THE PERICONSCIOUS SUBSTRATES OF CONSCIOUSNESS: AFFECTIVE STATES AND THE EVOLUTIONARY ORIGINS OF THE SELF, Jaak Panksepp, Department of Psychology, Bowling Green State University, Bowling Green, OH 43403, USA.
The periconscious substrates of consciousness: Affective states and the evolutionary origins of the SELF (PDF Download Available)
Abstract: An adequate understanding of ‘the self’ and/or ‘primary-process consciousness’ should allow us to explain how affective experiences are created within the brain. Primitive emotional feelings appear to lie at the core of our beings, and the neural mechanisms that generate such states may constitute an essential foundation process for the evolution of higher, more rational, forms of consciousness. At present, abundant evidence indicates that affective states arise from the intrinsic neurodynamics of primitive self-centred emotional and motivational systems situated in subcortical regions of the brain. Accordingly, a neural understanding of ‘the self’ may arise from a study of how various biological value-coding systems (emotional circuits) converge and interact with coherent brainstem representations of the body and nearby attentional/waking systems of the brain. Affective feelings may be caused by the neurodynamics of basic emotional circuits interacting with the neural schema of bodily action plans. One key brain area where such interactions occur is found within centromedial diencephalic midbrain areas such as the periventricular and periaqueductal gray (PAG) and nearby tectal and tegmental zones. Here I will envision that a Simple Ego-type Life Form (a primitive SELF structure) is instantiated in those circuits The ability of this ‘primal SELF’ to resonate with primitive emotional values may help yield the raw subjectively experienced feelings of pleasure, lust, anger, hunger, desire, fear, loneliness and so forth. A study of such systems is a reasonable starting point for the neurological analysis of affective feelings, which may lie at the periconscious core of all other forms of animal consciousness. If such a neurodynamic process was an essential neural preadaptation for the emergence of higher levels of consciousness, it may help us close the explanatory gap between brain circuit states and the psychological nature of affective feelings. Thereby, it may also help us conceptualize the nature of psychological binding within higher forms of consciousness in new ways.
Toward a Neurobiological Conception of the Self
It is generally agreed that the self is experienced as a stable mental presence that provides a sense of felt affective unity and continuity to humans, commonly with strong cognitive overtones (Strawson, 1997). Indeed, some believe ‘the self’ is a natural conceptual category not much different than that of fish or fowl, created out of higher brain matters, while others believe it is largely a ‘narrative fiction’ (Dennett, 1991). Yet others, like myself, believe the matter goes much deeper, to a time in neural evolution when organisms first started to experience existence through the affective qualities of consciousness. I will here explore the proposition that those evolutionary passages yielded the essential brain system dynamics that need to be recognized and understood in order to clarify the emergence of a pre-propositional form of consciousness on the face of the earth. Of course, the fundamental nature of the self remains a matter of controversy, as highlighted by the two recent issues of this journal devoted to the topic. However, two critical aspects of the self continue to receive comparatively little attention, namely its neural and affective underpinnings.
Here, I advocate the position that the roots of the self go back to specific mesencephalic and diencephalic sensory-motor action circuits within the mammalian brain which can generate a primitive sort of intentionality (an automatized action readiness) and primitive forms of psychic coherence (global affective states of the brain) by interacting with various emotional and attentional circuits that encode basic biological values (for summary of systems, see Panksepp, 1998). These interacting circuits have specific neurochemical codes that may generate distinct types of neurodynamics within primitive core systems of selfrepresentation that first symbolized organisms as coherently active creatures in the world. This view of the self is based on the following five assumptions:
(1) I ascribe to the evolutionary view which assumes that the primordial self arises from certain body-linked neurosymbolic brain processes that we share homologously with all other mammals and perhaps a diversity of other creatures as well. Since clarification of such issues in mammalian species is hard enough, I will not dwell on the others, even though I am admittedly fond of the possibility that all vertebrates and perhaps even some other creatures have a smidgen of the neural architecture that permits a primitive (affective) consciousness that still lies at the root of our own immediately felt sense of existence. (
(2) Being a materialist, I believe that consciousness evolved from unconscious neural processes, and an essential key to all higher levels of analysis may lie in our ability to recognize and specify the primordial interface between the two. I ascribe to the proposition that every moment of our conscious lives is undergirded by feelings, and that if the biological infrastructure of those intrinsic value-signalling systems were destroyed, one’s sense of self would degrade.
