Skip to main content

Salience Theory: What is pain?

This morning I awoke to find a message from a Facebook user (who I am not friends with as yet) regarding the subject of pain:



"Spekulation: Pain: When the parameters upholding consciousness leaves the definition space for those parameters. Tickeling and pleasure: When you travel along the rand of the definition space of consciousness. Of course, the definition space changes as the neuroplasticity redefines how singlas are processed, hence pain happens when signals deviate too quickly from the normal. Do you know of any hypothesis which comes close to the above?"


Immediately the problem in this definition can be identified by realizing that biologically pain is truly a spectrum of alerts and is not a critical threshold where some system goes from signal to noise as would be the case if it were a rapid deviation from "normal" (however that is defined).

Biologically the pain receptors are distributed across the body along with other sensors that can identify pressure. The pain processing pathways and the somatosensory (pressure) processing pathways are therefor different to some degree. What degree would they need to be different in salience theory in order to be useful for consciousness without being terminal to it as asserted in this question is what is most important. It should be obvious that if consciousness were turned off as it were when any pain signal was received we'd have a hard time staying conscious. The function of TRP based molecules revealed in recent research show clearly how finely resolved is the experience of pain.



Pain sign ranges from notification to attention to continued awareness to agony. In the salience theory the dynamic cognition cycle divides dimensions of sensory experience into those that are externally driven and those that are internally driven. At first I was unsure of where pain actually went as it seemed to be triggered by both external and internal sensory factors, for example an obvious external factor that can induce pain is falling off a bike and obtaining bruises, conversely and important internal sensory factor that can induce pain is simply being hungry, the build up of acid in an empty stomach can lead to crippling pain that forces an individual to seek out food to quench.

So from this thought experiment it seems that pain is actually an input sensory dimension that can be triggered internally (we can cause pain to ourselves!) to some degree there seem to be pathways in place to subtract pain when we are causing it to ourselves (for example the mechanism by which self tickling is rendered moot) so there is some necessary feedback in the processing of the pain signal that enables this by attenuating self enabled sensations. However, the fact that pain is triggered by both told me immediately that in fact it was a salience factor akin to emotion. So how would it look like in salience theory?

Let's look at the simple Dynamic Cognition Diagram:







In this diagram,. pain would be triggered either by internal or external causation factors as previously described so where would it be in the cycle? It should be clear that because pain is used to inform action it would be a critical part of salience determination at step 3. The reason again is clearly shown by example to physiology, there are people who have varied ability to sense pain!

The pathologies draw mostly around the pain receptors not being formed at the nerves in the various locations they are distributed across the body and insensitivity to any external forces leading to various types of damage that people with properly functioning sensors don't exhibit. However, the pain receptors send the signal and salience indicates the importance of that signal.

It appears that since there are multiple sensors dedicated to different types of somatosensory experience (pain, pressure, temperature) all have a common salience module.

The subtraction of pain signalling from a self tickle indicates this module labels autonomic action differently from external action, there is likely a similar muting of temperature signals and pressure signals to prevent us from accidentally hurting ourselves in all three aspects.

In salience theory each is given it's on scale of gradation which would then enable feedback and labeling in the comparison stage that can then be used to inform goal selection for committing some sought out action. In the case of these signals this would be as a factor to modulate the cognitive selection process to bias to those options that are away from those that may be causing or have caused pain in the past.

I assert that this modulation is high resolution, dynamic across time in terms of the intensity of the signal reported but static as it is stored with memories associated with past experience. Comparison then simply results from setting a direction per compared salience factor associated with a stored memory versus an incoming experience in a given external dimension (vision, taste, touch (body map), smell,hearing) and then selecting either a stored option that has worked in the past toward achieving the optimal salience goal (if hot, take action to reduce heat. If hungry take action from evaluated options to reduce hunger..etc.).

A recent paper put forward a mechanism on how the cortex proceeds with goal selection that precisely matches with the hypothesis described for comparison in salience theory save for the fact that the paper had no means of describing the importance of salience itself.

A complex dynamic cognition diagram that I am working on attempts to provide these fine details of feedback between the salience module (including similar systems for metering and labeling of emotional import which a separate team has recently realized is granular just as I hypothesized years ago while forming salience theory) that diagram when finished will be the basis of my writing code to create a dynamic cognitive agent a some point in the near future.

That said, the assertion of the original question of pain being simply a threshold switch is obviously wrong it is a far more complex entity that has modes which are very important during conscious evaluation of salience for action, it can achieve levels of intensity that totally over ride actions that bias away from the pain reduction signal and thus that way direct conscious desire (toward escaping the pain exclusively) but that is not a switch.

Comments

Popular posts from this blog

Highly targeted Cpg vaccine immunotherapy for a range of cancer

Significance?


This will surely go down as a seminal advance in cancer therapy. It reads like magic:

So this new approach looks for the specific proteins that are associated with a given tumors resistance to attack by the body's T cells, it then adjusts those T cells to be hyper sensitive to the specific oncogenic proteins targeted. These cells become essentially The Terminator​ T cells in the specific tumor AND have the multiplied effect of traveling along the immune pathway of spreading that the cancer many have metastasized. This is huge squared because it means you can essentially use targeting one tumor to identify and eliminate distal tumors that you many not even realize exist.

This allows the therapy for treating cancer to, for the first time; end the "wack a mole" problem that has frustrated traditional shot gun methods of treatment involving radiation and chemotherapy ...which by their nature unfortunately damage parts of the body that are not cancer laden but …

Engineers versus Programmers

I have found as more non formally trained people enter the coding space, the quality of code that results varies in an interesting way.

The formalities of learning to code in a structured course at University involve often strong focus on "correctness" and efficiency in the form of big O representations for the algorithms created.

Much less focus tends to be placed on what I'll call practical programming, which is the type of code that engineers (note I didn't use "programmers" on purpose) must learn to write.

Programmers are what Universities create, students that can take a defined development environment and within in write an algorithm for computing some sequence or traversing a tree or encoding and decoding a string. Efficiency and invariant rules are guiding development missions. Execution time for creating the solution is often a week or more depending on the professor and their style of teaching code and giving out problems. This type of coding is devo…

AgilEntity Architecture: Action Oriented Workflow

Permissions, fine grained versus management headache
The usual method for determining which users can perform a given function on a given object in a managed system, employs providing those Users with specific access rights via the use of permissions. Often these permissions are also able to be granted to collections called Groups, to which Users are added. The combination of Permissions and Groups provides the ability to provide as atomic a dissemination of rights across the User space as possible. However, this granularity comes at the price of reduced efficiency for managing the created permissions and more importantly the Groups that collect Users designated to perform sets of actions. Essentially the Groups serve as access control lists in many systems, which for the variable and often changing environment of business applications means a need to constantly update the ACL’s (groups) in order to add or remove individuals based on their ability to perform certain actions. Also, the…