My personal definition of consciousness is tied up with memory. What I mean by this is that you can only be conscious of potentially remembered perceptions and that you never remember things that you were not originally conscious of. Maybe the act of implanting the memory is somehow consciousness. Perhaps it's the data compression of the perception prior to storage- replacing the actual data of the perception with smaller links to previous perceptions, or something like that. Any filtering out of non-interesting data happens before this.

I like this definition, because it allows for the huge amount of unconscious signal processing in the brain that we are not aware of. For example, we don't remember the color left eye rod #12579 at such and such a time, but we do remember that there was an orange cat sitting on the stairs.

Anyway, so I think a lot of visual processing is unconscious and it should be no surprise that parts of it happen in different parts of the brain. I don't buy that they are necessarily detecting conscious perception, just some part of the image processing.

So I’ve got an interesting question - how does this fit with the subjective experience (insofar as we can tell) of an Alzheimer’s patient? If they can’t remember the last 20 years say, does that mean they were unconscious for those 20 years?

Every time I follow this train of thought, I also end up pondering time’s arrow. I also wonder - since I’m conscious of typing this right now, can I assume that I will never get Alzheimer’s that will erase this precise moment from my memory?

I guess it depends on what gets damaged.. but you could imagine that the mechanism for consciousness exists even if the memory forming final stage is broken.

Also there are some non-experiential memories which do not require consciousness- I mean stuff like "muscle memory" for skills, and even perhaps location memory.

Gerald Edelman called consciousness the remembered present.

This research seems to be based on the assumption that visual illusions happen in the conscious domain.

Was that firmly established? That would imply for example that animals can't fall for optical illusions which seems wrong - https://www.youtube.com/watch?v=CcXXQ6GCUb8

The idea that animals are not conscious comes from religion, not science.

The only conscious entity that I’m 100% positive exists is myself. If you reject solipsism, none of the traditional criteria that tell apart humans from animals (e.g. language or ethics) hold up to scientific scrutiny as far as consciousness is concerned.

The criteria that have been scientifically vetted (based on information theory among others) also hold for animals and other living beings (genes known as transcription factors form network that are isomorphic in form and function to neuronal circuits).

>The idea that animals are not conscious comes from religion, not science.

and even then: opinions, as they say, vary wildly.

What is the definition for consciousnes anyway?

Is it the feeling that you are conscious, can you really differentiate it from proprioception that most animals have.

Is it the bahavior we see in animals recognizing themselves in the mirror?

Or is it language and the ability to produce valid sounding statements about oneself?

While you are right that we can't exclude the possibility of animals being consciousness, it's well accepted that their conscious level is very low compared to ours.

Is there some neuroscience backing that? Or is this an argument that consciousness is largely based on having language? Which sounds rather anthropomorphic.

It's an argument by induction. Bacteria (and chair legs) we assume must be less conscious than us. So that sets up a sliding scale with us and the higher mammals at the pinnacle.

What's a conscious level?

That sounds like something a theologian moving the goal posts in light of modern findings would say.

The problem is that the term "consciousness" has too many meanings, and any debate about it seems to devolve into people talking past each other.

They aren't looking at all visual illusions, they are only looking at the double-drift illusion. In the paper they say the goal of the study was to use the position shift from this particular illusion to investigate where that perceived position emerges in the processing hierarchy.

They say that the double-drift illusion reveals an integration of motion signals over a second or more, which they say makes it unlikely that early visual areas are responsible for the accumulation of position errors because they have short integration time constants.

It seems more like supporting evidence that some illusions are in the conscious domain? It would interesting to see if there have been any studies on the double-drift illusion and animals.

I get that.

But why can't we have later visual areas, but who are still at an unconscious level? From where the implication that if it's late or has long integration time is conscious?

I might not be understanding what you mean, or I am misinterpreting the paper, or this article is just doing a poor job communicating the research. I don't believe they are assuming or implying that consciousness is required for or detected by this illusion, if that's what you mean.

The authors don't outline what their working definition of consciousness is but it seems to me that the authors are using a higher-order theory of consciousness because they refer to a conscious percept as the end result of some hierarchy of information processing. Would you agree that you consciously perceive all illusions, even if the illusions are caused by some unconscious processes (ie outside conscious domain)?

It makes sense to me that if I were investigating what a conscious percept consists of, I'd take a look at what feeds into it. They say this particular illusion has properties that make it a useful probe which they use to find evidence for WHERE in the flow from sensory representation to conscious percept this unique illusion emerges. It turns out we would not necessarily require consciousness for this illusion (that's not the claim being made), but it's still part of the neural correlates of conscious perception, hence the title of the paper: "Neural correlates of conscious visual perception lie outside the visual system: evidence from the double-drift illusion."

The long integration time in this case really only means that we are unlikely to find emergence in early visual areas, which they confirm with the first experiment that showed an illusory path doesn't share any activation patterns with a matching Gabor path (that has no internal drift) in early visual areas. Then they explored other areas with a whole-brain searchlight analysis and found a shared representation in anterior regions of the brain associated with higher-order processing. That does mean that the representation is stored outside what is usually classified as the visual system, so this evidence suggests the illusion emerges somewhere after the visual system but before the conscious percept.

> That would imply for example that animals can't fall for optical illusions.

why?

What would it mean for there to be an illusion outside of consciousness?

Whats the point of knowing about how perception works? If we can perceive our surroundings, why do understand it and do something good back to the surroundings?

Understanding how we can count things doesn't amount to any good. If we can count things, count the bad things that are happening. Next time reduce the count. That's the only purpose of knowledge.

We don't know what a new discovery will be good for until after we make it.

If you are curious, then the point of figuring out how something works is to satisfy your curiosity.

If you're not curious, then there is no point to it.

On the other hand, curious people poking at things sometimes make discoveries that turn out to be useful. For that reason, even the incurious have learned to tolerate and even encourage the investigations of the curious, even though they often seem pointless.