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PubMed1982

Conscious attentional demands of encoding and retrieval from long-term memory.

The importance of allocating conscious attention to encoding and retrieval from long-term memory was investigated. Encoding, retrieval, and reactivation hypotheses were tested. College students were shown schematic faces in a secondary task and numerical problems as a primary task. The primary task was imposed both when the faces were encoded on study trials and when they were retrieved on recognition test trials. Difficulty of the primary task (easy vs. hard) was varied on both study and test trials. The easy problems permitted conscious attention to be given to the secondary faces whereas the hard problems prevented such allocation. Instructions about encoding the faces (incidental vs. intentional) were given to different groups. The degree of conscious attention that was allocated to the faces on study trials was assessed by means of interference, intention, and retrospection criteria of attended processing. Recognition of the faces was better when subjects allocated conscious attention to encoding than when they did not, in consistent support of the encoding hypothesis. The data ruled out a reactivation explanation. Finally, at times, paying special attention at retrieval improved recognition performance, providing weak support for the retrieval hypothesis.

Attention↗
PubMed1995

Consciousness.

Consciousness offers a major challenge to the neurosciences. Even though consciousness is by definition subjective and private to the organism concerned, we consider it to be an intrinsic feature of biological processes in the brain. As such, it should be viewed in the Darwinian perspective of natural selection which implies that the conscious brain function does have survival value and cannot be a mere epiphenomenon. We attempted a neurophysiological approach by assessing perceptual processing of simple somatic sensory inputs in humans. We found that short-latency cortical potentials evoked by a target finger stimulus attended by the subject are strongly enhanced, thus manifesting a remarkable potentiation of the cognitive representations in primary parietal cortex. About 80 msec later, the dorsolateral prefrontal cortex discloses enhanced electrogeneses which we believe to reflect activation of somatic representations in 'working memory'. A functional 'binding' between these critical areas has been revealed by the transient and selective synchrony of 40 Hz oscillations recorded in the cortical areas of the parietal and prefrontal cortices. We consider these re-entrant interactions at 40 Hz to be an essential part of the conscious brain mechanisms that achieve the identification of an object (in this example, a finger) and the decision to release a motor behavioral response.

Brain↗
PubMed1993

Brain mechanisms and conscious experience.

The human brain enables a variety of unique mental capacities. Our special capacities for inference, personal insight into the reasons for our actions, deception, high level problem solving, for literally dozens of activities represent specialized systems that most likely reflect specialized neuronal circuits that have accumulated in our brain by selection processes over thousands of years of evolution. I believe many of these enriching capacities are not so much the advantageous computational products of a large neuropil as they are the product of a brain that has accumulated specific algorithms for adaptation. Our awareness, our consciousness of these capacities, is nothing more or less than a feeling about them. A correlate of this view is that there are many processes supporting human cognition of which we are neither aware nor conscious. When conscious appreciation or feeling is involved for a modality of sensation or action, neural pathways communicating this information must be intact, normally to the left hemisphere. This paper reviews evidence that supports this view of consciousness that distinguishes special human capacities and feelings about those capacities from the neural substrates that underlie these distinctions.

Animals↗
PubMed1997

Strain-gauge force transducer method for evaluating urethral motility in conscious dogs.

A new method has been developed that is suitable for physiological studies of urethral motility in the conscious state with a strain-gauge force transducer (force transducer). In anesthetized dogs, the contractile or relaxing responses of the urethral smooth muscle in the direction of the circular layers measured with the force transducer, elicited by either phenylephrine or isoproterenol, were significantly correlated to the increase or decrease in the intra-urethral pressure (r = 0.998 and 0.780, respectively). In conscious dogs, the fluctuation in the urethral tone was observed to be less than in the intra-urethral pressure, and a dose-dependent response to phenylephrine (1-30 micrograms./kg. i.v.) and isoproterenol (0.1-3 micrograms./kg. i.v.) was clearly recognized. Moreover, this conscious model provided a fairly reproducible pattern with the urethral contraction or relaxation related to the filling or voiding phase of the cystometrogram, which was abolished by anesthetization. These results indicate that the present force transducer method makes it possible to evaluate the further physiological characteristics of urethral motility in conscious dogs.

