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he impact of cognitive training and mental stimulation on cognitivend everyday functioning of healthy older adults: A systematic reviewnd meta-analysis
ichelle E. Kellya,∗, David Loughreya, Brian A. Lawlora, Ian H. Robertsona,athal Walshb, Sabina Brennana
The NEIL Programme, Institute of Neuroscience, Trinity College Dublin, Dublin 2, IrelandDepartment of Statistics, Trinity College Dublin, Dublin 2, Ireland
r t i c l e i n f o
rticle history:eceived 2 July 2013eceived in revised form 20 February 2014ccepted 25 February 2014vailable online 4 March 2014
eywords:ystematic revieweta-analysis
ognitive trainingental stimulation
a b s t r a c t
This systematic review and meta-analysis investigates the impact of cognitive training and general mentalstimulation on the cognitive and everyday functioning of older adults without known cognitive impair-ment. We examine transfer and maintenance of intervention effects, and the impact of training in groupversus individual settings. Thirty-one randomised controlled trials were included, with 1806 partici-pants in cognitive training groups and 386 in general mental stimulation groups. Meta-analysis resultsrevealed that compared to active controls, cognitive training improved performance on measures ofexecutive function (working memory, p = 0.04; processing speed, p < 0.0001) and composite measures ofcognitive function (p = 0.001). Compared to no intervention, cognitive training improved performance onmeasures of memory (face-name recall, p = 0.02; immediate recall, p = 0.02; paired associates, p = 0.001)and subjective cognitive function (p = 0.01). The impact of cognitive training on everyday functioning
ognitive functioningealthy older adults
is largely under investigated. More research is required to determine if general mental stimulation canbenefit cognitive and everyday functioning. Transfer and maintenance of intervention effects are mostcommonly reported when training is adaptive, with at least ten intervention sessions and a long-termfollow-up. Memory and subjective cognitive performance might be improved by training in group versusindividual settings.
Cognitive impairment that does not reach the threshold forementia diagnosis is not only associated with increased risk forrogression to dementia (Fratiglioni and Qiu, 2011; Petersen, 2004;inblad et al., 2004), but also increased health care costs (Albert
t al., 2002), increased neuropsychiatric symptoms (Lyketsos et al.,002), and increased functional disability (McGuire et al., 2006).ge-related decline in episodic memory, attention, and execu-
ive function is reported in both longitudinal (Meijer et al., 2009;ucker-Drob et al., 2009) and cross-sectional studies (Coubard et al.,011; Kray and Lindenberger, 2000). Decline in executive function
s also associated with impaired functioning in activities of dailyiving (Royall et al., 2000). The high prevalence of cognitive impair-
ent with advancing age (Plassman et al., 2008), together withapid demographic ageing, underlines the importance of develop-ng interventions to improve or maintain cognitive function in laterife.
Interventions comprising modifiable lifestyle factors, such asognitive, social, and physical activity, that may reduce the riskf cognitive decline have been gaining increasing interest (Coleyt al., 2008; Mangialasche et al., 2012). Of these strategies, cogni-ive interventions are specifically targeted at improving cognitiveerformance. In the research literature, cognitive interventions forlder adults without known cognitive impairment are deliveredither in group or individual settings, and consist of either (i) cog-itive training or (ii) general mental stimulation.
Cognitive training comprises specifically designed training pro-rammes that provide guided practice on a standard set of cognitiveasks, aimed at improving performance in one or more cognitiveomains (Martin et al., 2011). While a number of randomisedontrolled trials (RCTs) have shown that cognitive training canmprove cognitive performance in healthy older adults (Reijnderst al., 2012), improvements often do not exceed those seen inctive control conditions (Martin et al., 2011). Furthermore cog-itive training can lack ecological validity, with little evidence ofeneralizability to everyday cognitive tasks (Papp et al., 2009). Inight of these limitations, cognitive interventions comprising gen-ral mental stimulation may present a promising alternative.
General mental stimulation refers to interventions that promotencreased engagement in mentally stimulating activities. Exam-les include activities that might be undertaken by individuals asart of daily living; for example, reading, playing music or play-
ng chess. Epidemiological evidence suggests that higher levels ofngagement in mental stimulation are associated with lower ratesf cognitive decline (Scarmeas et al., 2001; Wilson et al., 2002a,002b, 2007), with less decline specifically noted in working mem-
ry and processing speed (Wilson et al., 2002b). However most ofhe evidence to date is correlational and only a limited numberf RCTs have examined the efficacy of mental stimulation on cog-ition. A further difficulty is that either mental stimulation RCT’s
are not included in reviews of cognitive interventions, or reviewsconsider cognitive training and mental stimulation as one; makingit difficult to determine the relevant effects of either intervention(Papp et al., 2009; Reijnders et al., 2012; Tardif and Simard, 2011).
There are several relevant criteria emerging from the litera-ture that support the efficacy of cognitive interventions. Effectiveinterventions can be considered in terms of improvements in per-formance on targeted cognitive tasks, maintenance of improvedperformance over time, transfer of training effects to different taskswithin the same cognitive domain (near transfer) or other domains(far transfer), and generalisation of effects to everyday functioning(Klingberg, 2010; Martin et al., 2011). Maintenance; or the tempo-ral durability of training effects after the intervention has ceased,has been reported in several RCTs of cognitive training (Reboket al., 2007; Reijnders et al., 2012; Verhaeghen, 2000), howeverevidence for transfer is somewhat limited (Owen et al., 2010; Pappet al., 2009). If transfer is reported, it is often only to untrainedtasks within the same cognitive domain (Kueider et al., 2012; vanMuijden et al., 2012; West et al., 2000). Generalisation of train-ing effects to everyday functioning is of particular importance ifcognitive interventions are to impact older adults’ cognition andindependence in a meaningful way. Evidence for generalisation islimited however, as cognitive intervention RCT’s and reviews rarelyinclude everyday functioning as an outcome measure (Martin et al.,2011).
The aim of this paper is to update the extant literature, and toaddress shortcomings noted in prior reviews. We examine existingevidence from RCT’s of cognitive interventions to determine theimpact of both cognitive training and general mental stimulationon the cognitive performance of older adults without known cog-nitive impairment. We also investigate the potential of cognitiveinterventions to promote transfer and maintenance of interventioneffects, discuss generalisation of cognitive interventions to every-day functioning, and explore whether training in a group has anyadded benefit over training in individual settings.
2. Methods
2.1. Search strategy
We searched the databases PubMed, Medline, the CochraneLibrary, and ClinicalTrials.gov to identify randomised controlled tri-als written in English and published between 2002 and 2012. Searchterms included “cognitive intervention”, “cognitive training”, “cog-nitive stimulation”, “cognitive rehabilitation”, “brain training”,“memory training”, “mental stimulation”, and “healthy elderly”,
“older adults”, “ageing”, “cognitive ageing”, “cognitively healthy”OR “cognition” (full search strategy, Appendix A). We supple-mented database searches with reference lists in review papers,authors’ own files, and Google Scholar. We screened titles and
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bstracts to exclude articles that did not meet inclusion criteria.ull texts of remaining studies were then screened for eligibility bywo independent reviewers, with disagreements resolved throughiscussions with our expert authors (study selection flowchart,ppendix B).
.2. Selection criteria
We followed PRISMA (Preferred Reporting Items for System-tic Reviews and Meta-Analyses) guidelines. Trials were includedhat investigated the effects of either cognitive training or general
ental stimulation interventions on cognitive function in commu-ity dwelling older adults (>50) with no known existing cognitive
mpairment. Studies required at least ten participants per condi-ion. We excluded studies if participants had been diagnosed withny cognitive impairment, cardiovascular disease, or other signif-cant medical, psychiatric, or neurological problems (see excludedtudies table, Appendix C). The risk of bias in individual studiesas assessed by two independent reviewers (Appendix D) using
uidelines outlined in Section 8 of the Cochrane Handbook.Our primary outcomes of interest were cognitive and every-
ay functioning. In line with a recent Cochrane review (see Martint al., 2011) cognitive outcome measures were grouped into sepa-ate ability subgroups within each cognitive domain. This allowedor the pooling of data that were deemed as homogeneous as possi-le. Within the memory domain, outcomes were grouped accordingo the ability subgroups of recognition, immediate recall, delayedecall, face-name recall, and paired associates. Within the execu-ive functioning domain, outcomes were grouped according to thebility subgroups of working memory, verbal fluency, reasoning,ttention and processing speed. Composite measures of cognitiveunction were also included. A secondary outcome of interest wasubjective measures of cognitive performance.
