is consciousness like a rapid series of photographs?

<i>"[Moving pictures] is an analogy that Henri Bergson used twenty years later,

in his 1908 book Creative Evolution, where he devoted an entire section to 'The

Cinematographic Mechanism of Thought, and the Mechanistic Illusion':</i>

<p>

'We take snapshots, as it were, of the passing reality, and...we have only to

string these on a becoming, ...situated at the back of the apparatus of

knowledge, in order to imitate what there is that is characteristic in this

becoming itself.... We hardly do anything else than set going a kind of

cinematograph inside us.... The mechanism of our ordinary knowledge is of a

cinematographical kind.'

<p>

<i>"Were James and Bergson intuiting a truth in comparing visual perception

�and indeed, the flow of consciousness itself�to such a mechanism? Are the

brain mechanisms that give coherence to perception and consciousness

somehow analogous to motion picture cameras and projectors? Does the

eye/brain actually 'take' perceptual stills and somehow fuse them to give a

sense of continuity and motion?"</i>

<p>

full text: <a href="http://www.nybooks.com/articles/16882">In the River of

Consciousness</a> by Oliver Sachs

Of course not.

<p>

While some part of consciousness can be related to visual

perception, very much isn't. Those who have been blind

since birth may have little

or no visual imagery, yet they are surely as conscious as

the sighted. Some parts of consciousness come mostly

through nonvisual senses, while some ideas, thoughts, emotions,

etc. can be perceived outside the context of any of the

traditional senses.

<p>

Or is your question more like "does the VISUAL portion of

consciousness work like a rapid series of photographs?" That's

a question fraught with problems of definition. One obvious

problem is how alike the two have to be before you decide to

answer in the affirmative.

<p>

Is life like an analogy?

Everybody likes to grab onto the latest hot technology in an effort to simplfy complex philosophical issues. Remember when holograms were the new 'hot' technology...there were articles in prestigious medical journals showing how the brain was 'like a hologram'.

 

Analogies make it easier to grasp something about a complex process but they cannot encompass the whole story.

No, it is like a movie.

I don't think it's possible to answer the question in the title of

thread because there isn't really a clear definition of

"consciousness." We'd really just be playing games with the

definition rather than making substantive arguments.

 

On the other hand, in answer to the question, "Does the eye/

brain actually 'take' perceptual stills and somehow fuse them to

give a sense of continuity and motion?" I'd say that, yes, that's a

credible model for what's happening. It's a workable explanation

for why we see the motion in movies as continuous and why,

when we scan our eyes across a scene, we perceive it as a

continuous motion rather than a series of small, discrete

movements (saccades).

Lot of "mechanisms" and "mechanistic" words in your thread. This recalls me an article about the beginning of the psychology as science, when researchers tried to built a psychology by the rules of the natural sciences: all subjectivism had to be eliminated as it didn't belonged to the science. They tried to build an "objective" psychology using a mechanical model. Guess what their results looked like: measures of the response times to different stimuli� Does this look like psychology? The mechanical "objective" model of science didn't worked for it, because psychology is by definition subjectivism. Few years after this "positivist" adventure, psychology was born like a "human" science, a science of the "subjectivism". Now, consciousness is one of the main issues of the psychology, so all above applies to it too. Mechanics can never explain psychological (read subjective) issues. Mechanistic explanations cannot exceed the sensorial-perceptive level.

<cite>

"Does the eye/ brain actually 'take' perceptual stills and somehow fuse them to give a sense of continuity and motion?" I'd say that, yes, that's a credible model for what's happening.</cite>

<p>

It models some aspects OK, but like many analogies, it breaks down

if you try and analyze it too far. If the eye/brain works by

taking a series of discrete stills, one should be able to answer the

question "how many frames per second do we see?". But there's

no good answer to that very simple question.

<p>

An easy experiment

to determine the number of frames per second is to paint a

spinning disk half white and half black, and then watch it as

it spins at various speeds. If it's spinning at the frame rate

or a multiple thereof, we'll see the disk as half black and half

white, and stationary. A little faster than the frame rate,

and it'll appear to rotate slowly forward; a little slower than

the frame rate, and it'll appear to rotate slowly backward.

This is what you see in video/TV/Movie cameras. You may

have seen a variation of the effect in old Western movies

when spoked wagon wheels on a moving wagon sometimes

appear to be stationary, or rotate slowly forward or backwards.

While this effect is always seen in any system that works

by taking a series of still photos, we never see this effect

with human eyes in continuous, nonflickering light.

(See the Shannon/Nyquist sampling theorem for theoretical

background of the aliasing effect).

<p>

So while a movie camera may model some aspects of the human eye/brain,

the two certainly don't behave identically.

Visual perception is not a simple recording of the scene onto the retina. The signal is interpreted by the brain. Some details are discarded as irrelevant, others -- such as movement -- are picked up quickly, other details again are filled in from memory, expectation and so on. The brain tries to form patterns in what we 'see'.

 

The other senses, other brain mechanisms (spatial perception) and our internal thoughts are also involved in forming our consciousness.

nope, it IS not, but they can be part of consciousness.<br>

Remember, in some cases they use completely non-visual stimulants to make somebody regain his/her consciousness... It's not accidental, that we have lots of senses(five, they say).

<br>Of course, the question is, as above mentioned, how do we define "consciousness".

<i>"we never see this effect with human eyes in continuous, nonflickering light." </i><br>

Interesting context, Richard. In fact, you need two flickering/flashing/rotating thing to get this effect; it's based on the difference between frequencies, so you do need two of them. In the same time, even if we (eye+BRAIN) also take successive pictures, instead of continuous seeing, the problem is, it will be limited not by an external frames/second factor, like when we look at a movie on a flickering screen, but by the intrinsic properties of our "detector". Which makes me think, that succession of pictures is perceived as a continuous stimulation just because the gap between two pictures are cut out by our preceiving system.<br>

We have the biggest effects filter in our head.

'We take snapshots, as it were, of the passing reality, and...we have only to string these on a becoming, ...situated at the back of the apparatus of knowledge, in order to imitate what there is that is characteristic in this becoming itself.... We hardly do anything else than set going a kind of cinematograph inside us.... The mechanism of our ordinary knowledge is of a cinematographical kind.'

 

I think what is being referred to here is not the mechanics of 24 frames per second film but rather the arrangement of ideas and perceptions of reality. In 1908, the evolution of film created a great deal of thought about the nature of time, illusion and visual perception. Events could be presented on screen in real time, but they could also be edited so that their meaning changes in juxtapostion with other events.

 

It was never before possible to visually present moving events in time without live theater, which is not something that can be edited. Much early Russian film is given to exploring how moving images relate to each other as they are presented together. The only other place previously that moving events, real or imagined, could be rearranged and juxtaposed to form new meanings and content is in the human mind.

 

In this sense, the mechanism of thought is mirrored in cinematography. Jumps in time, scale and perpective are all possible, as they are in the human mind. Seeing this for the first time must have been an amazing experience. The creation of cinema must have been something like the creation of the machine in Wim Wenders film "Until the End of the World" where dreams can be captured and played back in waking life.

<I>there were articles in prestigious medical journals showing how the brain was 'like a hologram'. </i><P>Holographic memory is still the prime model for describing how the brain stores information, and always has been. <P>To add to what Richard said, the brain not only discards certain pieces of information, but adds gaps between that data to fill in the blanks. I read a very interesting scientific piece years back that tried to quantify the amount of information that was transmitted and processed in the visual cortex. The amount of data amounted to gigabytes per second if it was even crudely sampled in an electronic medium. <P>I'm pretty sure the optic nerve doesn't work like a movie projector, and I believe the frequency of nerve impulses is a lot less than 24fps. How then can a baseball player hit a 100mph fastball leaves enough miracles to biomechanics. <P>Conceptually, a good way to think of how we process visual information is imagine our eyes projecting information into a vat of thick, photo sensitive fluid, and moving around the focus point so that our perceptual persistence never overlaps and is a seamless transition from one moment to the next. Much of the information fades and blurs away in the fluid of course within a few moments, but what we percieve as important remains static and drifts to the bottom of the container and stacks on other recorded moments.

