Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “UNCONSCIOUSNESS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,729 records · Page 96Linked to original sources
PubMed2001

Subliminal visual oddball stimuli evoke a P300 component.

OBJECTIVE: To provide evidence that a P300 component can be elicited by subliminal stimuli in an oddball paradigm. METHODS: The words LEFT and RIGHT were presented in a frequent-rare ratio (80-20%), counterbalanced between subjects. Stimuli were presented at the objective detection threshold (d'=0, via unmasked 1 ms presentations), a stringent measure for detecting any conscious perception. RESULTS: A significantly larger amplitude component was found for rare vs. frequent stimulus presentations across electrodes Fz, Cz, and Pz using both a broad 200-900 ms window (F(1,27)=5.75, P<0.012, eta(2)=0.18; one-tailed), and a more narrow 400-760 ms window defined using principal component analysis (F(1,27)=10.10, P<0.002, eta(2)=0.27; one-tailed). No significant component latency effects were found. An analysis of the conscious perception index (d') and the oddball effect (rare-frequent amplitude difference) revealed a negative relationship, further supporting the contention that conscious perception does not account for the finding, and suggesting that any conscious stimulus detection may inhibit this subliminal effect. CONCLUSIONS: Results provide evidence that an endogenous component can be elicited by undetectable subliminal stimuli in an oddball paradigm. Implications are discussed for comparing conscious and unconscious information processing, unconscious learning, and the measurement of ERPs to subliminal stimuli.

Adult↗
PubMed1991

Cognition and motivation in emotion.

The role of cognition--and to some extent motivation--in emotion, the ways meaning is generated, unconscious appraising, and the implications of this way of thinking for life-span development are addressed. It is argued that appraisal is a necessary as well as sufficient cause of emotion and that knowledge is necessary but not sufficient. This position is examined in light of what is known about emotions in infants and young children, the effects of drugs on acute emotions and moods, and recent patterns of thought about the brain in emotions. The discussion of how meaning is generated is the core of the article. Automatic processing without awareness is contrasted with deliberate and conscious processing, and the concept of resonance between an animal's needs and what is encountered in the environment is examined. The idea that there is more than one way meaning is achieved strengthens and enriches the case for the role of appraisal in emotion and allows the consideration of what is meant by unconscious and preconscious appraisal and the examination of how they might work.

Brain↗
PubMed1989

On the status of nonconscious processes in human cognition: comment on Reber.

Two issues are discussed. The first one pertains to the generality of the nonconscious learning processes and their somewhat paradoxical status in cognitive psychology. We argue that the ability of the human cognitive system to nonconsciously acquire complex knowledge structures is one of its elementary and indispensable properties. Moreover, the existence of this ability constitutes one of the necessary metatheoretical assumptions of contemporary cognitive psychology. Nevertheless, the contemporary cognitive psychology literature often implies that it is only one of many controversial and unusual phenomena. The second issue pertains to the distinction between the so-called primitive unconscious and the sophisticated unconscious as proposed by Reber (1989).

Concept Formation↗
PubMed1994

Toward a redefinition of implicit memory: process dissociations following elaborative processing and self-generation.

Does conceptual processing affect unconscious uses of memory? We used a process-dissociation procedure to separate automatic (unconscious) and consciously controlled uses of memory in a stem-completion task. Contrary to results from indirect test conditions, estimates derived from our procedure showed no effect of self-generation and no differential effect of semantic and nonsemantic study conditions on automatic uses of memory. These results provide evidence that (a) indirect tests are often contaminated by conscious uses of memory and (b) stem completion is highly dependent on prior perceptual (and perhaps lexical) processing. The experiments demonstrate the advantages of using process-dissociation procedures over comparisons between direct and indirect tests.

Adult↗
PubMed2003

Persistent complex subliminal activation effects: first experimental observations.

A strong recent focus on unconscious processes has increased interest in subliminal stimulation and other experimental activation technologies. Five experiments using male and female university students (N = 365) were carried out to compare 5-ms exposures of "mommy and I" stimuli with 5-ms control stimulation. Measures of self-mother similarity and other variables taken 7-14 days after exposure were more strongly correlated among experimental participants. Such complex, persistent effects may follow when powerfully activating stimuli administered under wholly unconscious conditions provokes schematic processing of social information and behavioral confirmation. These scientifically exciting and ethically problematic findings imply a need for further reduction of the role accorded to conscious volition and control in psychology.

Adult↗
PubMed1999

Sevoflurane requirement for laparoscopic tubal ligation: an electroencephalographic bispectral study.

