are simultaneously rendered conscious at discrete moments in time, sometimes even hundreds of milliseconds after stimuli were presented. (Time Slices: What Is the Duration of a Percept?) (emphasis added)
I, of course, completely support science going where the evidence leads and am not trying to shoehorn these findings into a Buddhist package. Nonetheless, that does sound a lot like a slimmed-down version of the five skandhas. Considering these and other recent findings in a Buddhist light may help science resolve more clearly what is actually happening in the brain/mind.
As for form-sensation-perception-activity-consciousness, you might suddenly think of your mother, or the history of China, or the spider that just climbed onto your shoulder.
In Buddhist terms, initially, each of those items is a form which leads to a sensation which leads to perception which leads to activity which leads to consciousness.
Obviously, the form of a spider on your shoulder differs from the form of the history of China. Yet both forms can be understood to produce positive, negative, or neutral sensations, after which we begin to perceive the form and then react to it with activity (either mental or physical or both) before becoming fully conscious of it.
In the case of the spider, the first four skandhas may happen so quickly, we will have reacted (activity) to it (the spider) before being conscious of what we are doing. The skandha of activity is deeply physical in this case, though once consciousness of the event arises our sense of what the first four skandhas were and are will change.
If we slapped the spider and think we killed it, our eyes will monitor it for movement. If it moves and we are sensitive in that way, we might shudder again and relive the minor panic that just occurred.
If we are sorry that we reacted without thinking and notice the spider is moving, we might feel relief that it is alive or sadness that it has been wounded.
In all cases, our consciousness of the original event, will constellate around the spider through monitoring it, our own reactions, and whatever else arises. Maybe our sudden movements brought someone else into the room.
The constellation of skandhas and angles of awareness can become very complex, but the skandhas will still operate in unique and/or feedback loops that can often be analyzed.
The word skandha means “aggregate” or “heap” indicating that the linear first-fifth explanation of how they operate is greatly simplified.
The above explanation of the spider can also be applied to the form skandhas of the history of China or your mother when they suddenly arise in your mind, or anything else.
We can also perceive the skandhas when our minds bring in new information from memory or wander. As we read, for example, it is normal for other forms to enter our minds from our memories. Some of these forms will enhance our reading and some of them will cause our minds to wander.
Either way, our consciousness is always slightly jumpy because it emerges continually at discrete points in a cascade of microbits, be they called skandhas or something else.
Edit: The first four skandhas can be stilled in meditation.