Animals↗
PubMed1997

A study of structure of phenomenology of consciousness in meditative and non-meditative states.

Twelve senior Kundalini (Chakra) meditators were assessed during meditation session and non-meditation or control session using Phenomenology of Consciousness Inventory. The data has been analyzed using structural analysis to measure the altered state of consciousness and the identity state by comparing meditative state with non-meditative state. The structural analysis of pattern of consciousness during the meditative state revealed altered experience in perception (percentile rank PR = 90), meaning (PR = 82) and time sense (PR = 87), while positive affect dimension showed increased joy (PR = 73) and love (PR = 67). The imagery vividness (PR = 72), self-awareness (PR = 77), rationality (PR = 73) and arousal (PR = 69) were found to be structurally different from the ordinary state. With regards to identity state meditative experience was found to produce statistically significant changes in terms of intensity in meaning (P < 0.05), time sense (P < 0.05), joy (P < 0.05), love (P < 0.05) and state of awareness (P < 0.01). Our results indicate that long term practice of meditation appears to produce structural as well as intensity changes in phenomenological experiences of consciousness.

Adult↗
PubMed2002

The association of handgun ownership and storage practices with safety consciousness.

BACKGROUND: As with other injury prevention practices, education about safe firearm storage is recommended to prevent injuries to children. OBJECTIVE: To assess whether parents who are safety conscious in other respects also practice firearm safety. METHODS: Data come from responses to a baseline survey administered as part of an intervention study. Participants were consenting adults who brought a child into an emergency department. These analyses were restricted to those parents who had young children (<7 years) and who kept a firearm in their house. A safety consciousness score was developed; participants earned a point for each of 7 home and car safety behaviors they reported practicing. The relationship between safety consciousness with handgun ownership and firearm storage practices was assessed with Wilcoxon-Mann-Whitney test. RESULTS: Of the 221 participants, most reported that they keep poisonous substances out of children's reach (92%), always keep children restrained when in cars (90%), have the telephone number for a poison control center (82%), change smoke alarm batteries annually (73%), keep electrical outlets capped (72%), and keep their tap water temperature at 120 degrees F (49 degrees C) or less (65%). Only 22% reported checking smoke alarm batteries monthly. The median safety score was 4 (mean [SD], 3.99 [1.4]). Fifty-six percent said there was a handgun in their home, 27% reported an unlocked gun, 20% reported a loaded gun, and 7% reported a loaded and unlocked gun. Results were not consistent with safety consciousness being associated with safe firearm storage practices or the absence of a handgun. CONCLUSION: Compliance with safety practices may not be associated with safe firearm storage.

Accident Prevention↗
PubMed1998

Isolated transient loss of consciousness is an indicator of significant injury.

OBJECTIVE: To determine if isolated transient loss of consciousness is an indicator of significant injury. SETTING: University-based level I trauma center. DESIGN AND PATIENT: Phase 1 retrospective case series of all patients with trauma admitted directly from the emergency department to the operating room or an intensive care unit who had transient loss of consciousness as their only trauma triage criterion. Phase 2 prospective case series of all trauma patients transported by emergency medical system personnel with transient loss of consciousness as their only trauma triage criterion. MAIN OUTCOME MEASURES: Emergency operation and intensive care unit admission. RESULTS: Phase 1: From January 1, 1992, to March 31, 1995, we admitted 10255 patients with trauma. Three hundred seven (3%) met the enrollment criteria and were admitted to the operating room (n = 168) or intensive care unit (n = 139). Of these, 58 (18.9%) were taken to the operating room emergently to manage life-threatening injuries: 11 (4%) had craniotomies and 47 (15%) had non-neurosurgical operations. Phase 2: From July 1 to December 31, 1996, 2770 trauma patients were transported to our facility; 135 (4.9%) met the enrollment criteria. Forty-one (30.4%) of these required admission, and 6 (4.4%) were taken emergently to the operating room from the emergency department (1 [1%] for a craniotomy, 3 [2.2%] for intra-abdominal bleeding, and 2 [1.5%] for other procedures). Two (1.5%) of the 135 patients died. CONCLUSIONS: Patients with isolated transient loss of consciousness are at significant risk of critical surgical and neurosurgical injuries. These patients should be triaged to trauma centers or hospitals with adequate imaging, surgical, and neurosurgical resources.

