***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Physical exercise has been shown to increase brain volume and improve cognition in r and omized trials of non-demented elderly . Although greater social engagement was found to reduce dementia risk in observational studies , r and omized trials of social interventions have not been reported . A representative sample of 120 elderly from Shanghai , China was r and omized to four groups ( Tai Chi , Walking , Social Interaction , No Intervention ) for 40 weeks . Two MRIs were obtained , one before the intervention period , the other after . A neuropsychological battery was administered at baseline , 20 weeks , and 40 weeks . Comparison of changes in brain volumes in intervention groups with the No Intervention group were assessed by t-tests . Time-intervention group interactions for neuropsychological measures were evaluated with repeated- measures mixed models . Compared to the No Intervention group , significant increases in brain volume were seen in the Tai Chi and Social Intervention groups ( p < 0.05 ) . Improvements also were observed in several neuropsychological measures in the Tai Chi group , including the Mattis Dementia Rating Scale score ( p = 0.004 ) , the Trailmaking Test A ( p = 0.002 ) and B ( p = 0.0002 ) , the Auditory Verbal Learning Test ( p = 0.009 ) , and verbal fluency for animals ( p = 0.01 ) . The Social Interaction group showed improvement on some , but fewer neuropsychological indices . No differences were observed between the Walking and No Intervention groups . The findings differ from previous clinical trials in showing increases in brain volume and improvements in cognition with a largely non-aerobic exercise ( Tai Chi ) . In addition , intellectual stimulation through social interaction was associated with increases in brain volume as well as with some cognitive improvements BACKGROUND Participation in leisure activities has been associated with a lower risk of dementia .  It is unclear whether increased participation in leisure activities lowers the risk of dementia or participation in leisure activities declines during the pre clinical phase of dementia . METHODS We examined the relation between leisure activities and the risk of dementia in a prospect i ve cohort of 469 subjects older than 75 years of age who resided in the community and did not have dementia at base line . We examined the frequency of participation in leisure activities at enrollment and derived  cognitive-activity and physical-activity scales in which the units of measure were activity-days per week . Cox proportional-hazards analysis was used to evaluate the risk of dementia according to the base-line level of participation in leisure activities , with adjustment for age , sex , educational level , presence or absence of chronic medical illnesses , and base-line cognitive status . RESULTS Over a median follow-up period of 5.1 years ,  dementia  developed in 124 subjects ( Alzheimer 's disease in 61 subjects , vascular dementia in 30 , mixed dementia in 25 , and other types of dementia in 8) . Among leisure activities , reading , playing board games , playing musical instruments , and dancing were associated with a reduced risk of dementia . A one-point increment in the cognitive-activity score was significantly associated with a reduced risk of dementia ( hazard ratio , 0.93 [ 95 percent confidence interval , 0.90 to 0.97 ] ) , but a one-point increment in the physical-activity score was not ( hazard ratio , 1.00 ) . The association with the cognitive-activity score persisted after the exclusion of the subjects with possible pre clinical dementia at base line . Results were similar for Alzheimer 's disease and vascular dementia . In linear mixed models , increased participation in cognitive activities at base line was associated with reduced rates of decline in memory . CONCLUSIONS Participation in leisure activities is associated with a reduced risk of dementia , even after adjustment for base-line cognitive status and after the exclusion of subjects with possible pre clinical dementia . Controlled trials are needed to assess the protective effect of cognitive leisure activities on the risk of dementia BACKGROUND Nearly two-thirds of elderly patients treated for depression fail to achieve symptomatic remission and functional recovery with first-line pharmacotherapy . In this study , we ask whether a mind-body exercise , Tai Chi Chih ( TCC ) , added to escitalopram will augment the treatment of geriatric depression design ed to achieve symptomatic remission and improvements in health functioning and cognitive performance . METHODS : One hundred twelve older adults with major depression age 60 years and older were recruited and treated with escitalopram for approximately 4 weeks . Seventy-three partial