Biomedical subjects

P Pauli

Publications and source records attributed to P Pauli.

At least 19 recordsLinked to original sources

PubMed2001

Repeated exposure of flight phobics to flights in virtual reality.

The present study examined the effects of repeated exposure of flight phobics to flights in virtual reality (VR). Flight phobics were randomly assigned either to complete one VR test flight followed by four VR exposure flights (VR group; N=15) in one lengthy session or to complete one VR test flight followed by a lengthy relaxation training session (relaxation group; N=15). All participants completed a second VR test flight at the end of the session. Fear reports and physiological fear reactions (heart rate, skin conductance level) during VR exposures were registered, and fear of flying was assessed psychometrically from 3 weeks before to 3 months after exposure. Exposure to VR flights elicited subjective and physiological fear responses in flight phobics, and these responses attenuated within and across VR flights. Fear reduction associated with repeated VR exposure was greater than fear reduction caused by relaxation training. Fear of flying improved in both treatment groups, but several outcome measures indicated greater effects in the VR treated group than in the relaxation group. These findings indicate that exposure in virtual reality may offer a new and promising approach for the treatment of fear of flying.

Adaptation, Psychological↗

PubMed2000

Appetitive nature of drug cues confirmed with physiological measures in a model using pictures of smoking.

RATIONALE: In smokers, pictures of smoking that increase desire for a cigarette are described as pleasant rather than unpleasant. This suggests that these smoking cues may be appetitive and not withdrawal-like or aversive as held by traditional theories of drug cue formation. OBJECTIVE: Cues for smoking were examined using physiological measures of motivational valence. METHODS: Non-deprived smokers, deprived smokers and deprived smokers who expected to smoke (n=54) viewed a computer screen presenting experimental and control scenes (experiment 1). The acoustic startle reaction and activity of the corrugator and the zygomatic facial muscles were then measured after onset of smoking cues and standardized pleasant, neutral or unpleasant control scenes. Individuals who never smoked (n=18) were also used to test for cue effects on startle (experiment 2). RESULTS: No evidence was found that smoking cues were aversive in smokers. The smoking cues affected the startle responses and corrugator activity in a way similar to that of pleasant control material but significantly different from that of unpleasant material; the cue effects on zygomatic activity was most similar to that of neutral material. The general pattern of effects was not influenced by overnight smoke deprivation, expectancy to smoke or smoke repletion, but it was different in never smokers where the smoking scenes were found to be similar to unpleasant control scenes. CONCLUSIONS: Nonsubjective measures of motivational valence further suggest that drug cues are conditioned stimuli having appetitive effects. Startle response modulated by drug cues may be useful for probing motivational processes underlying dependence in the human.

Adult↗

PubMed1999

Frontal brain asymmetry as a biological substrate of emotions in patients with panic disorders.

BACKGROUND: Right frontal hemisphere activation, as indicated by reduced frontal alpha amplitude, seems to represent activation of an avoidance-withdrawal system and seems to be associated with negative emotions. Since patients with panic disorder are characterized by both negative emotions and avoidance-withdrawal behavior, we expected them to show greater right than left frontal hemisphere activation. METHODS: Spontaneous electroencephalography was recorded from the left and right frontal and parietal scalp regions of 23 patients with panic disorder patients without a diagnosis of depression and from 25 healthy control participants during the following conditions: rest, confrontation with neutral, panic-relevant, anxiety-relevant but panic-irrelevant, or anxiety-irrelevant but emotionally relevant stimuli, and performance of a motor task. Their emotional state during these conditions was assessed by the Self-Assessment Manikin. RESULTS: In patients with panic disorders, there were asymmetries in frontal hemisphere activation during resting phases and when confronted with anxiety-relevant stimuli. Their right frontal alpha power was significantly decreased compared with the left, while control participants did not show frontal brain asymmetry during these phases. There was no frontal brain asymmetry when patients observed an emotionally neutral picture or performed a motor task. Under these conditions, left and right frontal hemisphere alpha activation of patients with panic disorder and healthy participants were comparable. CONCLUSIONS: These data support the hypothesis that patients with panic disorder are characterized by greater activation of a right frontal avoidance-withdrawal system in negatively valenced situations. The findings are interpreted as biological evidence for a disturbed cortical processing in patients with panic disorder.

