Differential effects of age and executive functions on the resolution of the contingent negative variation: a reexamination of the frontal aging theory.
The "frontal aging theory" assumes the deterioration of executive/inhibitory functions as causal factors for the cognitive decline in human aging. The contingent negative variation resolution (CNV-R) is an electroencephalographic potential elicited after the second (informative) stimulus in warned Go/NoGo tasks requiring a response to one type of stimulus (Go) but not to the other (NoGo). Whereas the CNV-R across conditions is a measure of executive functions, the augmented potential in the NoGo condition is a specific measure of inhibitory processes. The aim was to examine the presumed linkage between executive processes and the CNV-R with special regard to inhibition in the NoGo condition, and to test whether any effects of age on this potential can be explained by a failure of (inhibitory) executive functions. Nineteen young and 15 elderly non-demented healthy volunteers were examined in a Go/NoGo CNV-R paradigm and on a test of executive functions focussed on set shifting (Trail Making test). Results showed: (1) Better executive functions are associated with higher amplitudes of the CNV-R across conditions. (2) The CNV-R is higher for elderly than younger subjects; this increment is much stronger in the NoGo condition. In conclusion, the CNV-R across conditions reflects executive processes such as the shift of motor set. A higher CNV-R for elderly subjects (particularly of the inhibition-related NoGo CNV-R) indicates that this group is not impaired in the available amount of executive control but may exert such control for task demands where young subjects do not require it.
Dirnberger
Georg
G
Department of Neurology, Medical University of Vienna, Vienna, Austria. georg.dirnberger@weizmann.ac.il
Lang
Wilfried
W
Lindinger
Gerald
G
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000523:psychology*; D003265:Contingent Negative Variation / Q000502:physiology*; D056344:Executive Function / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged