Feeling safe, awesome, calm, and present is our default, natural, and effortless state of conscious existential being. But, unfortunately, most of us do not know what it is like to be in that awesome state of awareness. It is because we mostly feel unsafe, uninspired, restless, and preoccupied with a wandering mind and restless eyes. So, we follow some spiritual or meditative pathway. But we do not really understand how that works. We do not know what our essential being is. Naturally, we are not peaceful and happy most of the time. We read about a unique peaceful state of effortless oneness, nonduality, and natural bliss. But we do not know what it feels like. These four levels of safety, awe, calmness, and presence can be understood in terms of neuropsychophysiology and self-experience including awareness of body, mind, ego, self, and surroundings. One’s body can be observed from inside and outside. The outside-in view includes various bodily features such as movements, voice, speech, facial expressions, and actions. The inside-out look includes interoception, proprioception, temperature, heartbeat, breathing, and stomach and bladder fullness. We are also aware of our wandering mind, intentions, memories, thoughts, and feelings. Normally, we do not have much control over our conscious experience. It just happens to us, in our self-surround experiential loop. Our surroundings include not only physical objects but also people, animals, plants, and the whole cosmos. We are both embodied and embedded in a one universal ecosystem. SEQUENTIAL AND PARALLEL ATTENTION-AWARENESS-ACTION We have two modes of multimodal attention-awareness-action (AAA), namely, sequential and parallel. These two modes are analogous to the retinotectal and retinogeniculate neural paths for visual processing and experience. The sequential mode is slow, conscious, deliberate, intentional, explicit, declarative, or voluntary with a self-surround duality. It is processed by multiple forebrain networks of salience, default mode, frontoparietal, and dorsal-ventral attention networks. The typical duration of hippocampal processing is about 100 ms followed by a sequence of longer cognitive activity. The hippocampal-cortical circuits can map what, where, and when of experienced events. The parallel mode of AAA is fast, ballistic, and lifesaving. It is processed by the midbrain circuits with key nodes in the superior colliculus, periaqueductal gray, reticular formation, and ventral tegmental area. Such attention is holistic, multimodal, almost instantaneous with a latency of <50 ms. The superior colliculus has been shown to be not only a visual processor but also a multisensory-motor, orienting structure. It is called the orienting structure as the active agent or self orients itself to its instant situation. The fast actions include behavioral arrest, eye–head turning toward the salient stimulus, and the decision to act, capture pray, or escape (Knudsen, 2020; Wheatcroft et al., 2022). FEELING SAFE We continuously monitor our surroundings for threats or opportunities. That is our evolutionary and developmental heritage. Most of the early stages of evolution were about eating or getting eaten; hunt, or get hunted. That is how the early living cells got the mitochondria inside them. Then, complex intentional behaviors evolved in animals with efficient ways of hunting and defending. One of the theories of consciousness is that, as the threats and defenses became more sophisticated, the evolved animals became more sentient and self-conscious. With the evolution of mnemonic representations, symbols, language, and planning, we humans have reached enormous sophistication in our science of communication including our capacity for aggression and defense. Human conflicts and wars are still going on actively. No wonder, world peace remains a dream. The leading proposal on safety is the polyvagal theory (Porges, 2022). In brief, the vagal-sympathetic complex forms a neurophysiological platform for processing of threat, safety, and play. It is a trimodal neural circuit consisting of dorsal vagal complex (DVC), sympathetic nervous system (SNS), and ventral vagal complex (VVC). DVC can mediate a passive behavior to a threat-like immobilization or shutdown with feigning, collapse, or freeze. SNS is associated with fight or flight behaviors, which require activation of primary defense strategies recruited by mammals. It is associated with emotional behaviors such as fear and rage. VVC provides the neural structures that mediate the “social engagement system.” When safety is detected in the internal and external environment, the VVC supports prosocial behavior, social connections, and play. This trimodal vagal complex is consistent with the theory of three Gunas from the Sankhya philosophy. DVC, SNS, and VVC correlate respectively with Tamas, Rajas, and Sattva. Purusha is the acting-observing agent, and Prakriti is the material nature. The goals of Yoga therapy are to overcome fear, rage, lust, and greed and to actualize self-insight, wellness, peace, joy, and happiness (Sullivan et al., 2018). FEELING AWESOME “Awe is the feeling of being in the presence of something vast that transcends your current understanding of the world” (Keltner, 2024). The eight awesome wonders of life are moral beauty – someone’s courage, kindness, and strength; collective effervescence as in group activities such as folk singing, dancing, team sports, and cultural activities; being in nature with immersive experiences; musicality in listening and creating music; visual artforms in architecture, painting, and sculptures; spiritual experiences with stories of birth and death; and epiphanies – when we suddenly understand the essential truths of life. These moments of awe happen to almost all of us in our daily lives. We just have to be aware of these moments. The feeling of awe is processed in the brainstem periaqueductal gray area, ventral tegmental area, and mesolimbic dopamine network. These reward circuits are involved in novelty processing and exploratory behaviors. Novelty is defined as a novel entity, a stimulus, or an environmental change that an individual has not previously experienced. Novelty can lead to a positive or negative experience followed by an approach or avoid response (Tapper and Molas, 2020). We face novel situations many times. This is what I call the awesome novel presence! As the Zen saying goes, “The sacred is in the ordinary.” I personally enjoy being in nature and noticing small or vast things. I love nature photography. Many times, I am inspired to write a poem or an essay. These novel enjoyable activities can instantiate self-insight. During these awesome moments, there is a reduced sense of ego and self-referential processing, especially in the default mode network (van Elk et al., 2019). FEELING CALM A calm mind is precious, dynamic, and pristine. It is like the calm flow of a majestic river. But most of the time our mind is turbulent with rough waves of fear, anxiety, rage, lust, and greed. Jaak Panksepp did the foundational work in affective neuroscience. I liked the cartoon from his book, “The Archeology of Mind” (Panksepp and Biven, 2012). It showed that at the base of all mental activity is the everfresh psychophysiological arousal. The primary emotions include fear, rage, panic, seeking, care, play, and sexuality. The secondary emotions are trust, empathy, pride, blame, guilt, and shame. The tertiary emotions are distancing skills, mindfulness, containment, mentalization, and naming feelings. In this emotional hierarchy, the primary emotions are processed in the periaqueductal gray and midbrain-diencephalic circuits. The secondary emotions are processed in the limbic and basal ganglia circuits. The tertiary emotions are mediated by the neocortical networks, which include the five major networks – Cingular-insular salience network, frontal-parietal executive network, the default mode network, and the dorsal and ventral attentional networks. MEDITATIVE SYNCHRONY Meditative synchrony implies an integrated experience with the coherence of multiple neural psychophysiological oscillatory circuits. Presumably, this is what happens in an immersive meditative state. Such a coherent psychophysiological state is our natural, default mode of being. This effortless aware state is hypothesized to show synchronized electroencephalogram alpha rhythm at multiple cortical and precortical regions. I have described a family of alpha rhythms during an effortless meditative awareness (Deshmukh, 2023). During such awareness, the whole family of alpha rhythm is synchronized including Occipital-Parietal alpha, Frontal eye-field alpha, Somatosensory alpha, Mu rhythm, Midtemporal auditory alpha, and Cingulate-Precuneus alpha. Any mental, cognitive effort and activity instantly desynchronize the alpha family activity. An overview of different brain rhythms and their correlated psychological functions have been documented. (Köster and Gruber, 2022) Alpha rhythm (8–13 Hz) implies attentional gating. Gamma activity (30–90 Hz) is involved in the binding of multisensory information and representations. Theta activity (4–8 Hz) serves as a pacemaker for human cognitive control and mnemonic processing. Theta-gamma coupling mediates attentional sampling, mnemonic updating, prediction, and generation of action plans. Alpha-gamma coupling mediates attention and memory. Alpha-beta coupling is evident in walking. Alpha-gamma coupling is seen in cognitive work and problem-solving. Interpersonal action coordination and psychophysiological hypersynchrony have been shown in team activities such as choir singing (Delius and Müller, 2023). There is some evidence to suggest that we are not only embodied but also embedded in nature. Human bioelectric circuit seems to be connected with the earth-atmospheric Schumann resonance frequency of 7.83 Hz. Nature’s direct current flows through the earth, plants, animals including human beings (Koniver, 2023). HOLISTIC PRESENCE Feeling present in a situation is hard to describe. In other words, our holistic presence is ineffable. My first inspired book was titled, “Presence: The Key To Mental Excellence” (Deshmukh, 1990). The first few words from my 1981 journal were, “Truth is now. Be present.” “The observed ever changes. The observable observer also changes. The integrate presence is change-free. This is our true nature. Discover it.” Now, I realize that presence is a holistic experience. For example, when I video a butterfly on a flower, I become an essential participant of that awesome loop of events. When we minimize our narrow-mindedness and expand our horizon to include all that is happening now, we implicitly embrace all things in our holistic presence, a sense of oneness. The “I” seems to complete the psychophysiological activity pattern, subject–object duality, and action-perception-integration loop. The “I” remains implicitly a nondual aware being. It cannot be objectified. One knows it by being it. This “I” has been a great puzzle for both philosophers and scientists for millennia. A few descriptors of “I” are (a) a Strange Loop, (Hofstadter, 2008) (b) Ipsundrum, (Humphrey, 2023) c) complex Brain-Body-Environment Loop (Humphrey, 2023), and (d) I AM THAT (Dikshit S. S., 1973). What is that “I” that ever knows itself? That only the “I” knows!

