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

Human-type Consciousness

My term “human-type consciousness” encompasses Gerald Edelman’s term “higher-order consciousness” (Edelman; Universe of Consciousness, 102), and Antonio Damasio’s term “extended consciousness” (Damasio; Feeling of What Happens, 16).

Human consciousness is mediated by a greatly expanded brain facility compared with other animals. Most prominent among these is a greatly expanded frontal cortex and the uniquely human Broca and Wernicke language areas. The hugely expanded frontal cortex, facilitating cognitive reasoning, thinking, planning and decision making has coevolved with the special language areas. The human brain also has a special area for processing and recognizing the visual images of human faces. Humans can quickly see, remember and recognize a human face. (Within some time limits, however. I must confess that at my high school reunion I was embarrassed more than once when failing to recognize a classmate!)

Human-type consciousness is closely allied with a number of functionalities of the brain. Consciousness is an emergent property of neural activity in the dynamic core, which is closely related to the functionality of working memory and attention.  Emergence is a typical property of complex systems. Underlying consciousness and forming a major part its functionality are emotion and motivation, which forms what Ledoux calls the traditional tripartite amalgam: cognition, emotion, and motivation.

Consciousness at any instant is simply the integrated product of the information represented in the activated thalamocortical networks at that instant. That includes sense of self; awareness of body; and awareness of the world, be it real or fictive.  (Hobson; Consciousness, 141)   [Edelman's dynamic core]

Although consciousness has no formal definition at the current state of the science, and we should leave it this way for now, it is useful to distinguish between human consciousness and the consciousness of other animals.

• Human-type consciousness is dependent upon the function of Core Consciousness.

• In general, Mammals have Core consciousness. Also, I believe Birds have some aspects of consciousness.

• Reptiles have a few characteristics of Core consciousness.

• Lower animals such as Insects and Lobsters do not have consciousness. Although some have the capability for simple learned behaviors, most are innately-wired automatons. A spider building a web has no idea what it is doing; the nervous system is innately wired to do its thing.

Extended consciousness requires working memory and explicit long-term memory (including both semantic and episodic memories). (Damasio & Meyer; Consciousness Overview, 9)

Key elements of our autobiography correspond to our identity, to our recent experiences, and to the experiences that we anticipate, especially those in the near future. (Damasio; Feeling of What Happens, 221)

Nearest we may come to sharing someone else's consciousness is via poetry, paintings, and music. (Greenfield; Private Life of Brain, 180)

Language is a major contributor to extended consciousness. (Damasio; Feeling of What Happens, 108)

Critical elements of our autobiography arise from a continuously reactivated network based on convergence zones, which are located in the temporal and frontal higher-order cortices, as well as in subcortical nuclei such as those in the amygdala. (Damasio; Feeling of What Happens, 221)

Know so little how the brain constructs narrative. (Hobson; Consciousness, 134)

Consciousness is best conceived as the brain's awareness of its own activity, including such modular functions as perception, memory, thinking, and feeling, each of which has some degree of anatomical localization or functional specialization. (Hobson; Dream Drugstore, 88)

Working memory is the gateway to subjective experiences, emotional and nonemotional ones, and is indispensable in the creation of a conscious emotional feeling. (LeDoux; Emotional Brain, 296)

Active consciousness has its major activity involved with anterior cortical, related thalamic, and basal ganglia neural sites, which are known to be crucially involved with actions of either direct motor action or of thought, planning. (Baars; Neuronal Mechanisms of Consciousness, 274)

The coordinated activity within the thalamus, anterior cingulate cortex (ACC), the ventral lateral prefrontal cortex (VLPFC), posterior parietal cortex (PPC), and the brain stem probably regulate the content of consciousness through mechanisms of executive attention. (Vogt; Cingulate Neurobiology, 384)

 

Human-type Consciousness builds upon Core Consciousness

Nervous systems evolved in animals as a way of providing command signals for the control of movement in a competitive environment. Higher, non-human primates may have some aspects of human-type consciousness. Human-type consciousness as I am using the term here probably arose about the time hominoids migrated out of Africa, or perhaps somewhat later, about 50 thousand years ago.

Brains evolved as a way to emulate reality for predicting movements required to locate and compete for mates, forage for food, chase prey, and avoid predators. Human-type consciousness includes characteristics such as:

• Time sense -- Distant Past to Future Planning.

• Ideas -- mental representation of hypothetical episodes and relationships, planning. Ideas hallmark: (1) observe the world, (2) conjure desired arrangement. Squirrel-with-nuts behavior is innate, no ideas.

• Language -- helpful for manipulating and communicating ideas, but not necessary for consciousness. Core consciousness can survive damage to the Broca and Wernicke areas.

• Creativity -- logically connecting ideas and mental objects to fashion desirable relationships.

• Abstract thinking -- examples include mathematics, symbolic representation of ideas and external objects.

• Moral behavior -- sense of right and wrong, good and evil.

