THE DEVELOPMENT, VALIDATION, AND APPLICATIONS OF A COMPUTERIZED MEASUREMENT OF COGNITIVE IMPAIRMENT
Mari Nakagawa (Wakayama Medical College, Japan), Shinichiro Maeshima (University of Sydney, Australia), Masaru Nakagawa (Wakayama University, Japan), Yasuhiro Takeuchi, Masahiro Kitagawa, Yoko Hamaji (Kinki University, Japan)
The aim of this study is to investigate the construct validity of a computer-assisted battery of neuropsychological tests which was recently designed to screen the young and old people for cognitive impairment.
We examined 141 normal volunteers (males 109, females 32), who ranged from 18 to 72 years (40.7±15.3) with no history of substance abuse, psychotic disorder, or neurological disorder. Mini- mental state examination (Folstein 1974) was performed to exclude subjects with dementia. Subjects were examined using the Brain Alarm; a computer-assisted battery which consists of 12 neuropsychological tests.
Subjects need only 30 minutes to perform these tasks. All correlations between neuropsychological tests were positive and significant. There were negative correlations between the subject's age and the rate of correct answer and reaction time. These data can be input into database and graphs produced immediately.
We conclude that this computer-assisted battery of neuropsychological tests is useful in conducting utility assessment and evaluating its validity.
NOGO P3 AS A TEST OF INHIBITORY COGNITIVE FUNCTION
Mikio Osawa, Mutsumi Iijima, Makoto Iwata (Department of Neurology, Neurological Institute, Tokyo Women's Medical College, Tokyo, Japan)
Nogo P3 is known to be an event-related potential (ERP) which reflects inhibition-process in motor responses. The purpose of this study was to investigate inhibitory cognitive function in cerebrovasculardisorders (CVDs) using Nogo P3.
Subjects included 20 CVD patients in their 60-70's and 40 normal controls consisting of 20 in their 20's and 20 in their 60-70's. Go/Nogo P3 was elicited by a push/wait paradigm. On a CRT screen, two Japanese words, "押せ (push)" and "待て (wait)", appeared randomly with a probability of occurrence of 50%. The subjects were instructed to push a button whenever the "押せ" signal appeared. ERPs were recorded from Fz, Cz, Pz and Oz referred to linked earlobes. Several neuropsychological tests were performed.
In the normal controls, age effects were more remarkable on Nogo P3 than on Go P3, especially at Fz. In CVD patients, incidence of Nogo P3 abnormality was higher than that of Go P3 abnormality at Fz. The neuropsychological tests which correlated with Nogo P3 were not the same as those which correlated with Go P3.
These findings suggest that not only Go P3 but also Nogo P3 may be a useful tool for evaluating cognitive function in normal aging and CVD.