(3) Considering the evident fact that deeply valenced feelings reside at the core of our being, most especially when we are young, I favour the view that the fundamental nature of the self and affective experience is closely related to the hard problems of consciousness (Chalmers, 1995; Gray, 1995), the hardest of which, in my estimation, is understanding the nature of the most ancient evolutionary qualia (I shall here refer to them as equalia). Equalia directly reflect the neuronal encoding within mammalian brains of the animals’ most important bodily concerns. They reflect how basic emotional and motivational feelings (i.e. internal value indicators) inform animals of major survival issues. In other words, equalia tell organisms where they stand with respect to environments and actions that will enhance or detract from the likelihood of their own survival as well as of their kind.
(4) Considering the importance of such values for all subsequent levels of brain organization, I would anticipate that selfness is a neural process that is re-represented hierarchically at many levels of neural and mental development. Hence, while the roots and trunk lines may be similar across all mammalian species, the activities within the cerebral canopies and resulting psychological consequences are bound to vary considerably.
The essential neural roots of consciousness may, by necessity, be embedded in fundamentally unconscious dynamics of the brain. The level that most critically needs to be explained is the interface between the unconscious properties of neural tissues and those that permitted the emergence of consciousness. I refer to the latter as the ‘periconscious substrates of consciousness’.
(5) Since the self should be established on very stable neural coordinates, I believe the sources of primary process core-consciousness are intertwined more intimately with intrinsic motor than with exteroceptively driven sensory processes within the brain. This is not to deny the importance of afferent and reafferent processes converging at the core of the self (e.g. Sheets-Johnstone, 1998), but to bring to the forefront of discussion the potentially essential role of central motor processes in anchoring the periconscious substrates of consciousness.
In essence, the proposal is that within the very core of the self, we must find a neural ‘stage manager’ who does not observe, but rather, has the ability to generate various coherent acts in response to archetypal survival challenges. The resulting neural resonances that can inundate this central stage manager (henceforth, the SELF), and which can radiate widely in the brain, may constitute the foundation of our basic feelings — the affective equalia we experience as we navigate the major challenges of the world. Among the prototypic equalia, we find the feelings of eagerness, fear, anger, lust, loneliness, nurturant warmth and playful joy, as well as the pleasures and displeasures of various consummatory acts (Panksepp, 1998).
Although highly valenced feelings can certainly be triggered by external events and higher appraisals, they are not created from those transient sensations (qualia) and thoughts, but from the stable evolutionary equalia that are neurosymbolically coded, as cladistic birthrights, by the efferent/integrative subcortical emotional circuits of the mammalian brain.
To restate the above view, I assume that the most fundamental forms of affective consciousness within the mammalian brain arise from a neurodynamic scaffolding that provided a stable self-referential set of internal motor coordinates upon which various sensory and higher perceptual/learning mechanisms could operate. This self-referential scaffolding is essential for ever more sophisticated forms of psychobehavioural coherence as encephalization proceeded in each species’ quest for fitness (i.e. as monitored by internal affective homeostasis). Indeed, the neural substrates for our rich exteroceptive qualia, apparently more recently evolved (Deacon, 1990),1 may be integrally dependent, in some presently unfathomed way, on primitive integrative functions that give rise to affective equalia — the global internal feeling states that reflect the various intrinsic emotional and motivational values that all mammals share in remarkably homologous ways.
It may be that the evolution of a coherent self, that could participate in the generation of global internal states, suffices to bind many other psychic activities of the brain. If this perspective is on the right track, the way to search for the neural foundations of the self would be to identify the areas of the brain where there is a massive convergence of a diversity of basic emotional systems (fundamental value schema), various simple sensory abilities (perceptual schema), and primitive but coherent response systems (action schema). I believe such essential convergence zones may be quite ancient in brain evolution, existing perhaps among the evolutionarily conservative neural bridgeworks of mesencephalic and diencephalic circuits residing in primitive midline regions of the brain. I assume we may be able to gain considerable insight [1].