It is hypothesized that being mindfully aware is a spontaneous state of being. It is imbued with joy, peace and happiness. Such a state is periodically revealed during restful attentiveness or presence. It is also associated with spontaneous brain alpha activity of 8-13 Hz. In deep nonrapid eye movement sleep, there is synchronous delta activity at a coherent frequency of 0.1 Hz. Both of these brainwave ground states are spontaneous, calm and effortless. When any physical or mental effort is made, the alpha rhythm is desynchronized, and it is superposed by faster brain waves of beta (13-30 Hz) and gamma frequencies (30-150 Hz). This is associated with a stream of dualistic conscious experiences with contents. During deep sleep, delta activity is superposed by beta and gamma activity with microarousals resulting in dream experiences. During effortless, meditative awareness, the whole family of alpha rhythm is synchronized including (a) Occipital-parietal alpha with visual clarity, formless color, and the absence of visual imagery (b) Frontal eye-field alpha with relatively motionless eyes, and the absence of voluntary actions or plans to move the eyes in some direction, along with nonactive working memory, (c) Somatosensory alpha or Mu rhythm from the somatic motor-sensory cortex with the resultant stillness of the body including head, face, larynx, spine, hands and legs, (d) Mid-temporal auditory alpha with vocal quietness and internal verbal silence (Maunam) with a feeling of spontaneous silence and serenity, (e) Cingulate and precuneus alpha resulting in freedom from autobiographical memories and the sense of agency or ego. The insular cortex serves as a gatekeeper, a hierarchical controller to switch between conscious engagement or disengagement from the internal or the external world. It switches between the default mode network and the executive frontoparietal networks, between the sequential and the parallel modes of functioning. Mindful consciousness is local and dualistic, whereas mindful awareness is nonlocal and nondual.