responders to escitalopram continued to receive escitalopram daily and were r and omly assigned to 10 weeks of adjunct use of either 1 ) TCC for 2 hours per week or 2 ) health education ( HE ) for 2 hours per week . All participants underwent evaluations of depression , anxiety , resilience , health-related quality of life , cognition , and inflammation at baseline and during 14-week follow-up . RESULTS Subjects in the escitalopram and TCC condition were more likely to show greater reduction of depressive symptoms and to achieve a depression remission as compared with those receiving escitalopram and HE . Subjects in the escitalopram and TCC condition also showed significantly greater improvements in 36-Item Short Form Health Survey physical functioning and cognitive tests and a decline in the inflammatory marker , C-reactive protein , compared with the control group . CONCLUSION : Complementary use of a mind-body exercise , such as TCC , may provide additional improvements of clinical outcomes in the pharmacologic treatment of geriatric depression OBJECTIVES We reported the interim findings of a r and omized controlled trial ( RCT ) to examine the effects of a mind body physical exercise ( Tai Chi ) on cognitive function in Chinese subjects at risk of cognitive decline . SUBJECTS 389 Chinese older persons with either a Clinical Dementia Rating ( CDR 0.5 ) or amnestic-MCI participated in an exercise program . The exercise intervention lasted for 1 year ; 171 subjects were trained with 24 forms simplified Tai Chi ( Intervention , I ) and 218 were trained with stretching and toning exercise ( Control , C ) . The exercise comprised of advised exercise sessions of at least three times per week . RESULTS At 5th months ( 2 months after completion of training ) , both I and C subjects showed an improvement in global cognitive function , delayed recall and subjective cognitive complaints ( paired t-tests , p < 0.05 ) . Improvements in visual spans and CDR sum of boxes scores were observed in I group ( paired t-tests , p < 0.001 ) . Three ( 2.2 % ) and 21(10.8 % ) subjects from the I and C groups progressed to dementia ( Pearson chi square = 8.71 , OR = 5.34 , 95 % CI 1.56 - 18.29 ) . Logistic regression analysis controlled for baseline group differences in education and cognitive function suggested I group was associated with stable CDR ( OR = 0.14 , 95%CI = 0.03 - 0.71 , p = 0.02 ) . CONCLUSIONS Our interim findings showed that Chinese style mind body ( Tai Chi ) exercise may offer specific benefits to cognition , potential clinical interests should be further explored with longer observation period BACKGROUND The present study examined whether aerobic fitness training of older humans can increase brain volume in regions associated with age-related decline in both brain structure and cognition . METHODS Fifty-nine healthy but sedentary community-dwelling volunteers , aged 60 - 79 years , participated in the 6-month r and omized clinical trial . Half of the older adults served in the aerobic training group , the other half of the older adults participated in the toning and stretching control group .  Twenty young adults served as controls for the magnetic resonance imaging ( MRI ) , and did not participate in the exercise intervention . High spatial resolution estimates of gray and white matter volume , derived from 3D spoiled gradient recalled acquisition MRI images , were collected before and after the 6-month fitness intervention . Estimates of maximal oxygen uptake ( VO2 ) were also obtained . RESULTS Significant increases in brain volume , in both gray and white matter regions , were found as a function of fitness training for the older adults who participated in the aerobic fitness training but not for the older adults who participated in the stretching and toning ( nonaerobic ) control group . As predicted , no significant changes in either gray or white matter volume were detected for our younger participants . CONCLUSIONS These results suggest that cardiovascular fitness is associated with the sparing of brain tissue in aging humans . Furthermore , these results suggest a strong biological basis for the role of aerobic fitness in maintaining and enhancing central nervous system health and cognitive functioning in older adults The hippocampus shrinks in late adulthood , leading to impaired memory and increased risk for dementia . Hippocampal and medial temporal lobe volumes are larger in higher-fit adults , and physical activity training increases hippocampal perfusion , but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown . Here we show , in a r and omized controlled trial with 120 older adults , that aerobic exercise training increases the size of the anterior hippocampus , leading to improvements in spatial memory .  