Psychotic-like experiences in non-clinical subgroups with and without specific beliefs.

BACKGROUND: Assuming a transdiagnostic and extended psychosis phenotype, psychotic-like experiences (PLEs) and psychotic symptoms are on a phenomenological and temporal continuum between clinical and non-clinical populations. Recent research points towards differences in PLE proneness in different subgroups and clinical impact of different PLE subtypes. This study examines the prevalence of PLEs in three groups of individuals with and without specific sets of beliefs aiming to elucidate the question whether proneness to PLEs varies according to traditional versus less traditional supernatural beliefs. METHODS: The anonymized 16-item version of the Prodromal Questionnaire (PQ-16) was used to assess PLEs in three groups including individuals with religious beliefs (RB), belief in esoterism and paranormal phenomena (EB), and those embedded in scientific evidence approach and scepticism towards para-scientific theories (non-believers, NB). Male and female participants between 18 and 90 years were eligible for participation. RESULTS: The sample comprised 159 individuals including 41 RB individuals, 43 EB individuals, and 75 NB individuals. The mean PQ-16 score of the EB individuals (6.86 ± 4.13) was significantly higher compared to NB individuals (3.43 ± 2.99) and to RB individuals (3.38 ± 3.23) with almost twice the score (both p-values < 0.001). There was no significant difference between the PQ-16 scores of the NB group and the RB group (p = 0.935). No significant impact of age (p = 0.330) and gender (p = 0.061) was found on the PQ16-Score. Group affiliation to esoterism was associated with a higher PQ-16 score compared to group affiliation to religious beliefs (p < 0.001) and group affiliation to scepticism (p = 0.011), while the latter two did not differ significantly (p = 0.735). No significant difference was found between the three groups in the degree of distress related to the affirmatively answered PQ-16 items (p = 0.74). CONCLUSION: Under the assumption of a transdiagnostic psychosis phenotype, our findings provide more insight which subgroups within non-clinical samples have a higher likelihood of reporting PLEs.

Vulvar cancer patients' quality of life: a qualitative assessment.

To develop a vulvar cancer-specific quality of life (QOL) subscale to accompany the Functional Assessment of Cancer-General (FACT-G) questionnaire, semistructured interviews were performed with 15 patients treated for vulvar cancer (FIGO stage 0-3). All but one patient, who received chemoradiotherapy, were treated by radical vulvectomy and six patients received a groin lymph node dissection. Patients experienced reductions in several aspects of QOL including emotional functioning, physical functioning, social functioning, sexuality, and body image. Six patients suffered from lymphedema of the legs with a mean severity of 3.5 on a 10-point scale. Four patients reported pruritus (severity rating 8.5). Seven patients expressed a need for more information about the illness and treatment. Only four patients returned to employment after treatment, and all of these patients reported work-related problems. Reductions in sexual functioning were a major concern for five patients, all younger than 65 years. Other topics were groin discomfort after removal of the lymph nodes and disturbance by odor from the vulva. Results of this study revealed vulvar cancer-specific reductions in QOL for inclusion in the newly developed vulvar cancer-specific subscale.

[Partner interactions and coping activity of migraine patients]. / Partnerschaftliches Interaktionsverhalten und Stressverarbeitung von Migränepatientinnen.

Empirical studies suggest that an inefficient, negative communication could represent a source of stress in the patient's everyday life and that this kind of communication would also imply chronic migraine. The present study used the "Kategoriensystem für partnerschaftliche Interaktion (KPI)" to determine whether the communication patterns of 12 women with migraine and their partners differed from 12 women with chronic headache and their partners and 12 healthy couples. The communication was video-filmed during the about 10 min lasting interaction in a personally relevant conflict situation. As predicted, women with migraine and their partners made more negative and fewer positive statements than the couples with tension headache and the control dyads. Furthermore, a higher load in female migraine sufferers compared to normal controls was indicated by coping activity.

Brain DC potential changes of computerized tasks and paper/pencil tasks.

