Biomedical subjects

P Philippot

Publications and source records attributed to P Philippot.

At least 19 recordsLinked to original sources

PubMed2007

Is the P300 deficit in alcoholism associated with early visual impairments (P100, N170)? An oddball paradigm.

OBJECTIVE: Studies exploring chronic alcoholism with event-related potentials (ERPs) have shown delayed latency and reduced amplitude of the P300, a long-lasting positive potential reflecting decisional processing. This P300 deficit in alcoholism is generally interpreted as a disturbance in central nervous system inhibition or in memory/attention. The present study aimed at identifying if this electrophysiological deficit is already present on earlier components, and advances a new hypothesis concerning the interpretation of the P300 alteration. METHODS: Patients suffering from alcoholism and matched healthy controls had to detect, in an oddball paradigm, emotional faces among a succession of neutral faces. Behavioral performance and ERP data (recorded from 32 electrodes) were analyzed. RESULTS: In line with previous studies, data showed that alcoholism led to a P300 deficit. Moreover, we observed for the first time that this deficit begins at earlier visual (P100) and face-processing (N170) stages, and we found high positive correlations between P100, N170 and P300 for amplitude and latency values, suggesting cumulative deficits on the cognitive continuum. CONCLUSIONS: We suggest that the P300 deficit observed in chronic alcoholism could be linked to earlier visuo-spatial deficits rather than being an impairment of the specific processes linked to the P300. SIGNIFICANCE: These results call for reconsidering the interpretation of P300 impairments at a fundamental and clinical level, and shows that earlier ERP components must be taken into account in future studies.

Alcoholism↗

PubMed2005

Emotional deficit in subjects with psychopathic tendencies as assessed by the Minnesota Multiphasic Personality Inventory-2: an event-related potentials study.

On the basis of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), 20 male students were separated in low (LP) versus high (HP) subjects with psychopathic tendencies. Pictures from the Ekman and Friesen series were used in an event-related potentials study to investigate the neurophysiological correlates of the emotional deficit described in psychopathy. Subjects were confronted with a visual oddball design, in which they had to detect, as quickly as possible, deviant happy, sad or fearful faces amongst a train of standard stimuli (neutral faces). Behavioral results suggest that LP subjects are more efficient in the detection of emotional deviant faces. This emotional deficit was neurophysiologically indexed, in HP subjects, by a decreased N300 component, which is supposed to be particularly sensitive to affective features of stimuli rather than to physical characteristics. Moreover, independently of the nature of the deviant faces, the P3a component shows an earlier latency in the HP group as compared to the LP group, whereas the reversed pattern was shown for the P3b component. Implications of these results were discussed.

Antisocial Personality Disorder↗

PubMed2005

The perception of fearful and happy facial expression is modulated by anxiety: an event-related potential study.

Anxiety is supposed to interfere with cognitive and emotional processing and high level of trait-anxiety has been associated with an attentional bias for fearful faces, even in sub-clinical anxiety. On the basis of the Spielberger State and Trait Anxiety Inventory (STAI), twenty students were grouped as low vs. high anxious. Pictures from the Ekman and Friesen series were used in an event-related potentials study to investigate the neurophysiological correlates of the emotional processing of fear and happiness in sub-clinical anxiety. Subjects were confronted with a visual oddball design, in which they had to detect, as quickly as possible, deviant happy or fearful faces amongst a train of standard stimuli (neutral faces). Anxiety does not modify early perceptual (N100, P100, N170, VPP) or attentional (N2b) component, but later components are affected. Indeed, high anxious subjects are faster to detect deviant faces as suggested by earlier reaction times and P3b component. However, they show a reduced ability to process the emotional content of faces, this deficit being indexed by a decreased N300 component. Indeed, N300 is supposed to be particularly sensitive to affective features of stimuli rather than to physical characteristics. We propose that the earlier P3b observed in high anxious subjects could be interpreted as a way to overcome the deficient emotional appraisal by a more salient conscious processing.

Adult↗

PubMed2005

Event-related potentials (ERPs) in ecstasy (MDMA) users during a visual oddball task.