It is proposed that consciousness is different from awareness. Consciousness can be thought of as a dualistic, embodied, and embedded cognitive process, whereas awareness is a nondual and nonlocal process. Nonlocal awareness is the ever-present, ever-fresh, and an affective self-awareness that can be aware of itself as well as of the ongoing subject-object duality, and cognitive conscious contents. This nonlocal awareness is our default mode state. Although very few of us are aware of it due to our habitual mental preoccupation and mind-wandering. We need to relax, learn to meditate, let go of all preoccupations, and return to our default mode state of being, which is peaceful, silent, fulfilling, energetic, and ever-fresh. Then, one feels effortlessly alive and free and at home in the world. This is the essence of meditation for living a happy, peaceful, and meaningful life. The rest of the article provides details of meditative presence, yoga meditation, and mindfulness meditation with their current practice and applications. The main focus of the article is on the neurobiology of meditation, which is discussed in detail. It covers the experientially perceived mind-space including personal, peripersonal, and extrapersonal space, the concepts of mind in the Western and Eastern literature, and the neurobiological foundation in the brain stem, reticular-limbic system, forebrain including the five thalamo-cortical-basal ganglia circuits, multiple sensory modalities, integrated perception, speech production, language communication, voluntary movements, and intentional actions. The wholeness of conscious mind is expressed as bio-psycho-social-abstract/spiritual.