Throughout this manuscript, I will assume that neural tissues which reflect more rostral and lateral expansions of the neuroaxis generally reflect more recent evolutionary developments than those that are situated more caudally and medially. Although we obviously do not have fossilized brains that can affirm such evolutionary assertions, this principle is generally accepted by neuroembryologists since it confirms how neural systems are typically laid out in development. [2] Here, it is assumed that certain basic affective feelings reflect the types of psychobiological issues that constitute evolutionary memories as opposed to matters learned during the individual life span of an organism. The affective feeling states are envisioned as evolutionary memories (i.e. equalia) that help to efficiently sustain behavioral plans into the future, and to provide a general purpose mechanisms for allowing organisms to efficiently learn about the potential values that appear to be embodied in environmental events (see Panksepp, 1998). into the nature of the core SELF within human brains by studying the dynamics of such homologous structures in animal brains (Panksepp, 1982; 1998). To help guide the search for specific brain systems that subserve basic SELF functions, a focus on three neuro-empirical attributes may help us:
(1) At key brain areas, global psychobehavioural abilities should be compromised to the greatest extent with the smallest amounts of brain damage across a diversity of species.
(2) The most intense and coherent affective/emotional behavioural states should be capable of being provoked with the lowest levels of exogenously applied brain stimulation, whether it be electrical or chemical.
(3) Anatomically, such information-rich convergence zones should receive the greatest concentrations of inputs from other brain areas, and they should also have, neuron for neuron, the most prolific outputs. In my estimation, the brain area that would win in any such competition is the periaqueductal gray (PAG).
Accordingly, the PAG and closely related brain areas will be postulated to be the epicenter of the primordial self. Although no one has pursued a systematic programme of empirical investigations with these empirical goals in mind, a great deal of evidence suggests that midbrain areas such as the PAG as well as the adjacent colliculi do have all the needed characteristics (Strehler, 1991). There is much indirect evidence for the existence of foundational self-referential types of neuronal functions within the centromedial midbrain and diencephalon which may be essential for purely affective types of consciousness — global states commonly referred to by terms such as fear, anger, desire, joy and the other basic emotional and motivational feelings. All of these feelings appear to be embodied in specific types of neural circuits, and presumably distinct types of neurodynamics (Panksepp, 1998). If this idea is on the right track, then future neurophysiological recordings from well-positioned electrodes within such core brain systems may provide objective dynamic signatures reflecting the various archetypal, global states of the self, and hence the various dynamic forms of primary processes ‘affective consciousness’ (Panksepp, 1999a).
Let me highlight some reservations at the outset. If such a basic system for ‘the self’ and ‘primary affective consciousness’ exists, it will certainly not directly help explain higher forms of human consciousness, including the various qualia created by our more recently evolved neocortex and exteroceptive apparatus. However, it might begin to explain the fundamental nature of equalia, the distinct affective states that arise from the arousal of the basic emotional systems of the brain. It may also provide insights into how higher and lower processes become interdependent in the brain during development — with emotional faculties emerging earlier and more cognitive-rational faculties later in life. In early development, cognitive abilities may be strongly linked to and limited by affective correlates, and only later in development may they emerge as seemingly self-sufficient entities.
There are many conceptual and empirical opportunities to be pursued when we consider the possibility that coherences within the lower substrates of the emotional self may be essential for creating the binding that is subjectively evident in the more recently evolved processes, either through the ‘glue’ of specific neuro-rhythms (Jefferys et al., 1996) or neurochemicals (Panksepp, 1986; 1993). Although perceptual binding may require neural coherences of much higher frequencies than can be sustained by slowly firing (i.e. visceral) neuronal systems such as the PAG, the integrity of those higher functions may be critically dependent on the types of lower functions we will consider here. In short, my aim is to try to elucidate the necessary rather than the sufficient neural substrates for the sense of self within the brain.
