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PubMed2000

Time course of conscious and unconscious semantic brain activation.

Event-related brain potentials (ERPs) were used to investigate the neurophysiological correlates of conscious and unconscious semantic processing. Masked words, which do not enter consciousness, as well as visible words, were shown to modulate the N400 ERP potential to subsequently presented, meaningfully related target words. The N400 is known as an electrophysiological index of semantic processing. However, for unconsciously perceived words semantic brain activation decays fast within 200 ms, but increases with time for consciously perceived words. Thus, conscious and unconscious semantic activation involves similar brain areas, but both forms of processes exhibit distinct, qualitatively different time courses.

Adult↗
PubMed2002

Lack of conscious recognition of one's own actions in a haptically deafferented patient.

How do we become aware of our own actions? This classical question is still a matter of debate: does consciousness depend on central efferent signals or derive from peripheral information? In this paper, we had the opportunity to study a haptically deafferented patient using a well-tested experimental paradigm where a cognitive conflict is produced between motor intention, proprioception and visual feedback. Our results show that the patient was able to solve the conflict and to generate accurate movements to a target in the absence of proprioceptive feedback and with very limited visual feedback from her movements. Yet, she could not report any conscious perception of the conflict and showed no conscious knowledge of her actual performance. We suggest that information derived from efferent processes cannot in themselves be a source for conscious experience about our own actions.

Adult↗
PubMed2002

Modification of a functional motor task by non-consciously perceived sensory stimuli.

In recent years it has been suggested that processing of visual information is divided between a ventral stream, responsible for object recognition and conscious processing of object properties, and a dorsal stream mediating automatic integration of visual information into a motor task. We used metacontrast masking to prevent conscious perception of visual cues concerning the load of an object to be lifted in a precision grip. It was found that when such non-consciously perceived cues warned of a load change, they allowed the subjects to produce the grip force profile appropriate to the new load. It is concluded that non-consciously perceived visual information can be utilised to adapt a functional motor task to actual conditions.

Adult↗
PubMed1994

Clinical recovery of consciousness after traumatic coma.

OBJECTIVE: To describe early clinical stages in the recovery of consciousness, using selected items from the Glasgow Coma Scale and the Liège Coma Scale. DESIGN: Validation cohort study, conducted in a tertiary care center. SETTING: Neurosurgical intensive therapy unit in a university teaching hospital. PATIENTS: Patients (n = 137) with traumatic coma who were selected according to the following criteria: a) coma due to blunt head trauma with an initial Glasgow Coma Score of < or = 7; b) admission to the neurosurgical intensive therapy unit within the first 24 hrs after trauma; c) patients > 14 yrs of age; requiring endotracheal intubation, mechanical ventilation, and the administration of drugs; and d) survival period allowing analysis of the recovery of consciousness. MEASUREMENTS AND MAIN RESULTS: Arousal, as expressed by stimulated opening of the eyes and recorded as a delay in days, was correlated with the appearance of the localized pain response, capacity to obey commands, blink reflex, and the cessation of drugs in three groups of patients. These groups were defined according to the time in which there was an appearance of the stimulated opening of the eyes: < 8 days (group 1); between 8 and 15 days (group 2); and after 15 days (group 3). When the three groups of patients were compared, significant differences existed between the mean delays of appearance of stimulated eye opening and the appearance of the blink reflex. Extubation coincided with the appearance of spontaneous eye opening, with a mean delay of 13.5 days. CONCLUSIONS: This study confirms the classical clinical sequence of arousal and recovery of consciousness, with the appearance of stimulated eye opening and the blink reflex first, followed by spontaneous eye opening, and the capacity to obey commands in intubated, traumatized, coma patients. A direct correlation existed between the delay of arousal and the complete recovery of consciousness. When groups of patients with various mean delays for the appearance of stimulated eye opening are considered, reappearance of the blink reflex did not always coincide with stimulated eye opening, suggesting differing structural and functional brain recovery processes.

Acute Disease↗
PubMed1978

Intracellular electrolytes in erythrocytes during and after shock: relation to impaired consciousness.

Of 32 patients in shock and catabolic state following shock with impaired consciousness 31 exhibited raised sodium content in their erythrocytes. On the assumption that the erythrocyte membrane acts the same as nerve cell membrane, the hypofunction of erythrocyte membrane may result in impaired consciousness. The hypofunction of erythrocyte membrane is assumed by its increased permeability in shock. A positive osmotic discrepancy between measured and calculated levels denotes altered membranous permeability. Subjectively, impaired consciousness was evaluated by clinical grading. Meanwhile, as a trial of quantification of conscious levels, we applied a new technique of analysis of power spectrum obtained by computer on the autocorrelogram of the EEG during intermittent photic stimulation. This new analytic method was useful in evaluating objective changes of cerebral function. There was a good correlation between raised sodium content in erythrocytes and depressed power spectrum. The degree of increased sodium in erythrocytes seems to correlate with patients' clinical prognosis.

