Secondary consciousness is an individual's accessibility to their history and plans. The ability allows its possessors to go beyond the limits of the remembered present of
primary consciousness.
[Edelman, G. M. (2003). Naturalizing consciousness: a theoretical framework. Proc. Natl. Acad. Sci. U.S.A. 100, 5520–5524.] Primary consciousness can be defined as simple awareness that includes
perception and
emotion. As such, it is ascribed to most animals. By contrast, secondary consciousness depends on and includes such features as self-reflective awareness, abstract thinking, volition and
metacognition
Metacognition is an awareness of one's thought processes and an understanding of the patterns behind them. The term comes from the root word '' meta'', meaning "beyond", or "on top of".Metcalfe, J., & Shimamura, A. P. (1994). ''Metacognition: knowi ...
.
The term was coined by
Gerald Edelman.
Brief history and overview
Since
Descartes's proposal of
dualism
Dualism most commonly refers to:
* Mind–body dualism, a philosophical view which holds that mental phenomena are, at least in certain respects, not physical phenomena, or that the mind and the body are distinct and separable from one another
** ...
, it became a general consensus that the mind had become a matter of
philosophy
Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...
and that science was not able to penetrate the issue of consciousness- that consciousness was outside of space and time. However, over the last 20 years, many scholars have begun to move toward a science of consciousness. Such notable neuroscientists that have led the move to neural correlates of the self and of consciousness are
Antonio Damasio and
Gerald Edelman. Damasio has demonstrated that emotions and their biological foundation play a critical role in high level cognition, and Edelman has created a framework for analyzing consciousness through a scientific outlook. The current problem consciousness researchers face involves explaining how and why consciousness arises from neural computation. In his research on this problem, Edelman has developed a theory of consciousness, in which he has coined the terms
primary consciousness and secondary consciousness.
The author puts forward the belief that consciousness is a particular kind of brain process; linked and integrated, yet complex and differentiated.
Evolution towards secondary consciousness
Edelman argues that the
evolutionary emergence of consciousness depended on the
natural selection of neural systems that gave rise to consciousness, but not on selection for consciousness itself. He is noted for his theory of neuronal group selection, also known as
Neural Darwinism, which posits that consciousness is the product of natural selection. He believes consciousness is not something separate from the real world, thus the attempt to eliminate
Descartes’ "
dualism
Dualism most commonly refers to:
* Mind–body dualism, a philosophical view which holds that mental phenomena are, at least in certain respects, not physical phenomena, or that the mind and the body are distinct and separable from one another
** ...
" as a possible consideration. He also rejects theories based on the notion that the brain is a computer or an instructional system. Instead, he suggests that the brain is a selectional system, one in which large numbers of variant circuits are generated
epigenetically. He claims the potential connectivity in the neural net "far exceeds the number of elementary particles in the universe"
[Edelman, G. M. (2004). Wider than the sky: a revolutionary view of consciousness. Penguin Press Science, London, UK.]
Dynamic core hypothesis and re-entry
Dynamic core hypothesis
Edelman elaborates on the dynamic core hypothesis (DCH), which describes the thalamocortical region- the region believed to be the integration center of consciousness. The DCH reflects the use and disuse of interconnected neuronal networks during stimulation of this region. It has been shown through computer models that neuronal groups existing in the
cerebral cortex and
thalamus interact in the form of synchronous
oscillation. The interaction between distinct neuronal groups forms the "dynamic core" and may help explain the nature of conscious experience.
Re-entry
Edelman integrates the DCH hypothesis into Neural Darwinism, in which
metastable interactions in the thalamocortical region cause a process of selectionism through
re-entry, a host of internal
feedback
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...
loops. "Re-entry", as Edelman states, "provides the critical means by which the activities of distributed multiple brain areas are linked, bound, and then dynamically altered in time during perceptual categorization. Both diversity and re-entry are necessary to account for the fundamental properties of conscious experience." These re-entrant signals are reinforced by areas Edelman calls "degenerate". Degeneracy doesn't imply deterioration, but instead redundancy as many areas in the brain handle the same or similar tasks. With this brain structure emerging in early humans, selection could favor certain brains and pass their patterns down the generations. Habits once erratic and highly individual ultimately became the social norm.
Exhibiting secondary consciousness in the animal kingdom
While animals with
primary consciousness have long-term memory, they lack explicit narrative, and, at best, can only deal with the immediate scene in the remembered present. While they still have an advantage over animals lacking such ability,
evolution has brought forth a growing complexity in consciousness, particularly in
mammals. Animals with this complexity are said to have secondary consciousness.