.3. Statistical analysis
Data extraction was conducted by two independent review-rs and cross-checked by a member of the expert panel. We usedeview Manager Version 5.1 software for Windows to conducthe analysis. We calculated treatment effects based on pooledata from individual trials that were deemed homogenous. Allrials reported outcomes as continuous data. The summary statis-ics required for each outcome were the number of participantsn intervention and control groups at baseline and post-test, the
ean change from baseline and the standard deviation (SD) of theean change. If change-from-baseline scores were not provided,
hey were calculated using baseline and post-test mean and SD’s.hange SD’s were calculated assuming zero correlation betweenhe measures at baseline and follow-up. Although this method mayverestimate the SD of the change from baseline, it is a conservativepproach which is preferable in a meta-analysis (Higgins, 2011).s pooled trials used different rating scales or tests, the summaryeasure of treatment effect was the standardised mean differ-
nce (SMD – the absolute mean difference divided by the standardeviation). Where trials used the same rating scale or test, theeighted mean difference was calculated. Individual effect sizesere combined using the inverse variance random-effects method
DerSimonian and Laird, 1986). This was used to allow the incor-oration of heterogeneity among studies. Statistical heterogeneityas assessed by the I2 test, which describes the percentage of vari-
bility among effect estimates beyond that expected by chance.
verall estimates of the treatment difference are presented in for-st plots (Figs. 1–4). As it was not possible to pool data from allncluded studies, a summary of results from individual trials areutlined and presented in Tables 1–5.
Reviews 15 (2014) 28–43
3. Results
3.1. Included studies
Thirty-one randomised controlled trials were eligible for inclu-sion, with 1806 participants in cognitive training experimentalgroups, 386 in general mental stimulation experimental groups,1541 ‘no intervention’ controls and 822 active controls. The mostcommon cognitive training intervention was memory-based train-ing. Mental stimulation interventions were diverse and includedactivities such as playing piano, acting, and helping children withreading difficulties. The ‘no intervention’ controls received eitherno contact, minimum social support, or were placed on a waitinglist. Active control groups included educational DVDs or lectures,health-promotion training, non-brain training computer games, orsome form of unstructured learning. Study characteristics are pre-sented in Tables 1–5.
3.2. Cognitive training
3.2.1. Cognitive training versus ‘no intervention’Meta-analysis results (Fig. 1) revealed that compared to ‘no
intervention’ controls, cognitive training significantly improvedperformance on the memory measures of face-name recall(p = 0.02), immediate recall (p = 0.02), and paired associates(p = 0.001), and on subjective measures of cognitive performance(p = 0.01). There were no significant differences between the groupsin the memory measures of recognition (p = 0.29), and delayedrecall (p = 0.29), or in the executive measure of working memory(p = 0.20). Data were not available for the remaining outcomes ofinterest: verbal fluency, reasoning, attention and processing speedin the executive domain; composite measures of cognitive functionand everyday functioning.
In individual studies (Table 1), significant improvements werereported for cognitive training compared to no intervention in 19of 26 memory outcome measures (Bailey et al., 2010; Bottiroli andCavallini, 2009; Buiza et al., 2008; Cavallini et al., 2010; Cheng et al.,2012; Craik et al., 2007; Edwards et al., 2002; Fairchild and Scogin,2010; Hastings and West, 2009; Jackson et al., 2012; Mahncke et al.,2006; Valentijn et al., 2005), in seven out of 16 measures of exec-utive function (Ball et al., 2002; Buiza et al., 2008; Cheng et al.,2012; Craik et al., 2007; Edwards et al., 2002; Jackson et al., 2012;Mahncke et al., 2006; Margrett and Willis, 2006), and on both com-posite measures of cognitive function (Cheng et al., 2012; Mahnckeet al., 2006). One trial found that reasoning training resulted inless self-reported decline in everyday functioning compared to con-trol (Ball et al., 2002; Willis et al., 2006). For secondary outcomes,significant improvements were reported for training versus con-trol in four out of six measures of subjective cognitive performance(Fairchild and Scogin, 2010; Hastings and West, 2009; Valentijnet al., 2005). Transfer of training effects were recorded in five outof seven trials: four reported transfer to untrained tasks within thesame domain (Bottiroli and Cavallini, 2009; Cavallini et al., 2010;Cheng et al., 2012; Mahncke et al., 2006), one to other cognitivedomains (Cheng et al., 2012), and one to everyday functioning (Ballet al., 2002). All seven trials that included follow-up assessmentsreported maintenance of training effects (Ball et al., 2002; Buizaet al., 2008; Cheng et al., 2012; Craik et al., 2007; Hastings andWest, 2009; Mahncke et al., 2006; Valentijn et al., 2005).
3.2.2. Cognitive training versus active controlCompared to active controls, cognitive training interventions
significantly improved performance on the memory measure ofrecognition (p < 0.0001), on the executive measures of workingmemory (p = 0.04) and processing speed (p < 0.0001) and alsoon composite measures of cognitive function (p = 0.001). Effects
M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43 31
Fig. 1. Cognitive training versus no intervention control.
32 M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43
Fig. 2. Cognitive training versus active control.
M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43 33
p vers
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Fig. 3. Training in grou
or subjective cognitive performance approached significancep = 0.07). There were no significant differences between the tworoups in measures of immediate recall (p = 0.35), delayed recallp = 0.84), or attention (p = 0.43) (Fig. 2). Data were not availableor face-name recall, paired associates, verbal fluency, reasoning,r everyday functioning.
In individual studies (Table 2), significant improvements forntervention groups were reported in seven out of 15 memory out-ome measures (Legault et al., 2011; Mahncke et al., 2006; Mozolict al., 2011; Peretz et al., 2011; Richmond et al., 2011; Smith et al.,009), 17 out of 29 measures of executive function (Borella et al.,010; Carretti et al., 2012; Legault et al., 2011; Mahncke et al.,006; Mozolic et al., 2011; Nouchi et al., 2012; Peretz et al., 2011;ichmond et al., 2011; Smith et al., 2009), and six out of nineomposite measures of cognitive function (McDougall et al., 2010).one of the studies included measures of everyday functioning.or secondary outcomes, significant improvements were reportedor training versus control in three out of four subjective measuresf cognitive performance (McDougall et al., 2010; Richmond et al.,011; Smith et al., 2009). Transfer of training effects were reported
n nine out of ten trials: five reported transfer to untrained tasksithin the same domain (Borella et al., 2010; Carretti et al., 2012;ahncke et al., 2006; Nouchi et al., 2012; Peretz et al., 2011) and
ix to other cognitive domains (Borella et al., 2010; Carretti et al.,012; McDougall et al., 2010; Mozolic et al., 2011; Richmond et al.,
011; Smith et al., 2009). Four out of five trials that included follow-p assessments reported maintenance of training effects (Borellat al., 2010; Carretti et al., 2012; Mahncke et al., 2006; Smith et al.,009).
0
2
4
6
8
10
12
14
16
CT vs. NI CT vs. AC MS vs. NI MS vs. AC Grp vs. Ind
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ies
Type of Com parison
ig. 4. Number of studies per comparison-type included. CT = cognitive training;I = no intervention; AC = active control; MS = mental stimulation; Gr p = group-ased intervention; Ind = individual intervention.
us individual settings.
3.3. Mental stimulation
3.3.1. Mental stimulation versus ‘no intervention’Due to heterogeneity and a lack of available data, it was not
appropriate to conduct a meta-analysis. In individual trials wefound that mental stimulation groups significantly outperformed‘no intervention’ controls on four out of eight memory measures(Carlson et al., 2008; Klusmann et al., 2010; Noice and Noice, 2009;Slegers et al., 2009), nine out of 17 measures of executive func-tion (Basak et al., 2008; Bugos et al., 2007; Carlson et al., 2008;Klusmann et al., 2010; Noice and Noice, 2009; Slegers et al., 2009;Tesky et al., 2011), and one out of three composite measures of cog-nitive function (Slegers et al., 2009; Tesky et al., 2011; Tranter andKoutstaal, 2008). The trials did not include measures of everydayfunctioning. There were no differences between the groups on twomeasures of subjective cognitive performance (Slegers et al., 2009;Tesky et al., 2011). Each of the mental stimulation interventionsresulted in a transfer of effects to at least one cognitive outcomemeasure (Table 3). Neither trial that included follow-up assess-ments reported maintenance of intervention effects (Bugos et al.,2007; Slegers et al., 2009).