Adult↗

PubMed1999

Modulation of craving by cues having differential overlap with pharmacological effect: evidence for cue approach in smokers and social drinkers.

RATIONALE: An increased risk of drug intake produced by drug cues may reflect the fact that the cues are withdrawal-like or aversive, reflecting a conditioned adaptation to the drug's acute effects. More recent work suggests that they may also be appetitive, signalling the goal characteristics of drug taking. OBJECTIVE: These opposing mechanisms were tested in dependent smokers and in social drinkers by examining the motivational nature of drug cues that overlap differentially with the acute effects of the drug. METHODS: Pictures of different phases of smoking or alcohol drinking were presented to deprived and non-deprived smokers, to never smokers and non-deprived smokers or to social drinkers. Desire for cigarettes or alcohol and momentary pleasure and arousal were measured after viewing an experimental picture or a pleasant, neutral or unpleasant control scene. RESULTS: High desire for smoking was evoked by pictures of preparation for and actual smoking but not by scenes of the end of smoking, although the latter were best correlated with acute drug effect. This pattern was not affected by overnight smoke deprivation, it was seen in different smokers but not in never-smokers and it was replicated in social drinkers using pictures of alcohol consumption. Moreover, scenes evoking high desire to consume did not evoke states of momentary unpleasantness and they were seen as relaxing and not arousing. Control pictures had a minimal effect on desire to consume. CONCLUSIONS: In line with incentive models of drug cues, cues based on pictures of drug intake may be conditioned stimuli encoding cue approach and preparation for consumption.

Adult↗

PubMed1999

Pain sensitivity, cerebral laterality, and negative affect.

The right hemisphere is assumed to play a unique role for pain sensitivity and negative affect. Pressure pain thresholds were assessed daily in eight right-handed participants over a 6-week period in order to obtain reliable measures of pain sensitivity unaffected by situational influences. In an additional session, cerebral laterality was assessed with behavioral and an EEG measures. Psychometric measures were used to examine emotionality (depression, neuroticism). Pain thresholds were lower on the left compared with the right hand, and pain thresholds increased within the first 3-measurement weeks. Enhanced pain sensitivity as reflected in weekly pain threshold was associated with a increased right frontal compared with left frontal brain activity as indicated by EEG, with a left-visual field advantage in the perception of emotional faces, and with increased negative affect (depression, neuroticism). In addition, a significant positive correlation between a relatively increased right frontal brain activity and depression was found. Correlations between pain thresholds and 'non-emotional' laterality measures (central or parietal EEG asymmetry, dichotic consonant-vocal-recall test) were not significant. We conclude that a right frontal brain hyperactivity might be a biological marker for enhanced pain sensitivity and negative affect.

Adult↗

PubMed1999

Associations between cortical slow potentials and clinical rating scales in panic disorder: a 1.5-year follow-up study.

In a previous study of 15 panic patients, we demonstrated that body-related (somatic) word stimuli elicited an enhanced positive cortical slow wave compared to non-somatic word stimuli. Healthy controls did not show this difference. The present paper reports on psychometric ratings in relation to cortical slow waves in these patients. Patients were clinically reexamined after about 1.5 years. Although no significant correlations between neurophysiology and psychometric measures could be found at the onset of the study, there was a significant correlation between improvement over the follow-up period and neurophysiology. A decline in the Hamilton Anxiety Scale (HAMA), which proved to be the best estimate for improvement, was associated with the relative magnitude of the positive slow wave elicited by somatic stimuli. Our findings support cognitive models of panic disorder, which stress that abnormal processing of bodily symptoms is relevant for the development and/or maintenance of the disorder.

Adult↗

PubMed1999

Pressure pain thresholds asymmetry in left- and right-handers: Associations with behavioural measures of cerebral laterality.

