Visual reproduction subtest of the Wechsler Memory Scale-Revised: analysis of construct validity.

This study assessed the construct validity of Visual Reproduction (VR) Cards A (Flags) and B (Boxes) from the original Wechsler Memory Scale (WMS) compared to Flags and Boxes from the revised edition of the WMS (WMS-R). Independent raters scored Flags and Boxes using both the original and revised scoring criteria and correlations were obtained with age, education, IQ, and four separate criterion memory measures. Results show that for Flags, there is a tendency for the revised scoring criteria to produce improved construct validity. For Boxes, however, there was a trend in the opposite direction, with the revised scoring criteria demonstrating worse construct validity. Factor analysis suggests that Flags are a more distinct measure of visual memory, whereas Boxes are more complex and significantly associated with conceptual reasoning abilities. Using the revised scoring criteria, Boxes were found to be more strongly related to IQ than Flags. This difference was not found using the original scoring criteria.

Power spectral analysis and cortical coupling of EEG for young and old normal adults.

Power spectral analysis and cortical coupling were computed on eyes closed EEG recorded from 80 normal volunteers: 20 females and 20 males aged 25-35 years and 20 females and 20 males aged 55-70 years. Recordings were from Fz, Cz, C3, Pz and Oz areas. The results indicate that with increased age there was a greater uniformity of EEG activity across the brain. Magnitude of EEG power was significantly less variable across recording sites for the old than for the young. In addition, cortical coupling values were reliably higher for the older subjects indicating a greater congruity among EEG patterns. The EEG power and cortical coupling measures were significantly correlated and thus may indicate an underlying mechanism common to both. The results support a theory of decreased central inhibitory function in old age and may reflect an age-related breakdown of functional autonomy of cortical areas. Gender had no significant effect on either EEG power or cortical coupling.