Sense of Time — Past and Present

Retrieval memory and inference allow a 14 month old to detect logical connection between past and present. (Hobson; Consciousness, 100)

Gamma-Band Oscillations Associated with Consciousness

Synchronous gamma-band oscillations have been shown to correlate with consciousness in humans and animals. (Revonsuo; Inner Presence, 95)

Psychiatric Disorders and Medication

Natural disorders of consciousness, treated with medication. Depression treated with Prosaic, schizophrenia with dopamine.

Drugs of Abuse

Altered states of consciousness

Chemically induced pleasure, typically interact with neurotransmitters and/or their receptors in the brain.

Stroke and Tumor

Consciousness can survive most partial loss of brain functionality. However, damage to some areas of the brain can result in substantial changes in personality.

Spinal Cord Injury

Spinal cord damage resulting in retention of human-type consciousness with virtually no peripheral voluntary movement capability

Locked-In Syndrome

Brain stem damage resulting in retention of core or human-type consciousness with virtually no voluntary movement capability. Typically, the only residual capability is vertical movement of the eyes via the first two cranial nerves. A devastating predicament.

Vegetative State

Brain damage with some residual FAPs and movement, but no consciousness. (Abnormal Function of Brain)

 

 

Research study — Social Learning

 

Subjective Feel of Emotions Guides Choices for Survival

The feel of different emotions might be important in guiding choices and thus in aiding survival. (Greenfield; Private Life of Brain, 49)

Feelings, in Susan Greenfield's hypothesis, are the most basic form of consciousness. (Greenfield; Private Life of Brain, 163)

In evolutionary terms, we can view emotions as processes where a person is highly interactive with the environment.  If you are interacting with the environment, you are focusing on your senses. (Greenfield; Private Life of Brain, 49)

The ultimate question: How do subjective sensations -- different states of consciousness -- occur as a result of the shifting neuronal network activity within the physical brain? (Greenfield; Private Life of Brain, 163)

 

Excerpts from science experts

Higher-order consciousness leads to the construction of an imaginative domain, one of feeling, emotion, thought, fantasy, self, and will. (Edelman; Bright Air, 151)

Higher-order consciousness is built on the foundations provided by primary consciousness and is accompanied by a sense of self and the ability in the waking state explicitly to construct past and future scenes. Higher-order consciousness requires a semantic capability, and in its most developed form, a linguistic capability. (Edelman; Universe of Consciousness, 102)

Extended consciousness is also present in some nonhumans at simple levels; it only attains its highest levels in humans where it is also enhanced by language. (Damasio; Feeling of What Happens, 16)

Prefrontal cortices probably participate only in extended consciousness. (Damasio; Feeling of What Happens, 181)

Working memory affects extended consciousness but not core consciousness. (Damasio; Feeling of What Happens, 269)

Only the part of consciousness called self-awareness is capable of observing brains states. (Hobson; Dreaming as Delirium, 12)

Only human beings can engage in reflective thinking:  "That's a good idea"; "That's nonsense"; "I want to do that", (Greenspan; First Idea, 17)

Humans have very poor facial recall ability. Humans are experts as facial recognition. Babies will look at faces in preference to any other visual image. (Johnston; Why We Feel, 40-41)

Perception without awareness - The Hidden Persuaders, 'subliminal perception', Message "DRINK COKE" flashed briefly during a movie. (Edelman; Universe of Consciousness, 67)

 

 

Science 23 November 2007: Vol. 318. no. 5854, p. 1257

Theory of Mind Is Independent of Episodic Memory

R. Shayna Rosenbaum, Donald T. Stuss, Brian Levine, Endel Tulving

Department of Psychology, York University and Rotman Research Institute, Baycrest, Toronto, Ontario M3J 1P3, Canada.

 

Theory of mind (ToM) to infer other people's current mental states and episodic memory of personal happenings have been assumed to be closely related. We report two participants with severely impaired episodic memory who perform indistinguishably from healthy controls on objective ToM tests. These results suggest that ToM can function independently of episodic memory.

As humans, we are intrigued by who we are and how we differ from other creatures of evolution. Among the capacities thought to be uniquely human are autonoetic consciousness, the aspect of self-awareness that allows us to imagine our own experiences in different places at other times, and theory of mind (ToM), which allows us to infer other people's current mental states. The idea that ToM is closely related to, and that it may depend on, episodic memory and autonoetic consciousness seems perfectly natural: that in order to imagine and make sense of other people's thoughts, feelings, intentions, and actions, we must rely on our autobiographical recollections. The ability to consciously recollect past personal happenings has been shown to be necessary for imagining coherent and detailed personal happenings in the future. Both episodic memory and ToM emerge close in time in ontogenetic development. The neural substrate on which the two abilities rely is in many ways strikingly similar.

 

 

 

Link to — Core Consciousness

Link to — Consciousness Subject Outline

Further discussion — Covington Theory of Consciousness