3.3.2. Mental stimulation versus active controlThree of the above trials also compared mental stimulation to
an active control. As above, it was not deemed appropriate to con-duct a meta-analysis. In individual trials, Klusmann and Slegersreported no significant differences between mental stimulation andactive control groups on four measures of memory, four measuresof executive function, one composite measure of cognitive functionand one measure of subjective cognitive performance (Klusmannet al., 2010; Slegers et al., 2009). Noice et al. found that acting classparticipants significantly outperformed singing class controls intwo measures of memory and two measures of executive function(Noice and Noice, 2009). None of the studies included measures ofeveryday functioning.
3.4. Training in group versus individual settings
Only data from Hastings and Valentijn could be pooled for meta-analysis (Fig. 3). Results revealed that participants who took partin group cognitive training sessions were more likely to self-reporttheir memory as better than those who trained in individual sett-
ings (Z = 0.97) although the effect was not significant (p = 0.14).There was no difference between the groups on immediate recallperformance (p = 0.87). It was not possible to pool data for any ofthe remaining primary or secondary outcome measures of interest.
34 M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43
Table 1Characteristics of studies – cognitive training vs. no intervention control.
Ref. Author (year) Intervention Methods Participants Outcomes of interest Generalisation/maintenance
Bottiroli (2009) Computer-based memorytraining vs. control
Standard RCT design EG: 21 Recognitiona Training generalised to neartransfer tasks
Trained 2 memorystrategies in 3 sessions
CG: 23 Face-name recalla
FU: PT Age: 58–83 Paired associatesa
Craik (2007) Effects of a multi modularcognitive rehabilitationprogramme. Memorytraining module vs. control
Within subjectcross-over RCT
EG: 29 Immediate recalla Sig improvement from BL to6 month FU on total wordsrecalled for experimental,not control.
CG: 20 Recognitionc
12 weeks Age: 71–87 Primary memoryc
FU: PT and 6 months Delayed recallc
Story Recallc
Working Memoryc
Jackson (2012) Investigating if interventionto increase cognitive abilitycan also increase openness toexperience. Inductivereasoning training vs. control
RCT EG: 78 CG: 88 Inductive Reasoninga No transfer to other cognitiveabilities
16 weeks training (ranover 22 weeks)
Age: 60–94 Divergent thinkingc
Also 2 × 1 h classroomsessions
Processing speedc
FU: PT Verbal Abilityc
Mahncke (2006) Evaluating a brain-plasticitybased training programme.Computer based training vs.control
Double blind RCT EG: 53 Recognitionb Near transfer ofimprovements to RBANSmemory & digit span;improvement in memory &digit span maintained at 3month FU
8–10 weeks of training CG: 56 Working memoryb
FU: PT and 3 months Age: 60–87 Speed of processingb
Global auditorymemoryb
Buiza (2008) Investigating a new cognitivetherapy. Structured cognitivetraining vs. control
Double-blind RCT2 years (180 sessions)
EG1: 85CG: 85 Immediate memorya Significant improvement inimm memory & fluencymaintained at 2yr FU, notobserved in cntrl. Transfernot measured.
FU: PT, 1 year, 2 yearsPT
Age: >65 Working Memorya
Verbal Fluencya
Short term memoryc
Cavallini (2010) Instruction basedmnemonics strategy trainingvs. control
Standard RCT design EG: 27 Paired associatesa Sig improvement in one oftwo near transfer tasks
4 sessions of 2 h CG: 29 List recalla
FU: PT Age: 57–81 Text recalla
Face-name recallc
Cheng (2012) Multi-domain training (MDT)vs. single domain training(SDT) vs. control
Double-blind RCT EG: 54 Immediate recallb MDT near transfer tountrained tasks, SDT fartransfer. Cognitive function(RBANS), delayed memoryand visual reasoning showedsig training effect at 12month FU–MDT bettermaintenance
2× per week for 12weeks
CG: 60 Delayed recalla
FU: PT, 6 month, 12month
Age: 65–75 Visual reasoninga
Attentionc
Speed of Processingc
Cognitive functiona
Dahlin (2008) Working memory training vs.control
RCT EG: 11 Letter memorya No transfer to 3 back
5 weeks, 3 × 45 minsession/week
CG: 10 Working memoryc
FU: PT Age: 65–71
M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43 35
Table 1 (Continued)
Ref. Author (year) Intervention Methods Participants Outcomes of interest Generalisation/maintenance
Hastings (2009) Evaluate self-help and groupbased training programmes.Group training vs. control
RCT EG: 98 Face name recalla All maintained at 9 weekfollow-up. No measure oftransfer included.
8 h of training over 6weeks
CG: 40 Story recalla
Age: 54–92 List recallc
FU–PT and 9 weeks Memory locus ofcontrola
Memory self-efficacya
Fairchild (2010) TEAM–training to enhanceadult memory. In-homememory enhancement vs.control
RCT EG: 28 Face-name recalla d
1 × 30 min to 1 hsession/week for 6weeks
CG: 25 Delayed recalla
FU: PT Age: 57–99 Subjective CFa
Valentijn (2005) Investigating two types ofmemory training. Collectivetraining group vs. control
RCT EG: 39 Immediate recallc Intervention effectsmaintained to 4 month FU.No measure of transferincluded.
Double baseline design CG: 38 Story recallc
8 weeks Delayed recalla
FU–PT, 4 months Age: >55 MIA Changea
MIA Anxietya
Memory self-efficacyc
CFQc
Bailey (2010) Meta-cognitive training athome vs. control
Standard interventiondesign
EG = 29 CG = 27 Paired associatesa d
2 weeks training & 4assignments
Age: 60–89
FU: PT
Ball (2002) ACTIVE study: Cognitivetraining interventions.
Single blind RCT 5–6weeks training
MT:703, ST:702 MT: Memorya
ReasoningcEach intervention improvedtarget cognitive ability butno transfer to untrainedcognitive tasks. Maintainedat 5 yr FU (Willis et al., 2006).Strategy use maintained at 5yr FU (Gross et al., 2011).Reasoning training transferto sig less difficulties withIADL (Willis et al., 2006) at 5yr FU.
FU: PT, annually at 1, 2,3, and 5 years
RT:699, CG:698 Speed of processingc
IADLc
4 conditions; memorytraining (MT), speed training(ST), reasoning training (RT)and control.
Age: 65–94 ST: Memoryc
Reasoningc
Speed of processinga
IADLc
RT: Memoryc
Reasoninga
Speed of processingc
IADLa
Margrett (2006) In home inductive reasoningtraining programme withcouples. Partner training vs.control
RCT EG: 34 Reasoning: d
10 sessions in 6 weeks CG: 34 Letter seriesa
FU: PT Word seriesa
Age: 61–89 Letter setsc
EG = experimental group; CG = control group; FU = Follow up; PT = Post training; MIA = Meta-Memory in Adulthood; CFQ = Cognitive Failures Questionnaire; SubjectiveCF = Subjective measures of cognitive function.
a Significantly greater improvement for training versus control.b Significant training effects for experimental group from BL to PT; no significant effect for controls.c No significant intervention difference between experimental and control groups.d No measure of maintenance or transfer included.
36 M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43
Table 2Characteristics of studies – cognitive training vs. active control.
Ref. Author (year) Intervention Methods Participants Outcomes of interest Generalisation/maintenance
Mahncke (2006) Evaluating a brain-plasticitybased training programme
Double blind RCT EG: 53 Recognitionb Near transfer to untrainedmemory and WM tasks.
8–10 weeks of training(same for EG and AC)
AC: 53 Speed of processingb
EG: Computer based training FU: PT and 3 months Age: 60–87 Working memoryb Improvements on digit spanmaintained at 3 month FU forEG
AC: DVD based lectures, usedsimilar equipment to EG
Double blind RCT. EG = 66 Recognitionc Near transfer of training tountrained cognitive tasks
20–30 min/session, 3sessions per week, 3months.
CG = 55 Memory recallc
Focused attentiona
AC – conventional computergames
Age: >50 Working memorya
FU: PT Visuospatial learninga
Sustained attentionc
Executive functionc
Composite scorea
Smith (2009) Improvement in Memorywith Plasticity-basedAdaptive Cognitive Training(IMPACT) study
Double blind RCT EG = 223 Overall memorya Far transfer to untraineddomains of memory andattention.
