Welcome to DU! The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards. Join the community: Create a free account Support DU (and get rid of ads!): Become a Star Member Latest Breaking News General Discussion The DU Lounge All Forums Issue Forums Culture Forums Alliance Forums Region Forums Support Forums Help & Search

Jim__

(14,077 posts)
Tue Apr 12, 2016, 03:41 PM Apr 2016

How the brain produces consciousness in 'time slices'

EPFL refers to École polytechnique fédérale de Lausanne.

From MedicalXpress:

[center][/center]
EPFL scientists propose a new way of understanding of how the brain processes unconscious information into our consciousness. According to the model, consciousness arises only in time intervals of up to 400 milliseconds, with gaps of unconsciousness in between.

The driver ahead suddenly stops, and you find yourself stomping on your breaks before you even realize what is going on. We would call this a reflex, but the underlying reality is much more complex, forming a debate that goes back centuries: Is consciousness a constant, uninterrupted stream or a series of discrete bits - like the 24 frames-per-second of a movie reel? Scientists from EPFL and the universities of Ulm and Zurich, now put forward a new model of how the brain processes unconscious information, suggesting that consciousness arises only in intervals up to 400 milliseconds, with no consciousness in between. The work is published in PLOS Biology.

Continuous or discrete?

Consciousness seems to work as continuous stream: one image or sound or smell or touch smoothly follows the other, providing us with a continuous image of the world around us. As far as we are concerned, it seems that sensory information is continuously translated into conscious perception: we see objects move smoothly, we hear sounds continuously, and we smell and feel without interruption. However, another school of thought argues that our brain collects sensory information only at discrete time-points, like a camera taking snapshots. Even though there is a growing body of evidence against "continuous" consciousness, it also looks like that the "discrete" theory of snapshots is too simple to be true.

A two-stage model

Michael Herzog at EPFL, working with Frank Scharnowski at the University of Zurich, have now developed a new paradigm, or "conceptual framework", of how consciousness might actually work. They did this by reviewing data from previously published psychological and behavioral experiments that aim to determine if consciousness is continuous or discrete. Such experiments can involve showing a person two images in rapid succession and asking them to distinguish between them while monitoring their brain activity.

more ...
6 replies = new reply since forum marked as read
Highlight: NoneDon't highlight anything 5 newestHighlight 5 most recent replies
How the brain produces consciousness in 'time slices' (Original Post) Jim__ Apr 2016 OP
Fascinating. K&R Duppers Apr 2016 #1
quantum consciousness pscot Apr 2016 #2
Consciousness is a standing wavefront BB1 Apr 2016 #5
Only true on Tuesday pscot Apr 2016 #6
Great stuff, thanks lostnfound Apr 2016 #3
Is PLoS Biology a reputable journal? The paper is presented under the heading "Unsolved Mystery". xocet Apr 2016 #4

BB1

(798 posts)
5. Consciousness is a standing wavefront
Thu Apr 14, 2016, 05:42 PM
Apr 2016

according to some sf-writers. I always interpreted that as 'anything might happen at anytime, and everything might change because of that. Or nothing happens at all and nothing changes.' Meanwhile, sometimes something happens, so it seems to work out.

xocet

(3,871 posts)
4. Is PLoS Biology a reputable journal? The paper is presented under the heading "Unsolved Mystery".
Wed Apr 13, 2016, 01:56 PM
Apr 2016

Should one worry about the quality of such a paper?

The first paper referenced in Herzog, Kammer and Scharnowski's discussion section is from 1875; to wit, http://link.springer.com/article/10.1007%2FBF01659311.

Whatever that result may be, would the modern paper not benefit from a modern repetition of whatever experiment may have been done? (One might note that the referenced paper is so old that certain aspects of German orthography have even changed in the interim: a case of this is exemplified by line 6 of the second paragraph of the referenced paper - found on page 404 (ironically) Dieses habe ich gethan.... which would now be written as Dieses habe ich getan....)

More interestingly, in the referenced paper, a Hippschen Chronoskop

(https://books.google.com/books?id=pVjkAAAAMAAJ&pg=RA1-PA59&lpg=RA1-PA59&dq=Hippschen+Chronoskop&source=bl&ots=OPBJJ-r9uT&sig=s22MspoXrnzWaKEjgwZmzokBhpY&hl=en&sa=X&ved=0ahUKEwi-0o-jkIzMAhXF7D4KHTnfBpcQ6AEIMDAD#v=onepage&q=Hippschen%20Chronoskop&f=false)

is mentioned as the basis for some measurements that this older paper's author compares to some of his own results. He talks a bit about his data analysis verses another author's data analysis and so on. This older paper might be interesting to read. However, would it not have been better to repeat the measurements that are mentioned? Wouldn't modern error analysis also benefit the quality of the experimental results?

At any rate, these are just a few thoughts. The PLoS Biology paper might well be a good paper, but it's presentation under the heading "Unsolved Mystery" leaves me to wonder about the importance and/or the quality.



UNSOLVED MYSTERY

Time Slices: What Is the Duration of a Percept?
Michael H. Herzog, Thomas Kammer, Frank Scharnowski
Published: April 12, 2016


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.

...

http://dx.doi.org/10.1371/journal.pbio.1002433



About the Authors

Michael H. Herzog, Frank Scharnowski
Laboratory of Psychophysics, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland

Thomas Kammer
Department of Psychiatry, University of Ulm, Ulm, Germany

Frank Scharnowski
Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Zürich, Switzerland

Frank Scharnowski
Neuroscience Center Zürich, University of Zürich and Swiss Federal Institute of Technology, Zürich, Switzerland

Frank Scharnowski
Zürich Center for Integrative Human Physiology (ZIHP), University of Zürich, Zürich, Switzerland


http://journals.plos.org/plosbiology/article/authors?id=10.1371%2Fjournal.pbio.1002433
Latest Discussions»Culture Forums»Science»How the brain produces co...