Sunday 1 July 2012

Catherine Tallon-Baudry: Is Consciousness an Executive Function?


Abstract: In many theories and experiments, consciousness is conceived as an executive function, that distributes precise and detailed information guiding behavior.  Indeed, the neural mechanisms correlated with consciousness share a number of similarities with those involved in executive functions such as attention, memory and control, e.g. amplification and selection, engagement of fronto-parietal regions, oscillatory synchrony. This apparent similarity has been challenged by a number of experimental evidence showing partial or full dissociations between the neural correlates of consciousness and the neural correlates of other cognitive functions. Those results suggests that, from a neural point of view, consciousness may be less executive than previously thought. The current brain-as-a-computer metaphor, with neural mechanisms designed to support goal-oriented behavior, may therefore be an insufficient framework to understand the biological mechanisms underlying consciousness.

Catherine Tallon-Baudry, C. (2011) On the Neural Mechanisms Subserving Consciousness and Attention Frontiers in Psychology 2: 397.

Comments invited

18 comments:

  1. It seems to me that Tallon-Baudry is leaving us with two equally unsatisfactory options concerning consciousness : (1) it's nowhere to be found in action and therefore we should be skeptical about it; (2) if we still believe in consciousness then we should start to look away from action (but where?). However, if we do not know, for sure, what we are looking for (we are still undecided on the nature of consciousness) then why should we be surprised when we fail to distinguish neural processes interested in the production of action from neural processes interested in the production of consciousness?

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    1. I do not fully understand your point: you seem to imply that I showed that the neural processes involved in action production and the neural processes involved in consciousness production could not be distinguished. My point was precisely to show that the neural mechanisms of attention are distinct and independent of the neural correlates of visual awareness.

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  2. It's just yet another symptom of the fact that finding the explanation of what we do and can do does not explain how or why we feel...

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  3. Part of the tension/confusion may be attributed to the fact that part (if not all) of what we feel is acquired in similar ways as all we can do. The richness of our felt/conscious life is not magical, contrary to what Graziano thinks; even if it is for some ill-informed people. However, I think he is right when he insists on the necessity for shared knowledge (or feeling). Because our felt/conscious life would not be so rich if it wasn't for the contribution of others (beginning with our mother). As Dewey once said :
    "And babies owe to adults more than procreation, more than the continued food and protection which preserves life. They owe to adults the opportunity to express their native activities in ways which have meaning. Even if by some miracle original activity could continue without assistance from the organized skill and art of adults, it would not amount to anything. It would be mere sound and fury."
    Without this acculturation, we could not individually do all we can do; but in my view, we could not individually feel all we can feel.

    Moreover, like you suggested at the end of your conference this morning, if feeling is necessary for our valuations (and all behaviors depending on such valuation, beginning with politics) than we may have an idea (still in need of precision) of why feeling is a useful evolutionary adaptation.

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    1. What social experience do organisms have to have, or to have had, in order to feel pain?

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  4. I find it highly problematic that Pr Tallon-Baudry operationalized attention as reaction times instead of reaction times and response accuracy primarily because they both are influenced by attention and also because prior research on attention has used both variables (changing operational definitions makes linkage between findings more difficult).

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    1. Attention can both shorten RTs and improve accuracy, with sometimes a speed-accuracy trade-off. Beause accuracy is often at ceiling, the shortening of RTs is usually considered a reliable index of attentional processing.
      Besides, there is little doubt that attention is manipulated in the Posner task we have been using, as demonstrated by numerous studies. Another argument, developped in Wyart & Tallon-Baudry J Neurosci 2008, is based on the lateralization of alpha-band suppression, a phenomenon known to reflect attentional orienting.

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  5. Thanks Dr. Tallon-Baudry for the very interesting talk!

    I wonder what it would feel like to orient attention to the blind field in the case of Patient GY (with unilateral V1/V2 lesion and Type 2 blindsight)? (e.g. I am not consciously aware of that part of my visual field but I am going to try to pay attention there?)