Consciousness can never be explained with any technical comparison, however smart it may appear. In the same way we could ask: what is the world alike?

I wonder if internet discussion boards, that are dedicated to the neuro-psychology of consciousness, ever engage in conversations regarding photography?

 

If 'photography' is writing with light, and writing, when read, leads to conscious thought, then light that is detected by the eye/retina/optic nerve/visual cortex system is indeed 'writing', since it eventually results in conscious thought regarding the scene that was viewed. Hence, human vision is photography.

 

But visual perception and consciousness are not synonymous. One is a part of the other.

 

Well, the doctor says it time to go back to my room now. Goodnight.

Memory has more in common with a collage than a photograph. When we bring a past experience to consciousness, the memory is recreated on the fly out of a series of related 'items'. This collage can be different each time its created, as your emotions, and attitudes to these items alter your perception of the event. This is why False Memory Syndrome is possible.

SO the brain is like a rapid winder?

<i>"SO the brain is like a rapid winder?"</i>

<p>

more like a programmable robot kitchen. memories are not like loaves of bread that were baked at the time of the remembered event and have been sitting on a shelf somewhere in the brain since then, waiting to be retrieved by the conscious mind. instead, when a memory is "retrieved", it is as if a new loaf of bread is baked from scratch. all that remains from the time of the event is a general recipe for recreating it and some of the basic sensory ingredients.

<p>

since recipes tend to change over time, and ingredients get substituted, the newly baked loaf can substantially differ from the original.

<p>

the interesting question Dr. Sacks was posing was not whether consciousness mimics a movie camera in any great detail. instead he starts with the fact that human vision, like cinema, is made up of discreet snapshots that, presented in rapid sequence, provide the illusion of continuity. he then asks if, contrary to the continuity implied by a phrase such as "stream of consciousness", but rather like movies and vision, consciousness itself is a series of discreet "snapshots" that when sewn together by the brain provide the illusion of continuity?

<p>

in other words, are qualia made up of quanta?

Bergson was speaking here only of intellectual thought, not of vision. Sachs misunderstands. To Bergson, the matter-field is a hologram, but the brain is not simply a "hologram." Rather, the dynamics of the brain supports a modulated reconstructive wave within the hologram. This wave specifies a past form or transformation of the field as the "external image." Between saccades, this wave continues to specify this image. The image is time-scale specific, for example the "buzzing" fly in our normal scale, as opposed to a "heron-like" fly, barely flapping its wings, at a slower scale. This scale is imposed by the chemical velocities underlying the dyanmics of the brain. This reconstructive wave can be specific to a past transformation of the field since in Bergson's model of time, the time-evolution or motion of the matter-field is indivisible or non-differentiable, and therefore the "past" cannot be equated to that which has ceased to exist - there is no deviding line, no discrete demarcation between "past" and "present" or successive "instants" of time, each disappearing as the next arrives.

Memory is not stored in the brain (or in the brain "hologram") in this model. This modulated wave reconstructs past events in the 4-D field, just as modulating the frequency of a reconstructive wave, say from f1 thru f4, can reconstruct four successive wavefronts recorded upon a hologram corresponding to different images, e.g., a truck, a candle, a pen, a vase. Losses of memory - amnesias, aphasias, etc. - correspond to the destruction of the neural structures required to support the complex wave patterns corresponding to each experience, not to the loss of memories "stored" in the brain. In Bergson's model, vision or perception is not occuring solely within the brain in the first place, and so could not be exclusively stored there.