Adult↗
PubMed1994

Assessment of private and public self-consciousness: a Chinese replication.

The Chinese version of the revised Self-Consciousness Scale (C-SCS) of Scheier and Carver (1985) was administered to 500 Chinese university students. Both exploratory and confirmatory factor analyses revealed that three factors (Private Self-consciousness, Public Self-consciousness, and Social Anxiety) were abstracted from the scale, and reliability data also showed that the C-SCS and its three subscales are internally consistent. While the present findings are generally consistent with the conceptualization of Scheier and Carver (1985) and the data reported previously, an integration of the present study and the data in the literature suggests that some of the items and their related rationales in the original and revised Self-Consciousness Scale may require refinement and modification.

Anxiety↗
PubMed2005

Conscious sedation and analgesia for oocyte retrieval during in vitro fertilisation procedures.

BACKGROUND: Various methods of sedation and analgesia have been used for pain relief during oocyte recovery in IVF/ICSI procedures. The choice of agents has also been influenced by quality of analgesia as well as by concern about possible detrimental effects on reproductive outcome. OBJECTIVES: To assess the efficacy of conscious sedation and analgesia versus alternative methods on pregnancy outcomes and pain relief in patients undergoing transvaginal oocyte retrieval. SEARCH STRATEGY: We searched the Specialised Register of the Menstrual Disorders and Subfertility Group, The Central Register of Controlled Trials (CENTRAL) , MEDLINE (1966 to present), EMBASE (1980 to present), CINAHL (1982 to present), the National Research Register, and Current Controlled Trials. There was no language restriction. All references in the identified trials and background papers were checked and authors contacted to identify relevant published and unpublished data. SELECTION CRITERIA: Only randomised controlled trials comparing conscious sedation and analgesia versus alternative methods for pain relief during oocyte recovery were included. DATA COLLECTION AND ANALYSIS: Two reviewers independently scanned abstracts of the reports identified by electronic searching to identify relevant papers, extracted data and assessed trial quality. Interventions were classified and analysed under broad categories/strategies of pain relief comparing conscious sedation/analgesia with alternative methods and administration protocols. MAIN RESULTS: Our search strategy identified 390 potentially eligible reports and 12 papers met our inclusion criteria. There were no significant differences in clinical pregnancy rates per woman and patient satisfaction between the methods compared. Women's perception of pain showed conflicting results. Due to considerable heterogeneity, in terms of types and dosages of sedation or analgesia used, and tools used to assess the principal outcomes of pain and satisfaction, a meta-analysis of all the studies was not attempted. Of the three trials which compared the effect of conventional medical analgesia plus paracervical block versus electro-acupuncture plus paracervical block, there was no significant difference in clinical pregnancy rates per woman in the two groups (OR 1.01; 95% CI 0.73 to 1.4). For intra-operative pain score as measured by visual analogue scale (VAS), there was a significant difference (WMD -4.95; 95% CI -7.84 to -2.07), favouring conventional medical analgesia plus paracervical block . There was also a significant difference in intra-operative pain by VAS between patient-controlled sedation and physician-administered sedation (WMD 5.98; 95% CI 1.63 to 10.33), favouring physician -administered sedation. However, as different types and dosages of sedative and analgesic agents were used in these trials, these data should be interpreted with caution. For the rest of the trials, a descriptive summary of the outcomes was presented. AUTHORS' CONCLUSIONS: There is insufficient evidence to determine the effect of different methods of pain relief when compared with conscious sedation and analgesia used during oocyte recovery. In this review, no one particular pain relief method or delivery system appeared to be better than the other. In future, greater consensus is needed to determine both the tools used to evaluate pain and the timing of pain evaluation during and after the procedure. Pain assessment using both subjective and objective measures may merit consideration. In addition, future trials should include intra- and post-operative adverse respiratory and cardiovascular events as outcomes.

Analgesia↗
PubMed1983

Local cerebral glucose consumption in the rat. II. Effects of unilateral substantia nigra stimulation in conscious and in halothane-anesthetized animals.