The Roots of the SELF within the Midbrain and the Neural Nature of Emotional Feelings
I will henceforth consistently refer to this postulated fundamental neural substrate for primary process affective integration as the SELF (a Simple Ego-Type Life Form). The use of capitalization here for this ancient brain system serves as a convention to highlight that a distinct brain system is the referent as opposed to all the associated psychological states that coalesce during development. This precedent was originally used to designate the basic emotional systems of the brain by Panksepp and Miller (1996). Because of many converging facts, some already alluded to, I will situate this system’s epicenter in the PAG and the immediately surrounding tectal and tegmental layers, with substantial spread into midline diencephalic areas that are most intimately connected to the PAG (Cameron et al., 1995a,b). The converging anatomy of emotional circuits upon the SELF can be schematized effectively within the midbrain (see Figure 1). Around the aqueduct of Sylvius, we have the PAG (also historically known as the ‘central gray’) whose more rostral extensions in the diencephalon are typically called the periventricular gray. The PAG receives input from all of the major emotional systems of the brain. Just dorsal and lateral to the PAG, there are several simple motor maps of the body which are used for
[Figure 1 An overview of emotional circuitry converging on the mesencephalic periaqueductal gray (PAG) which is the lowest region of the brain to orchestrate various coordinated emotional responses via a variety of motor outputs. Motor representations for bodily orientation are found in the deep layers of the SC and for forward locomotor activity in the mesencephalic locomotor region (MLR), upon which there is a massive convergence of somatic information dorsally from the superior colliculus (SC), and visceral information from the PAG. Diverse ascending and descending connections of the PAG can integrate coherent emotional reactions throughout the neuroaxis. The figure is copyright by Oxford University Press and is reprinted from Panksepp (1998) with the publisher’s permission.]
reflexes (the deepest layers of the superior colliculus) as well as for generating stereotyped forward locomotor patterns (i.e., via the more laterally situated mesencephalic locomotor region (MLR)).
Surrounding these simple motor orientation and coordination maps, there are multi-modal layerings of major sensory systems, starting with somatosensory and vestibular (deep tectal), as well as auditory (inferior colliculi) and visual (superior colliculi) processing areas. Each of these layers of control has neuronal interconnections with the others, affording various types of coherent interactions that may constitute a coherent SELF-representation comprised of a generalized body map that can be buffeted from the ventral side by distinct affective processes and from dorsal inputs by a variety of simple perceptual states. The rostral, caudal and lateral relations to many brain areas (Cameron et al., 1995a,b), provide many avenues for the interaction of these value systems with attentional and exteroceptive consciousness mediating systems of the brain, as recently discussed in Panksepp (1998) and Watt (1998).
As Bandler (Bandler & Keay, 1996) and others have shown, the PAG has a columnar structure for many emotions such as fear and anger, as well as for sexuality at the lateral edges of the PAG (Shipley et al., 1996). The PAG is also integrally involved in pain modulation and may well contain the primordial ‘ouch’ generators in response to painful stimuli. An evolutionary outgrowth of the pain regulatory circuits, the separation response system, is also well represented in the PAG (Panksepp, 1998). Although most physiologists have preferred to focus on this structure as the ‘efferent motor system’ (for a comprehensive recent review, see Holstege et al., 1996), it surely elaborates brain processes more subtle than the mere motor outflow of coordinated emotional responses. There are good reasons to believe that the PAG lies at the very root of many integrated affective feelings of the brain. This core system of the SELF interacts closely with other nearby components for exteroceptive consciousness such as the Extended Reticular and Thalamic Activating System (ERTAS) introduced by Newman & Baars (1993), and most recently elaborated in Newman (1997) and Baars (1998). However, this SELF system is conceived to be anatomically distinct, albeit functionally interactive, with the ERTAS. According to the present view, the ERTAS is a slightly more recently evolved neural mechanism whereby endogenous commotion within the extended SELF system (reflecting bodily homeostatic imbalances) as well as primitive sign-stimuli from the environment are able to tune the various perceptual systems of the brain (i.e. the various higher tools of consciousness).
