Sunday, 1 July 2012

Joseph Ledoux: The Perplexing Relationship Between Emotions and Consciousness


 Joseph Ledoux  The Perplexing Relationship Between Emotions and Consciousness
Abstract: I propose a re-conceptualization of key phenomena important in the study of emotion—those phenomena that reflect functions and circuits related to survival, and that are shared by humans and other animals. The approach shifts the focus from questions about whether emotions that humans consciously feel are also present in other animals, and toward questions about the extent to which circuits and corresponding functions that are present in other animals (survival circuits and functions) are also present in humans. Survival circuit functions are not causally related to emotional feelings but obviously contribute to these, at least indirectly. The survival circuit concept integrates ideas about emotion, motivation, reinforcement, and arousal in the effort to understand how organisms survive and thrive by detecting and responding to challenges and opportunities in daily life.

LeDoux J. (2012) Rethinking the emotional brain. Neuron 73(4): 653-76. http://www.ncbi.nlm.nih.gov/pubmed/22365542  (PDF will be provided)

Comments invited

17 comments:

  1. If, as Doctor Ledoux has suggested, there is no centralized “feeling center”—that is, if instead of there being a centralized phenomenon called “feeling,” there are a variety of specialized survival circuits that represent different irreducible aspects of specialized, adapted behavior (emotion, motivation, reinforcement, arousal, etc.), then we may not be looking for the right kind of brain-event when we investigate into the nature of phenomenal consciousness.
    Could Ledoux’s view imply that what we call “feeling” is itself variegated and multifaceted? –that is, that we are attempting to flesh out the evolutionary advantage and function of a centralized “feeling,” whereas we should be looking for a host of related yet independent phenomena, which are all felt differently and are only superficially related?

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    1. I’m sorry, I must not have been clear. I apologize. Survival circuits are not “feeling centers.” They are survival mechanisms that have their origins in the first single cell organisms. Single cells do not have circuits but they do have survival functions that are then controlled in more sophisticated ways when organisms began to have nervous systems. Survival functions do not exist to make feelings but instead to allow organisms to survive and thrive in their environments. When the nervous system of an animal has the ability to be conscious of its own activities then feelings result. This is true of humans. To the extent is it true of other organisms is impossible to know. But it is highly likely that if other organisms have feelings they will be very different from the states that humans characterize with words like fear, sadness, anger, joy, love, much less pride, jealousy, or envy. Circuits that control defensive behavior are similar in humans and other mammals. But the subjective experience of fear, the feeling of being afraid, is not simply due to the activity of the defense system. What theory of emotion needs to explain and what it needs to be based on are different. Some emotions are contributed to by processes controlled by survival circuits and others are not. These underlying brain processes are part of what a theory of emotion needs to be based on. Survival circuit activity is not a qualification for something being an emotion, therefore we need a theory of emotion that accounts for both kinds of states called emotions (those that have connections to survival circuits and those that do not).

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  2. Ledoux's talk, specifically his comments on brain imaging of the fear circuit, highlights that brain imaging can lead to misleadingly simple explanations. I suspect that such oversimplifications apply to other functional networks as well.

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    1. Functional imaging is limited to roughly the mm level of resolution. Much of the action in the brain takes place in neurons and synapses at spatial resolutions on the um or even angstrom level. Imaging is very useful, so long as it limits are recognized. Imaging researchers know the limits, but those outside the field often misunderstand.

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    2. Especially in pluri-disciplinary gatherings such as this Summer Institute, the limitations of the research tools being used should definitely be underlined. It is difficult enough to come up with an adequate experimental paradigm for relating the different questions we are asking, never mind the practical limitations we are faced with! I don't remember if this was mentioned during the talks, but I recall reading an article on a dead salmon that caused some fMRI voxels to light up http://www.wired.com/wiredscience/2009/09/fmrisalmon/

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  3. LeDoux's talk seems to be rather pessimistic. Okay, emotions and systems that we have studied for many years are not the same thing, so lets forget about emotions and study those systems. It is good that he acknowledges this distinction, but I think that it only highlights the need for psychologists to develop better theories of emotions, When we will (finally) understand 'what is an emotion', then we can probably understand what is a 'fear system' in the brain, and how can does it relate with more primitive systems, such as the ones described by LeDoux.

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    1. I agree completely. We really need a good theory of emotion. What I have tried to do is outline what a theory of emotion needs to explain as opposed to what it needs to be based on. Emotions are subjective states, feelings. This is what needs explaining. Some emotions are contributed to by processes controlled by survival circuits and others are not. These underlying brain processes are part of what a theory of emotion needs to be based on. Survival circuit activity is not a qualification for something being an emotion, therefore we need a theory of emotion that accounts for both kinds of states called emotions (those that have connections to survival circuits and those that do not).

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  4. I am intrigued by something Dr. Ledoux briefly mentionned about olfactory stimuli taking a more direct route (by-passing the intra-amygdala circuit, if I remember correctly) to downstream circuits in comparison with other sensory stimuli elicing 'innate' fear. There is somewhat of a parallel in the memory system in that olfactory stimuli also have a more direct route to the entorhinal cortex (from piriform cortex) whereas other types of stimuli appear to first get integrated into multi-modal info.