Ecstasy is the common name for a drug mainly containing a substance identified as 3,4-methylenedioxymethamphetamine (MDMA). It has become popular with participants in "raves", because it enhances energy, endurance and sexual arousal, together with the widespread belief that MDMA is a safe drug [Byard, R.W., Gilbert, J., James, R., Lokan, R.J., 1998. Amphetamine derivative fatalities in South Australia. Is "ecstasy" the culprit? Am. J. Forensic Med. Pathol. 19, 261-265]. However, it is suggested that this drug causes a neurotoxicity to the serotonergic system that could lead to permanent physical and cognitive problems. In order to investigate this issue, and during an ERP recording with 32 channels, we used a visual oddball design, in which subjects (14 MDMA abusers and 14 paired normal controls) saw frequent stimuli (neutral faces) while they had to detect as quickly as possible rare stimuli with happy or fearful expression. At a behavioral level, MDMA users imply longer latencies than normal controls to detect rare stimuli. At the neurophysiological level, ERP data suggest as main result that the N200 component, which is involved in attention orienting associated to the detection of stimulus novelty (e.g. [Campanella, S., Gaspard, C., Debatisse, D., Bruyer, R., Crommelinck, M., Guerit, J.M., 2002. Discrimination of emotional facial expression in a visual oddball task: an ERP study. Biol. Psychol. 59, 171-186]), shows shorter latencies for fearful rare stimuli (as compared to happy ones), but only for normal controls. This absence of delay was interpreted as an attentional deficit due to MDMA consumption.

Adult↗

PubMed2004

Quantification of single fluid inclusions by combining synchrotron radiation-induced micro-X-ray fluorescence and transmission.

Fluid inclusions represent the only direct samples of ancient fluids in many crustal rocks; precise knowledge of their chemical composition provides crucial information to model paleofluid-rock interactions and hydrothermal transport processes. Owing to its nondestructive character, micrometer-scale spatial resolution, and high sensitivity, synchrotron radiation-induced micro-X-ray fluorescence has received great interest for the in situ multielement analysis of individual fluid inclusions. Major uncertainties associated with the quantitative analysis of single fluid inclusions arise from the inclusion depth and the volume of fluid sampled by the incident beam. While the depth can be extracted directly from the fluorescence spectrum, its volume remains a major source of uncertainty. The present study performed on natural and synthetic inclusions shows that the inclusion thickness can be accurately evaluated from transmission line scans. Experimental data matched numerical simulations based on an elliptical inclusion geometry. However, for one nonelliptical inclusion, the experimental data were confirmed using a computed absorption tomography reconstruction. Good agreement between the imaging and scanning techniques implies that the latter provides reliable fluid thickness values independent of the shape of the inclusion. Taking into consideration the incident angle, the incident beam energy, the inclusion fluid salinity, and the transmission measurement stability resulted in errors of 0.3-2 microm on calculated fluid inclusion thicknesses.

Journal Article↗

PubMed2004

A longitudinal study of the evolution of cognitive function and affective state in patients with amyotrophic lateral sclerosis.

OBJECTIVES: The study aimed to evaluate cognitive function and emotional reactivity in 18 patients with ALS, compared to 19 matched controls, and assess their evolution over a 12-month period. METHODS: 18 ALS patients and 19 matched controls were included, and assessed at inclusion, six months and twelve months later. Depression was evaluated with the Geriatric Depression Scale, and cognitive function with the Folstein Mini Mental State. A battery of psychometric tests (Wisconsin Card Sorting Test (WCST), the numerical Empan test, the Trail-making test, the Boston Naming Test, the 15-word Rey memory test, the Benton visual retention test and the Raven Progressive Matrix) was used to measure frontal processing and non-frontal function. Emotional reactivity was measured with the film-evoked emotions test. RESULTS: ALS patients were significantly more depressed than controls, as measured on the Geriatric Depression Scale, and depression increased over the study period. There was a very mild defect in cognitive function, and a performance deficit in the Trail-making test, a measure of frontal processing. These deficits, unlike neuromuscular function and depression, did not aggravate over the 12 months of the study. There was no observable change in non-frontal function. Emotional reactivity did not differ significantly between ALS patients and controls. CONCLUSIONS: This study provides further evidence for a mild defect in frontal cognitive processing in ALS patients that evolves only slowly, if at all, with time.