Secondary consciousness is seen in animals with
semantic capabilities, such as the four
great apes. It is present in its richest form in the
human species, which is unique in possessing complex
language made up of
syntax
In linguistics, syntax () is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure ( constituency) ...
and semantics. In considering how the neural mechanisms underlying primary consciousness arose and were maintained during evolution, it is proposed that at some time around the divergence of
reptiles
Reptiles, as most commonly defined are the animals in the Class (biology), class Reptilia ( ), a paraphyletic grouping comprising all sauropsid, sauropsids except birds. Living reptiles comprise turtles, crocodilians, Squamata, squamates (lizar ...
into mammals and then into
birds
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...
, the
embryological development of large numbers of new reciprocal connections allowed rich re-entrant activity to take place between the more posterior brain systems carrying out perceptual categorization and the more frontally located systems responsible for value-category memory.
The ability of an animal to relate a present complex scene to its own previous history of learning conferred an adaptive evolutionary advantage. At much later evolutionary epochs, further re-entrant circuits appeared that linked semantic and linguistic performance to categorical and conceptual
memory systems. This development enabled the emergence of secondary consciousness.
Self-recognition
For the advocates of the idea of a secondary consciousness, self-recognition serves as a critical component and a key defining measure. What is most interesting then, is the evolutionary appeal that arises with the concept of self-recognition. In non-human species and in children, the "
mirror test" has been used as an indicator of
self-awareness
In philosophy of self, self-awareness is the experience of one's own personality or individuality. It is not to be confused with consciousness in the sense of qualia. While consciousness is being aware of one's environment and body and lifesty ...
. In these experiments, subjects are placed in front of a mirror and provided with a mark that cannot be seen directly but is visible in the mirror.
[Prior, H., Schwarz, A., & Gunturkun, O. (2008). Mirror-induced behavior in the magpie (Pica pica): Evidence of self-recognition. Plos Biology, 6(8), 1642–1650.]
There have been numerous findings in the past 30 years which display fairly clear evidence of possessors of self-recognition including the following animals:
*
Chimpanzee
The chimpanzee (''Pan troglodytes''), also known as simply the chimp, is a species of great ape native to the forest and savannah of tropical Africa. It has four confirmed subspecies and a fifth proposed subspecies. When its close relative th ...
s,
orangutans and
gorillas.
*
Dolphins and
elephants
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae and ...
. Findings suggestive of self-recognition in mammals other than
apes have been reported.
*
Magpies.
It should be mentioned that even in the chimpanzee, the species most studied and with the most convincing findings, clear-cut evidence of self-recognition is not obtained in all individuals tested. Occurrence is about 75% in young adults and considerably less in young and old individuals. For
Monkeys
Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...
, non-primate mammals, and in a number of bird species, exploration of the mirror and social displays were observed. However, hints at mirror-induced self-directed behavior have been obtained.
Self-recognition study in the magpie
It was recently thought that self-recognition was restricted to mammals with large brains and highly evolved social cognition but absent from animals without a
neocortex
The neocortex, also called the neopallium, isocortex, or the six-layered cortex, is a set of layers of the mammalian cerebral cortex involved in higher-order brain functions such as sensory perception, cognition, generation of motor commands, sp ...
. However, in a recent study, an investigation of self-recognition in
corvids was carried out, and significant result quantified the ability of self-recognition in the magpie. Mammals and birds inherited the same brain components from their last common
ancestor
An ancestor, also known as a forefather, fore-elder or a forebear, is a parent or (recursively) the parent of an antecedent (i.e., a grandparent, great-grandparent, great-great-grandparent and so forth). ''Ancestor'' is "any person from whom ...
nearly 300 million years ago, and have since independently evolved and formed significantly different brain types. The results of the mirror and mark tests showed that neocortex-less
magpies are capable of understanding that a mirror image belongs to their own body. The findings show that magpies respond in the mirror and mark test in a manner similar to apes, dolphins and elephants. This is a remarkable capability that, although not fully concrete in its determination of self-recognition, is at least a prerequisite of self-recognition. This is not only of interest regarding the convergent evolution of social intelligence; it is also valuable for an understanding of the general principles that govern cognitive evolution and their underlying neural mechanisms. The magpies were chosen to study based on their empathy/ lifestyle, a possible precursor for their ability of self-awareness.
Research on animal consciousness
Many researchers of consciousness have looked upon such types of research in animals as significant and interesting approaches. Ursula Voss of the Universität Bonn believes that the theory of protoconsciousness may serve as adequate explanation for self-recognition found in this bird species, as they would develop secondary consciousness during REM sleep. She added that many types of birds have very sophisticated language systems. Don Kuiken of the University of Alberta finds such research interesting as well as if we continue to study consciousness with animal models (with differing types of consciousness), we would be able to separate the different forms of reflectiveness found in today's world.
Lucid vs. non-lucid dreaming as a model
In the last couple of decades, dream research has begun to focus on the field of consciousness. Through
lucid dreaming,
NREM sleep,
REM sleep
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream viv ...