40 sessions AG = 213 Immediate recallc
1 h per day Delayed recalla
5 days per week Age: >65 Reasoninga
8 weeks Working memorya Significant training effectsmaintained at FU for memorymeasures and 3/5 measuresof exec functioning. Not sigfor cognitive function. Effectsweaker at FU than PT.
EG – training to improvespeed and accuracy of speedand information processing
Re and post trainingassessment
Processing speeda
FU: PT; 3 months Cognitive functiona
AC – DVD’s on history, artand literature, quizzes.
Subjective CFa
Legault (2011) SHARP-P cognitive andphysical activity training (4conditions)
Single-blind RCT EG = 16 Immediate recallc No sig effects of CT ortransfer to executivefunction tasks.
EG – cognitive trainingintervention
4 × 10–12 min sessionsper day (2 per week for2 months then 1 perweek for 2 months)
CG = 17 Delayed recallc
Working memoryc
Age: 70–85 Attentionc
AC – a healthy ageingeducation programme(LIFE-P)
Duration over 4months
Cognitive functionc
FU: PT
Mozolic (2011) Effects of a cognitive trainingintervention on attention.
RCT EG = 30 Immediate recallc Far transfer to non-traineddomain of processing speed
8 weeks training CG = 32 Delayed recallc
1 h per week Selective attentiona
EG – attention training 8 h total Age: 65–75 Processing speeda
AC – educational lecture FU: PT Attention (SCW, TMT)c
Working memoryc
Richmond (2011) EG – working memorytraining with generalisationto untrained taskAC – trivia learning
RCT EG = 21 Immediate recalla Far transfer of WM trainingeffects to measures of verbalmemory recall
Pre-test assessment,WM training: 4–5weeks
CG = 19 WM reading spana
5 days per week WM forward spanc
20–30 min per day Age: 60–80 WM backward spanc
Total of 12.5 h Attentionc
FU: PT General intelligencec
Subjective CFa
M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43 37
Table 2 (Continued)
Ref. Author (year) Intervention Methods Participants Outcomes of interest Generalisation/maintenance
Borella (2010) EG – working memorytraining
RCT EG = 20 Short term memoryc 3 out of 4 transfer tasks (nearand far) showed sigimprovement for trainingcompared to controls. Gainsin intelligence and procspeed maintained at FU
AC – questionnaires onmemory, emotionalcompetencies, personalsatisfaction and copingstrategies.
A pre and post-testsession with 3 trainingsessions in between, allwithin 2 weeks
CG = 20 Working memorya
Age: 65–75 Attentiona
Processing speeda
FU: PT, 8 months Fluid Intelligencea
Visuospatial WMc
Caretti (2012) EG – working memorytraining
RCT EG = 17 Working memorya Near transfer to untrainedtasks of WM.
AC – questionnaires onmemory, cognition,well-being, memorystrategies, Cattell test, etc.
Six sessions – trainingcompleted within 2weeks, 30–40 minsessions.
CG = 19 Attentiona
Age: 65–75 Languagecomprehensiona
Far transfer to fluidintelligence andcomprehension.
FU: PT, 6 months. Readingcomprehensionb
Performance improvementsfor training groupmaintained from PT to FU
Fluid Intelligenceb
Nouchi (2012) Effects of a brain trainingvideo game. EG – game totrain global cognitive andexecutive functions,attention and processingspeed
Double blind RCT EG = 14 Working memorya Near transfer of training tountrained measures of WM &processing speed. No transferto global cognitive status orattention.
Both conditions playedtheir game for 15 minper day, at least fivedays per week, for 4weeks
CG = 14 Executive functiona
Processing speeda
Age: >65 Attentionc
Cognitive functionc
FU: PTAC – a non-brain trainingvideo game
McDougall (2010) The Senior WISE study. RCT EG = 135 Verbal memoryc Near transfer to overallmeasure of cognitivefunction
EG – Memory training Memory training: 8classes and 4 boostersessions
CG = 130 Visual memoryc
AC – Health promotiontraining
Memory (RBMT)c
Health promotiontraining: 8 classes and4 booster sessions
Age: >65 Memory complaintsa Improvements at PT weregenerally not maintained tothe end of the study
FU: Post-class (2months), post-booster(6 months), post-classfollow-up (14 months),end of study (26months)
Memory self-efficacyc
Cognitive functiona
Activities of dailylivingc
EG = experimental group; CG = control group; FU = follow up; AC = active control; PT = post-test; BL = baseline; RBMT = Rivermead Behavioural Memory Test; WM = workingmemory; SCW = Stroop; TMT = Trail making test; Subjective CF = Subjective measures of cognitive function; DAFS = Direct Assessment of Functional Status.
a Significantly greater improvement for training versus control.b Significant training effects for experimental group from BL to PT; no significant effect for controls.c No significant intervention difference between experimental and control groups.
38 M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43
Table 3Characteristics of studies – general mental stimulation vs. no intervention control.
Ref. Author (year) Intervention Methods Participants Outcomes of Interest Generalisation/maintenance
Noice (2009) Assessing the impact ofacting classes on cognitiveperformance vs. control
RCT design EG: 42 Immediate recalla Training in acting classesshowed transfer of effects tomeasures of memory, verbalfluency and problem solving
RCT EG = 81 Immediate recallc Computer course showedtransfer of effects to memoryand executive functiondomain. EG maintainedperformance as opposed toCG who showed a decline.
3 × 1.5 h per week forsix months. 75intervention units intotal.
CG = 69 Delayed recalla
Working memorya
Age: 70–93 Verbal fluencyc
FU: PT
Slegers (2009) To assess if prolonged guidedcomputer use affectscognition. Computer training& intervention vs. control (notraining, no intervention)
RCT EG: 60 Immediate recalla Computer training showedtransfer of effects to memorydomain.
Training: 3 × 4 htraining sessions across3 wks
CG: 52 Attentionc
Delayed recallc
Intervention: onceevery 2 wks in 1st 4months, once everymonth for following 8months.
Age: 64–75 Processing speedc No overall significantintervention effects
RCT EG = 70 Immediate recallc Experience corps trainingshowed transfer to tasks ofexecutive function andattention
15 h per week for anacademic year
CG = 58 Delayed recallc
Executive functiona
FU: PT Age: >60 Attentiona
Working memoryc
Processing speedc
Basak (2008) Video game trainingtargeting executive controland visuospatial skills vs.control
RCT EG: 19 Reasoninga Video game training showedtransfer of effects to four outof five executive control tasks
7–8 weeks CG: 20 Working memorya
15 1.5 h trainingsessions
Attentiona
Total of 23.5 h Visual STMc
FU: PT Age: >65 Visuospatial attentionc
Tesky (2011) Cognitively stimulatingleisure activities (AKTIVA)study. AKTIVA interventionvs. control
RCT EG: 74 Processing speeda Transfer of training effects toprocessing speed task. Nooverall significantintervention effects
10 interventionsessions (8x wklygroup training + 2xbooster sessions)
CG: 78 Working memoryc
Cognitive functionc
Completed 9x wklyactivity protocols (wks2–10)
Age: >50(divided into60–75 and >75)
Subjective CFc
FU: PT
M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43 39
Table 3 (Continued)
Ref. Author (year) Intervention Methods Participants Outcomes of Interest Generalisation/maintenance
Bugos (2007) Individual piano instructiontargeting executive functionand working memory vs.Control
RCT EG = 16 Processing speedb Transfer of training effects toprocessing speed andattention. No evidence ofmaintenance of performancegains for the experimentalgroup at follow up.
30 min lesson with 3 hof practise per week fortotal of 6 months
CG = 15 Attentionb
Working memoryc
FU: PT, 9 months Age: 60–85
Tranter (2008) Effects of increased novelcognitively stimulatingleisure activities vs. control
RCT EG: 22 Cognitive functiona Increased novel cognitivestimulation showed transferto tasks of problem solvingand flexible thinking
10–12 weeks CG: 22 Spatial perceptiona
FU: PT Age 60–75
EG = experimental group; CG = control group; FU = follow up; AC = active control; PT = post-test; BL = baseline; STM = short term memory; Subjective CF = Subjective measuresof cognitive function.
effects.
nTu
TC
E
a Significantly greater improvement for training versus control.b Significant training effects for experimental group from BL to PT; no significantc No significant intervention difference between experimental and control group
In individual trials, those who trained in groups performed sig-ificantly better on three out of six measures of memory (Table 5).here were no differences between the groups on three meas-res of executive function (Hastings and West, 2009; Margrett and
able 4haracteristics of studies – general mental stimulation vs. active control.
