Short- and long-term implicit memory in aging and Alzheimer's disease

Implicit memory processes were investigated via picture naming in healthy young and older adults and in persons with mild Alzheimer's disease (AD). Repetition priming in picture-naming was intact in all groups over the course of a short retention interval (seconds), and only the AD group revealed a deficit over a longer interval (72 hours). In addition, the AD group showed impaired procedural memory, with no benefit of practice on picture-naming. Impaired long-term priming was related to severity of AD. Both theoretical and methodological implications are discussed.     

Incremental validity of the MMPI-2 PSY-5 scales in assessing self-reported personality disorder criteria

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Personality Psychopathology-Five (PSY-5) scales were developed to measure abnormal personality symptomatology. The present study examines the incremental validity of the PSY-5 scales beyond the clinical and content scales in assessing criteria associated with personality disorders. The current sample includes 240 male and 407 female clients from private practice settings who completed the MMPI-2 and the Multiaxial Diagnostic Inventory (MDI), a self-report checklist of Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) symptoms. Six of the MDI personality disorder scales, conceptually related to the PSY-5 scales, are used as criteria. Hierarchical regression analyses determine the incremental validity of each PSY-5 scale. In most analyses, PSY-5 scales add a significant increment of variance to the clinical and content scales. Implications of the results are discussed.     

Spatial updating relies on an egocentric representation of space: Effects of the number of objects

Models of spatial updating attempt to explain how representations of spatial relationships between the actor and objects in the environment change as the actor moves. In allocentric models, object locations are encoded in an external reference frame, and only the actor’s position and orientation in that reference frame need to be updated. Thus, spatial updating should be independent of the number of objects in the environment (set size). In egocentric updating models, object locations are encoded relative to the actor, so the location of each object relative to the actor must be updated as the actor moves. Thus, spatial updating efficiency should depend on set size. We examined which model better accounts for human spatial updating by having people reconstruct the locations of varying numbers of virtual objects either from the original study position or from a changed viewing position. In consistency with the egocentric updating model, object localization following a viewpoint change was affected by the number of objects in the environment.