The Association between Mental,
Social and Physical Activity and
Cognitive Performance in Young
and Old Subjects
H. CHRISTENSEN, A. MACKINNON
Summary
The influence of mental, social and physical activity on fluid, crystallized and memory tasks was
examined in 60 young and 56 elderly subjects using multiple regression. Once the influence of education,
age, health and psychiatric morbidity was removed, physical activity was associated with higher fluid test
performance in old but not in young subjects. Moreover, mental activity was associated with higher
performance on fluid and crystallized tasks for subjects with low education but not for subjects with high
education.
Introduction
Continued mental activity and an engaged
lifestyle are commonly believed to influence
cognitive performance in old age [1, 2]. Support
for this has come from three main sources.
First, there have been studies showing relation-
ships between the extent of physical, social or
mental activity and higher performance on
experimental or psychometric tests in old peo-
ple [1, 3-9]. Second, there have been studies
showing that the cognitive performance of old
people can be improved through brief training
interventions [10-12]. Finally, there have been
studies comparing animals exposed early in life
to enriched environments and given complex
experience with animals provided with the
usual cage environment. Neurons in the brains
of animals exposed to enriched environments
showed more dendritic branches and synaptic
connections [13].
There are various limitations to these find-
ings. The studies examining the extent of
physical and mental activity and cognitive per-
formance have generally failed to examine the
type of activities engaged in by elderly subjects
[1, 9] and are characterized by great hetero-
geneity. There have been differences in whether
past or current activity was measured. Rarely
have investigators clearly defined the type of
activity (for instance, social, physical, mental)
being measured. Physical and mental activity
have been