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Biomedical subjects

P Brugger

Publications and source records attributed to P Brugger.

At least 55 records · Page 3Linked to original sources
PubMed1994

From superstitious behavior to delusional thinking: the role of the hippocampus in misattributions of causality.

Nearly half a century ago B. F. Skinner proposed the hypothesis that human superstitiousness would be equivalent to the 'superstitious' behavior displayed by animals in operant situations involving response-independent reinforcement. Surprisingly, no attempt has ever been made to test this equivalence hypothesis experimentally. In the light of recent evidence for a common neurological basis of both superstitious beliefs held by normal subjects and delusional ideas of psychotic patients, Skinner's hypothesis has become topical again. We present an extension of the hypothesis which assumes dysfunction of the medial temporal lobe, in particular of the hippocampus, to be responsible for conditioned superstitions in animals, for common everyday superstitions, and for schizophrenic delusions. This hypothesis is based on (1) the observation of an enhanced 'superstitious' reactivity in hippocampectomized animals, (2) findings of an increased occurrence of popular superstitions in patients with a temporal-limbic epileptic focus, and (3) morphological and pharmacological evidence for schizophrenic delusions to be causally related to hippocampal damage.

Animals↗
PubMed1994

Heautoscopy, epilepsy, and suicide.

Heautoscopy (the doppelgänger experience), epilepsy, and suicide is a triad primarily known from literary accounts. This paper reports a patient with complex partial seizures who tried to commit suicide during the experience of heautoscopy.

Adult↗
PubMed1994

Perseveration in healthy subjects: an impressive classroom demonstration for educational purposes.

Perseveration, that is, the inappropriate maintenance of an activity, is not exclusively observed in patients with brain pathology. We present a brief calculation task that requires healthy subjects to add eight numbers sequentially. While the first seven steps of the addition involve the repeated application of a particular rule, this rule does not apply for the last step. However, a high percentage of subjects (approximately 70%) will commit a perseverative error at this last step and hence obtain an incorrect final result. This simple task is a highly informative illustration of the principle of perseverative behavior. When applied in a classroom setting, it is an impressive demonstration of the ease with which perseveration can be evoked in healthy persons.

Attention↗
PubMed1994

Are "presences" preferentially felt along the left side of one's body?

The "feeling of a presence" is the distinct awareness of the physical presence of somebody in the near extracorporeal space. Although fairly frequently confined to one side of the body, systematic documentation of the lateralization of the phenomenon has not yet been attempted. A brief tabular summary of 11 cases of the unilateral feeling of a presence in association with focal brain pathology (seven left-hemisphere lesions, four right-hemisphere lesions) shows lateralization to the left in five, to the right in six cases. The data, together with the scattered reports of unilaterally felt presences in patients with nonfocal brain pathology and in healthy individuals, do not support claims that the left hemispace is the preferred location. Any models of hemispheric specialization in the sense of self which are derived from observations of felt presences remain speculative. Nevertheless, clinicians are encouraged to document carefully all the unilateral aspects of the feeling of a presence as well as of other reduplicative phenomena involving the self.

Attention↗
PubMed1994

Repetition avoidance in responses to imaginary questions: the effect of respondents' belief in ESP.

42 subjects were given the Myers-Briggs Type Indicator which demands checking either one of two response variants for each of 81 questions. Before, they had completed an imaginary questionnaire version, that is, checked 81 times either "a" or "b" without seeing any questions. Three main findings emerged. (1) Over all subjects, repetitions of the same response alternative were significantly avoided only in the imaginary version, indicating that item content in the Myers-Briggs Type Indicator overrode response stereotypy. (2) On the imaginary version, repetition avoidance was significant for those subjects who said they believed in extrasensory perception (ESP) but not for nonbelievers, corroborating previous reports of an association between belief in ESP and repetition avoidance. (3) In comparison to nonbelievers, believers in ESP scored higher on the dimension "feeling" (as opposed to "thinking") of the Myers-Briggs Type Indicator. This result is in line with the assumption that belief in ESP is associated with a style of thinking more typical for the right hemisphere.

Adult↗
PubMed1993

The Easter bunny in October: is it disguised as a duck?

To study the influence of motivational expectancy on perception, the ambiguous drawing of a duck/rabbit was shown to 265 subjects on Easter and to 276 subjects in October. The ambiguous drawing, though perceived as a bird by a majority of subjects in October, was most frequently named a bunny on Easter. This biasing effect of expectancy upon perception was observed for young children (2 to 10 years) as well as for older subjects (11 to 93 years).

Adolescent↗
PubMed1993

Random-number generation and the menstrual cycle: preliminary evidence for a premenstrual alteration of frontal lobe functioning.

