Detection of malingering on Raven's Standard Progressive Matrices: a cross-validation.

A formula for detecting faked Raven's Standard Progressive Matrices profiles was cross-validated on 46 experimental malingerers and 381 people from the standardization sample. The formula yielded a cross-validated 26% false-negative rate and a 5% false-positive rate.

Detection of malingering on the Luria-Nebraska Neuropsychological Battery: an initial and cross-validation.

A formula for detecting faked LNNB profiles was validated on 68 experimental malingerers and adequately motivated patients matched on education, age, and severity of profile. The formula was then cross-validated on 51 malingerers and 202 patients. The formula yielded a cross-validated 23% false negative rate and a 9% false positive rate, for an overall hit rate of 88%. If normal and profoundly impaired profiles are eliminated from the cross-validation analysis, the false negative rate is 17% and the false positive rate 7%, for an overall hit rate of 91%.

Recall memory deficit in schizophrenia. A possible manifestation of prefrontal dysfunction.

Patients with schizophrenia have memory deficits when compared to other neuropsychiatric and normal samples, but the mechanism by which the deficits arise is obscure. In the present study, 13 older, less educated normal subjects, and 31 inpatients with schizophrenia were administered the Selective Reminding test. In addition, the schizophrenic patients received the Mini Mental State Exam and the Brief Psychiatric Rating Scale. While normal subjects performed at a higher level on various measures of recall, a significant effect of repeated trials was present for each group for each measure, indicating that both groups learned. Normal subjects also outperformed the patients on a test of recognition memory. However, the patients exhibited a significantly greater disparity between recognition and recall than did the normal subjects, suggesting they were better able to acquire new information than to retrieve it ('forgetting to remember'). Moreover, anergia, a factor measure on the Brief Psychiatric Rating Scale, correlated significantly with recall, but not recognition memory, in the patient group. The data are suggestive of prefrontal-type cognitive and behavioral deficits in schizophrenia.

Further evidence for dementia of the prefrontal type in schizophrenia? A controlled study of teaching the Wisconsin Card Sorting Test.

Recent physiological and cognitive studies of schizophrenia have implicated dysfunction of prefrontal cortex as a possible explanation for some of the disabling intellectual and social aspects of the disorder. To investigate the potential reversibility of cognitive deficits and the role of state variables, eg, attention and motivation, three groups of patients with schizophrenia were administered the Wisconsin Card Sorting Test on six consecutive occasions. Two of the groups received incremental information on how to do the test, including explicit card-by-card instruction. The third group served as a control. Regardless of the degree of instruction, patients who could not do the test could not learn it. The deficit did not appear generalized, as patients were able to learn word lists on the Selective Reminding memory test and were not globally demented on the Mini-Mental State Examination. These data suggest that prefrontal-type cognitive deficits in schizophrenia may be more profound than is generally appreciated.