A Structural Model of Mind and Cognition

This article refines and extends the ideas discussed in a previous article - An Overview of Cognition: The Hardware - and is the basis for the Cognitive Styles Pilot Questionnaire in the last blog posting. Future posts will discuss the functioning of the model, and how it compares to other popular models (i.e., Baddeley's Working Memory model). Summary of results obtained by poll questions about preferences for different types of thinking, and the pilot questionnaire will also be posted in the near future.

Note: Some aspects of this model have been more validated by background literature research than others.

Major theoretical elements and factors:

Based on general distinctions in types of information (modalities), and gross divisions in major information processing routes (pathways) of the brain's cerebral cortex, gleaned loosely from cognitive neuroscience, I present here a model of mind and it's functioning in cognition. It should be noted however, that neuroscience is not the primary focus here, but has been included to be suggestive of ways in which parsimony between the more subjective informational states and processing systems of cognition may link up with the more objective, biological, and anatomical architecture of the brain. As such, any reference to anatomical brain regions should not be taken as definitive, but instead as suggestive. This said, it is from a point of reference to anatomical structure from which this model will be discussed and constructed. The main aim here being to provide an organisational structure by which to understand and order the broad and diverse information that is inherent to cognitive science.

The structure of the human mind and brain can be grossly divided into 4 functional regions, consisting of 5 modalities, with 3 major processing pathways. The 4 major functional regions are internal-management, external-sensory, static-relations, and dynamic-referents. The 5 major modalities are spread across the first two regions and throughout all of the latter two, they are; motivation, orientation, behavioural, communication, and environmental. Finally, the 3 major processing pathways are contextualising, specifying, and translational. All of these functional, modal, and processing pathway structures are interconnected and interact in the production of cognition and thought.

The 4 major functional regions are associated with anatomical divisions of the brain. The first region of internal-management deals with information and processes that are involved in decision making, evaluation, and volitional control. The internal-management region is associated with the frontal, rostral-anterior regions of the cortex in both hemispheres. The second region of external-sensory processes information related to external sensory organs, the eyes and ears. This region is associated with the rear, caudal-posterior regions of the cortex in both hemispheres. The third static-relations region deals with information about fixed interrelationships and is associated with the left-hemisphere. The fourth and final functional region is dynamic-referents, which deals with coordinate, reference point information, and is associated with the right-hemisphere.

The internal-management region consists mainly of two information processing modalities. These modalities are motivation and orientation. The motivation modality processes and stores information about value outcomes, and the orientation modality processes and stores information about domains. The external-sensory region consists mainly of two other modalities. These modalities are communication and environmental. The communication modality stores and processes information about audio, sound, and language, whereas the environmental modality stores and processes information about visual elements like space, hue, and texture. The fifth processing modality is located between the internal-management and external-sensory regions and occupies space in both regions. It is thus considered as both internal-management and external-sensory. This modality is behavioural and processes and stores information about bodily movement.

These modalities are found in both the static-relations and dynamic-referent, hemispheric regions. Individual modalities may however be dominant in one of these regions over the other. For example, the communication modality is dominant in the static-relational region, the left hemisphere. The environmental modality however may well be dominant in the dynamic-referent region, the right hemisphere.

Within hemispheres there are three major information processing routes or pathways. The first pathway runs along the top of the brain, across its superior surface and is called the contextualising pathway. This pathway processes information into contexts and interrelationships and is largely associated with spatial information. The second pathway runs along the lower, inferior surfaces of the brain and is called the specifying pathway. This pathway processes information into specific elements, details, and discrete objects. The final pathway runs from the outer surfaces to the inner surfaces of the brain, lateral to medial, and is called the translational pathway. The outer surfaces of the brain deal with information to do with the reception and apprehension of information, whilst those in the middle deal with information about expression and assertion of information into other regions and modalities.

The 5 modalities can be distinguished into two sub-modalities based on the contextualising and specifying pathways which define different types of information. For the motivation modality the upper, or superior, sub-modality of the contextualising pathway processes information about qualities. The lower, or inferior, sub-modality of the specifying pathway processes information about values. The sub-modalities of the orientation modality are domain (contextualising) and principle (specifying). For the behavioural modality they are coordination (contextualising) and response (specifying). The communication modality has tonal (contextualising) and articulation (specifying). Finally, the environmental modality is divided into spatial (contextualising) and material (specifying).