Thus, the PAG-centred emotional SELF system may be seen as the very core of the visceral-hypothalamic-limbic axis (which is essential for affective, interoceptive consciousness), while the ERTAS is the core of the adjacent somatic-thalamic-neocortical axis (which is essential for exteroceptive consciousness). As Watt (1998) has recently elaborated, the interaction between these systems is one way that biological values may persistently penetrate into higher cognitive activities. The most obvious linkages would be through modulation of the massive ascending acetylcholine, histamine, norepinephrine, and serotonin systems, which convey a variety of very generalized biases to all higher brain regions (Panksepp, 1986; 1993).
Although investigators continue to debate whether internally experienced feeling states are elaborated within the lower or higher reaches of the brain (Damasio, 1994; LeDoux, 1996; Panksepp, 1998; Watt, 1998), it is next to impossible to evoke affective responses via localized electrical stimulation of the neocortex, and quite difficult from most areas of the thalamus. Fragments of emotional feelings can be more easily evoked from higher limbic areas — of cingulate, frontal and temporal cortices — but one needs quite high current levels, often establishing epileptiform activities that invade lower brain systems (Gloor, 1997). By contrast, coherent and powerful emotional responses along with affective states are much easier to obtain by stimulating subcortical brainstem sites (for review, see Panksepp, 1985; 1998). Some of the most compelling evidence for mesencephalic epicenters for affect comes from attempts to localize the areas of the brain that are essential for opioid and psychostimulant reward processes. It is becoming evident that affective states are more integrally related to the lower than the higher reaches of emotional systems, since opioid reward is easier to establish there (Olmstead & Franklin, 1997; David & Cazal, 1996), while psychostimulant reward has been related to higher aspects of certain emotional systems such as the shell of the nucleus accumbens (Olmstead & Franklin, 1997; Schildein et al., 1998). As even this small sampling of available studies indicates, it would be extreme to believe that affective consciousness is simply elaborated by the PAG (since there are so many other hot spots for drug reward in the diencephalon and midbrain), but the main point of the present argument is that the PAG provides an essential multi-modal module where empirical enquiries into core features of many distinct affective states can be conducted. In my estimation, the PAG is the major epicenter for the generation of emotional feelings which is presently most susceptible to broad-scale empirical enquiry in animal models but not in human beings. In contrast, the amygdala is one convergence zone for various forms of emotional learning (LeDoux, 1996), that can now be readily studied in humans (Lane et al., 1997). Although the effects of extreme pain have been visualized in the PAG of humans (Hsieh et al., 1996), special techniques may need to be developed in order to adequately image milder forms of emotional arousal in such small, functionally diverse, slowly firing visceral areas of the brain.
Although affective consciousness, like every other brain function, is surely organized hierarchically, there is presently little evidence that the elaboration of affective valence requires the participation of higher brain areas such as the neocortex. Indeed, if decortication is done at a very young age in altricial animals such as rats, their affective apparatus appears to be largely spared, indeed intensified, perhaps because of diminished inhibition of lower processes by higher ones (Panksepp et al., 1994). Cortical areas appear only to modulate and to regulate the basic emotional tendencies — to increase the duration, intensity and subtlety of affective expressions in real-life interactions. Cortical modules do not appear to create emotional feelings locally. In sum, there are many reasons, only some of which can be reviewed here, to believe that the evolutionary roots of a coherent, albeit primitive, self-centred affective awareness first emerged subcortically. A great deal of evidence implicates the PAG as the most essential component of the many relevant neural systems.
