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Biomedical subjects

M Schredl

Publications and source records attributed to M Schredl.

At least 19 recordsLinked to original sources
PubMed2001

In healthy volunteers responses to challenge with cholecystokinin tetrapeptide differ between administration during REM and delta sleep.

This study was designed to examine the sensitivity of different sleep stages to the pharmacological provocation of nocturnal panic attacks by cholecystokinin tetrapeptide (CCK-4). In a balanced cross-over design, healthy participants were challenged with identical doses of CCK-4 both during REM sleep and during delta sleep. In nine subjects, stimulation with 50 microg CCK-4 during REM sleep failed to elicit a full-blown panic awakening, while the same dose, administered during delta sleep, produced full-blown panic attacks in two participants. Similarly, stimulation of six subjects with 100 microg CCK-4 during REM sleep resulted in only one panic response, whereas four of nine subjects awoke experiencing a panic attack following stimulation with the identical dose during delta sleep. Severity of panic symptomatology, as measured by the self-rated Acute Panic Inventory, was also significantly increased when CCK-4 was administered during delta sleep. CCK-4 can be used as a challenge agent with an abrupt onset of action making it possible to provoke panic attacks precisely during a particular sleep stage. Sensitivity to the panicogenic effects of CCK-4 seems to be higher during delta sleep than REM sleep.

Adult↗
PubMed2001

Reliability in dream research: a methodological note.

The coefficients of internal consistency and retest reliability had been rarely investigated within the methodology of dream content analysis. Analyzing a dream series of elderly, healthy persons obtained from weekly telephone interviews, the internal consistency of a series of 20 dreams and retests after 4 or 22 weeks, respectively, had been computed. The findings indicate that dream recall and dream length are quite stable, but dream characteristics such as bizarreness and emotional tone underlie large intraindividual fluctuations. In order to obtain reliable measures for these variables which will be important for correlational studies, including waking-life trait measures, one has to obtain as many dreams as possible (about 20) in a very short time period. Further research is needed to extend the present findings to diary dreams and laboratory dreams.

Aged↗
PubMed2001

Donepezil-induced REM sleep augmentation enhances memory performance in elderly, healthy persons.

Previous research in younger individuals has shown that acetylcholinesterase inhibitors may enhance REM sleep. The present study indicates that in the elderly, donepezil, an acetylcholinesterase inhibitor, also exerts a marked effect on REM sleep parameters--percentage of REM sleep and REM density were increased whereas REM latency was reduced. In addition, we also found a correlation between memory performance and REM sleep. Based on these findings, we conclude that there is an interrelationship between cognitive performance and amount of REM sleep in elderly humans as has been previously shown in animals and young adults.

Aged↗
PubMed2001

Dream recall frequency and sleep quality of patients with restless legs syndrome.

The present study investigated the dream recall frequency and the pattern of influencing factors of patients with restless legs syndrome in comparison with healthy controls. The patients' dream recall frequency did not differ from that of healthy controls. Dream recall, however, was negatively associated with the number of periodic leg movements with arousal (PLMAI). Subjective estimates of sleep quality or feeling of being refreshed in the morning, on the other hand, did not correlate with the PLMAI index. Whereas subjective sleep parameters were related to dream recall frequency in healthy controls, no substantial relationships were found in the patient group, except for the positive correlation between sleep latency and dream recall frequency. The results of the present study can not be interpreted as clear evidence for the arousal-retrieval model of dream recall; it seems plausible that other factors, e.g. the functional state of the brain, are of importance in explaining dream recall in this patient group.

Adult↗
PubMed2000

The effect of rivastigmine on sleep in elderly healthy subjects.

Previous research has shown that acetylcholinesterase inhibitors may affect REM sleep, however, results are inconclusive. From the present findings it is concluded that the effects of rivastigmine, a reversible acetycholinesterase inhibitor, on REM sleep are more pronounced in the elderly where we found REM latency to be significantly reduced. This may be explained by better bioavailability and/or by reduced stability of the circadian rhythmicity in elderly individuals. Because rivastigmine is used in the treatment of Alzheimer's disease, further research investigating the relationship between the REM enhancing properties of rivastigmine and cognitive functioning seems promising.

Aged↗
PubMed2000

Use of popular dream literature.

The present study investigated ratings of popular books on dream interpretation. Books were rated as helpful, especially those including explicit guidelines for working on dreams.

Adult↗
PubMed2000

Time series analysis in dream research.

The present study investigated the linear as well as nonlinear relationships between selected dream content scales and dream length. The results indicated that biases due to control solely for the linear components are almost negligible.

Adult↗
PubMed2000

The use of dreams in psychotherapy: a survey of psychotherapists in private practice.

Since the publication of Sigmund Freud's The Interpretation of Dreams, dream interpretation has been a standard technique often used in psychotherapy. However, empirical studies about the frequency of working on dreams in therapy are lacking. The present study elicited, via a self-developed questionnaire, various aspects of work on dreams applied by psychotherapists in private practice. The findings indicate that dreams were often used in therapy, especially in psychoanalysis. In addition, a significant relationship was found between the frequency of the therapists' working on their own dreams and frequency of work on dreams in therapy. Because work on dreams was rated as beneficial for the clients, further studies investigating the effectiveness and the process of working on dreams will be of interest.

Behavior Therapy↗
PubMed1999

The problem of dream length in analysis of content.

The present study investigated the linear as well as nonlinear relationships between scores on selected dream content scales and dream length. Analysis indicated that biases due to control solely for the linear components are almost negligible.

Adult↗
PubMed1998

Emotions in diary dreams.

Even though various investigations found a preponderance of negative emotions in dreams, the conclusion that human dream life is, in general, negatively toned is limited by several methodological issues. The present study made use of three different approaches to measure dream emotions: dream intensity rated by the dreamer, intensity rated by a judge, and scoring of explicitly mentioned emotions (Hall & Van de Castle, 1966). Results indicate that only in the case of external raters' estimates do negative emotions outweigh the positive ones; but in the case of self-ratings (i.e., those made by the dreamer himself/herself), the ratio was balanced. Analyses showed that this is mainly due to the underestimation of positive emotions in the external ratings. Additionally, a positive correlation was found between the intensity of dream emotions and dream recall frequency, whereas gender differences were nonsignificant as regards the emotional tone of diary dreams.

Adolescent↗
PubMed1998

Dreaming and insomnia: dream recall and dream content of patients with insomnia.

The present study investigated dream recall frequency and dream content of patients with insomnia in comparison to healthy controls. Patients' dream recall frequency was elevated, due mainly to their heightened frequency of nocturnal awakenings. Dream content seems to reflect waking life stressors found in these patients, i.e. dream emotions were more negative and dreams were characterized by themes of depression, 'negatives' in self-description and health themes. Patients taking antidepressants showed lower dream recall frequency than patients without any medication; benzodiazepine intake, however, did not affect dream recall frequency. Both drug groups reported more positively toned dreams than drug-free patients. It is suggested that future studies should use more dreams per subject in order to reduce error variance of the dream content measures and more detailed measures of waking life stress.

Adult↗
PubMed1998

Ratio of male and female characters in a dream series.

The present study investigated the change in gender ratio of dream characters in relation to the dreamer's environment in waking-life and found a preponderance of male characters in the subject's dream while living in a 'male' environment which was not present while living in a 'female' environment. The results support the continuity hypothesis of dreaming and stress the importance of situational factors rather than personality factors in the explanation of the gender ratio of dream characters.

Dreams↗
PubMed1998

Stability and variability of dream content.

The present study investigated the stability and variability, respectively, of selected dream content measures derived from diary dreams. The within-subject correlations were small when dream length was controlled. To obtain sufficient reliability for all scales dream series of 20 dreams or more would be necessary.

Adult↗
PubMed1998

[Dream contents of sleep disordered patients].

The present study investigates dreams reports of patients with sleep disorders. Whereas, the findings scarcely showed specific dream contents for different sleep disorders, e.g. problematic dreams in insomniacs, breathing-related dreams in sleep-apnea-patients, a remarkable relationship between waking life and dream contents did occur. Private problems and occupational stress are reflected in dreams by means of increased negative feelings, aggression and occupational themes. The results suggest that dreams can be made use of in psychological invention methods in sleep disorders, e.g. stress management.

Adult↗