Adult↗
PubMed2006

The Ferrier Lecture 1998. The molecular biology of consciousness investigated with genetically modified mice.

The question is raised of the relevance of experimental work with the mouse and some of its genetically modified individuals in the study of consciousness. Even if this species does not go far beyond the level of 'minimal consciousness', it may be a useful animal model to examine the elementary building blocks of consciousness using the methods of molecular biology jointly with investigations at the physiological and behavioural levels. These building blocks which are anticipated to be universally shared by higher organisms (from birds to humans) may include: (i) the access to multiple states of vigilance, like wakefulness, sleep, general anaesthesia, etc.; (ii) the capacity for global integration of several sensory and cognitive functions, together with behavioural flexibility resulting in what is referred to as exploratory behaviour, and possibly a minimal form of intentionality. In addition, the contribution of defined neuronal nicotinic receptors species to some of these processes is demonstrated and the data discussed within the framework of recent neurocomputational models for access to consciousness.

Animals↗
PubMed2004

Clinical holistic medicine: tools for a medical science based on consciousness.

Biomedicine focuses on the biochemistry of the body, while consciousness-based medicine--holistic medicine--focuses on the individual"s experiences and conscious whole (Greek: holos, whole). Biomedicine perceives diseases as mechanical errors at the micro level, while consciousness-based medicine perceives diseases as disturbances in attitudes, perceptions, and experiences at the macro level--in the organism as a whole. Thus, consciousness-based medicine is based on the whole individual, while biomedicine is based on its smallest parts, the molecules. These two completely different points of departure make the two forms of medicine very different; they represent two different mind sets and two different frames of reference or medical paradigms. This paper explains the basic tools of clinical holistic medicine based on the life mission theory and holistic process theory, with examples of holistic healing from the holistic medical clinic.

Clinical Medicine↗
PubMed2006

Human development II: we need an integrated theory for matter, life and consciousness to understand life and healing.

For almost a decade, we have experimented with supporting the philosophical development of severely ill patients to induce recovery and spontaneous healing. Recently, we have observed a new pattern of extremely rapid, spontaneous healing that apparently can facilitate even the spontaneous remission of cancer and the spontaneous recovery of mental diseases like schizophrenia and borderline schizophrenia. Our working hypothesis is that the accelerated healing is a function of the patient's brain-mind and body-mind coming closer together due to the development of what we call "deep" cosmology. To understand and describe what happens at a biological level, we have suggested naming the process adult human metamorphosis, a possibility that is opened by the human genome showing full generic equipment for metamorphosis. To understand the mechanistic details in the complicated interaction between consciousness and biology, we need an adequate theory for biological information. In a series of papers, we propose what we call "holistic biology for holistic medicine". We suggest that a relatively simple model based on interacting wholenesses instead of isolated parts can shed a new light on a number of difficult issues that we need to explain and understand in biology and medicine in order to understand and use metamorphosis in the holistic medical clinic. We aim to give a holistic theoretical interpretation of biological phenomena at large, morphogenesis, evolution, immune system regulation (self-nonself discrimination), brain function, consciousness, and health in particular. We start at the most fundamental problem: what is biological information at the subcellular, cellular, and supracellular levels if we presume that it is the same phenomenon on all levels (using Occam's razor), and how can this be described scientifically? The problems we address are all connected to the information flow in the functioning, living organism: function of the brain and consciousness, the regulations of the immune system and cell growth, the dynamics of health and disease. We suggest that life utilizes an unseen fine structure of the physical energy of the universe at a subparticular or quantum level to give information-directed self-organization; we give a first sketch of a possible fractal structure of the energy able to both contain and communicate biological information and carry individual and collective consciousness. Finally, thorough our analysis, we put up a model for adult human metamorphosis.

Adult↗
PubMed1996

Middle latency auditory evoked potentials during repeated transitions from consciousness to unconsciousness.