Analysis of slow cortical potentials and their topography is currently discussed as an indication of cortical activity associated with cognitive operations/performance. In this paper, changes of the EEG DC potential were analyzed in two computerized tasks (correcting typing errors, performing Excel) and two paper/pencil tasks (correcting typing errors, a cognitive test) to assess mental load related to ergonomical and task characteristics. DC recordings were analyzed for the mean values of baseline and the first and the second 4 min of each task from 24 persons. A 2 (computer usage experience low vs. high)x4 (Task)x3 (Time: baseline, first half of task, second half)x6 (Lead) MANOVA of DC potential changes (DCPCs) showed at F3, F4 and C3 positive DCPCs for paper/pencil tasks and negative DCPCs for computerized tasks. Ratings of task difficulty were related to high vs. low task demands, whereas DCPCs were related to task medium, time on task and lead. Highly experienced persons showed a pronounced left-right difference at parietal locations and at frontal and central locations related to task medium by trend. Results were interpreted as higher cortical activation associated with mental load caused by additional attentional/controlling demands of computerized tasks.

Motivations to control drinking behavior in abstainers, moderate, and heavy drinkers.

Motives and motivational concepts to control quantity (Q) and frequency (F) of alcohol consumption were investigated in 192 participants using a questionnaire of motives to control drinking (MCD-Q/F) developed earlier. The daily quantity of consumption was assessed by the "30 day by beverage questionnaire." Participants were grouped into heavy or moderate drinkers (limits: females 40, males 60 gram alcohol/day) and abstainers. Analyses of motives showed the importance of car driving, controlling appetite/desire, and prevention of impaired mental performance. The relative impact of motivational concepts were analyzed by cluster analysis of motives revealing three clusters: 1) emotional concepts/fear of addiction, 2) physiological sensations/interaction with concrete actual plans, 3) cognitive concepts (plans, self-control, no impairment/no desire). MANOVA of MCD-Q/F indicate highest scores for moderate drinkers and significant lower scores in heavy drinkers in controlling frequency of drinking (MCD-F). Group effect for emotional concepts failed significance, higher scores of physiological concepts were found in imbibers compared to abstainers, and scores of cognitive concepts were lower in heavy drinkers. Results indicate that for imbibers a reduced motivation to control frequency of drinking as well as low scores in cognitive concepts and a trend to high scores in emotional concepts are associated with heavy drinking.

Effects of an ELF (50 Hz, 1 mT) electromagnetic field (EMF) on concentration in visual attention, perception and memory including effects of EMF sensitivity.

To investigate psychological effects of an extremely low frequency (ELF)-electromagnetic field (EMF), an experiment with three conditions was designed. EMF field of 50 Hz and 1 mT accompanied by 45 dB SPL noise (EMF + noise), noise, and control. A group of 66 subjects (Ss) participated in the control and in one of the experimental conditions. The sequence of conditions (expositions) was balanced. Expositions were double-blind (except for the obvious control), lasted 1 h and were separated by a 1 h pause. During exposition Ss (three by three) performed tests on attention, perception, memory and filled out a psychological questionnaire. Statistical analysis (one-tailed probability) showed less attention (P < 0.05), perception (P < 0.05) and memory performance (P < 0.1) in Ss exposed to EMF + noise compared with control, whereas for noise versus control no difference was found. Comparing EMF + noise versus noise related to control, reduced perception, less memory performance and more discomfort was observed (P < 0.1). Dividing Ss according to their self-rated sensitivity to EMF, all differences disappeared in the low sensitivity group (N = 30) and were pronounced in sensitive Ss (N = 36). Results indicate an immediate reduction of cognitive performance in attention, perception and memory performance by a 50 Hz EMF of 1 mT. These effects seem to be modulated by the self-perception of sensitivity to EMF.

After-effects of human-computer interaction indicated by P300 of the event-related brain potential.