Overall, functional regions describe the broad purposes of the modalities that they contain. Modalities describe the general types of information that are stored and processed within the long-term memory networks of the cerebral cortex associated with them. Pathways describe information flow in cognitive processing within and across modalities. Lastly, sub-modalities define specific types of information that lend themselves to the logical flow of information in a cognitive process. For example, valued principles applied to a domain produce a sense of quality; value information interacting with principle information within a domain substantiates an evaluation of quality.

An Overview of Cognition - The Hardware

The Major Memory Systems and Processing Routes of the Human Cerebral Cortex

In cognitive terms, the cortex of the human brain can be divided into 3 distinctive regions of processing. Firstly, from front-to-back (along the rostral-caudal axis), regions at the front of the brain are associated with internal management information processing, whilst regions at the back of the brain are associated with external sensory information (e.g., from the eyes and ears). Secondly, from the top-to-bottom (superior and inferior to the rostral-caudal axis – dorsally and ventrally), regions at the top of the brain are associated with contextual information processing (e.g. the spatial “what” processing route), whilst regions at the bottom of the brain are associated with qualifying information processing (e.g., the “where” processing route). Lastly, from left-to-right (each hemisphere), regions in the left hemisphere are associated with preparatory information processing (e.g., perceiving input information), whilst regions in the right hemisphere are associated with formulation information processing (e.g. formulating new perceptions).

These divisions of the cortical surfaces are in general-level terms; that is they indicate the overall trend in information processing type. In more accurate terms most of these information processing types are distributed widely across the brain’s cortical surface. It should also be noted that in regards to hemispheric lateralisation of processing, the ‘preparatory’ and ‘formulation’ labels are somewhat deceptive. What is clearer is that the left hemisphere tends to process information more in earlier stages of an overall process, whilst the right hemisphere tends to process more information later in an overall process (as observed in fMRI data during cognitive tasks).

The brain itself is made up of 5 different major information processing systems. At the most frontal part of the cortex is the quality-value system. This acts as a motivator and is important in outcome evaluation and goal setting for cognitive information processing. It has associations with social-cognition and autobiographical memory. Next to this system is the principle-context system. This system contextualises and links information by principles. It is largely associated with episodic or time based processes and memory. In the middle is the response-coordination system. This system is associated with bodily movements and responses, and forms a bottleneck in cognitive processing. At the back of the brain, at the top most and bottom most regions is the visual-spatial system. This system processes sense information from the eyes into spatial and object perceptions. Sandwiched between this, but reaching further into the frontal regions than depicted in the above figure, is the audio-linguistic system. This system processes information from the ears into language and other auditory perceptions.

Overall, for the external information processing systems of the brain, information ‘flows’ from the back of the brain towards the central regions where the response coordination system is found. Regions further to the back process and store finer details such as lines and individual coordinates, whereas those closer to the centre of the brain process and store more definitive objects and regions. The same overall information flow pattern is also present for the internal information processing systems at the front of the brain, except flowing from the front towards the middle. In both cases regions further away from the response-coordination region of the brain can be considered as more ‘abstract’ whilst those closer to the middle can be considered more ‘concrete’.

Another two major processing routes or pathways run along the lower and upper sides of the brain, following the same inward flow pattern as described in the previous paragraph. Information that flows along the lower pathway qualifies perceptions and processes, whilst that which flows along the upper pathway contextualises them. For example, a visual object perception (e.g., an apple) is given colour and texture on the lower pathway, whilst the upper pathway defines its region in space and relative position to other objects in the visual field. This same general trend is also seen in all of the 5 major cognitive processing modalities. It should be noted though, that although there are major trends in information processing routes across the brains cortical regions and the 5 processing modalities, that these systems hold rich interconnections between themselves as well. Every processing modality is connected to every other modality via substantial fibre-tracts beneath the brain’s cortical surface.

Levels of Memory and Processing within the Major Systems

The manner in which information is processed and stored in memory within each of the 5 major modalities also follows some overall trends. The physical networks of the brain (i.e., neural networks) constitute what is called long-term memory, whereas the activity of those networks constitutes what is called working-memory. Long-term memory is information that the brain has stored within itself, and may or may not be active during information processing. Long-term memory is relatively static and unchanging, however is constantly being ‘updated’ and ‘modified’ due to the ongoing information processing activities of the cognitive system. On the other hand, long-term memory networks that are actively processing information in the moment form immediate memory and attention, known as working memory. Working memory is what a person is thinking about, aware of, and attending to in any given moment. Information that is actively processing may, or may not be, fully represented in long-term memory, and it takes some time (approximately 90 minutes) before information is transferred from immediate, working memory, into long-term memory storage.