We have investigated the relationship between changes in the middle latency auditory evoked potentials during alternating periods of consciousness and unconsciousness produced by propofol infusion combined with spinal anaesthesia for total knee replacement. Eleven patients completed the study, of whom two had recollection of events after the onset of the anaesthetic. There were no significant differences in heart rate or systolic arterial pressure between any conscious and unconscious period. With the first change from consciousness to unconsciousness, latencies of Na, Pa and Nb increased from mean (SD) starting values of 20.0 (1.4), 31.7 (1.0) and 42.8 (1.6) ms to 22.5 (2.0), 39.3 (2.1) and 57.8 (4.4) ms, respectively. During successive transitions from unconsciousness to consciousness, awake latencies were slightly higher than those of baseline awake, whereas anaesthetised latencies were similar to the ones obtained during the first period of unconsciousness. The consistent changes demonstrated, suggest that the auditory evoked potentials could represent a reliable indicator of potential awareness during anaesthesia.

Aged↗
PubMed1993

Respiratory alterations with intrapericardial procaine in the conscious rabbit.

1. Intrapericardial procaine, used to produce cardiac nerve blockade in both conscious and anaesthetized animals, has been reported to also produce changes in respiration. This study systematically investigated the effects of two doses of intrapericardial procaine on respiration in the conscious rabbit. 2. Rabbits were pre-instrumented with a chronic diaphragm electromyogram (dEMG) recording electrode and intrapericardial catheter. Arterial pressure, heart rate, dEMG and respiratory excursions (recorded with a pneumograph) were monitored in the conscious rabbit before and after intrapericardial and intravenous infusion of 2 and 5% procaine. Efficacy of cardiac nerve blockade was tested by intravenous infusion of phenyl biguanide. Arterial blood gases were determined at rest and during changes in respiration. 3. Following a low dose of intrapericardial procaine (12 mg), dEMG and respiratory excursions increased (65 +/- 13 and 76 +/- 32%, respectively) with no change in breathing frequency or arterial blood gases. Following a high dose of intrapericardial procaine (30 mg), four of six animals exhibited a similar response. However, four of the six rabbits also exhibited a second type of response pattern characterized by a further increase in respiratory efforts (430 +/- 336%), abolition of dEMG, and a mild hypoxaemia. 4. Intravenous infusion of a low dose of procaine was without effect, whereas intravenous infusion of a high dose of procaine produced minor behavioural responses. 5. In four additional anaesthetized rabbits, it was demonstrated that high doses of intrapericardial procaine anaesthetized the phrenic nerve to produce the observed alterations in respiration. 6. We conclude that if intrapericardial procaine is used to block cardiac nerves in conscious rabbits, it should be used in a low concentration and at the lowest possible total dose to avoid complications due to changes in respiration.

Absorption↗
PubMed1998

Ictal oroalimentary automatisms with preserved consciousness: implications for the pathophysiology of automatisms and relevance to the international classification of seizures.

A patient showing seizures presenting ictal automatisms with preserved consciousness is reported. A 30-year-old, right-handed man with normal development and without family history of epilepsy was referred for surgical treatment of epilepsy. At 15 he began to have seizures, starting with an epigastric aura, occasionally developing automatisms (lip-smacking, chewing), sometimes followed by tonic-clonic convulsions. At the time of referral, he averaged six convulsive seizures per year and one nonconvulsive per week. His sleep EEG showed sharpened slow activity over the right anterior quadrant magnetic resonance imaging (MRI) showed a benign lesion in the mesial aspect of the right occipital lobe. Simultaneous video monitoring and intracranial EEG with subdural strips recording from the right temporal and occipital lobes was undertaken. During one seizure, he had pronounced oroalimentary automatisms while holding a conversation with a technician, answering her questions, and explaining details of his seizures. Memory of this event was preserved. At seizure onset, spike activity was seen at the mesial occipital strips. At midseizure, high-voltage sharpened delta was seen throughout the right hemisphere. Left-sided scalp electrodes remained relatively uninvolved. The lesion, a dysembryoplastic neuroepithelial tumour was removed. Surgery was followed by abolition of seizures described. Because it is agreed that complex partial seizures require impaired consciousness, a history of automatisms with retained consciousness usually suggests nonepileptic attacks. This case suggests that automatisms in epileptic seizures can take place with minimal loss of consciousness, particularly if there is widespread but unilateral involvement. The need for a revision of the International Classification is suggested.

Consciousness↗
PubMed2001

Co-evolution of human consciousness and language.

This article recalls Cajal's brief mention of consciousness in the Textura as a function of the human brain quite distinct from reflex action, and discusses the view that human consciousness may share aspects of "animal awareness" with other species, but has its unique form because humans possess language. Three ingredients of a theory of the evolution of human consciousness are offered: the view that a précis of intended activity is necessarily formed in the brain of a human that communicates in a human way; the notion that such a précis constitutes consciousness; and a new theory of the evolution of human language based on the mirror system of monkeys and the role of communication by means of hand gestures as a stepping-stone to speech.

