Table 2.

Self-designed cognitive trainings.

References	Type of intervention	No of subjects and trial period	Cognitive domain focused	Findings	Limitations
McAvinue et al. (2013)	•Computerized training task •Control group	36 healthy older subjects Age range: 64–79 years old 5-week training period + a 6-month follow up	•Short-term memory •Working memory	•Improvement in short-term memory, together with transfer of training gains to long-term episode memory tasks •No significant improvement in working memory	•A small sample size •Lack of inclusion of a measure of visuo-spatial short-term or working memory •Non-adaptive version of the training program for control group
Yeo et al. (2018)	•Cognitive training system, BRAINMEM	240 healthy participants Age range: 60–80 years old 24 sessions over 8 weeks and three-monthly booster sessions	•Attention •Working memory •Delayed recall	•No significant differences in overall cognitive performance post-intervention between subjects	•Lack of a sham control •Unbiased testing of effect sustainability of the training not done •Lack of generalizability
Bozoki et al. (2013)	•Online games designed for the program •Active group only	60 Healthy older subjects Age range: 60–80 years old 6 weeks	•Visual attention •Working memory •Processing Speed •Reasoning	•No effects, only improvements on games	•A small sample size; a short-term trial •No control group •Low program intensity
Corbett et al. (2015)	•Problem-solving cognitive training (ReaCT) •General Cognitive Training (GCT) •A control treatment •Group	2,192 healthy older subjects; Age mean: 65 years old 6 months	•Reasoning •Problem solving •Attention •Memory •Visuospatial ability	•Improved cognition, particularly the reasoning skills, evident from week 6	•Only people who could access computer were included into the trial •Only people with higher levels of education; retention strategies need to be improved
Rose et al. (2012)	•Virtual Week Training •Program •Active Control •Group (ACG)	59 healthy older subjects Age mean: 67.4 years old 1 month 12 sessions, each 1 h long	•Prospective memory	•Improved prospective memory •Transfer to real-world settings, reflected in participants' daily activities	•A small sample size •A short-term trial period •A lack of effective strategies used by participants
Nouchi et al. (2016)	•Processing Speed Training Game (PSTG) •Knowledge and Quiz Training Game (KQTG) •Active control group	72 healthy older adults Age range: 60 years old or more 4 weeks	•Processing speed •Reasoning •Short term memory •Working memory •Episodic memory	•PSTG had a small improvement in processing speed, inhibition and depressive mood •No improved performance in reasoning, shifting, short term/working memory, and episodic memory	•Short-term training period •No follow-up assessment •A small effect size
Requena and Rebok (2019)	•Experimental control group •G1—Training with Lumosity •G2—Training with paper and pencil	54 healthy older adults •Age range: 65 years and older 32 sessions held weekly during the months of October to May during the years 2015–2017	•Attention •Memory •Psychological well-being	•No differences in the psychological well-being in either groups •Significant difference in attention, everyday memory and brain activity •CCT outperformed paper-and-pencil training	•Difference in age and educational level
Zhang et al. (2019)	•Multi-domain cognitive training via tablet	27 older adults with MCI Age range: 55 years and above Twice a week/12 weeks	•Reasoning •Memory •Visuospatial skills •Language •Calculation •Attention	•Improvement in immediate memory and visuospatial memory abilities •No significant difference in neuropsychological test scores observed from baseline	•A small sample size •Inadequate training duration •Lack of control group
Barnes et al. (2009)	•Computer-based cognitive training (CCT) program developed by Posit Science Corporation (San Francisco, CA)	47 subjects with mild cognitive impairment Age mean: 74 years old 100 min/day, 5 days/week for 6 weeks	•Processing speed •Accuracy •Primary Memory •Working auditory memory	•Primary outcome of global cognitive function between the intervention and control groups not statistically significant •Effect sizes for measures of verbal learning and memory consistently favored the intervention	•Small sample size •Stimulating cognitive and physical lifestyle activities outside of intervention not controlled
Marusic et al. (2016)	•Computerized spatial navigation training (CSNT) protocol •Experiment-control groups	16 healthy men Age range: 55–65 years old 14 days training, 28-day recovery program	•Executive function •Attention •Processing speed	•Improved spatial navigation •Improved performance (fidelity), but visible also across other cognitive domains known to be associated with brain areas sub served by those that involve spatial navigation	•A small sample size •A short duration
Herrera et al. (2012)	•Programmed training exercises (visual recognition task) •Attention training task	22 older adults with amnestic MCI Age range: 65–90 years old 12 weeks	•Memory •Attention	•Improved episodic memory •Transfer effect between recognition vs. recall •Attention training with the visual focused attentional tasks improved information processing	•Parameters very frequently manipulated so that training tasks would continue to challenge each patient's abilities throughout training
Gooding et al. (2015)	•Randomized clinical trial •Computerized Cognitive Training (CCT) •Cognitive Vitality Training (CVT) •An Active Control Group (ACG)	96 male participants Age mean: ~76 years old 30 h of training/16-weeks	•Memory •Attention •Executive Function	•CVT showed significant improvement relative to ACG •No significant difference between participants of CCT and CVT	•Restricted demographics sample •Did not include measures to assess everyday functioning