It has been shown in healthy volunteers that a concentration of volatile anaesthetic lower than 1 minimum alveolar concentration provides unconsciousness. We tested the hypothesis that, using the electroencephalogram bispectral index, less than 1 minimum alveolar concentration of sevoflurane can produce unconsciousness in patients. Anaesthesia was induced and maintained with sevoflurane in N2O and O2 (33%) in 32 ASA I-II women undergoing laparoscopic tubal ligation. For the first patient, the sevoflurane concentration was adjusted to 1 minimum alveolar concentration with an end-tidal concentration of 0.7%. The electroencephalogram bispectral index values were used to determine the concentration to be used for the next patient. The ED50 (effective dose) measured using end tidal concentrations of sevoflurane for laparoscopic tubal ligation in a 40-year-old patient was 0.70% (CI 95%: 0.63-0.77) and ED95 0.83% (CI 95%: 0.75-0.90). None of the patients had any operation-associated recall. It is concluded that the sevoflurane concentration needed for laparoscopic tubal ligation is not lower than 1 minimum alveolar concentration.

Adult↗
PubMed1999

Familial fatal and near-fatal third ventricle colloid cysts.

BACKGROUND: Despite having a presumed congenital origin, familial cases of colloid cysts have been reported only rarely. The first case of a brother and sister with colloid cysts is reported here, and the relevant literature is reviewed. METHODS: A 25-year-old man presented with a 24-h history of headache and vomiting. He rapidly became unconscious and fulfilled the criteria for brain death on arrival at hospital. No surgical intervention was performed. RESULTS: The patient's sister presented at the age of 41 with headaches and rapidly became unconscious. The sister had urgent bilateral ventriculostomies. followed by transcallosal removal of a colloid cyst. CONCLUSIONS: These cases support the hypothesis that colloid cysts are congenital lesions and provide some evidence of a possible genetic predisposition to their formation. Sudden death remains a real risk for patients harbouring a colloid cyst.

Adult↗
PubMed1999

[The general psychological concept in the later work of Eugen Bleulers. Comparison with a summarized description from a forgotten theory 60 years after the final publication (1939)].

Documents by Eugen Bleuler from 1921 to 1939 that go into general psychological topics of meaning of consciousness, formation of motive and will, are presented. An effort towards integration of seemingly incompatible, side by side standing, unrelated biological and psychological concepts that probably is most likely explainable by the contemporary background of ideas, is recognizable. In this context, Eugen Bleuler refers to an already (especially by Richard Semon) systematically developed theory called "Mnemism" that he interpreted and applied to the psychological circumstances mentioned above. That theory of "mnemism" that can be most adequately described as a biogenetic-vitalistic theory, is assuming, that all organic life--independent of the possibility of a self-reflecting consciousness--is able to learn experiences made by analysis of environment and to pass it on following generations. Pattern of stimulus reactions are in the sense of this theory memorized ("engraphiert") and reactivated under similar situational circumstances ("ekphoriert") by the psychological mode of association.--It can be shown that Bleuler pursued this theory for a period of more than ten years. It represents the benchmark for Bleuler's standpoints, for example for the question of determination of human acting, that as itselves are already known from his earlier documents, but here have found a more theoretically based explanation. The assumption of the efficacy of specific, not necessary consciously remembered "engramms" of memory, suggests the hypothesis of the existence of unconsciousness; in this context textual points of contact to the psychological concepts of S. Freud and C. G. Jung--mnemic memory and collective unconscious--are shown.

Consciousness↗
PubMed1987

Reversing severe hypoglycemia during pregnancy with glucagon therapy.

Glucagon therapy has been used to reverse severe hypoglycemia-induced unconsciousness, but no known study exists which reports its use during pregnancy. Pregnant diabetic women were eligible if they had either a prior hypoglycemic episode requiring intravenous glucose administration or had repeated capillary blood glucose determinations less than 40 mg/dl without any warning adrenergic symptoms. Of 51 insulin-dependent diabetic women, 16 were candidates for glucagon use during a recent 3 1/2-year period. Seven of these 16 persons required an injection on 12 occasions, and an immediate reversal of unconsciousness was encountered in 11 circumstances. No apparent short- or long-term maternal adverse effects were present. We conclude that glucagon therapy is needed infrequently for diabetic women during pregnancy but is helpful in reversing acute episodes of severe hypoglycemia.

Adult↗
PubMed1989

An indirect method of discovering primary traumatic experiences: two case examples.

Our primitive brain has the capacity to recall visual, auditory, olfactory, tactual, and postural memories. Consciously we all set limitations on our abilities to recall. The technique described here suggests that all of us can recall meaningful sensory experiences with the help of multiple subconscious reviews of an event. We are aware of moods unconsciously and can assign colors to these moods. The unconscious mind can localize the true site of pain even when the patient is consciously sure the pain is localized elsewhere. The methods of exploration are described, and possible values of the methods are pointed out.