The energy metabolism of 74 anatomically discrete central nervous structures was investigated by means of the autoradiographic 2-deoxy-D-(1-14C)glucose method (14C-DG) in conscious awake, as well as in halothane-anesthetized rats, following unilateral substantia nigra (SN) electrical stimulation. All the basal ganglia structures displayed bilateral metabolic activation in conscious animals, with only the contralateral subthalamic nucleus being unaffected. In anesthetized rats only the SN reticulata, globus pallidus, and subthalamic nucleus were affected ipsilaterally whereas anesthesia masked the effects of SN stimulation in SN compacta and striatum ipsilaterally, as well as within all the above structures contralaterally. The entopeduncular nucleus was bilaterally activated no matter the state of consciousness. Unilateral SN stimulation also increased glucose utilization within several thalamic regions (ventromedial, ventrolateral, ventroanterior, intralaminar, ventrobasal, and mediodorsal nuclei), the habenular complex, a few mesencephalic, brainstem (locus coeruleus and dorsal raphe) and cerebellar structures, mostly bilaterally and independently of the state of consciousness. Some of the factors suggested to be responsible for the masking effects of halothane-anesthesia on the metabolic activations elicited by unilateral SN stimulation are the following: (1) absence of movements in anesthetized rats, (2) halothane-induced depression of polysynaptic pathways mostly mediated through the thalamus, and (3) the stimulatory effect of halothane-anesthesia itself on metabolic activity in both parts of the SN.

Anesthesia, General↗
PubMed1987

Comparison of effects of ozone, cadmium chloride and carbon tetrachloride on [14C]antipyrine metabolism in conscious rats.

Previously, Graham et al. found evidence that pentobarbital-induced sleeping time was enhanced in various animals following exposure to 1 ppm of ozone in air. The present study was undertaken to investigate whether similar ozone exposure would cause inhibition of metabolism of another model drug, [14C]antipyrine, in conscious rats. Furthermore, this study also investigated whether, like that of ozone, other lipid-peroxidizing agents such as cadmium and carbon tetrachloride would affect metabolism of [14C]antipyrine in conscious rats. The results showed no significant effect of ozone exposure on subsequent metabolism of [14C]antipyrine in conscious rats as revealed by very similar 14CO2 exhalation rate (CER)-time profiles before and after ozone treatment under various exposure protocols. Even though the exposure to ozone caused no inhibition of antipyrine metabolism in conscious rats, cadmium and carbon tetrachloride, on the other hand, markedly inhibited metabolism of this model drug. In agreement with the reported sex-difference in toxic effects of cadmium, during the present study the cadmium-induced inhibitory effect on the CER-time profiles was observed in male but not in female rats. In contrast, no clear sex-dependency was noted in the inhibitory effect of carbon tetrachloride on [14C]antipyrine metabolism.

Animals↗
PubMedDate not supplied

Use of a head dome system to compare i.v. methacholine-induced bronchoconstriction in conscious vs anesthetized rhesus monkeys.

The use of a newly developed head dome system has allowed measurement of pulmonary function in conscious monkeys. Such information is often desired, so that pharmacological or toxicological effects of administered compounds can be measured in the absence of effects from anesthetic agents. The current study was conducted to gain experience with this method and to allow the determination of the effects of sodium pentobarbital anesthesia (30 mg kg-1 i.v.) on the bronchoconstriction seen during i.v. infusion of methacholine in rhesus monkeys. Bronchoconstriction was measured as changes in respiratory resistance using a Buxco LS20 pulmonary mechanics computer. Four male rhesus monkeys (4.2-5.1 kg) were used. For the anesthetized exposures, the animals were intubated with a 4.0-mm cuffed endotracheal tube attached to a size 'O' Fleisch pneumotachograph. For the conscious exposures, the animals sat in restraining chairs with a custom-built head dome attached to the same pneumotachograph. In both cases, transthoracic pressure was monitored with an intrapleural catheter. Each monkey was infused with methacholine in stepwise doses, while anesthetized and conscious, until a 75% increase in respiratory resistance was seen. The ED50 values of 0.134 and 0.180 mg ml-1 methacholine were not significantly different in anesthetized vs conscious monkeys, respectively.

Airway Resistance↗
PubMed2001

Functional magnetic resonance imaging and evoked potential correlates of conscious and unconscious vision in parietal extinction patients.