After-effects of human-computer interaction (HCI) were investigated by using the P300 component of the event-related brain potential (ERP). Forty-nine subjects (naive non-users, beginners, experienced users, programmers) completed three paper/pencil tasks (text editing, solving intelligence test items, filling out a questionnaire on sensation seeking) and three HCI tasks (text editing, executing a tutor program or programming, playing Tetris). The sequence of 7-min tasks was randomized between subjects and balanced between groups. After each experimental condition ERPs were recorded during an acoustic discrimination task at F3, F4, Cz, P3 and P4. Data indicate that: (1) mental after-effects of HCI can be detected by P300 of the ERP; (2) HCI showed in general a reduced amplitude; (3) P300 amplitude varied also with type of task, mainly at F4 where it was smaller after cognitive tasks (intelligence test/programming) and larger after emotion-based tasks (sensation seeking/Tetris); (4) cognitive tasks showed shorter latencies; (5) latencies were widely location-independent (within the range of 356-358 ms at F3, F4, P3 and P4) after executing the tutor program or programming; and (6) all observed after-effects were independent of the user's experience in operating computers and may therefore reflect short-term after-effects only and no structural changes of information processing caused by HCI.

Development of a multiple thin-film semimicro DC-probe for intracerebral recordings.

A thin-film multiple-electrode probe for measuring de potentials at eight sites with interdistances of 1 mm was constructed for the investigation of slow potential changes in deep regions of the human brain during surgery. The thin-film electrodes had to be placed on curved cylinder-shaped surgical instruments with dimensions of 2 mm diameter and 33 cm length used with the Freiburg stereotactic equipment. Several novel technological steps had to be introduced for the solution of the encountered problems: 1) Structuring of the metal layers on curved substrates was accomplished by using flexible masks. 2) Special feed-through technologies had to be invented in order to obtain reliable connections between the thin-film sensors and the copper wires inside the stereotactic instrument. 3) Thin-film Ag-AgCl electrodes had to be formed in order to obtain satisfying recordings of slow potential changes below 10 Hz. Slow potential changes were recorded from different depths in interdistances of only 1 mm with these new miniaturized thin film Ag-AgCl electrodes and bipolar recordings with an electrode interdistance of only 3 mm showed clearly the appearance of Bereitschaftspotentials.

Occurrence of infraslow potential oscillations in relation to task, ability to concentrate and intelligence.

The occurrence of infraslow potential oscillations (ISPOs) of the brain was investigated during a listening and a resting condition in 44 subjects (Ss) with high (HAC) and low ability to concentrate (LAC). The occurrence of ISPOs was found in 36% of the Ss. While in the HAC group the occurrence of ISPOs did not change from listening to resting, in the LAC group Ss with ISPOs were affected by experimental conditions, showing ISPOs during the listening condition. For Ss with ISPOs only during listening a lower score was found for ability to concentrate, suggesting ISPOs as a possible underlying mechanism. For Ss with stable ISPOs a higher I.Q. was found compared to Ss without ISPOs.

The electromyographic DC potential as a correlate of muscular activity.

The present experiment was undertaken to demonstrate the effect of muscular force as well as duration of muscular work on the electromyographic (EMG) DC potential. Thirty subjects had to lift different weights by flexing the right forearm within a defined and constant setting for 20 s. The experimental variables were weight (0.5, 1, 2, and 3 kg) and time. The EMG was recorded from the belly of the right biceps brachii muscle in a quasi-unipolar manner and split into an integrated ac channel (IEMG) and a dc channel (DC-EMG). The average IEMG showed a ramp-like shape. Analysis showed a positive relationship for weight (p less than 0.0001) and time (p less than 0.0001) with the IEMG. The average shape of the DC-EMG showed a negative initiation potential, a monotonically increasing negative potential during contraction (contraction potential), a positively peaking off potential and a slow return to baseline (after potential). Analyses of variance demonstrated a significant (p less than 0.001) relationship of weight to the magnitude of the initiation and the termination potential. Regression analyses displayed an inverse relationship of time to the termination (p less than 0.01) and to the resolution potential (p less than 0.001). The DC-EMG showed higher peaks (initiation and termination potential) for heavier weights. For the termination and after potential less positive deflections were found with increasing time (fatigue). A control condition (isometric contraction) indicated that the initiation, contraction, and termination potential of the DC-EMG may also be related to aspects of the movement. Results suggest that the DC-EMG is a more complex measure of muscular activity than the IEMG.