Adult↗
PubMed1994

Relational themes in the inpatient community meeting.

The authors present a model of psychiatric inpatient community meetings run as large group interpretive psychotherapy. They developed this model in part from Gill's notion that patients attach plausible meanings to therapist behavior based on the patient's characteristic and stereotypical ways of experiencing relationships. The model provides a framework for the description of 11 clinically derived "unconscious relational configurations" that can frequently be detected as organizing "relational themes" of community meetings. The authors present two clinical vignettes in which staff detect these themes and interpret them together with the defenses against them. They then discuss the prominent negative affective valence that characterizes the "unconscious relational configurations."

Ego↗
PubMed2001

Hamlet's delay.

This paper raises a question about Freud's understanding of Hamlet and offers a fresh psychoanalytic perspective on the play, emphasizing the psychological use made of Hamlet by the audience. It suggests Hamlet and Claudius both serve as sacrificial objects, scapegoats, for the audience, embodying, through a mechanism of both identification and disidentification, the fulfillment, punishment, and renunciation of the audience's forbidden (i.e. Oedipal) wishes. The play is thus seen to represent unconsciously a rite of sacrifice in which both Claudius and Hamlet, both the father and the son, are led, albeit circuitously, to the slaughter. The need for delay on the part of Hamlet is thus seen to arise not merely from Hamlet's psychology, whatever the audience may project onto it, but ultimately from the function (both sadistic and defensive) that the sacrificial spectacle, the play as a whole, serves for the audience. The paper also speculates somewhat on the role of tragic heroes and heroines in general, and points to the unconscious collusion that permits author and audience to make use of them. Finally, in an addendum, the paper discusses the work of René Girard, a nonpsychoanalytic thinker whose ideas nonetheless are somewhat similar to those presented here.

Adult↗
PubMed2000

F-waves and facilitated late responses of the mentalis muscle in patients with a cerebrovascular accident.

F-waves in the extremities result from the backfiring of antidromically activated anterior horn cells and F-waves of the mentalis muscle can be also elicited after stimulation of the marginal mandibular branch of the facial nerve. In order to investigate the influence of the descending pathway of the excitability of the facial motonucleus, the F-wave of the mentalis muscle and the facilitated late response, which follows F-waves and which seems to be the snout reflex due to their similar latency and habituation, were studied in 11 conscious patients with a hemispheric cerebrovascular accident (CVA) presenting with hemiparesis, and in 10 unconscious patients with CVA or head injury. The duration and the persistence of the F-waves increased significantly statistically on the normal side in the CVA patients compared with those of the palsy side and the normal subjects. In comatose patients the F-waves and the facilitated late response were not elicited. The latency (46.1 +/- 13.3 msec) of the facilitated late responses in the unconscious patients tended to increase compared with the latency (36.6 +/- 4.3 msec) in the conscious patients. These findings suggest that the hyperexcitability of the facial motoneuron is ipsilateral to any hemispheric lesion; the hemispheric lesion exerts a bilateral excitatory influence on the interneuron of the facilitated late response: and that the reticular formation may influence the facial motoneuron and any interneurons concerned in the facilitated late response. F-waves and facilitated late responses should be further examined as neurophysiologically useful diagnostic methods.

Consciousness Disorders↗
PubMed2002

Craniectomy position affects morris water maze performance and hippocampal cell loss after parasagittal fluid percussion.

Valid and reliable animal models are essential for mechanistic and therapeutic studies of traumatic brain injury (TBI). Therefore, model characterization is a continual and reciprocal process between the experimental laboratory and the clinic. Several excellent experimental models of TBI, including the lateral fluid percussion rat model, are currently in wide use in many neurotrauma laboratories. However, small differences in the position of lateral fluid percussion craniectomy are reported between labs. Additionally, differences in hippocampal cell death have also been reported. Therefore, we hypothesized that small changes in craniectomy position could affect commonly used outcome measures such as vestibulomotor function, Morris water maze (MWM) performance, hippocampal cell loss, and glial fibrillary acidic protein (GFAP) immunoreactivity. Four placements were systematically manipulated: rostral, caudal, medial, and lateral. The medial and caudal placements produced significantly greater impairments in the MWM acquisition task over the lateral and rostral placements. The rostral placement produced diffuse cortical damage but little hippocampal cell loss. In contrast, the medial, lateral, and caudal placements produced more mid-dorsally localized cortical damage and significant cell loss in the CA2/CA3 and hilus ipsilateral to the injury site. Furthermore, reactive astrocytosis was more pronounced in the medial, lateral, and caudal placements than in the rostral placement. All craniectomy position groups had similar durations of traumatic unconsciousness and similar impairment on motor tasks. We conclude that small alterations in craniectomy position produce differences in cognitive performance, hippocampal cell loss, and reactive astrocytosis but not in motor performance nor transient unconsciousness.