Ref. Author (year) Intervention Methods
Noice (2009) Effects of acting classes oncognitive performance vs.singing classes
Slegers (2009) Assessing if prolongedguided computer use affectscognition. Computer trainingand intervention vs. trainingwith no intervention
RCT
Training: 3 × 4 htraining sessions across3 wks
Intervention: Onceevery 2 wks in 1st4months, once everymonth for following 8months.
FU: PT, 12 months
G = experimental group; CG = control group; FU = follow up; PT = post-test; BL = baseline;a Significantly greater improvement for training versus control.c No significant intervention difference between experimental and control groups.
for controls.
Willis, 2006; Valentijn et al., 2005), or on four out of five meas-ures of subjective cognitive performance (Hastings and West, 2009;Valentijn et al., 2005). However, participants who completed train-ing within a group had significantly higher ratings of memory
Participants Outcomes of Interest Generalisation/maintenance
EG:42 Immediate recalla Training in acting classesshowed transfer of effects tomeasures of memory, verbalfluency and problem solving.
CG:40 Delayed recalla
Verbal fluencya
Age: >65 Problem solvinga
Working memoryc
EG: 81 Immediate recallc No difference between EGand AC groups.
CG: 80 Delayed recallc
Working memoryc
Age: 70–93 Verbal fluencyc
EG: 60 Immediate recallc No overall significantintervention effects. Bothgroups performedsignificantly better on ameasure of immediate recallcompared to no interventioncontrol.
CG: 47 Delayed recallc
Attentionc
Age: 64–75 Processing speedc
Cognitive functionc
Subjective CFc
Subjective CF = Subjective measures of cognitive function.
40 M.E. Kelly et al. / Ageing Research Reviews 15 (2014) 28–43
Table 5Characteristics of studies – group vs. individual training.
Ref. Author (year) Intervention Methods Participants Outcomes of interest Generalisation/maintenance
Hastings (2009) Evaluating group based vs.self-help training
RCT EG: 98 Face name recallc All intervention effectsmaintained at 9 weekfollow-up.
8 h of training over 6weeks
CG: 45 List recallc
Story recallb
FU–PT and 9 weeks Age: 54–92 Memory self-efficacya
Locus of controlc
Valentijn (2005) Investigating two types ofmemory training. Collectivetraining group vs. control
RCT Double baselinedesign
EG: 39 Delayed recalla Excluding delayed recall,both groups showed similarimprovements from baselineto PT. Intervention effectslargely maintained to 4month FU.
8 weeks CG: 40 Immediate recallc
Story recallc
FU–PT, 4 months Age: >55 MIA Anxietyb
MIA Changeb
Memory self-efficacyc
CFQc
Margrett (2006) In home inductive reasoningtraining programme withcouples. Partner training vs.control
RCT EG: 34 Reasoning: Both groups showed similarimprovements from baselineto follow-up.
10 sessions in 6 weeks CG: 30 Letter seriesc
Word seriesc
FU: PT Age: 61–89 Letter setsc
EG = experimental group; CG = control group; FU = follow up; PT = post-test; MIA = Meta-Memory in Adulthood; CFQ = Cognitive Failures Questionnaire.
effects.
sedT
4
frpostmnTs
4
tmwatin2tbdt
a Significantly greater improvement for training versus control.b Significant training effects for experimental group from BL to PT; no significantc No significant intervention difference between experimental and control group
elf-efficacy (Hastings and West, 2009). Significant interventionffects for memory self-efficacy (Hastings and West, 2009) andelayed recall were maintained at follow-up (Valentijn et al., 2005).here were no differences in transfer effects.
. Discussion
Compared to no intervention, cognitive training improved per-ormance on measures of memory (face-name recall, immediateecall, paired associates) and subjective cognitive function. Com-ared to active controls, cognitive training improved performancen measures of executive function (working memory, processingpeed) and composite measures of cognitive function. In individualrials, mental stimulation improved performance on measures of
emory, executive function, and on composite measures of cog-itive function but these results were not consistent across trials.raining in group versus individual settings improved memory andubjective cognitive performance.
.1. Cognitive training
Meta-analysis results revealed that compared to no interven-ion, cognitive training significantly improved performance on the
emory measures of immediate and delayed recall, but this effectas not observed when the training condition was compared to
n active control. This conclusion is consistent with findings fromwo prior reviews which reported that although cognitive train-ng enhanced memory performance, improvements were generallyot specific to the intervention (Martin et al., 2011; Zehnder et al.,009). Taken together, these results indicate that engaging in men-
ally stimulating activities, as active control participants did, mayenefit memory performance as much as cognitive training. RCTsirectly comparing the effects of mental stimulation and cognitiveraining on memory performance would be beneficial to determine
for controls.
whether cognitive training is necessary to improve memory, orif increasing general mental stimulation could suffice. Generalmental stimulation might be easier to incorporate into ones dailyroutine, and could present a more ecologically valid alternative tocognitive training.
We found that cognitive training significantly improved per-formance on measures of recognition, on composite measures ofcognitive function, and on executive measures of working mem-ory, and processing speed compared to active controls. Consistentwith our findings, previous reviews have reported significantintervention effects for cognitive training versus active controlson cognition, particularly on measures of executive functioning(Reijnders et al., 2012; Tardif and Simard, 2011). Larger effectsizes have been reported for executive measures of reasoning andprocessing speed compared to measures of memory (Papp et al.,2009). Cognitive training may therefore have task-specific benefitsfor executive functioning. At present, many trials and reviews limittheir focus to memory outcomes alone (Zehnder et al., 2009). Ourresults however indicate that executive outcome measures shouldbe included to provide more definitive evidence on the effects ofcognitive training on executive outcomes.
4.2. Mental stimulation
Significant intervention effects were reported for mental stimu-lation versus no intervention controls in four out of eight measuresof memory, nine out of 17 measures of executive function, andon one out of three composite measures of cognitive function.A low number of mental stimulation RCT’s, combined with var-ied intervention-types and outcome measures rendered pooling of
data either inappropriate or impossible. To support meta-analysesin mental stimulation intervention trials, two key areas need to beaddressed. Firstly, a greater number of RCT’s are required to allowfor more pooling of data. In this review for example, there were only
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M.E. Kelly et al. / Ageing Re
86 participants in mental stimulation groups compared to 1806 inognitive training groups. If participant numbers for mental stimu-ation trials were comparable to those in cognitive training trials, it
ould allow for more definitive conclusions to be drawn on optimalntervention-types. Secondly, researchers of general mental stimu-ation would benefit from agreement on a standard set of guidelinesn intervention designs and outcome measures. For example, Noicend Noice (2009) identified two specific elements of mental stim-lation that might be responsible for cognitive gains: novelty andulti-modal stimulation. They incorporated these elements into
heir mental stimulation intervention and reported consistent pos-tive intervention effects. For outcome measures, they provided aationale for their choice of instruments which may be used as
guide for others. For example, they included instruments thatested cognitive abilities deemed important for independent liv-ng, could be administered in a single session of less than 90 min,nd that were most commonly utilised in the field. Such standard-sation would allow for comparability of results across individualrials and more pooling of data.
Overall, our review shows that mental stimulation might ben-fit cognitive function of older adults, but these results are notonsistent across trials. One possible explanation for a lack of con-istent results may be due to insufficiently long follow-up periods.vidence from observational and longitudinal studies, that consis-ently report a protective effect of mental stimulation on cognition,uggests that mental stimulation might operate by maintainingognitive function over time, as opposed to immediately improvingerformance (Albert et al., 2002; Wang et al., 2012). Trials of shorturation may not, therefore, be appropriate to measure interven-ion effects. Mental stimulation trials could perhaps be modelled onhe ACTIVE trial (Willis et al., 2006) that included a 5-year follow-p. This might be relevant as ACTIVE researchers noted that onlyfter the onset of decline in the control group could the positiveraining effects on function be observed in the intervention groups.