On the Potential Neural Reiterations of the SELF
Throughout ontogenetic development, primordial affective capacities may be reiterated within higher brain areas to help organisms extend their basic feelings in space and time to more complex situations so as to allow basic psychobiological values to anchor and to interpenetrate long-term behavioural choices and strategies. From this point of view, the normal moral and cognitive development of a human child could be envisioned to be dependent as much on the various regulatory processes for affect as on the ability to elaborate propositional knowledge. Indeed, many cognitive abilities could be seen to be adaptive skills for maintaining desired levels of emotional stimulation and mood homeostasis (Panksepp et al., 1998; Panksepp & Miller, 1996). I am especially fond of Nietzsche’s (1885/1996) insightful assertion that ‘moralities are also merely a sign language of the affects’ (p. 100). In its basic form, the SELF is presumably reflexive and intentional3 only to the extent that a certain type of baseline neural activity in the system acts like a ‘settling point’ or ‘attractor’ to which various behaviours are referenced in a feedback manner (Panksepp, 1999a). Behaviours that reduce affective disturbances (i.e. represented perhaps as shifts in the resting neurodynamics of the reverberatory networks of the SELF) will be increased, and those that increase deviations from equilibrium will generate withdrawal behaviours. In simple terms, what has been added to a primordial form of affectively modulated SELF-representation during subsequent brain evolution is (1) the ability of this SELF-process to migrate (or perhaps more precisely, be reiterated) and thereby to develop extensively throughout neuroanatomically related areas of the brain, yielding widely distributed fractal representations of itself in many areas of the brain, and (2) the addition of various specialized cognitive tools, such as sophisticated forms of working memory to facilitate SELF-regulation. As the reverberatory patterns of the SELF come to be developmentally re-represented in many brain areas, perhaps a neural mirroring is established that can lead not only to increasing degrees of self-reflection and greater mind-reading abilities (BaronCohen, 1997; Rizzolatti & Arbib, 1998; Snodgrass & Thompson, 1997) but also potentials for multiple personalities in a single individual, with different personae being under the control of different global emotional state variables.
Central Motor Processes and the Neural Architecture of the SELF
Let me now discuss in a bit more detail why the primal neural scaffolding for the SELF could be concentrated in the PAG and overlying tectum. Briefly, the deeper layers of the colliculi constitute a basic motor mapping system of the body which interacts not only with visual, auditory, vestibular and somatosensory sytems (Strehler, 1991), but also with nearby emotional circuits of the PAG (Figure 1). The extended PAG elaborates a visceral type map of the body along with basic neural representations of pain, fear, anger, separation-distress, sexual and maternal behaviour systems (Depaulis & Bandler, 1991; Holstege et al., 1996; Panksepp, 1998). The primacy of motor functions within the neural representation of the SELF is suggested by the fact that functional eye-movement maps bordering the PAG remain geographically more stable than do the overlying sensory maps. In other words, the local sensory maps shift markedly in reference to stable motor coordinates when the motor map initiates specific actions (Sparks, 1988). Embedded within these primitive body orientation maps, we also find many neurons that can respond to pain, facilitating arousal of whole body attentional responses (Redgrave et al., 1996). In addition, there is a powerful executive motor system just adjacent to the PAG, namely the MLR, which is able to coordinate forward locomotion to achieve a variety of goal-directed activities (Brudzynski et al., 1993).
Contrary to traditional thinking on the matter, the above analysis affirms that affective consciousness may be more (or at least as) integrally linked in evolution to endogenous motor-related processes than to incoming sensory ones. It would be surprising if it were the other way, for ancient organisms needed broad and coherent motor plans before distal sensory guidance could produce anything useful.
