Biomedical subjects

C Huron

Publications and source records attributed to C Huron.

5 recordsLinked to original sources

PubMed2006

Directed forgetting in PTSD: a comparative study versus normal controls.

The most characteristic feature of Post-Traumatic Stress Disorder (PTSD) is the reexperiencing syndrome. The patient's memory seems to be fixed on the traumatic event, which may be due to disturbance of the autobiographic memory. To retrieve memories, others have to be inhibited. These inhibition mechanisms have been studied using the Directed Forgetting Paradigm, which measures the capacity to forget recently processed information and to retain the relevant information. Our hypothesis is that during PTSD, the memory is saturated with traumatic memories, so that the patients are no longer able to use the inhibitory processes. Therefore, during a Directed Forgetting Task (DFT) in which words "to remember" and words "to forget" are given, PTSD patients cannot inhibit the words "to forget", and so recall more words than the controls. We studied 30 patients with PTSD and compared them with 30 healthy controls, using DFT. The results show that the patients remembered significantly fewer words overall, and fewer of the words "to remember" than the controls, both for immediate and final recall. Our results are in favor of a reduction in directed forgetting in patients suffering from PTSD, resulting in difficulty in inhibiting irrelevant information from the overall information. There seems to be a deficit in the inhibitory processes in the memory in PTSD.

Adult↗

PubMed2002

Lorazepam, sedation, and conscious recollection: a dose-response study with healthy volunteers.

The role of sedation in the benzodiazepine-induced impairment of conscious recollection is still subject to debate. The aim of this study was to investigate further the role of sedation using the Remember-Know procedure and a physiological measure of sedation based on pupillography in addition to standard measures of sedation and attention (digit-symbol substitution task, symbol cancellation task, self-rated sedation). Twelve subjects were tested after the intake of placebo, lorazepam 0.026 mg/kg and lorazepam 0.038 mg/kg, administered in a randomized order, with a minimum interval of 8 days between each administration. On a recognition memory task, they were asked to give 'Remember', 'Know' or 'Guess' responses to items that were recognized on the basis of conscious recollection, familiarity, or guessing, respectively. Lorazepam selectively impaired recognition based on 'Remember' responses. This impairment was greater in the lorazepam 0.038 mg/kg than in the lorazepam 0.026 mg/kg groups. Measures of sedation were not correlated with the proportion of 'Remember' responses. These results suggest that sedation alone cannot account for the impairment of conscious recollection induced by lorazepam.

Adult↗

PubMed2001

Lorazepam and diazepam impair true, but not false, recognition in healthy volunteers.

RATIONALE: The deleterious effects of benzodiazepine on memory are well documented. However, their effects on false memories are unknown. OBJECTIVE: The aim of this study was to investigate the effects of lorazepam and diazepam on false memories and related states of awareness in healthy volunteers. METHODS: The Deese/Roediger-McDermott procedure was used in 36 healthy volunteers randomly assigned to one of three parallel groups (placebo, diazepam 0.3 mg/kg, lorazepam 0.038 mg/kg). Subjects studied lists of words semantically related to a non-presented theme word (critical lure). On a recognition memory task with both previously presented words and non presented critical lures, they were asked to give Remember, Know or Guess responses to items that were recognized on the basis of conscious recollection, familiarity, or guessing, respectively. RESULTS: The proportions of studied words correctly recognized and the proportions of Remember responses associated with true recognition were lower in the benzodiazepine groups than in the placebo group. In contrast, benzodiazepines did not significantly influence the proportions of critical lures falsely recognized or the proportions of Remember responses associated with false recognition. CONCLUSION: These results indicate that diazepam and lorazepam impair conscious recollection associated with true, but not false, memories.

Adolescent↗

PubMed1995

Impairment of recognition memory with, but not without, conscious recollection in schizophrenia.

