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Thierry d'Amato

Publications and source records attributed to Thierry d'Amato.

14 recordsLinked to original sources
PubMed2006

Impaired verbal source monitoring in schizophrenia: an intermediate trait vulnerability marker?

Patients with schizophrenia, particularly those with positive symptoms show impaired verbal source monitoring. Specific cognitive deficits have been observed during both active and remission phases of the illness as well as in groups of unaffected first degree relatives of patients with schizophrenia. This type of schizophrenia vulnerability marker may precede the onset of frank psychotic symptoms and contribute to their developments. The aim of this study was first to determine if unaffected siblings were impaired in discriminate internal vs. external generated events when compared to their remitted schizophrenics relatives and healthy subjects. Performances of healthy subjects were then compared with results from previous studies with acute hallucinating patients, acute non-hallucinating patients and patients with resistant auditory verbal hallucinations. Compared with healthy subjects, unaffected siblings are impaired (effect size, ES=0.7), remitted or acute non-hallucinating patients are more impaired than siblings (ES=1.4); patients with verbal auditory hallucinations (acute or resistant) are even more impaired than non-hallucinating patients (ES=2.1). Our results suggest that a source monitoring deficit could be considered as an intermediate vulnerability marker of schizophrenia.

Adult↗
PubMed2006

Abnormalities of auditory event-related potentials in students with high scores on the Schizotypal Personality Questionnaire.

Some auditory event-related potential (ERP) abnormalities characterize both patients with schizophrenia and subjects with schizotypal personality disorder. It was therefore hypothesized that subjects from the community with schizotypal traits might also present ERP abnormalities. In this study, we compared auditory ERP latencies and amplitudes in 13 subjects with high (H-SPQ) and 12 subjects with low (L-SPQ) scores on the Schizotypal Personality Questionnaire (SPQ), selected from 198 Tunisian students. Auditory ERPs were recorded at Fz, Cz, and Pz, with a standard oddball paradigm. Smaller P300 amplitudes and delayed P300 latencies were found in H-SPQ compared with L-SPQ participants. Confirming previous reports, our results suggest that reduced P300 amplitudes and delayed P300 latencies may be considered as vulnerability markers of the schizophrenia spectrum in nonclinical subjects from the community.

Adult↗
PubMed2006

Exaggerated leftward bias in the mental number line of patients with schizophrenia.

Several visuo-motor tasks can be used to demonstrate biases towards left hemispace in schizophrenic patients, suggesting a minor right hemineglect. Recent studies in neglect patients used a new number bisection task to highlight a lateralized defect in their visuo-spatial representation of numbers. To test a possible lateralized representational deficit in schizophrenia, we used the number bisection task in 11 schizophrenic patients compared to 11 healthy controls. Participants were required to orally indicate the central number of an interval orally presented. Whereas healthy subjects showed no significant bias, schizophrenic patients presented a significant leftward bias. Therefore, these results suggest an impairment in higher order representations of the number space in patients with schizophrenia, an impairment that is qualitatively similar to the deficit described in neglect patients.

Adult↗
PubMed2006

[Wiscosin card sorting task in patients with schizophrenia and thier siblings].

OBJECTIVE: This study's first objective was to confirm that patients with schizophrenia and their nonmentally ill siblings share the same impaired executive function when compared to healthy control subjects. The second objective was to study the relation between Wisconsin card sorting task (WCST) performance and the persistence and severity of clinical symptoms, as well as different clinical dimensions. METHOD: Ninety subjects were involved in this study, divided in 3 groups of 30 each: one group of patients with schizophrenia, one group of their siblings, and a control group. Symptom severity was assessed with the Positive and Negative Syndrome Scale (PANSS), and social functioning was measured by the Global functioning scale (GFS). The WCST was administered to all 3 groups. RESULTS: Patients with schizophrenia and their siblings had a significantly lower WCST performance than control subjects. Statistical analysis showed that the patient group had a significantly greater impaired WCST performance than the 2 other groups. Siblings also had a significantly lower performance than the control subjects. Furthermore, no significant relation was found between WCST performance and other variables, including age, gender, education, illness duration, treatment, and different PANSS and GFS scores. CONCLUSION: Patients with schizophrenia and their nonmentally ill siblings share the same impaired executive function. These findings suggest that WCST performance can be considered a schizophrenia vulnerability marker in siblings of patients with schizophrenia.

Activities of Daily Living↗
PubMed2005

Left temporo-limbic and orbital dysfunction in schizophrenia during odor familiarity and hedonicity judgments.