Meditation is the art and science of optimal self-integration. We are naturally nested in Nature. Meditation is being at-peace with oneself and at-home in the world. It is the art of self-observation, learning, and developing presence of mind and selfless love. It is a unique mode of being present in the moment. It is a natural state of health and happiness. We should let go of the vicious cycle of negative feelings and discover the virtuous cycle of positive feelings like joy, cheerfulness, equanimity, friendliness, compassion, and love. This is possible through meditative practices like yoga, mindfulness, flow-state, and nature-experience. With advancement in neurobiology, we can understand how these meditative skills are learned, developed, evolved, and mastered. These meditative skills and lifestyle are the key to positive psychology and mental health. These secular meditative practices are being recommended in our education and health care systems.

Bhramari is an ancient technique of the yogic pranayama practice. It has been described in the Vedic-Upanishadic literature. Currently, it is being actively practiced and taught in the yoga classes all over the world. Jala-Bhramari is a new term that I am proposing for doing the classical Bhramari while floating in water on one's back, swimming back-stroke, and while standing or sitting in water with both ears under water, while the face is in the air to breathe and vocalize. With this technique, one can hear the humming sound of Bhramari loud and clear through the water and feel the transmitted biomechanical vibrations in the head, face, chest, spine, and the whole body. It is a unique variation of the Bhramari technique with calming and energizing effects. The OM chanting is another very ancient yogic meditation practice from the Vedic-Upanishadic period. Mandukya Upanishad described this valuable meditative practice in detail and gave its rationale as well as the benefits. With this practice, one can achieve a state of profound stillness, silence, and serenity. One can become Atma-tushta, self-satieted, and Atma-shanta, at peace with self. One can also feel liberated from the stressful burdens of one's body, mind, and ego. Such a state was described as Turiya , the fourth state of consciousness. It is also called Kaivalya or the absolute self-freedom and a feeling of unity with the natural existence. Kaivalya is defined as the holistic state of absolute unity, self-liberation, and timeless serenity. Very few people can achieve such an advanced spiritual state and live a blessed life in nature. However, there have been many examples of sages and enlightened visionaries from India as well as other parts of the world. Most of us live with a limited outlook and an isolated individual perspective in this busy and challenging human world. Yogic meditation is a disciplined and purposeful process of self-discovery, which may lead to great insights and a blissful nondual self-awareness.

Dhyana-Yoga is a Sanskrit word for the ancient discipline of meditation, as a means to Samadhi or enlightenment.Samadhi is a self-absorptive, adaptive state with realization of one's being in harmony with reality.It is unitive, undifferentiated, reality-consciousness, an essential being, which can only be experienced by spontaneous intuition and selfunderstanding.Modern neuroscience can help us to better understand Dhyana-Yoga.This article discusses topics including brain-mind-reality, consciousness, attention, emotional intelligence, sense of self, meditative mind, and meditative brain.A new hypothesis is proposed for a better understanding of the meditative mind.Meditation is an art of being serene and alert in the present moment, instead of constantly struggling to change or to become.It is an art of efficient management of attentional energy with total engagement (poornata, presence, mindfulness) or disengagement (shunyata, silence, emptiness).In both states, there is an experience of spontaneous unity with no sense of situational interactive self or personal time.It is a simultaneous, participatory consciousness rather than a dualistic, sequential attentiveness.There is a natural sense of well being with selfunderstanding, spontaneous joy, serenity, freedom, and self-fulfillment.It is where the ultimate pursuit of happiness and the search for meaning of life resolve.One realizes the truth of one's harmonious being in nature and nature in oneself.It is being alive at its fullest, when each conscious moment becomes a dynamic process of discovery and continuous learning of the ever-new unfolding reality.

