Consciousness in schizophrenia: a metacognitive approach to semantic memory.

Recent studies have shown that schizophrenia may be a disease affecting the states of consciousness. The present study is aimed at investigating metamemory, i.e., the knowledge about one's own memory capabilities, in patients with schizophrenia. The accuracy of the Confidence level (CL) in the correctness of the answers provided during a recall phase, and the predictability of the Feeling of Knowing (FOK) when recall fails were measured using a task consisting of general information questions and assessing semantic memory. Nineteen outpatients were paired with 19 control subjects with respect to age, sex, and education. Results showed that patients with schizophrenia exhibited an impaired semantic memory. CL ratings as well as CL and FOK accuracy were not significantly different in the schizophrenic and the control groups. However, FOK ratings were significantly reduced for the patient group, and discordant FOK judgments were also observed more frequently. Such results suggest that FOK judgments are impaired in patients with schizophrenia, which confirms that schizophrenia is an illness characterized by an impaired conscious awareness of one's own knowledge.

Functional mechanisms underlying impaired recognition memory and conscious awareness in patients with schizophrenia.

BACKGROUND: Schizophrenia impairs episodic memory in its critical feature, autonoetic awareness, i.e., the type of awareness that is characterized by mentally reliving events from one's personal past. It spares noetic awareness, another form of awareness based on feelings of familiarity. We investigated the hypothesis that the impairment of autonoetic awareness is related to defective information that binds together separate aspects of events. METHODS: An experiential approach to recognition memory was used. Twenty-five patients with schizophrenia and 25 normal subjects performed or watched actions consisting of pairing objects. Then, they had to recognize pairs of objects and who paired them (source recognition). Subjects were also asked to provide a "remember" (autonoetic awareness) or a "know" (noetic awareness) response according to their subjective state at the time they recognized each pair of objects and each source. RESULTS: Patients exhibited an impaired recognition memory. When actions were observed, recognition of pairs of objects, but not of source, was no better than chance. There was a reduction in frequency of autonoetic awareness, its consistency throughout recognition of objects and source, and its relationship to source discrimination accuracy. Recognition was based largely on noetic awareness. CONCLUSIONS: Patients with schizophrenia are unable to link the separate aspects of events into a cohesive, memorable, and distinctive whole. The corollary of this defective relational binding is a quantitative and qualitative impairment of autonoetic awareness.

Confidence level and feeling of knowing for episodic and semantic memory: an investigation of lorazepam effects on metamemory.

The effects of lorazepam (0.026 or 0.038 mg/kg), a benzodiazepine, and of a placebo on metamemory, i.e. knowledge about one's own memory capabilities, were investigated in 36 healthy volunteers. Accuracy of confidence levels (CL) in the correctness of recalled answers and accuracy of feeling of knowing (FOK) the answers when recall fails were measured using a sentence memory task assessing episodic memory and a task consisting of general information questions and assessing semantic memory. Lorazepam impaired episodic memory. Unexpectedly, it also impaired performance in both the recall and recognition phases of the task assessing semantic memory, suggesting that it decreased the ability to distinguish between correct and incorrect information. In episodic memory, lorazepam 0.038 mg/kg-treated subjects exhibited an impaired CL accuracy, compared to placebo-treated subjects, and their FOK accuracy was at chance. In semantic memory, their overall CL and FOK accuracy was apparently spared. However, these subjects selectively overestimated their CL judgements for incorrect answers; moreover, secondary analyses showed that FOK accuracy for a subset of low-accuracy items was virtually nil. These results suggest that lorazepam impairs metamemory for both episodic and semantic memory.

Iron miners--a ten year follow-up.

1167 workers of Lorraine (France) iron mines, a random sample of 5600 workers aged 35 to 55 years, at work in 1975 constituted the initial cohort that was examined twice at 5-year intervals after the first examination. A questionnaire on respiratory symptoms and smoking habits (MRC questionnaire) plus questions on the work history of each participant was completed, vital capacity (VC), forced expiratory volume in one second (FEV1.0), residual volume (RV) and fractional uptake of CO (FuCO) were measured at the first examination and repeated five and ten years later. At the end of the ten year follow-up, 522 subjects were re-examined, 186 were lost to follow-up, 328 answered a mail questionnaire, and 111 had died. The total number of deaths was not different from that of the general population, but for lung cancer the standardized mortality ratio (SMR) was significantly increased (SMR = 3.7). For the miners re-examined, frequency of bronchitis and decrease of functional tests were more related to age and smoking habits than to occupation.

Pertussis in French adolescents: risk factors and respiratory sequels.

An analysis of the risk factors for pertussis and the possible respiratory sequels was carried out in a sample of 499 children and adolescents aged 10-16 years from the general population in north-eastern France. 44 subjects (8.8%) had pertussis during childhood; and the sex ratio was 1 in these cases. Pertussis was significantly associated with a maternal history of respiratory disease, residence in a rural area and coal heating. In a multiple logistic regression model, a maternal history of respiratory disease was the only significant factor (p = 0.01), the number of siblings being of borderline significance (p = 0.06). No increase in respiratory symptoms or asthma prevalence was found in our subjects who had pertussis during childhood.

Determinants of alveolar nitrogen slope and closing volumes in healthy adolescents.

The alveolar nitrogen slope (PIII), closing volume (CV), and closing capacity (CC) were measured by the single-breath nitrogen washout method (SBN2) in a group of 187 healthy children and adolescents (92 boys, 95 girls), 10 to 16 yr old, from the general population of Lorraine, France. The test was performed using a computerized system, which also made the calculations. About one out of five healthy subjects in this population were unable to satisfactorily perform the test; the failure rate was the same for the two sexes (20% in boys, 21.5% in girls) and significantly higher in younger children (26.6 and 14.5% for children under and over the age of 13, respectively; p = 0.03). The distribution of results was skewed for PIII and practically normal for log PIII, CV, VC, and CV/VC or CC/TLC ratios. PIII was highly significantly, inversely related to anthropometric variables; the highest coefficient was that for the age-weight interaction term in boys (= r -0.57 for PIII, -0.62 for log PIII) and for weight in girls (r = -0.57 for both PIII and log PIII). Because the anthropometric variables were strongly interrelated (r between 0.45 and 0.79), multiple regressions did not materially improve the prediction of PIII. In simple regression, weight alone explained 36% of the variability of log PIII in boys and 32% in girls. The mean PIII was significantly higher in girls as compared to boys (1.14 +/- 0.38 versus 0.98 +/- 0.17% N2/L, p = 0.02); CV and CC in milliliters were related to body build as other lung volumes; the CV/VC in girls and CC/TLC ratio in both sexes were not related to anthropometric variables. In boys, CV/VC decreased significantly with height (p = 0.035 for CV/VC versus height3).

[Effect of a sanguinarine mouthwash on children with and without upper extremity motor handicap]. / Effet d'un bain de bouche a la sanguinarine chez des enfants avic et sans handicap moteur des membres superieurs.

A survey was done at the Center of Child Readaptation at Flavigny (Meurthe-et-Moselle) to determine the effect of a mouth rinse containing 0.03% sanguinaria extract, on the plaque accumulation and gingivitis of 30 children 8 to 17 years old. 13 children had a motricity handicap of their superior members and 17 did not. All subjects rinsed their mouths twice with 15 ml of solution each time. The mouth rinses were performed in the morning and in the evening during three weeks. The children were photographed and examined using the P1I and GI indices on days 0, 7, 14, 21 and 35. No statistical significant difference was observed at any moment between children with or without handicapped upper limbs. After 3 weeks of treatment the Plaque Index had decreased 47.3% and Gingival Index 55.6%.