Tag Archives: neuroscience

Revising the Three Structure Model: Integration in Neuroscience: A Core Problem – Part 8

Slide1

A Three Structure Model of Neural Activity in Relation to Consciousness and Language

In the last post I expended on the three model structure relating unconscious activity,conscious experience and language. In particular I looked at is how unconscious activity could be divided into absolute unconscious activity which would never reach conscious experience and transient unconscious activity which could. These changes are reflected in the diagram below.

ThreeStructureModelRevisedHow do these two types of unconscious activity that I’m proposing relate to language? A valid model would need practical applications and be able to say something useful about reality. Let us consider the example of the optic nerve. I have assumed that as one of the cranial nerves which conveys information to the visual cortex that it would be devoid of conscious experience. I don’t think this is too unreasonable. Now the question is how does absolute unconscious activity reach the stage of language? In the three structure model I have proposed that language would need to be preceded by conscious experience.

Intuitively we might suppose it is obvious that the information being transmitted from the eye via the optic nerve could be directly translated into language. However although there is processing in the retina before the information is transmitted down the optic nerve I am assuming that this is absolute unconscious activity. Therefore there has to be an indirect way for this activity to reach the stage of language. My suggestion is that this would occur by inference.

The reader may suppose that it is simple enough to demonstrate that activity in the retina leads directly to language describing this experience. For instance the simple act of opening one’s eyes in the morning allows the rays of sunshine to permeate the retinal layer. We might then say “it is very bright this morning”. Surely the activity in the retina has led directly to language? However the answer in this case is that it has not. Activity in the retinal layer is conveyed by the optic nerve to the visual cortex and also to other areas by the accessory optic tract. I would argue that it is in the visual cortex and visual association cortices where the conscious experience is occurring that precedes language.

However there is something quite curious that we need to explain. How is it that we can anticipate what the world will look like if one of our eyes is closed? We know intuitively that one part of the visual field will be obscured. I would argue that this is inference. We use our sensory apparatus almost continuously during wakefulness. We have developed through the course of our life a good understanding of what effects occur when we cover one eye, blink rapidly or look up suddenly. This understanding occurs through our conscious experience which is triangulated with a conscious experience occurring in the visual association cortex, visual cortex and associated areas.

The inferences that we make about the eye and its structures occurs in conscious experience and transient unconscious activity. If I close my eye I’m aware of the eye the eyelid and the surrounding structures. I know from past experience what will happen to my visual perception when I close the eye. When I close my eye my visual perception will alter. I’m combining direct conscious experience with a conscious experience based on inference about absolute unconscious activity. The direct conscious experience is exemplified by the statements

the wall in front of me is a pale blue in colour

The inference about absolute unconscious activity is exemplified by the statement

I will no longer see the blue wall in front of me when I close my eyes

 The study of physiology may lead to an improvement in the inferences that we are able to draw in our conscious experience. We are in effect model building. The conscious experience of inference about our sensory apparatus is most likely distinct from our conscious experience of visual perception. Continuing with this compartmentalisation both these types of conscious experience are very distinct from the absolute unconscious activity occurring in the retina. We might distinguish between the experiential conscious experience of immediate visual perception and the more formalised conscious experience of inference.

The Anatomy of the Eye

Accommodation – The Role of the Lens

Refraction in the Eye

Accommodation – The Role of the Iris

A Little Speculation

All of this follows from the assumptions set out in the three structure model. There is room for a little speculation although in doing this the conclusions are much less firm and this is really an exercise in opening up new vistas. Firstly the conscious experience of visual perception and that of inference may be expected to occur in distinct brain areas. The conscious experience of visual perception may be expected to be closely linked to the emotional centres in brain. The reason I suggest this is that when we are experiencing a landscape for instance, we can be caught up in the moment and access our feelings in response to what we are seeing. There are some difficulties with this however. The visual cortex is located at the back of the brain whereas the Limbic structures (e.g Anterior Cingulate Cortex) and Insular Cortex are located much further forward. However the experience of being able to access emotions more easily with visual perception needs to be balanced by hard calculations. For instance we can calculate how many neuron relays there are between one location and another and then utilise this information together with the conduction velocities. placing too much reliance on the timing of conscious experiences during introspection is fraught with difficulty.

Related Resources on the TAWOP Site

In Support of Method

A Review of the Structure of Scientific Revolutions

An Interpretation of Scientific Revolutions

Integration in Neuroscience: A Core Problem – Part 1

Integration in Neuroscience: A Core Problem – Part 2

Integration in Neuroscience:A Core Problem – Part 3

Integration in Neuroscience: A Core Problem – Part 4: A Language for Mind and Brain?