20 women (M age = 30.4 yr.) were given the "Mental Dice Task" (randomization of the numbers from 1 to 6) once during the preovulatory and once during the premenstrual phases of their menstrual cycles. In addition, for both test sessions a premenstrual-symptom score was assessed reflecting self-rated severity of cognitive, affective, and somatic complaints during the preovular and the premenstrual phases. In comparison to series of real dice throws, the Mental Dice sequences of all the subjects showed a relative lack of repetitions and an excess of counting at both times of testing. Counting bias was significantly enhanced in the sequences generated during the premenstrual testing and the size of this bias was positively correlated with the self-rated severity of premenstrual symptoms. Pronounced counting despite the instruction to randomize was interpreted as reflecting decreased ability to suppress task-irrelevant cues and indicating a relative impairment of frontal lobe functioning. Resistance of the Mental Dice Task towards expectation biases renders a sociopsychological interpretation of these results improbable. We conjecture that, like other cognitive processes, frontal lobe functions also fluctuate with hormonal changes.

Adult↗
PubMed1993

Functional hemispheric asymmetry and belief in ESP: towards a "neuropsychology of belief".

30 right-handed subjects were given a lateralized tachistoscopic lexical-decision task. Subjects' belief in extrasensory perception (ESP) was assessed with a single six-point scale; 16 subjects were designated as believers in ESP and 14 subjects as nonbelievers. Believers in ESP did not exhibit a hemispheric asymmetry for the task while nonbelievers exhibited the expected right visual-field/left-hemisphere dominance documented in the literature. Believers' lack of asymmetry was not caused by an impaired left-hemisphere performance but rather by a significantly enhanced lexical-decision accuracy in the left visual field/right hemisphere compared to nonbelievers. These results are compatible with previous studies indicating a correlation between belief in ESP and a bias for right-hemisphere processing. Moreover, the results are relevant for a discussion of an association between paranormal beliefs and schizotypy: highly schizotypal individuals are not only particularly prone to believe in ESP but are also known to show an attenuation of hemispheric asymmetries in lateralized verbal tasks due to an enhanced contribution of the right hemisphere. We suggest that the neurological basis of delusion-like beliefs may involve a release of right-hemisphere function from left-hemisphere control and sketch the focus of research for a future "neuropsychology of belief."

Adult↗
PubMed1990

[Current findings on nocturnal catecholamine excretion in coronary patients].

In 10 patients after myocardial infarction (mean age 53 +/- 8 years) with a normal ejection fraction (EF) and in 10 healthy people (mean age 52 +/- 8 years) the night urinary excretion of noradrenaline and adrenaline was investigated. Additionally to that the vanillic acid vanilmandelic acid and serotonin were determined. Our results show that patients after myocardial infarction with normal EF have significant higher noradrenaline values at night than healthy people (1.95 +/- 1.26 micrograms/h vs. 0.96 +/- 0.37 microgram/h [p less than 0.01]). The night urinary excretion of adrenaline was also increased in patients after MI, but there were no significant differences between the 2 groups (0.51 +/- 0.28 microgram/h vs. 0.27 +/- 0.14 microgram/h [p less than 0.1]). Serotonin was higher in patients with coronary heart disease (CHD), but there was also no significant difference (0.15 +/- 0.14 mg/h vs. 0.08 +/- 0.05 mg/h). Cholesterol values were significantly higher in patients with CHD (245 +/- 56 mg%) than in the group of healthy people (177 +/- 45 mg% [p less than 0.01]). Our own results are of great interest because we found out (to our knowledge for the first time) that patients with CHD show significant higher levels of urinary noradrenaline excretion during the night than healthy volunteers. The raised noradrenaline values may present a particular risk factor for coronary heart disease.

Adult↗
PubMed1990

[Hyperlipidemia and coronary heart disease].

The coronary heart disease (CHD) is of great importance, because it is the leading cause of death in the western world. There is general agreement in the scientific and medical community that high levels of cholesterol and low density lipoproteins (LDL) play a dominant role in atherosclerosis, whereas high lipid lowering agents are associated with a reduced risk for CHD.

Adult↗
PubMed1989

Persistent cognitive impairment in climbers after repeated exposure to extreme altitude.

We performed neuropsychological testing in eight world class climbers who had reached summits higher than 8,500 meters without supplementary oxygen. Five had mildly impaired concentration, short-term memory, and ability to shift concepts and control errors. There were no defects in perception or other cognitive activities. The pattern of impairment suggests malfunctioning of bifronto-temporo-limbic structures. Repeated extreme-altitude exposure can cause mild but persistent cognitive impairment.

Adult↗
PubMed1989

[The effectiveness of barucainide in supraventriculr and ventricular arrhythmias].

The anti-arrhythmic efficacy of barucainide, a new class IB anti-arrhythmic agent, was evaluated in an open-label therapeutic study in a total of 15 patients with coronary artery disease. The majority of patients had a history of myocardial infarction. After a 3-day placebo run-in period barucainide was administered at a dose of 150 mg b.d. for 5 days followed by a 4-day placebo wash-out period. 24-h Holter monitorings were recorded in the run-in period, on day 4 of the treatment period, and on day 3 of the wash-out period. In addition, plasma levels were determined in all three periods. Statistical evaluation of the 24-h arrhythmia analyses revealed a decrease of premature ventricular contractions (PVCs) in all treated patients. Before treatment PVCs occurred at a median of 92.4/h (minimum 19/maximum 1537 PVCs/h); this value was reduced during treatment to a median of 7.9 (0/427) PVCs/h (p less than 0.01). A similar result was also found for the couplets which decreased significantly from a median (min/max) of 0.6 (0/11)/h before treatment with barucainide to 0.1 (0/3)/h after treatment (p less than 0.05). In 10 of 15 patients premature ventricular contractions were reduced by more than 80%. Ventricular tachycardia present in 4 of 15 patients was suppressed in all cases. Barucainide had only a slight effect on PQ and QTc intervals, QRS duration, heart rate, and blood pressure.