Adolescent↗

PubMed2003

Socioeconomic inequalities in depression: a meta-analysis.

Low socioeconomic status (SES) is generally associated with high psychiatric morbidity, more disability, and poorer access to health care. Among psychiatric disorders, depression exhibits a more controversial association with SES. The authors carried out a meta-analysis to evaluate the magnitude, shape, and modifiers of such an association. The search found 51 prevalence studies, five incidence studies, and four persistence studies meeting the criteria. A random effects model was applied to the odds ratio of the lowest SES group compared with the highest, and meta-regression was used to assess the dose-response relation and the influence of covariates. Results indicated that low-SES individuals had higher odds of being depressed (odds ratio = 1.81, p < 0.001), but the odds of a new episode (odds ratio = 1.24, p = 0.004) were lower than the odds of persisting depression (odds ratio = 2.06, p < 0.001). A dose-response relation was observed for education and income. Socioeconomic inequality in depression is heterogeneous and varies according to the way psychiatric disorder is measured, to the definition and measurement of SES, and to contextual features such as region and time. Nonetheless, the authors found compelling evidence for socioeconomic inequality in depression. Strategies for tackling inequality in depression are needed, especially in relation to the course of the disorder.

Confidence Intervals↗

PubMed2001

Impaired emotional facial expression recognition in alcoholism compared with obsessive-compulsive disorder and normal controls.

Emotional facial expression (EFE) decoding skills have been shown to be impaired in recovering alcoholics (RA). The aim of the present study is to replicate these results and to explore whether these abnormalities are specific to alcoholism using two control groups: non-patient controls (NC) and patients with obsessive-compulsive disorder (OC). Twenty-two alcoholic patients at the end of their detoxification process (RA) were compared to 22 OC and 22 NC matched for age, sex and education level. They were presented with 12 photographs of facial expressions portraying different emotions: happiness; anger; and fear. Each emotion was displayed with mild (30%) and moderate (70%) intensity levels. Each EFE was judged on 8 scales labeled happiness, sadness, fear, anger, disgust, surprise, shame and contempt. For each scale, subjects rated the estimated intensity level. RA were less accurate in EFE decoding than OC and NC, particularly for anger and happiness expressions. RA overestimated the emotional intensity for mild intensity level expressions compared with both OC and NC while no significant differences emerged for moderate intensity level expressions. Deficits in EFE decoding skills seem to be specific to RA when compared with OC. Comparison with other psychopathological groups is still needed. Possible consequences of EFE decoding deficits in RA include distorted interpersonal relationships.

Adult↗

PubMed2001

Deficits in recognition of emotional facial expression are still present in alcoholics after mid- to long-term abstinence.

OBJECTIVE: Emotional facial expression (EFE) decoding skills play a key role in interpersonal relationships. Decoding errors have been described in several pathological conditions, including alcoholism. The aim of this study was to investigate whether EFE decoding skill deficits persist after abstention from alcohol of at least 2 months. METHOD: Alcoholic patients abstinent for at least 2 months (n = 25) were compared with 25 recently detoxified patients and with 25 normal controls matched for age, gender and educational level. Subjects were presented with 40 photographs of facial expressions portraying happiness, anger, sadness, disgust and fear. Each emotion was displayed with neutral, mild, moderate and strong emotional intensity. Each facial expression was judged successively on eight scales labeled happiness, sadness, fear, anger, disgust, surprise, shame and contempt. For each scale, subjects rated the estimated intensity level. A complementary scale assessed the self-estimated difficulty in performing the task. RESULTS: Recently detoxified alcoholics were significantly less accurate than controls, making more EFE labeling errors and overestimating the intensity of the portrayed emotions. Deficits in decoding accuracy for anger and disgust were present in mid- to long-term abstinent patients; intensity overestimation was present in the former and absent in the latter. CONCLUSIONS: Deficits in decoding accuracy for anger and disgust, and to a lesser degree sadness, persist with an abstinence of 2 months and beyond. Right frontotemporal regions and cingulate could be implicated. These deficits may contribute to the social skills deficits frequently encountered in alcoholic patients.

Adult↗

PubMed2000

Effects of lorazepam on emotional reactivity, performance, and vigilance in subjects with high or low anxiety.