Integration in Neuroscience: A Core Problem – Part 5: A Three Structure Model

Integration in Neuroscience: A Core Problem – Part 6: Reflection on the Three Structure Model

Integration in Neuroscience: A Core Problem – Part 7: The Unconscious in the Three Structure Model

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

The Unconscious in the Three Structure Model: Integration in Neuroscience: A Core Problem – Part 7

Slide1

This is a continuation of an investigation into the problem of integration in neuroscience (see Appendix for earlier posts in the series).

IntegrationInNeuroscience

A Three Structure Model of Neural Activity in Relation to Consciousness and Language

Here I will consider the first two structures within the model – neural activity and consciousness. The model states that neural activity leads to conscious experience. However we do not need to reinvent the wheel. Freud had developed an eloquent model which incorporates conscious and unconscious activity and from an experiential perspective this has construct validity. As I write this I am breathing and my heart is beating. I am not aware of this until I attend to these phenomenon. I know that the Medulla Cardiovascular Centre regulates heart rate through sympathetic and parasympathetic outflow. As soon as the need arises the cardiovascular centre will modify the heart rate but I will not need to be aware of it. Indeed if I start to run quickly this will happen automatically. I do not have time to think about it.

For the Medullary Respiratory Centre the situation is the same. Activity in the neurons here will causes me to breathe more quickly. I do not focus my activity on the respiratory rate when I run quickly. I just breathe more quickly due to a number of factors including activity in the neurons in the Medullary Respiratory Centre. Again neuronal activity is happening which I am not consciously aware of. In this model, unconscious activity means one of two things.

1. Unconscious activity results from neuronal activity. This unconscious activity can become conscious experience if it is attended to.

2. Unconscious activity is neuronal activity. This activity can never become conscious experience as there is no mechanism for it to do so.

Thus two types of unconscious activity are described here and in practice both types are likely. I will refer to unconscious activity which can never become conscious experience as Absolute Unconscious Experience Activity. I would refer to activity in the Optic Nerve as being Absolute Unconscious Experience Activity.  Although activity here is essential for visual perception, the activity here occurs at an early stage of visual processing and would be referred to as sensation rather than perception. Activity in the Optic Nerve can impact on our conscious experience.

The second type of unconscious activity I will refer to as Transient Unconscious Activity Experience. In this case neuronal activity does not reach conscious experience when it is unconscious activity. However it is capable of reaching conscious awareness. An example of breathing will again help to illustrate the point. As I think about this sentence I am concentrating on the concepts but am unaware of my breathing. If instead I focus on my breathing I become aware of the air moving through my nose and the sensation of my lungs expanding as well as the rhythm of inspiration and expiration. Unconscious Activity experience has become conscious experience. The neuronal correlates are much more complex however and would likely include range from components of the Peripheral Nervous System through to the Medulla, the Thalamus, Insular Cortex, Primary and Secondary Somatosensory Cortex, Somatosensory Association Cortices, Primary Motor Cortex and Premotor Cortex. The neuronal activity needs to occur in these areas. In one state of mind however I am unaware of this. In the other state I am aware of some of this background neuronal activity.

The three structure model must expand to incorporate these two types of unconscious activity.

Related Resources on the TAWOP Site

In Support of Method

A Review of the Structure of Scientific Revolutions

An Interpretation of Scientific Revolutions

Integration in Neuroscience: A Core Problem – Part 1

Integration in Neuroscience: A Core Problem – Part 2

Integration in Neuroscience:A Core Problem – Part 3

Integration in Neuroscience: A Core Problem – Part 4: A Language for Mind and Brain?

Integration in Neuroscience: A Core Problem – Part 5: A Three Structure Model

Integration in Neuroscience: A Core Problem – Part 6: Reflection on the Three Structure Model

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.

Integration in Neuroscience: A Core Problem – Part 6: Reflection on the Three Structure Model

In Part 5 of the series we looked at a three structure model of conscious experience, neural activity and language. These three ‘structures’ are important components of any detailed discussion of the mind-brain distinction.

IntegrationInNeuroscience

A Three Structure Model of Neural Activity in Relation to Consciousness and Language

Looking more closely at this model it can be seen that there is something distinct about the ‘conscious’ component of the model. This cannot be properly described through external observation. Conscious experience is something that we experience or else can understand in others through an empathic process which usually involves drawing inferences from the language that is spoken to us. In this way, conscious experience is very distinct from language and neural activity. We can understood neural activity through physiological investigation – functional Magnetic Resonance Imaging, single electrode recording, electroencephalography, magnetoencephalography and so on.

We can understand language through meaning which implies using conscious experience to interpret this. However we can also analyse language by more abstract means which avoid the need for conscious experience. This can be demonstrated quite easily by making use of the Google translate feature. This feature translates text from one language to another. This is just one example of what happens when language is analysed without the medium of conscious experience. Conscious experience applies both to the subject being studied and to the observer. Theoretically therefore it is possible to study the neural correlates of abstract properties of language such as the number of times a certain word is used within a paragraph without the intermediary of conscious experience. Conscious experience may have been used earlier to construct the algorithms used to identify individual words and match them with words in a database. Once this work is done however the conscious experience intermediary is no longer needed. This is similar to the remarkable Gallant study where film footage was reverse engineered through the processing of fMRI data and movie data that had been watched previously. The conscious experience intermediary was obviated once these prior steps had been taken.

However considering neural activity and superficial aspects of language without looking at conscious experience is like being cast adrift in a rudderless ship. We may enjoy the ride but our destination remains a mystery. Conscious experience enables a narrative which shapes our inner world. The narrative breathes ‘life’ into action potentials and this ‘life’ becomes the spoken word. I may read a paragraph of writing. Each time I can speak it aloud without error. Each time I can understand what it is that is written. Each time I can rephrase it and retain the meaning. This is so obvious to our daily existence that we do not give it a second thought. But deconstruct it into the separate components above and the illusion shatters. We must then face the wondrous awe that is conscious experience assembled from the electrical activity of billions of neurons mediated through trillions of synapses. Happening from moment to moment. Without us needing to think about it.

Consciousness attracts people. Philosophers contemplate it. Romantics channel it. Empiricists deny it. Neurophysiologists measure it. Psychoanalysts explore it. Anaesthetists dampen it. Comedians brighten it. Adventurers actualise it. Authors communicate it. Anatomists localise it. Musicians play it. Dramatists exaggerate it. Leaders inspire it. Communities share it. And we all live in it. Yet when consciousness is modelled or described with colourful neuroimages there is an immediate sense that something wonderful has been lost. That an absurd reduction has been made which misses the point. What we are implicitly aware of is the magnificence of the show that the brain puts on for us. This is not just the output of lots of neurons showing their synergy. It is the output of layer upon layer of neurons, magnificent in their numbers but also magnificent in the specialisation of their assemblies. When we consider how all of these specialised neurons coordinate their roles so effortlessly it has become too much.

At the interface between mind and brain we see on one side the elegant stream of consciousness that Descarte’s homunculus sees on the brain’s projector screen. On the other side we see the projector, an elegant work of engineering whose activities match the stream of consciousness from second to second. We no longer have to leave it there. Little by little the architecture of the brain’s consciousness machinery is being clarified. There is a permission for our understanding of the stream of consciousness to become more refined. But along the way we must never lose sight of the special place that consciousness has and how we must cherish this meaning. Exploring the machinery of consciousness must not result in a dry taxonomy that can be processed without the need for conscious experience. Instead the machinery of consciousness must be contextualised as it is understood. Life must be breathed into this understanding so that it has social as well as academic meaning. So that this understanding inspires joy rather than caution or perplexion.

Related Resources on the TAWOP Site

In Support of Method

A Review of the Structure of Scientific Revolutions

An Interpretation of Scientific Revolutions

Integration in Neuroscience: A Core Problem – Part 1

Integration in Neuroscience: A Core Problem – Part 2

Integration in Neuroscience:A Core Problem – Part 3

Integration in Neuroscience: A Core Problem – Part 4: A Language for Mind and Brain?

Integration in Neuroscience: A Core Problem – Part 5: A Three Structure Model

Index: There are indices for the TAWOP site here and here Twitter: You can follow ‘The Amazing World of Psychiatry’ Twitter by clicking on this link. Podcast: You can listen to this post on Odiogo by clicking on this link (there may be a small delay between publishing of the blog article and the availability of the podcast). It is available for a limited period. TAWOP Channel: You can follow the TAWOP Channel on YouTube by clicking on this link. Responses: If you have any comments, you can leave them below or alternatively e-mail justinmarley17@yahoo.co.uk. Disclaimer: The comments made here represent the opinions of the author and do not represent the profession or any body/organisation. The comments made here are not meant as a source of medical advice and those seeking medical advice are advised to consult with their own doctor. The author is not responsible for the contents of any external sites that are linked to in this blog.