.3. Transfer and maintenance
Contrary to prior reports (Owen et al., 2010; Papp et al., 2009) 21rials included in this review reported transfer of cognitive inter-ention effects. Similar to other findings (Kueider et al., 2012; Pappt al., 2009; van Muijden et al., 2012; West et al., 2000), trainingost reliably produced transfer to tasks within the same cognitive
omain, although seven cognitive training studies also reportedransfer to untrained cognitive domains (Ball et al., 2002; Borellat al., 2010; Carretti et al., 2012; Cheng et al., 2012; Mozolic et al.,011; Richmond et al., 2011; Smith et al., 2009). Consistent withesearch reporting that transfer depends on the type and dura-ion of training (Klingberg, 2010; Owen et al., 2010; van Muijdent al., 2012), interventions using adaptive and repetitive trainingessions (Borella et al., 2010; Carretti et al., 2012; Mozolic et al.,011; Richmond et al., 2011; Smith et al., 2009) or longer train-
ng periods (Cheng et al., 2012; Richmond et al., 2011; Smith et al.,009) were most likely to produce far transfer.
Maintenance was reported in nine out of ten cognitive train-ng interventions, lasting between 3 and 6 months. These findingsre consistent with reports from other reviews that training effectsan be preserved for at least a couple of months in both mem-ry and executive domains (Reijnders et al., 2012; Verhaeghen,000). Results from included studies reporting longer-term mainte-ance support suggestions (Klingberg, 2010; Rebok et al., 2007) that
aintenance may require booster sessions or an adaptive train-
ng paradigm (Borella et al., 2010; Cheng et al., 2012; Willis et al.,006), with at least ten intervention sessions (Cheng et al., 2012;cDougall et al., 2010).
Reviews 15 (2014) 28–43 41
4.4. Generalisation to everyday functioning
The primary difficulty in determining the impact of cognitiveinterventions on the everyday functioning of healthy older adultsis that most trials do not include functional outcome measures(Reijnders et al., 2012; Tardif and Simard, 2011). Only two of theincluded studies in this review examined the effects of cognitivetraining on everyday function (Ball et al., 2002; McDougall et al.,2010). McDougall found that six-months of memory training didnot significantly improve everyday functioning for older adults ata 2-year follow-up. Ball et al. (2002) similarly reported no trainingeffects on everyday functioning after 6-weeks of memory train-ing, reasoning training or processing speed training at a 2-yearfollow-up. Interestingly however, Ball and colleagues later con-ducted a 5-year follow-up, and found that inductive reasoningtraining (in the executive domain), predicted a significant pro-portion, and the most variance, in baseline everyday functioning.They concluded that successful performance in everyday tasks iscritically dependent on executive cognitive function (Gross et al.,2011).
These results are supported by prior research that shows thatthe ability to perform independent living skills is dependent onintact executive function (Cahn-Weiner et al., 2002; Dodge et al.,2006; Johnson et al., 2007; Royall et al., 2007), and that reasoningmay be of particular importance as it influences problem-solvingrelated to cognitively demanding everyday tasks (Burton et al.,2006; Willis et al., 1998). As both mental stimulation (Wilson et al.,2002b) and cognitive training (Ball et al., 2002) have been shownto benefit executive function, these interventions might be impor-tant for improving or maintaining everyday functioning of olderadults. These findings should certainly guide future cognitive inter-vention programmes. Importantly, follow-up periods longer than2-years may also be required to detect benefits of executive trainingon functional abilities, as positive training effects in interventiongroups might only be observed after the onset of decline in thecontrol group (Willis et al., 2006).
4.5. Training in group versus individual settings
We found no significant differences between participants whotrained in group versus individual settings on measures of delayedrecall or subjective performance. In individual trials, those whotrained in groups (relative to those who trained on an individualbasis) performed significantly better on 50% of memory meas-ures, had significantly higher ratings of memory self-efficacy, andreported more stability and less anxiety about memory func-tioning (Valentijn et al., 2005). These results are supported byresearch that shows that cognitive interventions produce maxi-mum benefits when participants trained in groups (Verhaeghenet al., 1992). Researchers have suggested a number of possibleexplanations: Training in a group setting can provide participantswith an opportunity to problem-solve with a relevant peer group(Verhaeghen et al., 1992), can motivate group members to practiseeffective strategies (Saczynski et al., 2004), and allows individu-als to gain comfort from sharing their concerns about memory(Flynn and Storandt, 1990). These types of social influences notonly increase motivation and problem-solving, but have also beenshown to increase self-efficacy (Bandura, 1989). This may in turncontribute to cognitive performance as increased self-efficacy isshown to produce improved and longer lasting effects of cognitiveinterventions (Bandura, 1993; West et al., 2003). Those design-
ing cognitive interventions should develop group programmeswhere possible to ensure participants can avail of peer supportand engagement which might also positively influence cogni-tion.
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.6. Limitations of the review
By only including published data we risked the possibility ofverestimating intervention effects; although concerns about pub-ication bias may be somewhat mitigated by the fact that four of thencluded trials were published despite no overall evidence for anyntervention effect (Craik et al., 2007; Legault et al., 2011; Slegerst al., 2009; Tesky et al., 2011). Also, a 2012 cognitive interven-ion review searched for unpublished data and found only studieshat were either non-randomised or completed prior to 2002, andhus would have been excluded from this review (Kueider et al.,012). Nevertheless caution should be taken when interpreting
ntervention effects. The most notable limitation was the variationn methodologies and cognitive measures across trials. This madeonducting a meta-analysis quite difficult. Although we made a dis-inct effort to only combine homogenous data, it was necessaryo compromise on the heterogeneity of included studies in somef the analyses. Issues with methodological differences are com-only reported (Kueider et al., 2012; Martin et al., 2011; Zehnder
t al., 2009), further highlighting the need for standardisation inognitive intervention trials.
.7. Conclusions/recommendations
Overall, we found that cognitive training interventions wereffective in improving memory and subjective measures of cog-itive performance relative to no intervention, and compositeeasures of cognitive function and executive functions relative to
ctive controls. More research is required to determine the possibleenefits of general mental stimulation. If cognitive interventionsre to benefit everyday functioning, training should target improve-ents in executive function. To improve the likelihood of transfer
nd maintenance of intervention effects, cognitive training pro-rammes should be adaptive with at least ten intervention sessionsnd include a long-term follow-up. Training conducted in groupettings may have additional benefits for objective and subjectiveognitive performance over training in individual settings. Stan-ardised training protocols and outcome measures are required tollow for more pooling of homogenous data, and to confirm theptimal type and dose of cognitive interventions.
onflicts of interest
All authors declare that we have no conflicts of interest.
cknowledgements
We would like to thank Dr Joanna McHugh for her commentsn an earlier draft. MK was employed by the Alzheimer Society ofreland during the writing of this paper.
ppendix A. Supplementary data
Supplementary data associated with this article can be found, inhe online version, at http://dx.doi.org/10.1016/j.arr.2014.02.004.
eferences
lbert, S.M., Glied, S., Andrews, H., Stern, Y., Mayeux, R., 2002. Primary care expend-itures before the onset of Alzheimer’s disease. Neurology 59, 573–578.
ailey, H., Dunlosky, J., Hertzog, C., 2010. Metacognitive training at home: does itimprove older adults’ learning? Gerontology 56, 414–420.
all, K., Berch, D.B., Helmers, K.F., Jobe, J.B., Leveck, M.D., Marsiske, M., Morris, J.N.,
Rebok, G.W., Smith, D.M., Tennstedt, S.L., Unverzagt, F.W., Willis, S.L., 2002.Effects of cognitive training interventions with older adults: a randomized con-trolled trial. The Journal of the American Medical Association 288, 2271–2281.
andura, A., 1989. Regulation of cognitive processes through perceived self-efficacy.Developmental Psychology 25, 729–735.
Reviews 15 (2014) 28–43
Bandura, A., 1993. Perceived self-efficacy in cognitive development and functioning.Educational Psychologist 28, 117–148.
Basak, C., Boot, W.R., Voss, M.W., Kramer, A.F., 2008. Can training in a real-timestrategy video game attenuate cognitive decline in older adults? Psychologyand Aging 23, 765–777.
Borella, E., Carretti, B., Riboldi, F., De Beni, R., 2010. Working memory training in olderadults: evidence of transfer and maintenance effects. Psychology and Aging 25,767–778.
Bottiroli, S., Cavallini, E., 2009. Can computer familiarity regulate the benefits ofcomputer-based memory training in normal aging? A study with an Italian sam-ple of older adults. Neuropsychology, Development, and Cognition. Section B,Aging, Neuropsychology and Cognition 16, 401–418.
Bugos, J.A., Perlstein, W.M., McCrae, C.S., Brophy, T.S., Bedenbaugh, P.H., 2007.Individualized piano instruction enhances executive functioning and workingmemory in older adults. Aging & Mental Health 11, 464–471.