Animals↗
PubMed1994

Effect of addition of hyaluronic acid to highly concentrated insulin on absorption from the conjunctiva in conscious diabetic dogs.

Insulin absorption from the conjunctiva was investigated in five pancreatectomized diabetic mongrel dogs, with the nasolacrimal ducts occluded by micro plugs to prevent insulin absorption from nasolacrimal membrane. In the anaesthetized state, highly concentrated porcine insulin (1000 units mL-1, pH 7.4) was absorbed rapidly and significantly from the conjunctiva. Plasma immunoreactive insulin concentrations increased significantly up to 3 h after insulin administration to conjunctival membranes. Plasma glucose concentration decreased significantly compared with saline control experiments after insulin administration (10 units kg-1) at 3 h (8.3 +/- 0.1 vs 15.6 +/- 0.6 mmol, P < 0.01). However, in the conscious state, there was no significant increase in the plasma insulin levels after topical insulin administration. To improve insulin absorption in the conscious state, we examined the effect of increasing viscosity of insulin preparation with hyaluronic acid. In anaesthetized experiments, there were no significant changes in the bioavailability of insulin after addition of hyaluronate (0.84 +/- 0.11 vs 0.87 +/- 0.05%). In the conscious state, with addition of hyaluronic acid, the area under the curve of plasma insulin concentration was significantly increased (1842 +/- 383 vs 75 +/- 24 m units min L-1, P < 0.01). The bioavailability of insulin absorption was significantly increased after addition of hyaluronate (0.68 +/- 0.14 vs 0.03 +/- 0.01%, P < 0.01). From this study we could demonstrate that the conjunctiva is a potential route for insulin administration, and increased viscosity by the addition of hyaluronate was found effective in increasing the bioavailability of insulin absorption from conjunctival membrane in the conscious state.

Absorption↗
PubMed1986

Regional sciatic nerve and muscle blood flow in conscious and anesthetized rats.

The regulation of peripheral nerve blood flow is incompletely understood. Regional blood flow in the rat sciatic nerve (NBF) and hamstring muscle (MBF) was measured in both conscious and anesthetized normal rats and in rats that had undergone surgical exposure of one sciatic nerve just prior to measurement. The distribution of [14C]butanol following its bolus intravenous injection was used to determine the flows in a modification of the "indicator fractionation" technique. NBF in normal rats was similar in limb pairs and was unaffected by pentobarbital sodium anesthesia. The pooled value was 12.5 +/- 1.1 ml X min-1 X 100 g-1. NBF was unaffected by sham operation in the conscious rats but was doubled in operated limbs of anesthetized rats (P less than 0.001). MBF in conscious normal rats was five times that measured during anesthesia. As in NBF, sham operation significantly increased MBF only in anesthetized rats (P less than 0.01). [14C]butanol distribution is a sensitive indicator of NBF and MBF. Mere surgical exposure of the nerve significantly increases NBF and MBF in anesthetized, but not in conscious rats.

Anesthesia↗
PubMed2005

L-NAME- and ADMA-induced sympathetic neural activation in conscious rats.

Although studies in anesthetized, sino-aortic denervated animals indicate that inhibition of central nitric oxide (NO) causes an excitatory influence on efferent sympathetic nerve activity (SNA) that is normally offset by baroreflex activation, studies in conscious animals have not provided clear-cut evidence for a sympathoexcitatory effect of N(omega)-nitro-l-arginine methyl ester (L-NAME) or the endogenous circulating NO synthase (NOS) inhibitor asymmetric dimethylarginine (ADMA). Thus our goals were to 1) use surgical sino-aortic denervation to test for a sympathoexcititatory effect of intravenous l-NAME in conscious rats, and 2) to determine whether SNA responses to intravenous L-NAME can be extrapolated directly to intravenous ADMA. We recorded mean arterial blood pressure and renal SNA in both intact and sino-aortic-denervated conscious rats during 3 h of continuous intravenous infusion with either L-NAME or ADMA. When we eliminated the confounding influence of the sino-aortic baroreceptors, L-NAME produced a progressive increase in SNA with the peak response exceeding the baseline level of nerve firing by 150%. The same type of frank sympathetic activation was observed with intravenous ADMA. Taken together, these data offer straightforward evidence for l-NAME, as well as ADMA-induced sympathetic activation with direct recordings of SNA in conscious animals. These data confirm and extend the concept that circulating endogenous NOS inhibitors can constitute an excitatory signal to SNA.