Bhramari is an ancient technique of the yogic pranayama practice. It has been described in the Vedic-Upanishadic literature. Currently, it is being actively practiced and taught in the yoga classes all over the world. Jala-Bhramari is a new term that I am proposing for doing the classical Bhramari while floating in water on one's back, swimming back-stroke, and while standing or sitting in water with both ears under water, while the face is in the air to breathe and vocalize. With this technique, one can hear the humming sound of Bhramari loud and clear through the water and feel the transmitted biomechanical vibrations in the head, face, chest, spine, and the whole body. It is a unique variation of the Bhramari technique with calming and energizing effects. The OM chanting is another very ancient yogic meditation practice from the Vedic-Upanishadic period. Mandukya Upanishad described this valuable meditative practice in detail and gave its rationale as well as the benefits. With this practice, one can achieve a state of profound stillness, silence, and serenity. One can become Atma-tushta, self-satieted, and Atma-shanta, at peace with self. One can also feel liberated from the stressful burdens of one's body, mind, and ego. Such a state was described as Turiya, the fourth state of consciousness. It is also called Kaivalya or the absolute self-freedom and a feeling of unity with the natural existence. Kaivalya is defined as the holistic state of absolute unity, self-liberation, and timeless serenity. Very few people can achieve such an advanced spiritual state and live a blessed life in nature. However, there have been many examples of sages and enlightened visionaries from India as well as other parts of the world. Most of us live with a limited outlook and an isolated individual perspective in this busy and challenging human world. Yogic meditation is a disciplined and purposeful process of self-discovery, which may lead to great insights and a blissful nondual self-awareness.

Homeokinetics is an extension of the concept of homeostasis. „Homeo‟ means the same; „stasis‟ means a steady state and „kinetic‟ means a dynamic movement. Homeostasis is defined as a tendency toward a relatively stable internal environment in organisms through interacting physiological processes. It implies maintenance of an internal steady state of an organism by means of self-regulation. It also includes a stable psychological condition of an individual with respect to opponent psychodynamic forces like drives, desires, emotions, and motivations. Homeokinetics emphasizes a tendency toward relatively stable rate of change of internal environment of an organism and its mental activity. Organisms, including humans, are complex self-organizing systems, which are governed by thermodynamic principles with transportation of molecules, energy, and information across its biophysical and cognitive border to maintain their functional form, self-integrity, and behavior. A river represents a typical homeokinetic system. It is not static but a dynamic process. It consists of ever-fluctuating water molecules, „atomisms‟ at one level of observation, and a collective and continuous form, „continuum‟ at another. The river is both, ever-new, and ever-the-same, depending on one‟s perspective. Most of the complex living systems, like organism, mind, and society, are homeokinetically organized in a nested hierarchy. The mind (Antah-karana) in Vedanta is considered to be the internal organ of action (Karma), cognition (Jnaana), and experience (Bhoga). It includes four hierarchical components: sense of self with intentionality (Aham-bhava), memory (Chitta), discriminating intelligence (Buddhi), and thought-emotion (Manas). The main thesis of this article is that all of these mental processes are homeokinetic and that they regularly go through periodic cycles of activity and steady state. Whereas the steady state is a state of relative equilibrium or homeostasis, activity is like a homeokinetic vector with three phases of emergence, sustenance, and dissipation. These three phases apply to all forms of energy, information, and personal experience. A desire for the peace of mind and equanimity has been a persistent dream of humanity from time immemorial. It is probably the basis for many religious beliefs and practices. In Vedanta, Sthita-Prajnaa, the ideal of wisdom, equanimity, resiliency, and bliss, is well expressed in Bhagavad Gita, Upanishads, Brahma-sutra, and Yoga.

