This book traces the structures of the brain that provide Phenomenal Consciousness, which is also referred to as Sensory Consiousness and Primary Consh. There are dozens of exquisitely detailed diagrams of brains along the evolutionary journey to Consciousness created by Jill Gregory and Courtney McKenna. The diagram to the left is a schematic brain of the Lamprey, a living equivalent of the first animal that had an advanced Optic Tesctum which provided an isomorphic map of the visual field in an array of tissue that created a "mental image". The diagrams really elevate Gregory & McKenna to honorary co-authors.
I need to update: Notes on Consciousness!
In addition to the timeline of the evolution of the brain structures that support Sensory Consciousness, there are the system level constituent parts: Exteroception, Interoception and Affective Consciousness. (p. 131) Other 'ceptions discussed: proprioception and nosioception, also perception - not mentioned: Neuroception, Reception, Interception, Conception, Exception, Deception, or Inception.
Nice simple definition of Consciousness - that works for me:
p. 111: "But to us, real consciousness is indicated by the (optic tectum) making a multisensory map of the world and then attending to the most important object in this map and then signalling behaviors"... based on the map.
p.5 NSFCs are introduced. A bit like the NCCs of Christof Koch - Neural Correlates of Consciousness. NoSFCs are NeuroOntologically Subjective Features of Consciousness. This phrase is important for closing the Explanatory Gaps and the "hard problem".
1) Mental Unity - we have one coherent notion of Reality.
2) Qualia - subjective perceptrons of qualities.
3) Referral, aka Projection - Reality seems to be Out There, not in our heads.
4) Mental Causation, "Using our notion of Reality as a map to direct our actions to objects in the environment on which we cause affects." (imagining how to interact shapes what we see.)
p.18 Table 2.1 The Defining Features of Consciousness (gen-refl-spec):
Level 1: General Biological Features: life, embodiement, processes, self organizing systems, emergence, teleonomy & adaption.
Level 2: Reflexes of animals with nervous systems.
Level 3: Special Neurobiological Features (not exactly as in Table 2.1):
- Complex Hierarchy (of networks)
- Nested and non-nested processes, aka recursive, aka re-rentrant,
- Isomorphic representations and mental images
- Affective States
My ROUGH notes
Figure 10.8 - Big Picture of Primary Consciousness
p.153 Table 8.2. Criteria for identifying which animals have affective consciousness, as we realize consciousness has so much to do with feelings of good and bad.
The special neurobiological features that we enumerated in chapter 2 (table 2.1, p.18) and throughout this book must also be present. Only a unified brain that has evolved elaborate neural hierarchies creates the unique neural-neural interactions that mark the transition from nonconscious reflexes to subjective phenomenal consciousness. Multiple hierarchies, based on a wide variety of sensory modalities and receptors, may also be essential (vision, hearing, smell, touch: table 9.2, p.175, Criterion 2). The hierarchies require reciprocal interconnections and oscillatory binding for mental unity, and, for the distance senses, isomorphic representations that allow mental images. All these requirements are nicely illustrated by the huge architectural differences we found between the small, unconscious brains of the invertebrate chordates with short, simple sensory hierarchies (chapter 3) and the conscious brains of every vertebrate, with their long, complex neural hierarchies (figures 5.9-5.12, p.93, 6.4).
Based on the evidence we have uncovered, we can assemble the neurohierarchical features that allow sensory consciousness into one statement: Consciousness stems from unique neural interactions within and between discrete chains of neurons, for many specialized sensory modalities, each chain usually requiring four or more levels, and with the chains arranged as hierarchically organized, modality-specific pathways that merge to form a "neural map" that simulates the real world, or else feed into affective circuits, and ultimately serve sustained processing and behavior. Such hierarchies are documented and illustrated, in a nutshell, in figures 6.4, 6.5, p.106, fig 7.1, and 9.3D. Attention-directing and arousal mechanisms must also emerge, and memory centers must contribute (chapter 6).
To restate Postulate 1: the factors of life, emergence, and unique, complex neural hierarchies in combination can explain ontological subjectivity without invoking any unknown or "mysterious principles."
Large Scale Brain Networks
The image to the right is from Modha (2010) and not from Feinbergh/Mallatt 2016.
p.105 The hierarchies communicate back and forth and "sensory hierarchies, as the visual hierarchy receives input regarding sounds, for example. In this way, the isomorphic mapping becomes more complex, more multisensory, and more abstract toward the top of the processing hierarchy. Then, the most highly processed one-sense or multisensory representations are experienced as conscious mental images. The firing of neurons in coordinated, oscillating patterns also seems necessary for sensory consciousness, as suggested by many studies.These back-and-forth oscillations between brain regions are mostly gamma-frequency "brainwaves." They are thought to encode sensory information and then to integrate—or bind into one perception—all those neurons in a sensory hierarchy that are responding to the same sensed object or scene. Not confined to one-sense hierarchies (for example, not for vision alone), the synchronized oscillations would also bind the different types of sensation into one percept: joining the sound, texture, and visual appearance of an object being sensed. This would produce the unified, multisensory, image of consciousness, its "unitary scene"/" Also, oscillations focus attention.
p.108: In all vertebrates, the tectum shows extreme isomorphic mapping, not just of the visual input but also from other senses: touch, hearing, taste, mechanical from the lateral line, and electroreception—but not smell. As we recently stated, this multisensory mapping "is reflected in the tectum's neuronal layering or lamination [figure 6.6B], where the different layers receive different classes of sensory input, and the mapped inputs from the different senses are in topographic register with one another.' This patterning yields a unified and coherent map of sensory space. The tectum also connects to and interacts with many other parts of the brain. The tectum of lampreys (figure 6.4) is not especially simple or primitive but is typical for a vertebrate.18 The tectum has a number of functions, most of which are conserved across the vertebrates: (a) in its sensory function, it processes the sensory input it receives; (b) in its motor function, it signals behavioral actions; and (c) in its attentive function, it selectively directs attention. "
p.215: This book does not address higher levels of consciousness - full-blown self-awareness, meta-awareness, recognition of the Self in mirrors, Theory of Mind, Access to verbal self-reporting.
p.217 Consciousness is Adaptive - we evolved the NoSFCs for survival. They all provide distinct advantages to the beholder.
p.224 Mental Unity is a process, not locatable to a single brain region, it requires to synchronized oscillations to unify multiple networks.
Not true, or consciousness involves more that a pack of neurons. The emergent behaviors from complex hierarchies, etc, etc, make a qualitative difference. Given the books detailed explanations, the objective and the sensory aspects of consciousness can be explained to close the Explanatory Gap.
The addition of the evolutionary and philosophical explanations "bridge the gap" of NeuroOntological Subjectivity, which, essentially, solves the hard problem.
jch.com/jch/notes/FeinbergMallatt2016.html 2016.12.03 YON Book Notes