Pressure pain threshold (PPT) asymmetry of the left and right third digits was assessed in 12 right-handed and 12 left-handed subjects using an automatised pressure algometer. A clear PPT asymmetry was found in right-handed participants, while left-handed participants revealed no PPT asymmetry. The PPT asymmetry of right-handed participants was due to a reduced PPT or increased pain sensitivity at the left hand. Behavioural laterality tests revealed a right ear or left hemisphere advantage for the processing of verbal material (consonant-vocal syllables) and a left visual field or right hemisphere advantage for the processing of emotional faces in all participants. PPT asymmetry was not associated with cerebral laterality assessed with these tests. We conclude that PPT asymmetry is associated with handedness, but neither PPT asymmetry nor handedness are closely associated with measures of cerebral laterality. Copyright 1999 European Federation of Chapters of the International Association for the Study of Pain.

Journal Article↗

PubMed1999

Cross-modality priming between odors and odor-congruent words.

It is well known that the Stroop effect is subject to influence by same-modality primes, but the possibility of cross-modal priming effects is unclear. Smell is a fundamental sensory system that is assumed to have potent cross-modality priming effects. We might expect the presence of a specific odor to interfere with performance on Stroop cards containing odor-congruent words. Forty participants, half of whom were primed with an unpleasant odor and half with a pleasant odor, were examined with modified Stroop cards containing pleasant and unpleasant descriptive words. A significant Stroop card by odor group interaction was found, indicating that the presence of an odor interferes with the performance on an odor-congruent Stroop card. These findings demonstrate cross-modality priming between olfaction and vision.

Adult↗

PubMed1998

Decreased duration and altered topography of electroencephalographic microstates in patients with panic disorder.

The topography and temporal sequence of scalp electrical fields were analyzed by adaptive segmentation of the continuous electroencephalogram (EEG) in 27 patients with panic disorder and 28 control subjects during rest phases and during the viewing of a neutral (mushroom) or an emotionally relevant (casualty) picture. The results indicate decreased duration of brain microstates in panic patients during all conditions. Comparison of the resting phases with the viewing conditions revealed a significant acceleration of EEG microstates in both the patients and the control subjects. Patients and control subjects differed in the topography of the fields during rest: control subjects showed a left-anterior/right-posterior orientation, while panic patients showed a predominantly right-anterior/left-posterior orientation. Neither group displayed any topographic changes when viewing the mushroom picture. However, when viewing the anxiety-specific casualty picture, panic patients shifted fields in a different way than did control subjects. Centroid topography does not permit clear localization of the cortical generators. It is concluded that panic patients show a generally increased cortical activation compared with healthy control subjects, and activate different neuronal arrays when viewing an anxiety-specific stimulus.

Adult↗

PubMed1998

Attentional control of pain perception: the role of hypochondriasis.

The role of hypochondriasis in the attentional control of pain perception was investigated in 28 in-patients (12 women and 16 men) at a hospital for psychosomatic disorders, who had been classified into high- and low-hypochondriacal categories by means of the Illness Attitude Scales (IAS). The two groups did not differ in their basic pain sensitivity based on their heat pain thresholds. Attentional control was manipulated by a mental arithmetic task, resulting in one experimental condition with distraction and one without distraction. In both of the conditions, subjects rated the intensity and the unpleasantness of nonpainful and painful heat stimuli on visual analog scales (VAS). Distraction significantly reduced the perceived intensity and unpleasantness of the stimuli at painful levels but not at nonpainful levels. Contrary to our expectation, the individual level of hypochondriasis did not influence this result. Although distraction seemed to have a strong influence on pain perception, hypochondriasis as a symptom or a trait did not contribute to this effect.

Adult↗

PubMed1998

Dependence on smoking and the acoustic startle response in healthy smokers.