Self is difficult to define because of its multiple, constitutive streams of functional existence. A more comprehensive and expanded definition of self is proposed. The standard bio-psycho-social model of psyche is expanded to biophysical-mental-social and existential self. The total human experience is better understood and explained by adding the existential component. Existential refers to lived human experience, which is firmly rooted in reality. Existential living is the capacity to live fully in the present, and respond freely and flexibly to new experience without fear. Four common fears of isolation, insecurity, insignificance, and death can be overcome by developing a lifestyle of whole-hearted engagement in the present reality, creative problem solving, self-actualization, and altruism. Such integrative living creates a sense of presence with self-awareness, understanding, and existential well-being. Well-being is defined as a life of happiness, contentment, low distress, and good health with positive outlook. Self is a complex, integrative process of living organisms. It organizes, coordinates, and integrates energy-information within and around itself, spontaneously, unconsciously, and consciously. Self-process is understood in terms of synergetics, coordination dynamics, and energy-information-directed self-organization. It is dynamic, composite, ever renewing, and enduring. It can be convergent or divergent, and can function as the source or target of its own behavior-mentation. The experience of self is continuously generated by spontaneous activation of neural networks in the cerebral neocortex by the brainstem-diencephalic arousal system. The multiple constitutive behavioral-mental streams develop concurrently into a unique experience of self, specific for a person at his/her developmental stage. The chronological neuro-behavioral-mental development of self is described in detail from embryonic stage to old age. Self can be behaviorally-mentally oriented and realized in three complimentary modes of being: egocentric, allocentric, and ecosystemic or existential. The existential mode is both immanent and transcendent, and can be self-actualized, resulting in a healthy, creative, conflict-free, and meaningful life.

Primary headaches include migraine, tension, cluster headaches, paroxysmal hemicrania and miscellaneous headaches unassociated with structural lesions. A putative role of the retino-hypothalamic-pineal (RHP) axis in the pathophysiology of primary headaches is reviewed in terms of (1) retinal dysfunction, (2) hypothalamic dysfunction and human circadian desynchrony, (3) pineal melatonin dysfunction and (4) rostral limbic dysfunction mediating the human stress response. Unified RHP hypothesis is proposed, suggesting that an acute, periodic or chronic, circadian desynchrony and dysfunction of the whole or part of the RHP axis is implicated in the pathophysiology of primary headaches. Supportive evidence for the RHP hypothesis, including recent PET studies showing changes in dorsal pons, hypothalamus and rostral limbic structures, is presented.

To the Editor. —In response to the editorial on "violence" in the November 1991 issue of theArchives, the last 3 years' data (1989 through 1991) on violent brain injuries by gunshot were reviewed and analyzed from the Trauma Registry of the University Medical Center of Jacksonville, Duval County, Florida. University Medical Center is the only Trauma One medical facility in Duval County and surrounding northeast Florida and southeast Georgia. It serves about 600000 people in Jacksonville, and 1.2 million people in 20 counties of northeast Florida and southeast Georgia. This is not a "high crime" area. Therefore, these data reflect the incidence of violent brain injuries for this entire region. This search was limited to assault by firearms and explosives, E code E965. A total of 107 patients suffered from violent brain injuries by gunshot in the last 3 years (1989 through 1991). There were three subgroups in this

A preliminary study of event related potentials (P300) in a group of 16 cancer patients, without cerebral metastases or focal neurological deficits, is being reported. As compared to a group of 28 normal adults, 9 out of 16 cancer patients were found to have prolonged P300 latencies, and 6 made more than two errors in their cognitive performance. These subclinical cognitive impairments in cancer patients may be related to some remote effects of cancer. These patients had not undergone any chemotherapy or radiation therapy prior to P300 studies. Further studies in a larger group of patients with gynecological cancer are being conducted.

