Brain


The Damasio book which I’m crawling through at a snail’s pace due to social factors beyond my control is heating up.

To sum up, he breaks the self or rather representations of the self within the brain into the following ever closer to human sentiency levels:

The Proto-Self. The protoself is the foundation of the self. Higher levels of the self are not conscious of this layer. The proto-self consists of brain images of the fundamentals of the body – maps of the internal milieu, viscera, vestibular system and musculoskeletal frame. Brain structures required for the protoself include several brainstem nuclei which regulate body states and map body signals, the hypothalamus and basal forebrain which maintains the current state of the internal milieu and assists in regulating it, the insular cortex, the S1 cortices and the medial parietal cortices which are part of the somatosensory cortices. These structures produce what Damasio calls first-order maps of the organism.

As an organism interacts with objects, first-order maps of the organism are modified by first-order maps of objects. Structures which create first-order maps are early sensory cortices (eg visual and auditory cortices). However, the proto-self is not awareness of the casual relationship between first-order maps of object and organism. The integration required for this is provided by the next layer, the transient core-self.

Note that first order sensorimotor maps are not necessary for the proto-self in the sense that disruption of structures which produce these first order object maps do not disrupt the proto-self.

The Transient Core-Self. The transient coreself produces second-order maps of the changes in first-order maps of the organism and the object, thus casually relating one to the other. This is a non-verbal process and is the start of consciousness.

So, as the brain forms images of an object (through first-order maps of the object) and these images affect first-order maps of the organism, another level of brain structure creates a swift non-verbal account of the events that are taking place in varied brain regions activated as a consequence of the object-organism reaction. Damasio suggest that are multiple core consciousness generating structures which he lists as the superior colliculi, the entire cingulate cortex, the thalamus and some prefrontal cortices.

As there are always objects (objects can also be memories), the core-self is continously generated and thus appears to be continuous in time.

My notes: The core-self can be considered the intuitive and indivisible “I” which eludes further breakdown on introspection and which disappears when one is unconscious. Note also that the transient core-self is not the self that makes decisions, it is the awareness of “self” versus “object”. Damasio is quite interesting in that his hypotheses basically states there can be no self without objects, that the self is a dynamic entity which results from interaction.

My notes: As all this is language independent, the proto and core self is not just the domain of the humans. Looking into the cat’s eyes after reading this chapter was quite something. Awareness, consciousness, the sense of self as being different from other, the cat had it all.

Next: the autobiographical self and extended consciousness.

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