, and waking states, many dream researchers are attempting to scientifically explore consciousness. When exploring consciousness through the concept of dreams, many researchers believe the general characteristics that constitute primary and secondary consciousness remain intact:
"Primary consciousness is a state in which you have no future or past, a state of just being…. no executive ego control in your dreams, no planning, things just happen to you, you just are in a dream. Yet, everything feels real…Secondary is based on language, has to do with self-reflection, it has to do with forming abstractions, and that is dependent of language. Only animals with language have secondary consciousness".
Circuitry/anatomy
There have been studies used to determine what parts of the brain are associated with
lucid dreaming,
NREM sleep,
REM sleep
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream viv ...
and waking states. The goal of these studies is often to seek
physiological
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
correlates of dreaming and apply them in the hopes of understanding relations to consciousness.
Prefrontal cortex
Some notable, albeit criticized findings include the functions of the
prefrontal cortex that are most relevant to the self-conscious awareness that is lost in sleep, commonly termed as 'executive' functions. These include self-observation, planning, prioritizing and decision-making abilities, which are, in turn, based upon more basic
cognitive
Cognition refers to "the mental action or process of acquiring knowledge and understanding through thought, experience, and the senses". It encompasses all aspects of intellectual functions and processes such as: perception, attention, thought, ...
abilities such as attention, working memory,
temporal memory and behavioral inhibition Some experimental data which display differences between the self-awareness experienced in waking and its diminution in dreaming can be explained by deactivation of the dorsolateral prefrontal cortex during REM sleep. It has been proposed that deactivation results from a direct inhibition of the dorsolateral prefrontal cortical neurons by
acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Part ...
, the release of which is enhanced during REM sleep.
Research

Experiments and studies have been taken out to test neural correlations of lucid dreams with consciousness in dream research. Although there are many difficulties in conducting lucid dreaming research (e.g. number of lucid subjects, 'type' of lucidity achieved, etc.), there have been studies with significant results.
In one study, researchers sought physiological correlates of lucid dreaming. They showed that the unusual combination of hallucinatory dream activity and wake-like reflective awareness and agentive control experienced in lucid dreams is paralleled by significant changes in
electrophysiology. Participants were recorded using 19-channel
Electroencephalography
Electroencephalography (EEG) is a method to record an electrogram of the spontaneous electrical activity of the brain. The biosignals detected by EEG have been shown to represent the postsynaptic potentials of pyramidal neurons in the neocortex ...
(EEG), and 3 achieved lucidity in the experiment. Differences between REM sleep and lucid dreaming were most prominent in the 40-Hz
frequency band. The increase in 40-Hz power was especially strong at frontolateral and frontal sites. Their findings include the indication that 40-Hz activity holds a functional role in the modulation of conscious awareness across different conscious states. Furthermore, they termed lucid dreaming as a
hybrid state, or that lucidity occurs in a state with features of both REM sleep and waking. In order to move from non-lucid REM sleep dreaming to lucid REM sleep dreaming, there must be a shift in brain activity in the direction of waking.
[Voss, U., Holzmann, R., Tuin, I., & Hobson, J. A. (2009). Lucid Dreaming: A State of Consciousness with Features of Both Waking and Non-Lucid Dreaming. Sleep, 32(9), 1191–1200.]
Other well-known contributing scholars involved with lucid dream research and consciousness, yet primarily based in fields such as psychology and philosophy include:
*
Stephen LaBerge- most known for his lucid dreaming education and facilitation. His technique of signaling to a collaborator monitoring his
EEG with agreed-upon eye movements during REM sleep became the first published, scientifically-verified signal from a dreamer's mind to the outside world.
*
Thomas Metzinger- known for his correlate of neuroscience and philosophy in understanding consciousness. He is praised for his ability to probe and link fundamental issues between these fields.
*
Paul Tholey- most known for his research on rare, non-ordinary ego experiences and OBEs that arise with lucid dreaming. He has also studied the cognitive abilities of dream characters in lucid dreams through various experiments.
Protoconsciousness
The theory of protoconsciousness, developed by
Allan Hobson, a creator of the
Activation-synthesis hypothesis, has been developed through dream research and involves the idea of a secondary consciousness. Hobson suggests that brain states underlying waking and dreaming cooperate and that their functional interplay is crucial to the optimal functioning of both. Ultimately, he proposes the idea that
REM sleep
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream viv ...
provides opportunities to the brain to prepare itself for its main integrative functions, including secondary consciousness, which would explain the developmental and
evolutionary considerations to be taken with birds. This functional interplay which occurs during REM sleep constitutes a 'proto-conscious' state which preludes consciousness and can develop and maintain higher order consciousness.