This study examined the hypothesis that low doses of lorazepam modify emotional response. In accord with the results of prior studies that suggest a differential effect of benzodiazepines according to the subjects' anxiety level, the authors tested the effect of lorazepam (0.5 mg twice daily) on 2 groups of 32 subjects: those with high anxiety (HA) and those with low anxiety (LA). These groups were formed a priori on the basis of their scores on the Cattell Anxiety Scale and the Hamilton Rating Scale for Anxiety. The two groups were evaluated for psychomotor function and vigilance (visual analog scales [VAS], digit-symbol substitution test [DSST], and choice reaction time [CRT]), as well as emotional reactivity. Six emotions (fear, anger, disgust, sadness, joy, and neutral state) were induced by the presentation of six movie excerpts, and subjects' emotional responses were measured using the Differential Emotions Scale. The results suggest that at the doses studied, lorazepam led to an increase in negative emotions and a decrease in positive emotions, compared with placebo. This shift of emotional reactivity toward more negative emotions was slightly stronger with the HA than with the LA subjects. However, no reliable differences in the levels of performance and vigilance (CRT, DSST, and VAS) were observed as a function of either treatment or subject group. These findings suggest a possible relationship between benzodiazepine effects and subjects' anxiety level.

Adult↗

PubMed1999

Alcoholics' deficits in the decoding of emotional facial expression.

The present study investigated emotional facial expression decoding in alcoholics. Twenty-five alcoholic patients at the end of the detoxification process were compared with 25 volunteers matched for age, sex, and education. They were presented with facial expressions of neutral, mild, moderate, or strong emotional intensity. Results indicate that alcoholics overestimate the intensity of emotional expressions and make more errors in their decoding with a special bias for anger and contempt. Moreover, this decoding deficit is not perceived by the alcoholic patients. A general model is proposed that links visuospatial deficits, abnormal processing of social information, interpersonal stress, and alcohol abuse.

Adult↗

PubMed1998

Flashbulb memories and the underlying mechanisms of their formation: toward an emotional-integrative model.

Flashbulb memories (FBMs) are detailed recollections of the context in which people first heard about important events. The present study investigates three models of the formation and maintenance of FBM. Two models have previously been proposed in the literature (Brown & Kulik, 1977; Conway et al., 1994). A third model of FBM that integrates theories of FBM and recent developments in the field of emotions is proposed. The present study compares these three competing models by investigating the FBMs that Belgian citizens developed upon learning of the unexpected death of their king Baudouin. Structural equation modeling revealed that, as compared to the two previously proposed models, the third model, which takes into account emotional processes, better explains FBM.

Adolescent↗

PubMed1997

Effects of lorazepam on film-induced differentiated emotions in healthy volunteers.

We studied the effects of lorazepam, a benzodiazepine, on differentiated emotions in healthy volunteers. In order to induce differentiated emotions, film excerpts were selected on the basis of the type of emotion they induced (fear, anger and for affective tone neutral film). For 6 days (D1 to D6), ten healthy volunteers received lorazepam (1 mg bid) or placebo in a randomized cross-over double-blind trial. During each treatment period, emotional induction occurred on D4, D5 and D6. One film excerpt (fear, anger or neutral) was presented each morning after relaxation. Evaluation was performed before and after each emotional induction and included questionnaires (Differential Emotions Scale and physical activation visual analog scales), and neurophysiological parameters (systolic and diastolic blood pressure, heart rate and norepinephrine levels). Globally, the film excerpts induced the predicted emotions. An analysis of variance was undertaken and revealed a significant effect of lorazepam versus placebo. On the Differential Emotions Scale and during fear induction, lorazepam induced a significantly higher increase in fear, anxiety and disgust emotions than placebo, whereas no effect was observed after anger induction. Lorazepam also induced a significantly higher increase in diastolic and systolic blood pressure with no change in heart rate, and physical activation items ("tears" and "faster breathing") without no significant change in norepinephrine. In conclusion, our results are consistent with an overall increase in emotional reactivity with lorazepam (1 mg bid) as compared to placebo. The pertinence of film-induced differentiated emotions has to be confirmed for clinical pharmacological use.