Animals↗
PubMed2000

Electrical stunning and exsanguination decrease the extracellular volume in the broiler brain as studied with brain impendance recordings.

Electrical stunning in the process of slaughtering poultry is used to induce unconsciousness and immobilize the animal for easier processing. Unconsciousness is a function of brain damage. Brain damage has been studied with brain impedance recordings under ischemic conditions. This experiment studies brain impedance as a response to a general epileptiform insult caused by electrical stunning and ischemia caused by exsanguination. Brain impedance was recorded in 10 broiler chickens for each of three killing methods: whole body electrical stunning, which induces cardiac arrest; head only electrical stunning followed by exsanguination; and exsanguination without stunning. Brain impedance was converted into relative extracellular volume (ECV) values. Results showed that, immediately after electrical stunning, the ECV decreased 5.5% from base ECV. With exsanguination only, the ECV decreased from base ECV only after 4 min after neck cutting. The ECV decrease after 10 min did not differ between treatments. With a time of 228 s to reach one-half of the ECV decrease found at 10 min, electrical stunning resulted in a much faster change in ECV than exsanguination only (373 s). Within the head only stunning group, six animals showed a response similar to that found with whole body stunning; the other four animals responded similarly to the animals that were exsanguinated only. It was concluded that brain impedance recordings used with electrical stunning reflect brain damage. This damage was both epileptic and ischemic in nature. Whole body stunning induced immediate brain damage, suggesting that an adequate stun was delivered. The dual response found with head only stunning might indicate that this stunning method does not always produce an adequate stun.

Abattoirs↗
PubMed1996

Cricoid pressure: teaching the recommended level.

The Sellick maneuver or cricoid pressure is an effective means of preventing passive aspiration of gastric contents. Recent studies recommend a pressure of 20 newtons (N) when the patient is awake, increasing to 30-40 N with unconsciousness. This study was proposed to determine whether with education and practice, anesthesia providers and assistants could be taught a recommended cricoid pressure and retain this skill. Cricoid force was measured using a life-size laryngotracheal model on a calibrated infant scale. Fifty-three participants were divided into six groups: MD faculty; CA-1, 2, and 3 Residents; certified registered nurse anesthetists (CRNA); and Others. Each was asked to apply pressure to the blinded model to simulate application of the Sellick's maneuver to an "awake" and "unconscious" patient on four occasions: before instruction of the recommended pressures (Preinstruction), after being informed of the recommended magnitudes of 20 N/awake and 30-40 N/anesthetized (Postinstruction), after a period of unblinded practice (Postpractice), and 3 mo or longer after practice (Follow-up). Initial attempts revealed inadequate force by all participants, "awake" and "anesthetized". All participants were able to learn the recommended amount of applied pressure and were able to retain this knowledge after 3 mo. This model represents an easy and practical means of teaching the application of the optimal level of force to practitioners and assistants.

Analysis of Variance↗
PubMed1992

Fear of abandonment and binge eating. A subliminal psychodynamic activation investigation.

Dependency and fear of abandonment by significant others have been theoretically linked to eating disorders, particularly bulimia. This research investigates the hypothesis that unconscious fear of abandonment is one variable underlying binge eating episodes in bulimia. An analogue population of 40 "high eating disorder" undergraduate women and 40 undergraduate women with normal eating patterns viewed either an abandonment or a control stimulus presented at either subliminal (4 msec) or supraliminal (200 msec) exposure durations. Following exposure to an abandonment stimulus, the high eating disorder group ate significantly more crackers in a bogus cracker rating task (p less than .001) than did subjects in any other condition. Contrary to predictions, a subliminal stimulus did not lead to a significant change in self-reported mood. Results provide preliminary support for the psychoanalytic hypothesis that binge eating is a defense against unconscious fear of abandonment.

Adaptation, Psychological↗
PubMedDate not supplied

Consciousness, coma, and caring for the brain-injured patient.

In this article, a preliminary conceptual framework is presented for exploring nursing interventions and research aimed at improving care of the unconscious brain-injured patient during the early subacute phase of brain injury. The cue-response framework presented is derived from multidisciplinary sources and has specific clinical relevance to critical care nurses caring for unconscious brain-injured patients. A key aspect of this framework is the attention focused on the timing of nursing interventions in response to how nurses interpret the physical, physiological, and secondary cues they observe when caring for comatose patients. A case exemplar is used to present one example of how this framework may be used in the clinical setting.

Adult↗