Memory, for both long-term storage and information processing is structured in a hierarchical and categorical fashion. Categorical information that is ‘higher up’ the memory network links to related sub-category or instance information below that, which then links in the same kind of manner to memory below that, and so on. For example, the idea of ‘animals’ may link to ‘mammals’, ‘fish’, ‘birds’, and ‘reptiles’. Each of those sub-categories then links to further sub-categories or instances depending on how sophisticated and developed the memory structure is for the person. Overall however, the links between levels in the memory structure appears to be limited to about 4 bits of information per level. This limit affects information processing and storage at the working memory level, and probably represents limitations in the physical interconnectivity between neurons and neural networks within the brain’s cortex. Whilst it is easiest to understand such memory structures in terms of definitive ‘bits’ of information like ‘animals’ and the colour ‘red’, in practicality such ‘bits’ of information may be far more idiosyncratic and abstract in terms of the true memory network structure (e.g. categories and sub-categories may have many more than 4 instances associated with them; in such cases non-descriptive linking sub-categories, or dummy-categories, may intersperse levels within the structure).

When information is being actively processed through a memory network, at the working memory level, activation may flow either up or down the structure. Activated nodes within the network increase the likelihood of all of the other connected nodes, above and below it, to also become active. Active nodes may also decrease the likelihood of other, unrelated memory network structures becoming active. Activation or inhibition between networks is based on different types of neurotransmitter systems, which themselves likely perform different types of connective function within the brain.

The flow of inhibition and activation through a memory network governs the manner in which attention and information processing is focused and changed. Whilst there are limitations on how much of a long-term memory network within one of the 5 modalities can be active at one time (approximately 4 bits of information), active processing in working memory can occur concurrently within each of the 5 modalities as well as across the various divisions of that modality (i.e., left and right hemisphere, and along the qualifying-contextualising axis). Because the 5 modalities are interconnected, changes in one network can lead to changes in another. As such information is parsed from one modality to another, allowing for complex cognitive processing and thought when the brain is considered as a whole.

Overall, information processing in the internal management modalities at the front of the brain are characterised by sustained activation, whilst those at the back of the brain in the external sense modalities show more fluctuation. In both cases, neural activity is biased towards processing changes and differences in the cognitive processing environment, whilst that which stays the same is likely accounted for by memory itself. Information about value-qualities and principle-context information tend to be held consistent in order to focus attention in a goal-direct and evaluative manner onto specific features and elements of a more dynamic influx of sensory information that is processed by visual-spatial and audio-linguistic modalities. The response-coordination system sits somewhere in-between, having both internal-management and external-sense related functions. Intended behavioural responses are most likely held consistently online, whilst more sensory driven and automatic behaviours help keep the sensory organs aligned and focused on specific aspects of the environment.

Rhythms and Timing Intervals in Attention and Memory

There are various timing intervals that are associated with active information processing within a long-term memory network, as well as how long it takes for information to be encoded into memory. These timing intervals create limitations on the attentional and information processing capacities of the human cognitive processing system and are based on biological processes in the brain. Each timing interval follows a base-3 system; that is they are made up of one unit of time length that occurs in processing streams of three units of time in total length. The first unit is an active attention phase to information being processed. The second unit is a linking phase, connecting the previously attended to information to other information. The third and final unit is an inactive, encoding/storage phase. Whilst individual processing threads follow this pattern, multiple overlapping threads occur concurrently with each other in a staggered manner. Half way through one processing threads first unit marks the beginning of a second concurrent thread’s first unit, such that active and linking phases link the threads together.

At the level of working memory, the timing intervals have a base unit of around 3 seconds and a total interval length of around 9 seconds. These units, as with all other levels of timing, are rough population averages, and vary from individual to individual and are also influenced by other neurochemical factors such as arousal level. Information that first enters into working memory then takes approximately 90 minutes before it leads to structural changes in the long-term memory networks of the brain, in a process known as Long-Term-Potentiation. This 90 minute interval also follows the base-3 code, with a 30 minute active phase, and 30 minute linking phase, and a 30 minute encoding/storage phase. Between the 9 second interval level and the 90 minute interval level, and also beyond that level there are also other levels of timing interval. These levels of timing interval affect when, and for how long, information becomes available and/or active in cognitive processing. For example, the 90 minute interval level determines a person’s capabilities to sustain attention on a subject and retain optimal memory performance; the empirical data showing this to be about 45 minutes (2 attentional threads of 30 minutes that overlap). The following table indicates some of these timing intervals.

For further information on Information Processing Modalities as well as discussion on Cognitive Control, read my PhD Critical Review;

Episodic and Motivational Influences on Shifting Attention: A Critical Review of the Literature