Adult↗

PubMed1996

[Psychological consequences of the 1994 massacres in Rwanda].

A research program on the prevalence of reactions of posttraumatic stress is described in this article. The program is specifically centered on the psychological consequences of the April 1994 events in Rwanda and the genocide that followed. It includes three psycho-epidemiologic studies: 1) a study of non-accompanied Rwandan children; 2) a study of a small group of belgian cooperants; and 3) a study of an important sample of belgian civilians and militaries having been through the rwandan events. The psychological impact of the rwandan events is described in terms of prevalence of symptoms of posttraumatic stress.

Adolescent↗

PubMed1994

[Clinical aspects of depression in the psychotic patient].

In order to study clinical aspects of depression in psychotic patients, it is necessary to first differentiate between the following states, as a function of the currently accepted international classification of mental disorders: 1) depressions correlated with psychotic symptomatology (delirium, hallucinations); 2) psychotic disorders with depressive symptomatology; 3) schizo-affective disorders. The greatest interest is currently in the assessment of the second category, in particular study of depression in schizophrenics. This is due to a number of factors, including the relatively great frequency of the disorder, its differential significance as a function of the time in the natural history of the disease, as well as prognostic and therapeutic implications. Proper clinical evaluation is thus important. Until the last few years, this evaluation was based primarily upon use of depression scales or factorial scores, either from general psychopathology scales or specific schizophrenia scales. A number of empirical studies have recently cast some doubt upon validity of these scales for evaluation of depression in psychotic patients, and more specific instruments such as the Calgary Depression Scale (CDS) and the Psychotic Depression Scale (PDS) have been developed. The first validation studies with these scales open up an interesting perspective, in particular for the evaluation of the effects of neuroleptics.

Depressive Disorder↗

PubMed1990

Social schemata of peripheral changes in emotion.

Psychophysiological research failed to establish consistent physiological patterns differentiating emotion. Recent data showed that people verbally report experiencing peripheral changes that differ among emotions. The present studies tested the hypothesis that these reports originate in social schemata. Study 1 showed that Ss' reports of peripheral changes experienced during actual emotion do not differ from those defined in social schemata. Studies 2 and 3 showed that these schemata are similar across cultures. Overall, these data suggest that (a) people can directly access schemata about peripheral changes in emotion, (b) people are likely to do so when they believe to be reporting actual memories of such changes, and (c) the specific patterns revealed by past research may reflect prototypical knowledge of emotion. Finally, the data highlight the various peripheral patterns as they exist in schematic knowledge of emotion.

Adult↗

PubMed1990

Age and social competence in preschoolers' decoding of facial expression.

This study examines the relationship between social competence and decoding of emotions in children aged between three and five years. Children were shown videotaped scenarios depicting emotional situations and were asked to choose which of three facial expressions, representing happiness, sadness and fear, would be most appropriate for the character in the situation. Children's level of social competence was assessed by a standardized questionnaire completed by their parents. Results showed that subjects with relatively higher social skills were better decoders than subjects with relatively lower social skills, and that decoding performance improved with age. The results are discussed in terms of the role of non-verbal behavioural skills in general social competence.

Child Development↗

PubMedDate not supplied

Alcoholism and emotional reactivity: more heterogeneous film-induced emotional response in newly detoxified alcoholics compared to controls--a preliminary study.

Alcoholics are thought to be characterized by irregular emotional responses, having trouble reaching an optimal level of emotional arousal. They therefore may use alcohol to restore emotional homeostasis. This study investigated whether recently detoxified alcoholics show different emotional responses as compared to controls. Film excerpts were used to induce emotions in 14 newly detoxified alcoholics (9 men, 5 women) and matched controls in a standardized laboratory setting. Subjective emotional (questionnaires) and physiological measures were employed. Depression and cognitive deterioration were controlled. Based on subjective ratings, alcoholics displayed greater variability of emotion; they displayed also fewer or no physiological arousal changes. Subjective emotional responses were exceedingly high or low. These differences were not accounted for by depression or cognitive deterioration. We hypothesize that alcohol could be used to restore an optimal level of emotional arousal. This homeostatic function of alcohol is yet to be clearly assessed.

Adult↗