Tag Archives: passive frame

Making sense of the sense of smell

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This is another post on Morsella’s ideas.

In developing the Passive Frame theory of consciousness, the group uses olfaction as the sensory source to focus on. This seems surprising at first, but they have good reasons for this.

First, it is an old system from an evolutionary viewpoint. As in this quote from Shepherd: “the basic architecture of the neural basis of consciousness in mammals, including primates, should be sought in the olfactory system, with adaptations for the other sensory pathways reflecting their relative importance in the different species”.

Second, its connections are simple compared to vision and hearing. Olfactory signals go straight to the cortex rather than arriving in the cortex via the thalamus and they enter an old part of the cortex, the paleocortex rather than the neocortex (which has primary processing areas for the other senses). The processing of smell is more or less confined to one area in the frontal region and does not extend to the extensive areas at the back of the brain where visual and auditory processing occurs. The sense of smell is much easier to track anatomically than the other ‘higher’ senses. To understand minimal consciousness, it is reasonable to use the least elaborate sense as a model.

Third, looking at what lesions interfere with olfactory consciousness, it seems that connections outside the cortex are not needed for awareness of odours. This implies that at a basic level consciousness does not require the thalamus or mid-brain areas (although consciousness of other senses does require those areas). Some links to the thalamus and other areas may be involved in further processing smell signals but not in being conscious of them.

Fourth, the addition of a smell into the contents of consciousness has a sort of purity. The sense is only there when it is there. We are aware of silence and of complete darkness but we are not aware of a lack of odour unless we question ourselves. If odours are at very low concentrations or if we have habituated to them because they are not changing in concentration, we are not conscious of those odours and also not conscious of their absence. “The experiential nothingness associated with olfaction yields no conscious contents of any kind to such an extent that, absent memory, one in such a circumstance would not know that one possessed an olfactory system.” So addition of a smell to the contents of consciousness is a distinct change in awareness and can of itself focus attention on it.

Fifth, olfaction is not connected with a number of functions. There are no olfactory symbols being manipulated and the like. It is difficult to hold olfactory ‘images’ in working memory. Also “olfactory experiences are less likely to occur in a self-generated, stochastic manner: Unlike with vision and audition, in which visually-rich daydreaming or ‘ear worms’ occur spontaneously during an experiment and can contaminate psychophysical measures, respectively, little if any self-generated olfactory experiences could contaminate measures.”

As well as these reasons given by Morsella in justifying the choice of olfaction in developing the Passive Frame theory, it occurs to me that there is a significant difference in memory. There is a type of recall prompted by smell that seems instantaneous, effortless and very detailed. For example, when you enter a house that you have not been in since childhood and the house has changed in so many ways over the years, the first breath gives a forgotten smell and a vivid sense of the original house along with many images from memories you know you could not normally recall. There seems to be some direct line between the memory of a ‘place’ and the faint odour of that place.

This olfactory approach to consciousness does cut away much of the elaborations and fancy details of consciousness and allows the basic essentials to be clearer.

Lingua Franca of the brain

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Ezequiel Morsella has been kind enough to send me more information on the Passive Frame theory of consciousness. So here is another posting on ideas from that source.

From time to time I encounter notions of there being a ‘language of the brain’ or a brain coding system. Although I would not say that there was no extra language layer (who knows?), I have never seen the necessity for it. The idea seems a product of thinking of the brain in the context of software algorithms, digital transmission, information theory, universal Turing machines and the like rather than in biological cell to cell communication.

Look at forming and retrieving episodic memories: they are conscious experiences before they are stored and conscious experiences when they are retrieved. Awareness is in the form of consciousness and so is the access of various parts of the brain to information from other parts. We understand movement of ourselves and others in similar terms. The Passive Frame proponents talk of perception-like tokens - “they represent well-crafted representations occurring at a stage of processing between sensory analysis and motor programming” and are presumably accessible to both. Here we can have a lingua franca for sensory-motor interaction.

Of course for both sensory and motor processing we need a space and viewpoint for the perception-like tokens. This is often thought of as a stage or a sensorium, but I like to think of it as a model of the environment with the organism active in it. In this ‘space’ the objects we perceive can be placed and our actions can be simulated.

Passive Frame Theory

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ScienceDaily has an item (here) on a paper by Morsella and others on the Passive Frame Theory of consciousness. This theory is one of my favorites!!

The passive frame presents information but does not create or act on that information. This consciousness is like an interpreter Morsella says, “the information we perceive in our consciousness is not created by conscious processes, nor is it reacted to by conscious processes. Consciousness is the middle-man, and it doesn’t do as much work as you think.” It is intuitive to think that consciousness is in control of the things it reports (actions, thoughts, feelings, perceptions). But really consciousness simply passively presents these things.

Morsella also says that consciousness is not a connected stream. “One thought doesn’t know about the other, they just often have access to and are acting upon the same unconscious information. You have one thought and then another, and you think that one thought leads to the next, but this doesn’t seem to be the way the process actually works.”

This theory also puts action at a more central place in the function of consciousness than perception.

I do not have access to the original paper (Morsella, Godwin, Jantz, Krieger, Gazzaley; Homing in on Consciousness in the Nervous System: An Action-Based Synthesis; Behavioral and Brain Sciences 2015). But here is the abstract:

“What is the primary function of consciousness in the nervous system? The answer to this question remains enigmatic, not so much because of a lack of relevant data, but because of the lack of a conceptual framework with which to interpret the data. To this end, we developed Passive Frame Theory, a internally-coherent framework that, from an action-based perspective, synthesizes empirically supported hypotheses from diverse fields of investigation. The theory proposes that the primary function of consciousness is well-circumscribed, serving the somatic nervous system. Inside this system, consciousness serves as a frame that constrains and directs skeletal muscle output, thereby yielding adaptive behavior. The mechanism by which consciousness achieves this is more counterintuitive, passive, and ‘low level’ than the kinds of functions that theorists have previously attributed to consciousness. Passive Frame Theory begins to illuminate (a) what consciousness contributes to nervous function, (b) how consciousness achieves this function, and (c) the neuroanatomical substrates of conscious processes. Our untraditional, action-based perspective focuses on olfaction instead of on vision and is descriptive (describing the products of nature as they evolved to be) rather than normative (construing processes in terms of how they should function). Passive Frame Theory begins to isolate the neuroanatomical, cognitive-mechanistic, and representational (e.g., conscious contents) processes associated with consciousness.”