This pattern is also evident in the higher reaches of the brain. Emotional systems appear to be much more concentrated in frontal motor/planning areas than posterior sensory/perceptual regions. As a consequence, much greater personality disturbances result from frontal cortex damage than injuries of comparable size occurring to posterior sensory cortices (Damasio, 1994; MacLean, 1990). The critical role of motor processes in the elaboration of consciousness may also help solve the paradox of the infinite regress of observers within sensory sytems. To put it in Dennettian (1991) terms, the stable feature of the ‘Cartesian Theater’ may not be any ultimate observer but a virtual actor,4 the SELF, which resonates with bodily needs as well as external inputs signifying values that may alleviate those needs. In other words, the stable features of our experience may not be due to an internal self-observing function, but an agent, made capable of instinctual action by the neural structures of the SELF. It is admittedly hard to envision how subjective feelings might be critically linked to the motor apparatus. After all, our most vivid and common perceptual qualia (vision and hearing) are quite obviously tightly linked to our sensory processors. However, we should not be too easily tempted to assume that our equalia must be similarly controlled. Our tendency to relate primary consciousness more to sensory than to motor processes, may be largely an illusion created by the captivating complexity of our exteroceptive sensory inputs (Ramachandran & Hirstein, 1997). There is certainly no intrinsic reason to believe that the internally experienced qualities of central affective states are more critically linked to sensory processing than motor control and planning functions within the brain. For this reason, psychobiologists call many of the intervening abilities ‘sensory-motor functions’. Although it would be foolish to neglect the various sensory components, the probability is high that the stability of primary-process consciousness is created as much by the intrinsic stability of motor coordinates as by any power inherent in sensory processing. As is being increasingly recognized, proprioceptive feedback from motor actions is critical in allowing our brains to actively create conscious perceptions in many realms (Sheets-Johnstone, 1998). In affective experience, a direct motor preparatory linkage appears to be especially evident, although the induction of feelings is surely strongly facilitated by reafferents aroused by the ensuing motor acts. 4 ‘
Virtual actor’ is used here in the sense that this neural circuit represents the primordial body which emerged in a distant evolutionary past, and hence may be quite homologous in all mammalian species. When the term ‘neurosymbolic’ is used in this essay, there is a similar evolutionary referent: namely, functional circuits that have been evolutionarily constructed to represent ancestral memories, as opposed to memories derived during the lifespan of an organism. For a discussion of issues concerning such virtual realities in consciousness, see Revonsuo (1995).
Of course, the higher cortical ‘tool-boxes’ of consciousness are more intimately linked to sensory processes. In line with the above, I would suggest that emotional feelings depend critically on the convergence of evolutionarily derived information (from various emotional sensory-motor command circuits — Panksepp, 1998) onto a primordial integrative map of the body that finds its evolutionary origin within the central zones of the midbrain. Ontogenetically, this brain function may migrate or reiterate through the medial zones of the diencephalon and telencephalon to more rostral limbic cortical areas that have long been recognized as higher repositories of emotion regulation (MacLean, 1990).
Indeed, considering how closely human language appears to be related to feelings of selfhood, it is noteworthy that the medial limbic cortex of the anterior cingulate is essential for motivating the use of language; when anterior cingulate is damaged, a syndrome of akinetic mutism emerges, where people can speak but they do not desire to do so (Devinsky et al., 1995). Although such higher areas, including distinct specializations of the cerebral hemispheres (Ross et al., 1994) are clearly important for regulating affective processes, the massive convergence of information onto a primitive representation of the body makes the centromedial areas of the midbrain an excellent candidate for the essential integrative framework that first permitted a primitive form of emotional awareness. For instance, the endogenous oscillatory activity of the SELF may establish a resting tone throughout the brain and body which serves as a ground state for deviations from equilibrium that are experienced as affectively valenced forms of bodily arousal. The intrinsic neurodynamics of such affective, motor tone-setting circuits, along with various converging somatic and visceral inputs, may create a pervasive and fractally propagated feeling of self-ness within the organism. When the shift in this feeling tone is precipitous, we call the response an emotional one; when the changes are more gradual and sustained, we may call them moods. If the system becomes chronically imbalanced, the changes may be deemed of psychiatric significance. If this view is on the right track, we may anticipate that the neurodynamics of emotions may eventually be reliably measured via EEG recordings from electrodes placed in the neural trajectories of these systems as well as from the concurrent quantification of the dynamics of spontaneous bodily movements (Freeman, 1995; Panksepp, 1999a). Although it should be possible to monitor the activities of the SELF using modern neurophysiological tools, whether they can be captured clearly on the neocortical surface remains uncertain.
By the time the neurodynamic ripples reach such distant shores, the signals may be so degraded that only a modest amount of emotion-specific information remains evident (Panksepp & Bekkedal, 1997). ……..
{Note: this might be why the often incoherent emotional content of our dreams and nightmares arises in sleep, when the neocortex is effectively shut down/offline while the subconscious remains active. Indeed, it is on the cusp of sleep that we suddenly experience images that are unconnected to the familiar ‘world’ we customarily attend to. I’ve forgotten the names for these states, which occur predominantly when we are ‘falling alseep’ but also at times when we are on the cusp of awakening. With these observations I’ll stop copying and pasting this essential paper by Panksepp and let y'all pursue it online.}