Impairments of olfactory processing in patients with schizophrenia (SZ) have been reported in various olfactory tasks such as detection, discrimination, recognition memory, identification, and naming. The purpose of our study was to determine whether impairments in odor familiarity and hedonicity judgments observed in SZ patients during a previous behavioral study are associated with modifications of the activation patterns in olfactory areas. Twelve SZ patients, and 12 healthy comparison (HC) subjects, were tested using the H2(15)O-PET technique and 48 different odorants delivered during 8 scans. In addition to an odorless baseline condition, they had either to detect odor, or to judge odor familiarity or hedonicity, giving their responses by pressing a button. Regional cerebral blood flows during olfactory conditions were compared with those for baseline condition. Between-group analyses were then performed, and completed by regions of interest analyses. Both groups had equivalent ability for the detection of suprathreshold odorants, but patients found odors less familiar, and pleasant odors less pleasant than HC subjects. These behavioral results were related to functional abnormalities in temporo-limbic and orbital olfactory regions lateralized in the left hemisphere: the posterior part of the piriform cortex and orbital regions for familiarity judgments, the insular gyrus for hedonicity judgments, and the left inferior frontal gyrus and anterior piriform cortex/putamen region for the three olfactory tasks. They mainly resulted from a lack of activation during task conditions in the SZ patients. These data could explain olfactory disturbances and other clinical features of schizophrenia such as anhedonia.

Adult↗
PubMed2005

Effects of emotion and identity on facial affect processing in schizophrenia.

We used facial affect labeling and matching tasks to study effects of (1) emotion and (2) identity on facial affect processing in patients with remitted schizophrenia (n=30) compared with healthy controls (n=30). The patients (1) had a specific deficit for labeling facial affects of sadness and anger but not happiness, disgust and fear; they (2) performed as well as controls in matching facial affects in one face but were impaired in matching facial affects in two different faces. The patients' impairment in facial affect processing may be emotion-specific. The effects of identity on facial affect processing are discussed in the light of several hypotheses (a deficit of context processing, a global-local processing impairment or a selective attention deficit), and may be related to frontal, prefrontal or amygdala dysfunctions.

Adult↗
PubMed2005

Slow transcranial magnetic stimulation can rapidly reduce resistant auditory hallucinations in schizophrenia.

BACKGROUND: Almost a quarter of patients with schizophrenia present with resistant auditory verbal hallucinations (AVH), a phenomenon that may relate to activation of brain areas underlying speech perception. Repetitive transcranial magnetic stimulation (rTMS) at 1 Hz reduces cortical activation, and recent results have shown that 1-Hz left temporoparietal rTMS may reduce AVH. The aim of this study was to replicate recent data and investigate whether low-frequency rTMS with a high total stimulation number delivered in a shorter 5-day block produces similar benefit. METHODS: Ten right-handed schizophrenia patients with resistant AVH received 5 days of active rTMS and 5 days of sham rTMS (2,000 stimulations per day at 90% of motor threshold) over the left temporoparietal cortex in a double-blind crossover design. The two weeks of stimulation were separated by a 1-week washout period. RESULTS: AVH were robustly improved (56%) by 5 days active rTMS, whereas no variation was observed after sham. Seven patients were responders to active treatment, five of whom maintained improvement for at least 2 months. CONCLUSIONS: These data confirm the efficiency of low-frequency rTMS applied to the left temporoparietal cortex, compared with sham stimulation, in reducing resistant AVH. This improvement can be obtained in only 5 days without serious initial adverse events.

Adult↗
PubMed2004

Neural correlates of action attribution in schizophrenia.

Patients with first-rank symptoms (FRS) of schizophrenia do not experience all of their actions and personal states as their own. FRS may be associated with an impaired ability to correctly attribute an action to its origin. In the present study, we examined regional cerebral blood flow (rCBF) with positron emission tomography during an action-attribution task in a group of patients with FRS. We used a device previously used with healthy subjects that allows the experimenter to modulate the subject's degree of movement control (and thus action attribution) of a virtual hand presented on a screen. In healthy subjects, the activity of the right angular gyrus and the insula cortex appeared to be modulated by the subject's degree of movement control of the virtual hand. In the present study, the schizophrenic patients did not show this pattern. We found an aberrant relationship between the subject's degree of control of the movements and rCBF in the right angular gyrus and no modulation in the insular cortex. The implications of these results for understanding pathological conditions such as schizophrenia are discussed.

Adult↗
PubMed2003

Left temporoparietal transcranial magnetic stimulation in treatment-resistant schizophrenia with verbal hallucinations.

Left temporoparietal repetitive transcranial magnetic stimulation (rTMS) reportedly diminishes verbal hallucinations. A 21-year-old schizophrenic man, who had killed his mother in the belief that she was a demon, failed to respond to combined treatment with a variety of antipsychotic agents. His persistent hallucinations consisted of two voices (God and the Devil). As an adjunct to continued antipsychotic medication, the patient received a course of rTMS: 10 sessions of 1-Hz stimulations near Wernicke's area. After rTMS, the patient's hallucinations grew less intrusive and he no longer required isolation. Although the improvement could be a delayed effect of medication, further trials of rTMS in cases of this type appear justified.