AIM model
As the
activation-synthesis hypothesis has evolved, it has metamorphosed into the three-dimensional framework known as the AIM model. The AIM model describes a method of mapping conscious states onto an underlying
physiological
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
state space. The AIM model relates not just to wake/sleep states of consciousness, but to all states of
consciousness. By choosing activation, input source, and mode of
neuromodulation as the three dimensions, the proposers believe to have selected "how much information is being processed by the brain (A), what information is being processed (I), and how it is being processed (M).
[Hobson, J. A., Pace-Schott, E. F., & Stickgold, R. (2000). Dreaming and the brain: Toward a cognitive neuroscience of conscious states. Behavioral and Brain Sciences, 23(6), 793-+.]
Hobson, Schott, and Stickgold propose three aspects of the AIM model:
*Conscious states are in large part determined by three interdependent processes, the level of brain
activation ("A"), the origin of inputs ("I") to the activated areas, and the relative levels of activation of aminergic (
noradrenergic and
serotonergic) and
cholinergic neuromodulators ("M").
*The AIM Model proposes that all of the universes' possible brain-mind states can be exemplified with a three-dimensional state space, with axes A, I, and M (activation, input, and mode), and that the state of the brain-mind at any given instant of time can be described as a point in this space. Since the AIM model represents brain-mind state as a sequence of points, Hobson adds that time is a fourth dimension of the model.
*The AIM model proposes that all three parameters defining the state space are continuous variables, and any point in the state space can in theory be occupied.
Criticism of lucid dreaming model
Secondary consciousness, as it remains a controversial topic, has received often contrasting findings and beliefs regarding
lucid dreaming as a model, which entails the true difficulty in understanding consciousness.
The most common of recent criticisms include:
* The analyzed circuitry involved in lucid dreaming,
REM sleep
Rapid eye movement sleep (REM sleep or REMS) is a unique phase of sleep in mammals and birds, characterized by random rapid movement of the eyes, accompanied by low muscle tone throughout the body, and the propensity of the sleeper to dream viv ...
,
NREM sleep, and waking states used to determine reflective ability. If, as many scholars have come to suggest, typical non-lucid REM dreaming reflects
primary consciousness, the belief that typical non-lucid dreaming is accompanied by de-activation of the DL-PFC becomes significant. Although the
Dorsolateral Prefrontal Cortex (DL-PFC) is believed to be the site of "executive
ego
Ego or EGO may refer to:
Social sciences
* Ego (Freudian), one of the three constructs in Sigmund Freud's structural model of the psyche
* Egoism, an ethical theory that treats self-interest as the foundation of morality
* Egotism, the drive to ...
control", it has never been tested.
* The idea of "executive
ego
Ego or EGO may refer to:
Social sciences
* Ego (Freudian), one of the three constructs in Sigmund Freud's structural model of the psyche
* Egoism, an ethical theory that treats self-interest as the foundation of morality
* Egotism, the drive to ...
control" and its articulation. Kuiken has stated that typical non-lucid REM dreaming may involve another form of self-regulative activity that is not related to activation of the DL-PFC. There is evidence that the subtle self-regulation characteristic of
musical improvisation
Musical improvisation (also known as musical extemporization) is the creative activity of immediate ("in the moment") musical composition, which combines performance with communication of emotions and instrumental technique as well as spontaneous ...
is similar in pattern to the activations and de-activations (including de-activation of the DL-PFC) that characterize REM sleep. It is probable that the loss of one conscious form of self-regulation during non-lucid dreaming creates the possibility for the adoption of an unconscious, but "fluid" form of self-regulation that resembles that of musical improvisation. It is possible, he believes, that non-lucid dreaming entails self-regulated but fluid openness to 'what comes,’ rather than the direct self-monitoring and inhibition that enable 'rational' planning and decision making. In a recent study, it has been proven that unconscious task-relevant signals can actively trigger and initiate an inhibition to respond, thereby breaking the alleged close correlation between consciousness and inhibitory control.
[van Gaal S., Ridderinkhof K.R., van den Wildenberg W.P.M., Lamme V.A.F.(2009). Dissociating Consciousness From Inhibitory Control: Evidence for Unconsciously Triggered Response Inhibition in the Stop-Signal Task. Journal of Experimental Psychology: Human Perception and Performance, 35 (4), 1129–1139.] This proves that self-regulative activities (a characteristic of secondary consciousness for many scholars) can occur independently of consciousness of consciousness.
* Using lucid dreaming as a model of secondary consciousness. Some scholars believe lucid dreaming does not constitute a single type of reflectiveness. It is already argued that there may be different kinds of reflectiveness that might define secondary consciousness, so the difficulty in using lucid dreaming as a model is greatly increased. For example, there may be a realization in a dream that will often go without gaining control. There are different amounts of 'executive functions' taken between lucid dreams, thus displaying how there are many different types of reflectiveness involved in 'lucid' dreaming.
See also
*
Consciousness
*
Lucid dream
*
Primary consciousness
*
Neural Darwinism
References
{{Consciousness
Consciousness