Impaired Picture Arrangement subscores (WAIS-III) associated with decreased place orientation and frontal/occipital blood flow in Alzheimer's disease: Implications for social judgment dysfunction. The Osaki-Tajiri Project

Alzheimer's deterioration in intellectual and neurobiological staging supports the retrogenesis model: a double dissociation between verbal/non-verbal judgments and the left/right parieto-temporal glucose metabolism. A retrospective data analysis from the Tajiri Project

BACKGROUND

Alzheimer disease (AD) patients demonstrate various clinical features reminiscent of children (the retrogenesis model). The Binet test is available for assessing mental development and deterioration. However, neuroimaging correlations remain to be clarified. Although AD patients also manifest social judgment disability, there are few cognitive tests, contrary to so many memory tests. Among the database, we noticed that the Binet test includes the subscale of social judgement using illogical sentences and pictures. The aim of this study is to clarify the neuroimaging correlations for the Binet test, especially for the illogical questions.

METHODS

Forty participants were selected from the database of the Tajiri Project. The Tanaka-Binet test was used to evaluate the mental age and the basic age. The latter is the age level at which the patient can completely accomplish all questions at the immediately lower age level and is used for calculating the mental age. Using the subtests of illogical sentences/pictures, logical judgment abilities were assessed. Using magnetic resonance imaging, we performed four-grade visual evaluation for cortical atrophy. The cerebral metabolic rate for glucose (CMRglc) was measured using an autoradiographic method of ¹⁸ F-fluoreodeoxyglucose - positron emission tomography (FDG-PET).

RESULTS

There was a significant Spearman's correlation between the clinical stage and the basic age. Degree of frontal, temporal and hippocampal atrophy were correlated with the basic age. The entire grey matter and frontal and temporal CMRglc were associated with the basic age. The illogical sentences scores were correlated with the bilateral temporal, hippocampal and the left parieto-temporal CMRglc, whereas the illogical picture scores were correlated with the right parieto-temporal CMRglc.

CONCLUSIONS

We found that frontal and temporal atrophy as well as hypometabolism were associated with the basic age. Regarding the illogical judgment, the current PET data analysis disclosed that there may be a double dissociation between verbal/non-verbal judgments and the left/right parieto-temporal areas.

Intellectual factors in false memories of patients with schizophrenia

The current study explored the intellectual factors in false memories of 139 patients with schizophrenia, using a recognition task and an IQ test. The full-scale IQ score of the participants ranged from 57 to 144 (M = 100, SD = 14). The full IQ score had a negative correlation with false recognition in patients with schizophrenia, and positive correlations with high-confidence true recognition and discrimination rates. Further analyses with the subtests' scores revealed that false recognition was negatively correlated with scores of performance IQ (and one of its subtests: picture arrangement), whereas true recognition was positively correlated with scores of verbal IQ (and two of its subtests: information and digit span). High-IQ patients had less false recognition (overall or high-confidence false recognition), more high-confidence true recognition, and higher discrimination abilities than those with low IQ. These findings contribute to a better understanding of the cognitive mechanism in false memory of patients with schizophrenia, and are of practical relevance to the evaluation of memory reliability in patients with different intellectual levels.