The object of this article is to present a novel physiological classification of Limbic-Autonomic (LA) arousal on the basis of human physiological data, specifically the oro-nasal breathing patterns in man. It is proposed that the multidimensional LA arousal can be classified into five grades: Grade I: Non-nasal (NN) or oral breathing with bilateral nasal congestion, and nonactive behavior, Grade II: Left Nasal (LN) breathing and quiet behavior, Grade III: Right Nasal (RN) breathing and active behavior, Grade IV: Bilateral Nasal (BN) breathing and very active behavior, and Grade V: Oral and Bilateral Nasal (ON) breathing with maximal behavioral activation. The data from polygraphic electroencephalographic recordings from five healthy volunteers, before, during and after exercise are presented in support of this physiological classification of LA arousal. On the basis of Limbic-Autonomic asymmetry a novel concept of "Visceral Dominance" is also proposed.

It is proposed that biological forms are not determined by a single molecule or a single process but by multiple forms of energies, acting on a network of molecules. The molecular organization of biological form is determined by not only its molecular composition but also the different forms of internal and external energies acting on those molecules. A concept of cascading morphoregulatory energy is proposed which is defined as the quantal, differential energy - total internal minus total external energy - that acts on the biological form at a given moment in time. It is a quantal composite form of energy consisting of chemical, electromagnetic and phononic or quantum fluid mechanical energy. It is further proposed that biological forms are extremely dynamic and are constantly dominated by internal and external flow-induced fluid forces and energy patterns. Some of the well known variables that influence these fluid patterns include internal and external temperature, salinity, proton and other ionic gradients, surface tension, hydrostatic pressures and organic compositions. A biological process and its products form a unit. A biological process serves as a source and its products are subject to local dispersive fluid forces constrained by chaotic streamlines. The process and products together form a unitary biological form. The biomolecular fluid patterning seems to follow curvilinear geometry. On the basis of these general principles computer simulations of most biological structures seem to be feasible. This would provide a good beginning for the physical modelling of biological forms.

A new physiological classification of sleep-wake states, based on a novel Tri-Vesicular (3V) model of the brain is proposed. The 3V model consists of an interconnected network of three primal brain vesicles, namely, right and left Arch-Encephalon (Mesencephalon + Diencephalon + Telencephalon) and one DeuterEncephalon (Metencephalon + Myelencephalon). Nine sleep-wake states are defined on the basis of the central activational index (activation and/or inhibition of the 3 brain vesicles), and the level of global arousal. Four sleep states I-IV, four wake states I-IV, and one transitional sleep-wake state, are characterized. The four sleep states correspond with the four non-REM sleep stages, the transitional sleep-wake state correlates with REM sleep, and four wake states are defined in terms of minimal, low, moderate, and high, global behavioral arousal. Three sets of data in the form of polysomnographic and aerobic exercise studies in five adult subjects, and 30 days' data of self-monitored arousal and oro-nasal breathing patterns, are provided in support of this physiological classification of sleep-wake states and the 3V brain model.

It is proposed that the higher incidence of chronic stress-adaptation failure in patients with Alzheimer's disease is of specific etiopathological significance. Such chronic stress-adaptation failure leads to a vicious circular reaction, namely: intense, stressful stimuli →neocortico-limbic excitation →hypothalamo-pituitary-adrenocortical (HPA) axis activation →excessive secretion of neurohormones including cortisol →stimulation of inhibitory glucocorticoid sensitive hippocampal neurons →failure to terminate the HPA axis response →chronic excessive secretion of neurohormones including cortisol →overstimulation degeneration of glucocorticoid sensitive hippocampal inhibitory neurons →progressive cognitive-affective behavioral disorganizational failure which is typical of dementia of the Alzheimer's type. Possibilities of neuropharmacological corrections and neurobehavioral re-education are suggested.

Eight pieces of evidence, from a variety of experimental paradigms, seem to converge in support of the minimum prosencephalic or cortical-subcortical processing time of about 300 ms±25 ms