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    1. The orienting of attention in the blind field has been described originally by Kentridge, Heywood and Weiskrantz (Proc Roc Soc Lond B, 1999), a paper that could answer some of your questions.
      To get a feeling for what it means to pay attention in the blind field, imagine attending to a place behind your head, for instance paying attention to the field above your left ear versus below your left ear

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  6. POSTED ON FACEBOOK BY DAVID MAILLET :

    "It is interesting to see how different speakers had such different ideas of what consciousness is, and how to measure it. I found Dr. Tallon-Baudry's dissociation between attention and awareness particularly striking."

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    1. PAULINE CLAUDE :
      "
      We are aware as long as we pay attention to what is felt. But a feeling that is not felt because we do not pay attention to it doesn't mean that it doesn't exist because it didn't technically reached the level of consciousness. For instance, if you are extremely concentrated (if you put all your attention on a single objet because its appears to be extremely relevant for your survival for instance), you wont "feel" the minor other feelings that you would have noticed otherwise if your attention was not focused on that specific stuation. But would selective attention be the answer to the function of consciousness and would it be the way consciousness drive our behavior?"

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  7. From Tallon-Baudry's talk I gleened that it was possible to distinguish attention from awareness in an experiment. I found this way of doing quite clever.

    I've been trying to reconcile it with the experiments presented to us by other speakers. In a way was the task with the error that pointed either to or away from the future target a bit like the priming tasks Lau and Haggard presented? In a way manipulating attention to go one way to examine if responses (as measured by time or accuracy or even sentiment of agency in Haggard's case) changed when the prime and target were consistent vs inconsistent.

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  8. I have two questions about the relation between attention and consciousness, both based on a definition issue. First, are automatisms a kind of unconsciousness attention? Secondly, if there are a lot of different kinds of attention, are there also different kinds of consciousness or just different interactions between attention and consciousness?

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    1. I think attention and consciousness are hard to separate. It is not for nothing that some studies use a certain task to study attention and others use the same task to study consciousness. I feel both can be studied as a 'state' or as a kind of phenomenological experience.
      Is there consciousness without attention; is there attention without consciousness?

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    2. What do you mean by the claim that consciousness can be studied as a state as opposed to a kind of phenomenological experience? Consciousness (in the sense we are interested in the summer school) just is phenomenological experience. Also, Dr. Tallon-Beaudry explicitly stated that, according to her findings, there is consciousness without attention and attention without consciousness. Consciousness without attention occured when the subject reported being conscious of a stimuli (by choosing 'seen'), but the stimuli was in an unattended location (and the reaction time was thus lengthened). Attention without consciousness occured when the subject attended to the place where the stimuli appeared (and his reaction time was shortened by doing so), but reported not being conscious of the stimuli (by choosing 'unseen'). Moreover, she found neural correlates in the occipital lobe that correlated with attention and consciousness separately (oscillations at around 60Hz for attention and at around 80Hz for consciousness if I remember correctly).

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  9. Completely dissociating two processes is possible is we take really controlled environments, but most of the time, these two components (if they really are two) seem to interact and to be much more intertwined than in Dr. Tallon-Beaudry’s experiments. Don’t get me wrong, I thought her experiments were extremely elegant and the results are pure food for thoughts, but different types of task have to be used and her results have to be replicated in order to really state that these two processes are separated. Once we are there, the extent to which there processes are dissociated (in terms of time, complexity of stimuli and task, etc.) and how do they interact still needs to be assessed.
    If a pig can fly, can all pigs fly? When we found a flying pig (or in this case a clear dissociation between attention and consciousness) we have to assess if all pigs could fly or if we just found one strange pig!

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    1. I agree that Dr. Tallon-Baudry's experiments were elegant, but we have to be careful about what exactly she was dissociating. In your second paragraph, you mention the distinction between "attention and consciousness". But can we really equate consciousness to visual awareness (which is really what she was investigating)? I think not. In any state of wakefulness, a person will be aware (conscious/feel) of something. Visual awareness is just one type of modulation that the overarching 'feeling' system is sensitive to.

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  10. Xavier Dery ‏@XavierDery

    I still entertain some hope that the speakers will collectively contribute to a good definition of attention and consciousness... #TuringC

    2:18 PM - 30 Jun 12 via Twitter for Android

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