OBJECTIVE: To test the hypothesis that there is a link between the memory deficit associated with schizophrenia and an impairment of consciousness, an experiential approach was used to assess recognition memory and awareness in schizophrenic patients and normal subjects. METHOD: On a recognition memory task with low- and high-frequency words, the schizophrenic (N = 30) and normal (N = 30) subjects gave "remember" responses to recognized items that were accompanied by conscious recollection and "know" responses to items that were recognized on the basis of familiarity without any recollective experience. RESULTS: Schizophrenia selectively impaired recognition based on recollective experience, as measured by "remember" responses, but had no effects on "know" responses. In the comparison group, low-frequency words, relative to high-frequency words, enhanced conscious recollection but not familiarity. The schizophrenic patients did not display the same word-frequency effect. CONCLUSIONS: These results indicate that schizophrenia affects differentially two means of access to the personal past: it impairs recognition memory with, but not without, conscious recollection. They suggest that the impairment of conscious recollection observed in schizophrenic patients could be due to a failure of elaborative processing of information.

Adult↗

PubMedDate not supplied

[Clinical and therapeutic characteristics of social phobia in French psychiatry (Phoenix study)].

Only few clinical epidemiologic studies have been conducted on social phobia in France to date. It is however a frequent disorder, with often severe alteration of social adaptation and quality of life, and for which effective treatments exist. Thus, it seems really important to further explore how these patients are nowadays identified and treated in psychiatry. It was the objective of the Phoenix study. In this observational multi-center study, 952 psychiatric in- or out-patients, with a primary diagnosis of social phobia according to DSM IV criteria, were included. Numerous diagnostic and psychometric evaluations were carried out, in order to evaluate the comorbidity (Mini International Neuropsychiatric Interview, Hospital Anxiety and Depression Scale), the intensity of social anxiety (Liebowitz Social Anxiety Scale), and various aspects of the functional and emotional impact (Various Impact of Social Anxiety scale, Sheehan Disability Scale, SF-36, Positive and Negative Emotionality scale). The patients were in majority females (57.6%), with a mean age 37.5 years, and with a mean duration of social anxiety disorder 12.5 years. The mean scores of social anxiety on Liebowitz scale was 40.3 +/- 12.6 for the fear factor, and 38.3 +/- 13.6 for the avoidance factor. The generalized social anxiety subtype (anxiety in most social situations) was present in 67.8% of the patients. A major depressive disorder was found in 47.7% of the sample, and the prevalence of agoraphobia was even higher (49.2%). As known in clinical practice and in other studies, the prevalence rates of current alcohol dependence and substances abuse were also important in this population (respectively 10.6% and 12.7%). Mean scores of the Hospital Anxiety and Depression (HAD) sub-scales were 13.9 +/-3.8 for anxiety and 9.1 +/-4.5 for depression. About 15% of the patients had a history of suicide attempt, and a suicidal risk was present in nearly 40% of the sample. The psychosocial impact and the alteration of quality of life (with especially a poor physical health perception) were very significant, in the family, educational or occupational and social domains. Mean scores of the Sheehan Disability Scale were 6.1 +/- 2.6 for professional impairment, 5.0 +/- 2.7 for familial impairment, and 6.6 +/- 2.3 for social life impairment. In addition to the disability due to social phobia intensity, an important part of the burden was due to depressive symptoms. Approximately 60% of the patients had already a psychiatric treatment at the time of the survey (since 1,7 years in average), but only 17% had a cognitive behavioral therapy (CBT), and 48% had an antidepressant treatment. These proportions increased in a significant way after the consultation during which the investigation was carried out: an antidepressant was prescribed to 72% of the patients, and a CBT is proposed to 48%. On the whole, this study confirmed the severity and the morbidity of social phobia in a very large sample of French psychiatric patients. The depressive disorders, suicidal risk, and social impairment associated with this condition should incite to more detect and treat it. Seeing the long duration of the disease in our sample, and the lack of specific therapies in many cases, the identification and the treatment of social phobia must be improved, and the role of the psychiatrists in this process seems very important.

Adult↗