Recent data from nicotine-dependent rats (14) and healthy smokers (18) would suggest that nicotine withdrawal modulates the acoustic startle reflex in a way similar to that of fear (5,20). We examined this directly using nonsmokers and healthy smokers who had no deprivation, brief deprivation (2-3 h), or prolonged deprivation (15 h). Groups differences in heart rate (HR), alveolar carbon monoxide (CO) levels, and desire and craving for cigarettes confirmed the presence of smoking withdrawal. However, there were no significant differences in the magnitude of the baseline startle response among the differently deprived smokers or between the smokers and the nonsmokers. Subsequent startle tests were carried out in the smokers during repeated sequences of preparing a cigarette for smoking (smoking cues) and then smoking. Whereas we did find statistically significant interactions of smoking deprivation with smoking cues and with renewed smoking, there was only weak confirmation of a priori predictions of motivational effects of smoking cues or of smoking. We conclude that smoking dependence may not affect the acoustic startle response itself; modulation seems to occur, but only after experience with the test situation. Discussed were possible mechanisms of this modulation in both humans and animals and further application of the startle response for providing interdisciplinary assessments of the motivational effects of nicotine withdrawal.

Acoustic Stimulation↗

PubMed1998

Effects of cortical polarization on mental arithmetic.

A biofeedback procedure was used to influence participants' cortical polarity before the presentation of single digit multiplication problems. To ensure that participants could solve the problems by direct memory retrieval of arithmetic facts, only nine different multiplication problems were used, and participants received extensive pre-experimental practice on these problems. After biofeedback training, cortical positivity before problem presentation was associated with faster response initiation times, a measure of mental calculation time, for correctly solved problems and with more multiplication errors than cortical negativity. Response execution time, a measure of motor speed, was not affected by cortical polarity. The shift in positivity from the amplitude of the slow cortical potential (SCP) before problem presentation to the amplitude of the positive slow wave (pSW) after problem presentation was less in positivity-required compared to negativity-required trials, mainly because of the manipulation of SCP starting points by biofeedback. We assume that cortical positivity is associated with direct retrieval of arithmetic facts, more precisely with the inhibition of incorrect answers. Cortical positivity before task presentation results in a reduced positive shift, a sign of less inhibition before answer production. The effect of less inhibition during positivity-required trials is to produce faster responses and more errors. The opposite might to be true of cortical negativity.

Acoustic Stimulation↗

PubMed1998

Conditioned responses elicited by experimentally produced cues for smoking.

Several theories of drug-craving postulate that a signal for drug elicits conditioned responses. However, depending on the theory, a drug cue is said to elicit drug similar, drug compensatory, positive motivational, and negative motivational effects. Since animal data alone cannot tease apart the relative importance of different cue-related processes in the addict, we developed and examined a model of drug cues in the human based on a two-sound, differential conditioning procedure using smoking as the reinforcer. After multiple pairings of a sound with smoking, there was a preference for the smoking cue on a conditioned preference test. The acute effects of smoking (increased heart rate, respiration rate, skin conductance level, skin conductance fluctuations, EEG beta power and trapezius EMG, decreased alpha power) were not affected by the smoking cue, although subjects drew more on their cigarette in the presence of the smoking cue than in the presence of a control cue. Moreover, the cue did not change baseline behaviour except for a possible increase in EEG beta power and an increase in trapezius EMG at about the time when smoking should have occurred. The findings confirm the value of experimental models of drug cues in the human for comparing different cue phenomena in the dependent individual. They indicate that an acquired signal for drug in the human may elicit incentive motivational effects and associated preparatory motor responses in addition to possible conditioned tolerance.

Acute-Phase Reaction↗

PubMed1997

Behavioral and neurophysiological evidence for altered processing of anxiety-related words in panic disorder.

Body-related and nonsomatic words were presented tachistoscopically to 15 panic patients and 15 healthy controls at each participant's threshold for correctly identifying 50% of neutral words. Behavioral (proportion of words correctly recognized) and electrocortical (event-related brain potentials [ERPs]) measures were registered. Panic patients recognized more body-related than nonsomatic words, and body-related as compared with nonsomatic words elicited, in these patients, significantly larger P300 amplitudes and enhanced positive slow waves (600 to 800 ms after stimulus presentation). In healthy controls, the number of correct recognized words and the ERPs were not differentially affected by the 2 word types. These results are grossly consistent with cognitive models of panic disorders, assuming that certain bodily sensation are perceived and processed in an affective manner that differentiates panic patients from healthy controls.