We describe recent functional magnetic resonance imaging (fMRI) and event-related potential (ERP) studies of visual extinction in patients with right parietal damage who can detect isolated visual stimuli on either side, yet often miss contralesional (left) stimuli during bilateral stimulation. We consider the neural fate of such extinguished visual stimuli and how neural responses differ for consciously detected versus extinguished stimuli. fMRI findings indicate that extinguished stimuli evoke activity in striate and ventral extrastriate visual cortex, despite escaping awareness. Activations for extinguished stimuli can be found even in category-specific (face-responsive) areas of the fusiform gyrus. On the other hand, activations in visual cortex are stronger for consciously detected versus extinguished stimuli, with parietal and frontal areas of the intact left hemisphere also implicated in this comparison. Recent ERP data likewise suggest differential neural responses for consciously detected versus extinguished stimuli. We discuss these findings in relation to current speculations about the neural basis of conscious and unconscious perception.

Attention↗
PubMedDate not supplied

The effect of felodipine on bile flow in pentobarbital anaesthetized rats and conscious rats receiving bile salt supplementation.

Felodipine, a vasoselective dihydropyridine calcium antagonist, has been given i.v. (0.2 mumol/kg) to anaesthetized and conscious male rats. There was no effect of pentobarbital anaesthesia on bile flow over a 6 h observation period. Felodipine increased the 6 h recovery of bile by approximately 25% in the conscious rat but in the anaesthetized rat there was a 20% decrease in bile flow following i.v. felodipine. A positive effect of Na-taurocholate infusion (1 mumol/min/100 g body weight) on bile flow in conscious rats was reinforced by concomitant felodipine dosing. Accumulated 6 h recoveries were 2.32 +/- 0.80 g/100 g body weight (control), 3.09 +/- 0.91 g/100 g body weight (taurocholate) and 5.00 +/- 0.80 g/100 g body weight. (taurocholate plus felodipine). The excretion of felodipine in the bile was significantly reduced during anaesthesia and during infusion of 2% bovine serum albumin (0.01 ml/min/100 g body weight) to conscious rats.

Anesthesia↗
PubMed2003

[Accessible price lists at the anaesthesiologist's workplace enhance cost consciousness as a part of process and cost optimization].

The imminent introduction of the DRG (diagnosis-related-group) system is putting hospitals in Germany under considerable pressure. This requires that personnel are efficiently allocated by optimizing organizational procedures and that the limited resources be distributed in a cost-effective manner. One prerequisite for this is a marked cost-consciousness on the part of those who "incur costs" in providing a service. To increase the awareness of costs in clinical physicians, the cost structures must be transparent. In order to achieve this goal, a project was initiated at the Department of Anaesthesiology at the University Hospital of Heidelberg, which aimed to enhance the cost-consciousness of the staff by making price lists available to anaesthesiologists at the workplace. In addition to the price lists, the 25 most expensive medications and medical products were added as an ABC analysis. The departmental staff was interviewed by questionnaire as to whether this project was reasonable. After 1 year the interview was repeated. The results of the questionnaire showed that in the opinion of the staff, price lists are an effective tool, as cost-consciousness on the part of clinical physicians can be enhanced by making price structures transparent. This is a major prerequisite for individual motivation in the cost-effective management. Although the ABC analyses demonstrate no long-term effect of the price-transparency on the cost structures, the staff showed increased cost-consciousness and individual motivation for economic tasks.

Anesthesia Department, Hospital↗
PubMed2004

[Cerebral functions in brain-damaged patients. What is meant by coma, vegetative state, minimally conscious state, locked-in syndrome and brain death?].

Comatose, vegetative, minimally conscious or locked-in patients represent a problem in terms of diagnosis, prognosis, treatment and everyday management at the intensive care unit. The evaluation of possible cognitive functions in these patients is difficult because voluntary movements may be very small, inconsistent and easily exhausted. Functional neuroimaging cannot replace the clinical assessment of patients with altered states of consciousness. Nevertheless, it can describe objectively how deviant from normal the cerebral activity is and its regional distribution at rest and under various conditions of stimulation. The quantification of brain activity differentiates patients who sometimes only differ by a brief and incomplete blink of an eye. In the present paper, we will first try to define consciousness as it can be assessed at the patient's bedside. We then review the major clinical entities of altered states of consciousness encountered in the intensive care unit. Finally, we discuss the functional neuroanatomy of these conditions as assessed by positron emission tomography (PET) scanning.