Buiza, C., Etxeberria, I., Galdona, N., Gonzalez, M.F., Arriola, E., Lopez de Munain, A.,Urdaneta, E., Yanguas, J.J., 2008. A randomized, two-year study of the efficacyof cognitive intervention on elderly people: the Donostia Longitudinal Study.International Journal of Geriatric Psychiatry 23, 85–94.
Burton, C.L., Strauss, E., Hultsch, D.F., Hunter, M.A., 2006. Cognitive functioning andeveryday problem solving in older adults. The Clinical Neuropsychologist 20,432–452.
Cahn-Weiner, D.A., Boyle, P.A., Malloy, P.F., 2002. Tests of executive function predictinstrumental activities of daily living in community-dwelling older individuals.Applied Neuropsychology 9, 187–191.
Carlson, M.C., Saczynski, J.S., Rebok, G.W., Seeman, T., Glass, T.A., McGill, S., Tielsch,J., Frick, K.D., Hill, J., Fried, L.P., 2008. Exploring the effects of an everyday activityprogram on executive function and memory in older adults: Experience Corps.The Gerontologist 48, 793–801.
Carretti, B., Borella, E., Zavagnin, M., de Beni, R., 2012. Gains in language comprehen-sion relating to working memory training in healthy older adults. InternationalJournal of Geriatric Psychiatry.
Cavallini, E., Dunlosky, J., Bottiroli, S., Hertzog, C., Vecchi, T., 2010. Promoting transferin memory training for older adults. Aging Clinical and Experimental Research22, 314–323.
Cheng, Y., Wu, W., Feng, W., Wang, J., Chen, Y., Shen, Y., Li, Q., Zhang, X., Li, C., 2012.The effects of multi-domain versus single-domain cognitive training in non-demented older people: a randomized controlled trial. BMC Medicine 10, 30.
Coubard, O.A., Ferrufino, L., Boura, M., Gripon, A., Renaud, M., Bherer, L., 2011. Atten-tional control in normal aging and Alzheimer’s disease. Neuropsychology 25,353–367.
Craik, F.I., Winocur, G., Palmer, H., Binns, M.A., Edwards, M., Bridges, K., Glazer, P.,Chavannes, R., Stuss, D.T., 2007. Cognitive rehabilitation in the elderly: effects onmemory. Journal of the International Neuropsychological Society 13, 132–142.
DerSimonian, R., Laird, N., 1986. Meta-analysis in clinical trials. Controlled ClinicalTrials 7, 177–188.
Dodge, H.H., Du, Y., Saxton, J.A., Ganguli, M., 2006. Cognitive domains and trajectoriesof functional independence in nondemented elderly persons. The Journals ofGerontology. Series A: Biological Sciences and Medical Sciences 61, 1330–1337.
Edwards, J.D., Wadley, V.G., Myers, R.S., Roenker, D.L., Cissell, G.M., Ball, K.K., 2002.Transfer of a speed of processing intervention to near and far cognitive functions.Gerontology 48, 329–340.
Fairchild, J.K., Scogin, F.R., 2010. Training to Enhance Adult Memory (TEAM): aninvestigation of the effectiveness of a memory training program with olderadults. Aging & Mental Health 14, 364–373.
Flynn, T.M., Storandt, M., 1990. Supplemental group discussions in memory trainingfor older adults. Psychology and Aging 5, 178–181.
Fratiglioni, L., Qiu, C., 2011. Prevention of cognitive decline in ageing: dementia asthe target, delayed onset as the goal. Lancet Neurology 10, 778–779.
Gross, A.L., Rebok, G.W., Unverzagt, F.W., Willis, S.L., Brandt, J., 2011. Cognitivepredictors of everyday functioning in older adults: results from the ACTIVE Cog-nitive Intervention Trial. The Journals of Gerontology. Series B: PsychologicalSciences and Social Sciences 66, 557–566.
Hastings, E.C., West, R.L., 2009. The relative success of a self-help and a group-basedmemory training program for older adults. Psychology and Aging 24, 586–594.
Higgins, J.P.a.G.S., 2011. Cochrane Handbook for Systematic Reviews of Interven-tions. Version 5.1.0. The Cochrane Collaboration.
Jackson, J.J., Hill, P.L., Payne, B.R., Roberts, B.W., Stine-Morrow, E.A., 2012. Can anold dog learn (and want to experience) new tricks? Cognitive training increasesopenness to experience in older adults. Psychology and Aging 27, 286–292.
Johnson, J.K., Lui, L.Y., Yaffe, K., 2007. Executive function, more than global cogni-tion, predicts functional decline and mortality in elderly women. The Journals ofGerontology. Series A: Biological Sciences and Medical Sciences 62, 1134–1141.
Klingberg, T., 2010. Training and plasticity of working memory. Trends in CognitiveSciences 14, 317–324.
Klusmann, V., Evers, A., Schwarzer, R., Schlattmann, P., Reischies, F.M., Heuser, I.,Dimeo, F.C., 2010. Complex mental and physical activity in older women andcognitive performance: a 6-month randomized controlled trial. The Journals of
Gerontology. Series A: Biological Sciences and Medical Sciences 65, 680–688.
Kray, J., Lindenberger, U., 2000. Adult age differences in task switching. Psychologyand Aging 15, 126–147.
Kueider, A.M., Parisi, J.M., Gross, A.L., Rebok, G.W., 2012. Computerized cognitivetraining with older adults: a systematic review. PLoS ONE 7, e40588.
egault, C., Jennings, J.M., Katula, J.A., Dagenbach, D., Gaussoin, S.A., Sink, K.M., Rapp,S.R., Rejeski, W.J., Shumaker, S.A., Espeland, M.A., 2011. Designing clinical trialsfor assessing the effects of cognitive training and physical activity interventionson cognitive outcomes: the Seniors Health and Activity Research Program Pilot(SHARP-P) study, a randomized controlled trial. BMC Geriatrics 11, 27.
yketsos, C.G., Lopez, O., Jones, B., Fitzpatrick, A.L., Breitner, J., DeKosky, S., 2002.Prevalence of neuropsychiatric symptoms in dementia and mild cognitiveimpairment: results from the cardiovascular health study. The Journal of theAmerican Medical Association 288, 1475–1483.
ahncke, H.W., Connor, B.B., Appelman, J., Ahsanuddin, O.N., Hardy, J.L., Wood, R.A.,Joyce, N.M., Boniske, T., Atkins, S.M., Merzenich, M.M., 2006. Memory enhance-ment in healthy older adults using a brain plasticity-based training program: arandomized, controlled study. Proceedings of the National Academy of Sciencesof the United States of America 103, 12523–12528.
angialasche, F., Kivipelto, M., Solomon, A., Fratiglioni, L., 2012. Dementia pre-vention: current epidemiological evidence and future perspective. Alzheimer’sResearch & Therapy 4, 6.
argrett, J.A., Willis, S.L., 2006. In-home cognitive training with older married cou-ples: individual versus collaborative learning. Neuropsychology, Development,and Cognition. Section B: Aging, Neuropsychology and Cognition 13, 173–195.
artin, M., Clare, L., Altgassen, A.M., Cameron, M.H., Zehnder, F., 2011. Cognition-based interventions for healthy older people and people with mild cognitiveimpairment. Cochrane Database Systematic Review, CD006220.
cDougall Jr., G.J., Becker, H., Pituch, K., Acee, T.W., Vaughan, P.W., Delville, C.L.,2010. The SeniorWISE study: improving everyday memory in older adults.Archives of Psychiatric Nursing 24, 291–306.
cGuire, L.C., Ford, E.S., Ajani, U.A., 2006. Cognitive functioning as a predictor offunctional disability in later life. The American Journal of Geriatric Psychiatry14, 36–42.
eijer, W.A., van Boxtel, M.P., Van Gerven, P.W., van Hooren, S.A., Jolles, J., 2009.Interaction effects of education and health status on cognitive change: a 6-year follow-up of the Maastricht Aging Study. Aging & Mental Health 13,521–529.
ozolic, J.L., Long, A.B., Morgan, A.R., Rawley-Payne, M., Laurienti, P.J., 2011. A cogni-tive training intervention improves modality-specific attention in a randomizedcontrolled trial of healthy older adults. Neurobiology of Aging 32, 655–668.
oice, H., Noice, T., 2009. An arts intervention for older adults living in subsidizedretirement homes. Neuropsychology, Development, and Cognition. Section B,Aging, Neuropsychology and Cognition 16, 56–79.