Adult↗

PubMed1996

Smoking produces a smaller increase in heart rate in the natural smoking environment than in the laboratory.

We tested whether the physiological effects of smoking a cigarette under standard conditions in a laboratory are similar to those seen in a room at home. On two separate test days ten healthy smokers were prepared with a small physiological recorder and were then requested to carry out a protocol requiring them to smoke one of their cigarettes in their usual way either (1) in the laboratory where they had never smoked previously, or (2) at home, alone in a quiet room where they regularly smoke. The experiment which counterbalanced the order of testing showed that in both test situations smoking produced a clear increase in heart rate (HR) and in skin conductance (SC); however, when testing was carried out in the home environment the increase in the HR was significantly less than in the laboratory. No significant differences were found for the baseline HR values in the two environments and there were no significant situational effects in the SC data. It was concluded that under conditions of normal smoking, data on the physiological effects of a cigarette in the laboratory may not be fully generalizable to those seen in the natural smoking situation. Several possible mechanisms of this situationally-specific effect of smoking were discussed.

Adult↗

PubMed1996

Covariation bias in panic-prone individuals.

Covariation estimates between fear-relevant (FR; emergency situations) or fear-irrelevant (FI; mushrooms and nudes) stimuli and an aversive outcome (electrical shock) were examined in 10 high-fear (panic-prone) and 10 low-fear respondents. When the relation between slide category and outcome was random (illusory correlation), only high-fear participants markedly overestimated the contingency between FR slides and shocks. However, when there was a high contingency of shocks following FR stimuli (83%) and a low contingency of shocks following FI stimuli (17%), the group difference vanished. Reversal of contingencies back to random induced a covariation bias for FR slides in high- and low-fear respondents. Results indicate that panic-prone respondents show a covariation bias for FR stimuli and that the experience of a high contingency between FR slides and aversive outcomes may foster such a covariation bias even in low-fear respondents.

Adult↗

PubMed1996

Neurophysiological correlates of mental arithmetic.

Thirteen subjects were extensively trained on nine multiplication problems varying in difficulty. Practice was associated with a reaction time speed up and an attenuation of the problem size effect. The introduction of previously unpracticed problems led to a performance rebound to pretraining levels, indicating practice specificity. The eventrelated potentials were characterized by a late positive complex, followed by a positive slow wave. Offset latency of positive slow wave and preresponse amplitude at parietal electrodes showed practice specificity effects that systematically changed with practice and problem size, indicating an association with the load imposed on working memory. The peak of the late positive complex probably reflects task learning or adaptation effects because it was attenuated by practice predominantly at frontal electrodes, showed no practice specificity, and was not affected by problem size.

Adult↗

PubMed1996

Paced smoking in the laboratory and in the natural smoking setting: differential situation-specific effects in light and heavy smokers.

The present study examined the situation-specific effects of smoking using a paced regimen of smoking to control the smoke intake. The subjects were first required to sham smoke and then actually smoke one of their cigarettes in two different test contexts: 1) in the laboratory where they had never previously smoked and 2) at home, alone in a quiet room where they regularly smoke. Light (< 10 cigarettes/day) and heavy smokers (> 15 cigarettes/day) were studied to test for a possible effect of the paced regimen itself. In the light smokers, smoking produced a larger increase in heart rate (HR) in the laboratory than in the natural smoking environment; however, in the heavy smokers the smoking had a larger effect in the normal smoking environment than in the laboratory. There were no significant group or test situation differences for baseline HR, skin conductance and finger temperature. The groups also did not differ in the intensity of drawing on the cigarette or inhaling, as indicated by a puff sensor and a respiratory belt, respectively. It was concluded that differences between the effects of a cigarette in a laboratory setting and in a natural smoking environment may reflect pharmacodynamic effects of smoking that are modified by the subjects' prior experience with smoking. The data are discussed with regard to conditioned tolerance to the effect of smoking.

Adult↗