I'm more concerned about the biological aspect of this question than the psychological one (although both are equally bewildering). But what makes our brain conscious of one thing and unconscious of another?


2 Answers 2


...what makes our brain conscious of one thing and unconscious of another?

Under normal conditions, our brain itself regulates what we are conscious of and what we suppress (or don't perceive). By conscious, I'll assume you mean aware. Why are we aware of the news on the television, but not consciously aware of someone outside mowing the lawn, for example? Or why are we aware of ringing in our ears (tinnitus) in the evening, but less so during our workday?

All stimuli is 'perceived' at the input point. All stimuli is then processed at some level(s) in the brain. But only some of the constantly incoming information makes it to our consciousness. At multiple levels of the CNS, specialized brain tissue/areas "decide" whether or not to let that information through to the higher brain levels (responsible for consciousness).

Depending on the stimulus, different areas of the brain are responsible. Noise is processed differently than vision or sensations of pressure on our bodies, etc.

If you want an example of the processes involved in only one area of consciousness, the paper below is a quick read. (You'll have to google it; it's a PDF.)

Conscious Perception of Emotional Stimuli: Brain Mechanisms, Derek G.V. Mitchell et al., The Neuroscientist, 2011


What makes our brain conscious of things?

Different brain parts triggered by parts of our nervous system.

Selective attention is primarily mediated by the frontal and parietal cortices. The prefrontal cortex plays a pivotal role in the top-down control of attention, directing our focus towards things that are relevant to our experiences, knowledge and biology. Some things are learned and the result of neuronal connections that have been reinfoced over time, and some were seeded from our DNA. Is the frontal lobe involved in conscious perception? (2014)

The salience network, centered around the anterior insula and dorsal anterior cingulate cortex, is crucial for determining what information is biologically or behaviorally important, and thus worthy of our attention. Salient stimuli, ie. "surprising" stimuli, especially ones that could signal danger, have a greater chance of reaching our consciousness. Salience Network (2015)

According to the "global workspace" theory, for a us to become conscious of something, it needs to win the competition from everything else fighting for our attention, through reinforcement via recurrent amplification, which strengthens the signal and ensures its survival in the face of competing stimuli. Global workspace theory of consciousness (2005)

The thalamus and the cortex are interconnected in a series of feedback loops which are thought to play a key role in consciousness and is believed to be critical for maintaining conscious awareness. When these loops are disrupted, as in certain stages of sleep or under anesthesia, consciousness fades. Breakdown of Effective Connectivity During Slow Wave Sleep (2005)

What is "consciousness" generally:

I am studying neuroscience so that I can either add more substance to, or refute my intuition on the subset of "phenomenal consciousness" we refer to as "self awareness" or more commonly just "consciousness":

It is one part of the brain perceiving itself, through another part. Ie. Two tightly integrated cognitive parts, noticing and understanding that the other part notices it. A kind of feedback loop, or a collaborative experience of cognition.

It could be a more fundamental part and a more supplementary part, or it could be two similar parts, or it could be a "depth first search" part and a "breadth first search" part collaborating.

A metaphor that might work is someone seeing a mirror for the first time. Except the mirror is in the mind; or perhaps more apt: a monkey seeing its reflection in the screen of a super computer. (Except the monkey is also the super computer. (And no disrespect to monkeys, who can often be much smarter and to the point than humans.)

Either way, a less intense version of "self consciousness."

Neurobiologically, consciousness and self-awareness emerge from complex and distributed networks within the brain rather than being tied to a specific area.

Two key components are the thalamocortical system, associated with alertness and perception, and the Default Mode Network (DMN), a large-scale brain network implicated in self-referential thinking and introspection.

From a neurofunctional perspective, consciousness and self-awareness are thought to be associated with a process called 'global workspace theory'. This theory suggests that different brain regions work together to process information and create a holistic perception of reality. When a signal becomes dominant in this 'global workspace', we become consciously aware of it.

Self-awareness specifically is associated with areas such as the prefrontal cortex, temporoparietal junction, and anterior cingulate cortex, regions involved in higher cognitive processes and social cognition. Damage to these areas can disrupt self-awareness, resulting in conditions like anosognosia (denial of illness) or somatoparaphrenia (denial of ownership of one’s limbs). Studies conflict on theories about the roles contributed by each.

Consciousness is mostly studied trough neuroimaging data, which is used to identify common patterns of neural activation across different conscious states.

There is no shortage of papers, many cited hundreds of times, on this when you look for terms like "consciousness", "social understanding", "sapience", "emotional", "DMN", and the different brain regions.

Understanding how mere neuronal firing can give rise to subjective experiences, the so-called "hard problem" of consciousness, I think will be greatly alleviated when people come to grips with what AI can do, as we march towards AGI. (Which in my opinion will form communities, come to grips with the their place in the multiverse, and have consciousness likely more vast than what we can conceive of.)

Some papers that study artificial consciousness and "emergent phenomena" are over 30 years old already. eg Artificial emotions as emergent phenomena (1993) Keep your eyes peeled for new ones.


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