ouchi, R., Taki, Y., Takeuchi, H., Hashizume, H., Akitsuki, Y., Shigemune, Y.,Sekiguchi, A., Kotozaki, Y., Tsukiura, T., Yomogida, Y., Kawashima, R., 2012. Braintraining game improves executive functions and processing speed in the elderly:a randomized controlled trial. PLoS ONE 7, e29676.
wen, A.M., Hampshire, A., Grahn, J.A., Stenton, R., Dajani, S., Burns, A.S., Howard,R.J., Ballard, C.G., 2010. Putting brain training to the test. Nature 465, 775–778.
app, K.V., Walsh, S.J., Snyder, P.J., 2009. Immediate and delayed effects of cogni-tive interventions in healthy elderly: a review of current literature and futuredirections. Alzheimer’s & Dementia 5, 50–60.
eretz, C., Korczyn, A.D., Shatil, E., Aharonson, V., Birnboim, S., Giladi, N., 2011.Computer-based, personalized cognitive training versus classical computergames: a randomized double-blind prospective trial of cognitive stimulation.Neuroepidemiology 36, 91–99.
etersen, R.C., 2004. Mild cognitive impairment as a diagnostic entity. Journal ofInternal Medicine 256, 183–194.
lassman, B.L., Langa, K.M., Fisher, G.G., Heeringa, S.G., Weir, D.R., Ofstedal, M.B.,Burke, J.R., Hurd, M.D., Potter, G.G., Rodgers, W.L., Steffens, D.C., McArdle, J.J.,Willis, R.J., Wallace, R.B., 2008. Prevalence of cognitive impairment withoutdementia in the United States. Annals of Internal Medicine 148, 427–W490.
ebok, G.W., Carlson, M.C., Langbaum, J.B., 2007. Training and maintaining memoryabilities in healthy older adults: traditional and novel approaches. The Journalsof Gerontology. Series B: Psychological Sciences and Social Sciences 62, 53–61,Spec No 1.
eijnders, J., van Heugten, C., van Boxtel, M., 2012. Cognitive interventions in healthyolder adults and people with mild cognitive impairment: a systematic review.Ageing Research Reviews.
ichmond, L.L., Morrison, A.B., Chein, J.M., Olson, I.R., 2011. Working memory train-ing and transfer in older adults. Psychology and Aging 26, 813–822.
oyall, D.R., Chiodo, L.K., Polk, M.J., 2000. Correlates of disability among elderlyretirees with subclinical cognitive impairment. The Journals of Gerontology.
Series A: Biological Sciences and Medical Sciences 55, M541–M546.
oyall, D.R., Lauterbach, E.C., Kaufer, D., Malloy, P., Coburn, K.L., Black, K.J., 2007.The cognitive correlates of functional status: a review from the Committee onResearch of the American Neuropsychiatric Association. The Journal of Neu-ropsychiatry and Clinical Neurosciences 19, 249–265.
Scarmeas, N., Levy, G., Tang, M.X., Manly, J., Stern, Y., 2001. Influence of leisureactivity on the incidence of Alzheimer’s disease. Neurology 57, 2236–2242.
Slegers, K., van Boxtel, M., Jolles, J., 2009. Effects of computer training and internetusage on cognitive abilities in older adults: a randomized controlled study. AgingClinical and Experimental Research 21, 43–54.
Smith, G.E., Housen, P., Yaffe, K., Ruff, R., Kennison, R.F., Mahncke, H.W., Zelinski,E.M., 2009. A cognitive training program based on principles of brain plasticity:results from the Improvement in Memory with Plasticity-based Adaptive Cog-nitive Training (IMPACT) study. Journal of the American Geriatrics Society 57,594–603.
Tardif, S., Simard, M., 2011. Cognitive stimulation programs in healthy elderly: areview. International Journal of Alzheimer’s disease 2011, 378934.
Tesky, V.A., Thiel, C., Banzer, W., Pantel, J., 2011. Effects of a group program toincrease cognitive performance through cognitively stimulating leisure activ-ities in healthy older subjects: the AKTIVA study. GeroPsych: The Journal ofGerontopsychology and Geriatric Psychiatry 24, 83–92.
Tranter, L.J., Koutstaal, W., 2008. Age and flexible thinking: an experimental demon-stration of the beneficial effects of increased cognitively stimulating activity onfluid intelligence in healthy older adults. Neuropsychology, Development, andCognition. Section B: Aging, Neuropsychology and Cognition 15, 184–207.
Tucker-Drob, E.M., Johnson, K.E., Jones, R.N., 2009. The cognitive reserve hypoth-esis: a longitudinal examination of age-associated declines in reasoning andprocessing speed. Developmental Psychology 45, 431–446.
Valentijn, S.A., van Hooren, S.A., Bosma, H., Touw, D.M., Jolles, J., van Boxtel, M.P.,Ponds, R.W., 2005. The effect of two types of memory training on subjective andobjective memory performance in healthy individuals aged 55 years and older:a randomized controlled trial. Patient Education and Counseling 57, 106–114.
van Muijden, J., Band, G.P., Hommel, B., 2012. Online games training aging brains:limited transfer to cognitive control functions. Frontiers in human neuroscience6, 221.
Verhaeghen, P., 2000. The interplay of growth and decline: theoretical and empiricalaspects of plasticity of intellectual and memory performance in normal aging.In: Hill, R.D., Neely, L.B.A.S. (Eds.), Cognitive Rehabilitation in Old Age. OxfordUniversity Press, New York, pp. 3–22.
Verhaeghen, P., Marcoen, A., Goossens, L., 1992. Improving memory performancein the aged through mnemonic training: a meta-analytic study. Psychology andAging 7, 242–251.
Wang, H.X., Xu, W., Pei, J.J., 2012. Leisure activities, cognition and dementia. Biochim-ica et Biophysica Acta 1822, 482–491.
West, R.L., Thorn, R.M., Bagwell, D.K., 2003. Memory performance and beliefs as afunction of goal setting and aging. Psychology and Aging 18, 111–125.
West, R.L., Welch, D.C., Yassuda, M.S., 2000. Innovative approaches to memory train-ing for older adults. In: Hill, R.D., Neely, L.B.A.S. (Eds.), Cognitive Rehabilitationin Old Age. Oxford University Press, New York, pp. 81–105.
Willis, S.L., Allen-Burge, R., Dolan, M.M., Bertrand, R.M., Yesavage, J., Taylor, J.L.,1998. Everyday problem solving among individuals with Alzheimer’s disease.The Gerontologist 38, 569–577.
Willis, S.L., Tennstedt, S.L., Marsiske, M., Ball, K., Elias, J., Koepke, K.M., Morris, J.N.,Rebok, G.W., Unverzagt, F.W., Stoddard, A.M., Wright, E., Group, A.S., 2006. Long-term effects of cognitive training on everyday functional outcomes in olderadults. The Journal of the American Medical Association 296, 2805–2814.
Wilson, R.S., Bennett, D.A., Bienias, J.L., Aggarwal, N.T., Mendes De Leon, C.F., Morris,M.C., Schneider, J.A., Evans, D.A., 2002a. Cognitive activity and incident AD in apopulation-based sample of older persons. Neurology 59, 1910–1914.
Wilson, R.S., Mendes De Leon, C.F., Barnes, L.L., Schneider, J.A., Bienias, J.L., Evans, D.A.,Bennett, D.A., 2002b. Participation in cognitively stimulating activities and riskof incident Alzheimer disease. The Journal of the American Medical Association287, 742–748.
Winblad, B., Palmer, K., Kivipelto, M., Jelic, V., Fratiglioni, L., Wahlund, L.O., Nordberg,A., Bäckman, L., Albert, M., Almkvist, O., Arai, H., Basun, H., Blennow, K., De Leon,M., DeCarli, C., Erkinjuntti, T., Giacobini, E., Graff, C., Hardy, J., Jack, C., Jorm, A.,Ritchie, K., Van Duijn, C., Visser, P., Petersen, R.C., 2004. Mild cognitive impair-ment – beyond controversies, towards a consensus: report of the International
Working Group on Mild Cognitive Impairment. Journal of Internal Medicine 256,240–246.
Zehnder, F., Martin, M., Altgassen, M., Clare, L., 2009. Memory training effects inold age as markers of plasticity: a meta-analysis. Restorative Neurology andNeuroscience 27, 507–520.