Exercise training increased hippocampal volume by 2 % , effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF , a mediator of neurogenesis in the dentate gyrus . Hippocampal volume declined in the control group , but higher preintervention fitness partially attenuated the decline , suggesting that fitness protects against volume loss . Cau date nucleus and thalamus volumes were unaffected by the intervention . These theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood , which is accompanied by improved memory function Objective To evaluate the effects of Tai chi exercise on balance , sleep quality , and cognitive performance in community-dwelling elderly in Vinh city , Vietnam . Design A r and omized controlled trial . Participants One hundred two subjects were recruited . Intervention Subjects were divided r and omly into two groups . The Tai chi group was assigned 6 months ’ Tai chi training . The control group was instructed to maintain their routine daily activities . Outcome measures The Falls Efficacy Scale ( FES ) , Pittsburgh Sleep Quality Index ( PSQI ) , and Trail Making Test ( TMT ) were used as primary outcome measures . Results Participants in the Tai chi group reported significant improvement in TMT ( part A ) ( F [ 1 , 71 ] = 78.37 , P < 0.001 ) and in TMT ( part B ) , ( F [ 1 , 71 ] = 175.00 , P < 0.001 ) in comparison with the control group . Tai chi participants also reported better scores in FES ( F [ 1 , 71 ] = 96.90 , P < 0.001 ) and in PSQI ( F [ 1,71 ] = 43.69 , P = 0.001 ) than the control group . Conclusion Tai chi is beneficial to improve balance , sleep quality , and cognitive performance of the elderly Background . This cross-sectional study examined the effect of aging on performing finger-pointing tasks involving choices and whether experienced older Tai Chi practitioners perform better than healthy older controls in such tasks . Methods . Thirty students and 30 healthy older controls were compared with 31 Tai Chi practitioners .  All the subjects performed a rapid index finger-pointing task . The visual signal appeared r and omly under 3 conditions : ( 1 ) to touch a black ball as quickly and as accurately as possible , ( 2 ) not to touch a white ball , ( 3 ) to touch only the white ball when a black and a white ball appeared simultaneously . Reaction time ( RT ) of anterior deltoid electromyogram , movement time ( MT ) from electromyogram onset to touching of the target , end-point accuracy from the center of the target , and the number of wrong movements were recorded . Results . Young students displayed significantly faster RT and MT , achieving significantly greater end-point accuracy and fewer wrong movements than older controls . Older Tai Chi  practitioners had significantly faster MT than older controls . Conclusion . Finger-pointing tasks with a choice paradigm became slower and less accurate with age . Positive findings suggest that Tai Chi may slow down the aging effect on eye-h and coordination tasks involving choices that require more cognitive progressing BACKGROUND Our objective was to assess the effects of targeted exercise programs on health-related quality of life compared with usual care based on the ability to perform activities of daily living ( ADL ) and the Neuropsychiatric Inventory scores in geriatric institutionalized persons . METHODS A r and omized controlled trial of 2 exercise programs vs usual care was conducted in 160 institutionalized persons 65 years or older who were able to underst and basic motor comm and s and to move from one position to another . Interventions were performed over 6 months and were either an adapted tai chi program ( 4 times 30 min/wk ) or a cognition-action program ( 2 times 30 - 45 min/wk ) that focused primarily on an adapted guidance of patient-centered communication skills . The control group received usual care . The study was conducted at 4 setting s. The main outcomes were changes in health-related quality of life based on ADL and Neuropsychiatric Inventory scores after 12 months . RESULTS The control group experienced a decline in ADL over the 12-month period compared with the adapted tai chi and cognition-action groups , but the differences were not significant ( P = .24 and P = .15 , respectively ) . Also , the components of ADL , eg , ability to walk , continence , and nutrition , were maintained better in the intervention groups than in the control group . The total Neuropsychiatric Inventory score also worsened significantly in the control group , 
    Output:
    
Findings from nonr and omized studies add further evidence that Tai Chi may positively affect these and other domains of cognitive function .
CONCLUSION Tai Chi shows potential to enhance cognitive function in older adults , particularly in the realm of executive functioning and in individuals without significant impairment .