Changes in discrimination learning and brain activity (ERP's) due to combined exposure to NO and CO in rats.

Carbon monoxide (CO) and nitric oxide (NO) are air pollutants frequently appearing in combination. Information available on the mechanisms of NO intoxication suggests that in mixtures with CO additive effects should be assumed. In this study CO and NO-induced changes and their interaction were investigated at different levels of integration: carboxyhemoglobin (COHb) and methemoglobin (met-Hb) formation as well as centrally mediated effects were analyzed using evoked potential techniques and behavioral data from a complex discrimination learning experiment. Slight enhancements of COHb and met-Hb concentrations were seen for the combined CO + NO exposure conditions at low and high exposure levels when compared to isolated exposure conditions. The performance decrease was clearly higher under NO exposure than under CO exposure. Decrements were overadditive when simultaneous CO + NO exposure was used in higher concentration. Both gases affected early evoked potential components (P10, N30) in the same way: latencies were prolonged and amplitudes increased. Later potential components were differently influenced by CO and NO. Mainly the N150 amplitude was decreased in NO exposure and increased in CO conditions. N150 amplitude was also decreased after combined CO + NO exposure. At high levels this effect was overadditive indicating a dominant role of NO in the CO + NO combinations used in this experiment.

Contingent negative variation (CNV) influenced by preceding slow potential shifts (pSPSs).

The study was undertaken to elaborate the influence of slow potential shifts preceding S1 on the CNV. Eighteen subjects participated in a forewarned reaction time task. The EEG was recorded from F3, F4, Cz, P3 and P4 referred to linked mastoids. Selected averages of EOG-corrected trials with negative, positive and no shifts greater than 8 microV - within 2 sec before S1 at the respective location - were compared. Results showed greater CNV after positive shifts compared to negative shifts (P less than 0.05) and no significant interaction with location. Slow potential shifts before S1 did not affect reaction time. Evidence of a baseline effect is discussed as a ceiling effect as well as an expression of an active regulatory mechanism responsible for a desired activation at S2. As slow potentials may also interact with task conditions, it is suggested first to control the baseline in order to obtain reliable CNV measures, and secondly to use baseline effects as a tool to get insight into brain regulatory mechanisms.

Moderate carbon monoxide exposure during sleep: neuro- and psychophysiological effects in young and elderly people.

In order to assess age-related effects of carbon monoxide (CO) on brain wave-activity and sleep, auditory evoked potentials (AEP) were measured during sleep in 10 healthy young volunteers (20-25 years) and in a group (N = 10) of healthy elderly Ss (55-72 years) under control- and exposure-conditions in counterbalanced order. Sleep-stages were classified according to the Rechtschaffen and Kales scoring-system. In addition to electrophysiological measures memory-performance and subjective feeling (mood-scale) was assessed before and after sleep. Eight hours of CO-exposure (100 ppm) gave rise to about 8% COHb. In the group of young Ss there was a significant (p less than 0.05) increase of deep sleep (stages 3,4), and a decrease of stage REM-sleep during CO-exposure, whereas in elderly Ss similar but non-significant sleep-changes occurred. Some CO-related AEP-changes within different sleep-stages, namely shorter latencies in elderly Ss and higher amplitudes in young Ss, approached significance. Within the group of young Ss there was a tendency to more depressed mood after CO-exposure, as well as to CO-related impairment of memory consolidation; no such effects were observed in elderly Ss. The general hypothesis of more pronounced CO-susceptibility of elderly people was, therefore, not supported in this study.