Scientific Understanding of Consciousness
Consciousness as an Emergent Property of Thalamocortical Activity

Dispositions

A disposition is a habit, a preparation, a state of readiness, or a tendency to act in a specified way. (Wikipedia)

 

Nested hierarchies of motor command procedures

Nested hierarchies of motor command procedures, variously called Fixed Action Patterns (FAPs) or Central Pattern Generators (CPGs) or Dispositions emanating from the basal ganglia, premotor cortex, motor cortex, brain stem and spinal cord produce movement patterns unconsciously.

We have inherited from many prior species, abundant networks of dispositions that run our basic mechanisms of life management. They include the nuclei that control our endocrine system and the nuclei that serve the mechanisms of reward and punishment in the triggering and execution of the emotions. (Damasio; Self Comes to Mind, 135)

The foundations for the processes of consciousness are the unconscious processes in charge of life regulation -- the blind dispositions that regulate metabolic functions and are housed in brainstem nuclei and hypothalamus; the dispositions that deliver reward and punishment and promote drives, motivations, and emotion; and the mapping apparatus that manufactures images, in perception and recall, and that can select and edit such images. (Damasio; Self Comes to Mind, 176)

Dispositions are a space-saving mechanism for information storage. (Damasio; Self Comes to Mind, 140)

Long-term memory beliefs are better seen as acquired dispositions to have particular active working memory beliefs. (Hurley, Dennett, Adams; Inside Jokes, 105)

A committed belief in long-term memory is a disposition to construct future active beliefs and use those contents in acts of reasoning. (Hurley, Dennett, Adams; Inside Jokes, 111)

 

Dispositions can generate actions of many kinds

Dispositions produce a variety of results. They can generate actions of many kinds in many levels of complexity -- the release of hormones into the bloodstream; the contraction of muscles in the viscera or of muscles in a limb or in the vocal apparatus. (Damasio; Self Comes to Mind, 143)

Dispositions can be used to reconstruct the maps in early sensory cortices, and the format in which they were first experienced. (Damasio; Self Comes to Mind, 140)

Cell ensembles at the top levels of the processing hierarchies would not hold explicit representation of the maps for objects and events. Rather, the ensembles would hold know how, i.e. dispositions, for the eventual reconstruction of explicit representations when they become needed. (Damasio; Self Comes to Mind, 140)

Dispositions act on a host of early sensory cortices originally engaged by perception. (Damasio; Self Comes to Mind, 141)

Dispositions are commanding the process of reactivating and putting together aspects of past perception, wherever they have been processed and then locally recorded. (Damasio; Self Comes to Mind, 141)

Dispositions act by way of connections diverging from the disposition site back to early sensory cortices. (Damasio; Self Comes to Mind, 141)

The locus where memory records would actually be played back would not be that different from the locus of original perception. (Damasio; Self Comes to Mind, 141)

 

Dispositional Space

Cortical dispositional space includes all the higher-order association cortices in temporal, parietal, and frontal regions. (Damasio; Self Comes to Mind, 143)

An old set of dispositional devices remains beneath the cerebral cortex in the basal forebrain, basal ganglia, thalamus, hypothalamus, and brain stem. (Damasio; Self Comes to Mind, 143)

Dispositional space is that in which dispositions hold the knowledge base as well is the devices for the reconstruction of that knowledge in recall. (Damasio; Self Comes to Mind, 143) (c.f. Metaphor of Object-Oriented Programming)

Dispositional space is the source of images in the process of imagination and reasoning and is also used to generate movement. (Damasio; Self Comes to Mind, 143)

Dispositional space is located in the cerebral cortices that are not otherwise occupied by the image space (the higher-order cortices and part of the limbic cortices) and in numerous subcortical nuclei. (Damasio; Self Comes to Mind, 143)

When dispositional circuits are activated, they signal to other circuits and cause images or actions to be generated. (Damasio; Self Comes to Mind, 143)

The contents exhibited in the image space are explicit, while the contents of the dispositional space are implicit. (Damasio; Self Comes to Mind, 143)

 

Image Space

The image space is the space where explicit images of all sensory types occur, including both the images that become conscious and those that remain unconscious. (Damasio; Self Comes to Mind, 143)

The image space is located in the map-making brain, a large territory formed by the aggregate of all the early sensory cortices, the regions of cerebral cortex located in and around the entry point of visual, auditory, and other sensory signals into the brain. (Damasio; Self Comes to Mind, 143)

Image space also includes the territories of the nucleus tractus solitarius, parabrachial nucleus, and superior colliculi, which have image making capability. (Damasio; Self Comes to Mind, 143)

We can access the contents of images, if we are conscious, but we never access the contents of dispositions directly. (Damasio; Self Comes to Mind, 143)

Of necessity, the contents of dispositions are always unconscious. (Damasio; Self Comes to Mind, 143)

The image space is controlled by a number of cortical and subcortical sites whose circuits contain dispositional knowledge recorded in dormant form in the convergence-divergence neural architecture. (Damasio; Self Comes to Mind, 189)

Memories and Language Activated by Dispositions

All of our memories, inherited from evolution and available at birth or acquired through learning thereafter -- exist in our brains in dispositional form, waiting to become explicit images or actions. (Damasio; Self Comes to Mind144)

The rules with which we put words and signs together, the grammar of a language, are also held as dispositions. (Damasio; Self Comes to Mind, 144)

 

 

Link to Movement Control

Link to Fixed Action Patterns (FAPs)

Link to Central Pattern Generators

Link to Declarative Memory As Reconstruction