    I wonder where this priority given to olfaction come from? From our rodent ancesters? :) Of course I am assuming that what he described about the fear circuitry applies to humans as well?

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    1. The preferential access of the olfactory system to the amygdala is indeed due to our early mammalian ancestors who were ground dwelling animals living on the dark floor of the forest where sight is of limited value. The connections are conserved in humans.

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  5. I'm wondering a little about the distinctions between emotion, feeling and system brought up. Could they be categorized by function?

    The direct life-preserving (homeostatic) systems like: hunger, cold, feeling tired, feeling afraid...

    Social-states that modulate our experience of others: Jealousy, love, admiration, ...

    Or do they operate in different ways completely?

    Also, I'm wondering whether it would be possible to be in these states without being aware of it? Acting jealous, in love, admiring, hungry, afraid...without being aware of FEELING these things (as in being able to report feeling) and even without actually FEELING these things?
    It's a bit confusing.

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  6. 1. Emotions are felt, hence they are feelings.

    2. "Having" an unfelt emotion makes as little sense as "having" an unfelt feeling.

    3. Homeostasis is just the maintenance of internal states. A thermostat is a homeostat.

    4. And homeostasis is doing, not feeling.

    5. Appetite is felt homeostasis -- but the fact that it is homeostasis does not explain how or why it is felt.

    6. You can feel jealousy without realizing that what you are feeling is jealousy, just as you can see a mirage without realizing that you are seeing is a mirage: You find out later what you were feeling (or seeing) earlier (maybe based on your later feelings or behavior).

    7. But while you are feeling something, you always know you are feeling like that: What it feels like is what it feels like. (It just may not yet feel like jealousy.) (What felt like a stress headche might turn out to have been a migraine.)

    8. Or another way to put it might be that you do not yet realize that feeling like that means you are feeling jealous.

    9. Feeling like that, and knowing it means you're feeling jealous, feels different from feeling like that and not knowing it means your jealous.

    10. In other words, it feels like something to mean, and meaning something else feels like something else, even if the difference is small or subtle.

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  7. Originally posted on facebook

    TURING CONSCIOUSNESS:
    “eDoux talk: Question is not whether your cat feels same as you, but whether it feels (and why/how). http://users.ecs.soton.ac.uk/harnad/TuringEvolutionConsciousness.htm#_edn3 ”

    MARJORIE MORIN :
    “Will we ever be able to answer this question since we rely on language to know if humans "feel" and the "language" of the other animals is unknow to us? Also, I haven't completely comprehend how Mr. Edelman showed that the octopus WAS in fact conscious. It sees, it learns, it seems to understand some things, but does it feel? We don't and can't know that? ”

    TURING CONSCIOUSNESS:
    "I don't need language to feel that my cat feels. Probably it would be the same if I had an octopus. "

    MARJORIE MORIN :
    “But does you feeling that your cat feels mean he does? How can something you feel be a reality for another being? I don't really know how to say that, but it's like saying you feel your computer feel, it doesn't make it true. Maybe I don't understand what you mean, but I think their consciousness (I do think they have one) isn't accessible to us. We anthropomorphize them a lot but the reality is we don't really know what's going on for them, how it works, how it feels in their shoes. What it feels for them to feel their paws on the ground, or feel hunger etc. I know that it's not really the focus of the summer school but it's still very intriguing. I'm really puzzled by your comment could you elaborate a little please? “

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    1. The other-minds problem guarantees that we can never be sure that any entity other than ourselves.

      But we can be pretty sure. For example with other people, because they act like they feel (and not just because they say to).

      Animals too.

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  8. Dr. Ledoux makes the case that there is no unified fear system. Rather there are various survival circuits that trigger different kinds of fear responses (e.g. fear of predator as opposed to fear of starving). Assuming this, I wonder why it often seems to us that all fearful feelings have something in common in virtue of which we can recognize them immediately as feelings of fear (in normal circumstances). To put it in a philosophical terms: I wonder why it often seems to us that fearful feelings have a similar phenomenology and that we can report and identify such feelings in virtue of their similar phenomenology. (I know LeDoux did not want to speculate on the mechanisms that gives rise to fearful feelings, so this is certainly not meant as a criticism.) Does it entail that feelings of fear (as opposed to fear responses) to have to be produced by (or linked to) a singular system or mechanism?

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  9. Xavier Dery ‏@XavierDery

    Hearing "We don't know" a lot, but to me it indicates honest, sound science. 'Not knowing' now can be on the way of finding out. #TuringC

    09:40 AM - 30 Jun 12 via Twitter for Android

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  10. I'm curious about how phobias (i.e. fears that are irrational given the likelihood or amount of danger posed by the feared item) relate to what Ledoux discussed.
    a) Are phobias neurally stereotyped? For example, do they bear more resemblance to learned or innate fear responses? Do they differ based on the nature of the phobia or individual?
    b) Are they uniquely human? Of course a phobia of an abstract concept requires knowledge of the concept, but do animals justifiably exhibit phobias? Is a dog's intense fear of a vacuum cleaner evolutionarily validated by the fact that loud noises are typically to be avoided?
    c) Are phobias just a vague category generated by a behavioral definition that bears little relevance to the associated neural phenomena?

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