Brain Death↗
PubMed2000

Effects of galanin(1-16) on pancreatic secretion in anesthetized and conscious rats.

Galanin, a 29-amino acid peptide, has been demonstrated in pancreatic nerve endings and found to inhibit insulin release in the rat. However, the data available concerning its effects on exocrine pancreatic secretion are contradictory. The aim of the present study was to evaluate the effects of a synthetic porcine galanin sequence, Gal(1-16), on stimulated pancreatic secretion in hyperglycemic anesthetized and conscious rats. Male Wistar rats were anesthetized and surgically prepared with pancreatic and femoral vein catheters. In anesthetized animals, the pancreatic secretion was continuously stimulated with 150 ng cholecystokinin octapeptide (CCK-8)/kg body weight per 30 min, dissolved in saline or 10% glucose. Synthetic Gal(1-16) (0.3 or 1 nmol/kg per h) was infused over a 60-min period. In conscious rats, 1, 3, or 10 nmol Gal(1-16)/kg per h was administered in a continuous saline or 10% glucose infusion over a 30-min period. The pancreatic secretory volume and protein output were determined in 30-min samples in both models. In anesthetized rats, 0.3 nmol Gal(1-16)/kg per h did not modify pancreatic secretion during CCK-8 stimulation. However, both the pancreatic secretory volume and the protein output were significantly inhibited compared with the basal levels by 1 nmol Gal(1-16)/kg per h. The inhibitory effect of Gal(1-16) on pancreatic secretion was more marked with CCK-8/glucose (53.9%) than with CCK-8/saline stimulation (20.1%). In conscious rats, significant inhibitory effects of 1 nmol Gal(1-16)/kg per h in saline were observed (18%). During glucose infusion, a dose-dependent inhibition of 1, 3, and 10 nmol Gal(1-16)/kg per h on pancreatic secretory volume and protein output (35% inhibition at 1 nmol/kg per h) was observed. In conclusion, the inhibitory effect of Gal(1-16) on exogenous and endogenous CCK-stimulated pancreatic secretion was found to be more potent in the presence of glucose both in anesthetized and in conscious rats. These results may suggest an indirect (insulin-mediated) inhibitory effect of porcine Gal(1-16) on pancreatic secretion in the rat.

Anesthesia↗
PubMed1993

Pressor response to microinjection of clonidine into the hypothalamic paraventricular nucleus in conscious rats.

We have reported that intracerebroventricular (i.c.v.) injection of clonidine causes pressor response in conscious rats. To determine the effective brain site, cardiovascular responses induced by unilateral microinjection of clonidine into various hypothalamic nuclei of conscious rats were studied. Microinjection of clonidine (5-20 micrograms/0.5 microliter) into the paraventricular nucleus (PVN) of conscious rats dose-dependently produced a long-lasting pressor response with a decrease in heart rate, which mimicked the response to i.c.v. injection of clonidine. However, clonidine (10 micrograms) injection into various hypothalamic nuclei (anterior, posterior, ventromedial and dorsomedial nucleus) caused a small or no pressor response. In anesthetized rats, clonidine injected into the PVN induced a long-lasting depressor response concomitant with bradycardia. PVN pretreatment with the alpha 2-adrenoceptor antagonist, yohimbine (1 and 10 micrograms), dose-dependently inhibited the pressor response to PVN injected clonidine, but the alpha 1-adrenoceptor antagonist, prazosin (1 microgram), had no significant effect. Central (i.c.v.) pretreatment with the vasopressin (AVP) V1-receptor antagonist, [d(CH2)5Tyr(Me)]-AVP (0.5 and 2.0 micrograms), dose-dependently inhibited the pressor response to PVN injection of clonidine (10 micrograms), while systemic (i.v.) and local (intra-PVN injection) pretreatments with V1-receptor antagonist (2.0 micrograms) had no effect. These results suggest that the pressor response to microinjection of clonidine into the PVN of conscious rats is mediated by endogenous brain AVP, which is released by activation of alpha 2-adrenoceptors. It is also suggested that the PVN is a possible brain site for the pressor response to i.c.v. injected clonidine.

Adrenergic alpha-Antagonists↗