Animals↗
PubMed2001

Hypotensive and sedative effects of clonidine injected into the rostral ventrolateral medulla of conscious rats.

We examined the effects of clonidine injected unilaterally into the rostral ventrolateral medulla (RVLM) of conscious, unrestrained rats. We also examined whether the local alpha(2)-adrenoceptor mechanism contributed to the action of clonidine injected into the RVLM. Injection of clonidine but not vehicle solution significantly decreased the mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) in conscious, unrestrained rats as well as in propofol-anesthetized rats. The frequency of natural behavior was significantly lower after clonidine injection than after vehicle injection. The depressor and sympathoinhibitory responses were significantly larger in the propofol-anesthetized rats than in the conscious rats. Coinjection of a selective alpha(2)-adrenoceptor antagonist, 2-methoxyidazoxan, with clonidine into the RVLM significantly attenuated the depressor, bradycardiac, sympathoinhibitory, and sedative effects of clonidine injected alone. In conclusion, clonidine injected into the RVLM decreased MAP, HR, and RSNA and caused sedation in conscious, unrestrained rats. The action of clonidine in the RVLM was at least partly mediated by alpha(2)-adrenoceptor mechanisms.

Adrenergic beta-Antagonists↗
PubMed1984

Evaluation of renal function during intrarenal norepinephrine infusion in conscious rats.

Previous studies have shown that intrarenal infusion of norepinephrine (NE) causes acute renal failure in anesthetized dogs and rats. We hypothesized that anesthesia prevents the kidney of escaping from the ischemic insult. In this paper, we report measurements of renal function parameters during acute as well as during chronic intrarenal NE infusion in conscious freely moving rats. Intrarenal NE application in doses of 4 and 36 micrograms/kg X h was performed via the suprarenal artery by means of subcutaneously implanted minipumps. During acute intrarenal NE infusion over a 2-hour period in anesthetized as well as conscious rats, renal blood flow (RBF) was determined by means of the pulsed Doppler flowmeter technique. During long-term NE administration for 5 days, glomerular filtration rate (GFR) was determined as clearance of 51Cr-EDTA and effective renal plasma flow (ERPF) as clearance of 125I-hippuric acid. Clearance measurements were performed on control day, and on the 1st and 4th day of intrarenal NE infusion; furthermore, on the 1st and 4th day after stopping the intrarenal NE infusion. Acute intrarenal administration of doses of NE higher than 12 micrograms/kg X h, in anesthetized rats immediately reduced RBF to zero levels. However, in conscious rats, neither acute nor chronic intrarenal NE application induced severe long-lasting reductions in GFR or RBF respectively ERPF at any dose of NE applied. Therefore, we conclude that no acute renal failure is induced during intrarenal NE infusion in conscious rats; this is probably due to protective neurogenic mechanisms which are relatively inactivated during pentobarbital anesthesia.

Acute Kidney Injury↗
PubMed1980

Reflex cardiovascular and respiratory effects of serotonin in conscious and anesthetized dogs.

Cardiovascular and respiratory effects of intra-left atrial or intra-left ventricular injection of serotonin were studied in conscious dogs (n = 8), anesthetized closed-chest dogs (n = 13) and anesthetized open-chest dogs (n = 9). Serotonin (50-200 microgram), injected as a bolus, resulted in an initial bradycardia and hypotension followed by a delayed tachycardia and hypertension in the conscious dogs. The hypertension was seen as an increase of 21.5 +/- 2.7 (mean +/ SE) mm Hg from a control pressure of 102.5 +/- 1.9 mm Hg, whereas the initial decrease in pressure was 22.6 +/- 1.9 mm Hg. The tachycardia was 23.3 +/- 3.9 beats/min above a control heart rate of 104.9 +/- 3.9 beats/min whereas the bradycardia was 58.5 +/- 3.7 beats/min below control. There was a significant attenuation of the hypotension in both groups of anesthetized dogs. In fact, no hypotension was elicited in the open-chest anesthetized dogs. Open-chest anesthetized dogs showed only a hypertensive response (mean increase 67.2 +/- 5.5 mm Hg). Stimulation of respiration was seen in all groups of dogs. In conscious dogs there was a 214.8 +/- 15.4% increase in respiratory depth and a 20.8 +/- 3.1 breaths/min increase in respiratory rate. Atropine significantly reduced the bradycardia and abolished the hypotension in conscious dogs. Bilateral cervical vagotomy did not abolish the response in open-chest anesthetized dogs. We conclude that the so-called "hypertensive coronary chemoreflex" is altered dramatically by the state of the preparation and by anesthesia.

Anesthesia↗