Adult↗
PubMed2002

Gaze direction determination in schizophrenia.

It has been proposed that an impairment in gaze determination is responsible for the paranoid symptoms reported in schizophrenia. To address this, we examined the gaze discrimination system in schizophrenia. Thirty-two patients suffering from schizophrenia (20 patients with persecutory delusions and 12 patients without such delusions) were compared to 32 control subjects on two specific tasks. In the first task, the subjects had to determine whether 130 portraits were looking right or left. In the second task the subjects were asked to determine whether or not 130 portraits were looking at them. The absolute threshold of difference used to investigate the influence of instruction on gaze discrimination did not show any difference between patients with schizophrenia, whatever paranoid or not, and control subjects. Paranoid patients, as well as controls, displayed a significantly finer discrimination threshold in the right vs. left judgment than in the self vs. non-self judgment. Subjects with schizophrenia were able to discriminate gaze direction in the two tasks, but they took significantly more time in the task requiring to determine the presence or the absence of a mutual gaze contact than in the other one, whereas controls took the same duration to elicit both tasks. These data are consistent with those reporting that perceptual abilities are spared in schizophrenia while delusions are related to an impairment of a higher level of analysis.

Adult↗
PubMed2002

Validity of the depressive dimension extracted from principal component analysis of the PANSS in drug-free patients with schizophrenia.

Depressive symptoms frequently occur during the course of schizophrenia. This study explored the relationships between the schizophrenia symptomatology and three measures of depression. Eighty-one drug-free inpatients with acute schizophrenia were assessed with the positive and negative syndrome scale (PANSS), the Calgary depression scale for schizophrenia (CDSS), and the Hamilton rating scale for depression (HAM-D). The depressive subscale of PANSS (PANSS-D) was also considered as a third scale for measuring depression. A principal component analysis (PCA) of PANSS items identified five clinical dimensions of schizophrenia called 'negative', 'positive', 'anxio-depressive', 'excitement', and 'disorganisation and others'. Our anxio-depressive dimension (PANSS-ad) was strictly identical with the PANSS-D. Scores on CDSS and HAM-D were highly inter-correlated and highly correlated with the PANSS-ad. Furthermore, while scores on CDSS were correlated only with this dimension, scores at HAM-D were also positively correlated with the negative dimension and negatively correlated with the excitement dimension. In conclusion, our results suggest that PANSS evaluation itself may be sufficient to give a correct approximation of the depression in patients with schizophrenia. However, depression scales are of course needed to assess specifically depressive symptoms in patients with schizophrenia; hence, the CDSS could be a more specific instrument than HAM-D.

Acute Disease↗
PubMed2002

Exploring imagined movements in patients with schizophrenia.

Patients with schizophrenia demonstrate impairments indicative of an inability to accurately monitor internally generated images. Motor imagery measures the ability to generate internal images of intended but not executed motor movements. Ten patients with schizophrenia completed actual and imagined versions of a pointing task with a well defined speed-accuracy trade-off function. For controls, movement time increases as target size decreases for both actual and imagined movements. Despite showing the expected speed-accuracy trade-off for actual movements, the imagined movements of schizophrenics showed no reliable relationship to target size. This was true for each patient and appeared to be independent of symptom profile. These results suggest that patients with schizophrenia are unable to generate accurate internal images of their own motor movements.

Adult↗
PubMed2002

Cannabis use correlates with schizotypal personality traits in healthy students.

The literature suggests that cannabis use and schizotypal traits both constitute risk factors for the later development of schizophrenia. However, their interrelationships remain to be evaluated. The present study examined the association between cannabis use and schizotypal traits in 232 healthy students who ranged in age from 18 to 25 years. All the students had completed the Schizotypal Personality Questionnaire and four of the Chapman Psychosis Proneness Scales: the Magical Ideation Scale; the Perceptual Aberration Scale; the Revised Physical Anhedonia Scale; and the Revised Social Anhedonia Scale. Subjects were divided into three groups according to cannabis use typology: those who had never used cannabis, those who were past or occasional users, and those who were regular users. Higher scores on the Schizotypal Personality Questionnaire and the Magical Ideation Scale characterized the regular and past or occasional users compared with those who had never used cannabis. The co-occurrence of cannabis use and schizotypal traits appeared to be independent of anxiety and depression dimensions. These data suggest that cannabis use and schizotypal traits have to be jointly considered in further longitudinal studies of schizophrenia risk factors.

Adolescent↗