Anti-Arrhythmia Agents↗
PubMed1989

In vitro cardiac effects and antiarrhythmic properties of guanfacine.

Guanfacine (Estulic, Tenex), a centrally acting antihypertensive, was investigated for its effects on the heart using isolated cardiac preparations and in patients for antiarrhythmic properties. The tachycardic effects of sympathetic nerve stimulation in spontaneously beating atria were concentration-dependently suppressed by guanfacine. A 50% inhibition was observed in atria from Syrian hamsters, guinea-pigs and rabbits with 1, 5.4 and 20 nmol/l, respectively. In guinea-pig atria the concentration-response curve of guanfacine was shifted to the right in a parallel manner by rauwolscine (pA2 8.58) but was not displaced by prazosine 1 mumol/l. In rabbit right papillary muscles guanfacine 1 to 10 mumol/l increased force of contraction by 13 to 91%. The positive inotropic effect was antagonized by prazosine 1 mumol/l but was not influenced by cimetidine 1 mumol/l or rauwolscine 1 mumol/l. It is concluded that guanfacine activates cardiac postsynaptic a1- and neuronal presynaptic a2-adrenoceptors with a preference to the latter of about 2 orders of magnitude. Direct membrane stabilizing effects in guinea-pig atria were negligible. In 4 patients with coronary heart disease associated with arrhythmia guanfacine 1 mg per day during 10 days decreased ventricular premature contractions, couplets and abolished appearance of ventricular tachycardias. These preliminary clinical results indicate that guanfacine may reduce cardiac risk factors.

Aged↗
PubMed1988

[Sports and coronary heart disease].

The effectivity of an endurance physical training must not be ignored any longer as it is known that physical activity as well in the job as in the leisure time diminishes the risk of coronary artery disease and their consequences. The training should be put through according to the vigorous exercise training with 70 to 80% of the maximal work load in a dynamic work continuously for at least 10 minutes. The optimum duration appears to be about 30 to 40 minutes a day, repeated 3 to 4 times weekly. The best sports for coronary patients are jogging, cycling or bicycle ergometry, country cross skiing, walking in the mountains as well as at diminished performance capacity, gymnastic, walking, golf and with some restrictions swimming.

Coronary Disease↗
PubMed1988

[Assessment of the genotoxic risk caused by the gyrase inhibitor ofloxacin using sister chromatid exchange rate analysis].

Ofloxacin (Tarivid) is a 4-quinolone of the latest generation. Its mechanism of action is the inhibition of the enzyme gyrase which plays a central role in the bacterial DNA-metabolisms. Thus Ofloxacin blocks the reading of the chromosomes and impairs the cell's function and ability to reduplicate leading to eradication of the pathogens. The genotoxicity of Ofloxacin was assessed by analyses of SCE (sister-chromatid-exchange-rates), which is a sensitive and qualitative parameter indicating chromosomal damages. In vitro no change of the SCE-frequencies could be demonstrated in human lymphocytes; in vivo, however, a slight influence not be excluded, which is also true for eventual additive on synergistic effect with other mutagenic factors.

Dose-Response Relationship, Drug↗
PubMed1987

[Ventricular function in patients with silent myocardial ischemia before and following aortocoronary bypass operation].

In 12 patients with silent myocardial ischemia (fall of the ejection fraction (EF) greater than or equal to 5%, without angina pectoris) and in 15 symptomatic patients with coronary heart disease (fall of the EF during exercise EF greater than or equal to 5%, with angina pectoris), the left ventricular ejection fraction and the diastolic function (Peak Filling Rate, PFR; Time to Peak Filling Rate, TPFR) were evaluated before coronary artery bypass surgery and afterwards by the aid of the Nuclear Stethoscope. Our results showed a slight insignificant improvement in the EF from 60 +/- 8.3 per cent at rest to 66 +/- 7.9 per cent vs. 57 +/- 12 per cent to 62.6 +/- 9 per cent in patients with silent ischemia and in patients with angina pectoris after surgery. In contrast to this the EF increased significantly during exercise both in patients with silent ischemia from 52.0 +/- 15.2 per cent to 70.1 +/- 7.9 per cent and in symptomatic patients after revascularisation from, 49 +/- 11.7 per cent on to 64.2 +/- 8.4 per cent (both p less than 0.0001). There was also a similar significant improvement in the diastolic function, whereby the PFR was enhanced from 2.52 +/- 0.54 EDV/sec to 3.31 +/- 0.87 EDV/sec (p less than 0.02) in patients with silent myocardial ischemia and from 2.55 +/- 0.86 EDV/sec to 3.40 +/- 0.98 EDV/sec (p less than 0.02) in symptomatic patients. The TPFR showed a similar improvement.

Angina Pectoris↗