Table 1. Studies involving interventions with CT games.

Authors (year)	Participants	Intervention			Cognitive and/or neuropsychological tests	Results
		Experimental group	Control group	Frequency and duration
Bozoki et al. 19 (2013)	n = 60; age: 60–80 years.	n = 32; Photoflaw (visual attention, visual WM), Headline Clues (verbal memory, reasoning and PS), Sokoban (spatial executive processing and non-verbal reasoning) and Keep It In Mind (WM).	n = 28; Thoughts In Motion (online video news clips of the day), Sound Thinking (audio news clips of the day), and Headline Clues (textual news stories of the day, with pictures).	6 weeks; 5 sessions of at least 30 minutes per week; follow-up: after 2 months.	MON, IDN, CPAL, CPAR, OCL, OWL, OWLR, ONB, and PRD.	Learning effects for the suite of games were relatively small due to large variations in amount of time devoted to game play, and reluctance to pursue more challenging levels, in which participants had full independence in terms of choices during the intervention.
Lee et al. 20 (2013)	n = 31; age: 60–70 years.	n = 15; brain-computer interface with a card-pairing memory game.	n = 16; passive control.	8 weeks; 3 sessions of 30 minutes per week.	RBANS	The memory training game with neurofeedback showed promise in improving memory and attention in healthy elderly people. The adherence rate was very high, suggesting a high level of motivation among participants.
Simon et al. 21 (2018)	n = 82; mean age: 73.1 (±6.1) years.	n = 41; adaptative Cogmed program.	n = 41; non-adaptative Cogmed program.	5 weeks; 5 sessions of 40 minutes per week.	VMST, DST, WMS-R, TMT-A and B, COWAT, and Semantic Fluency.	The WM training game evidenced improvement in trained tasks and on an untrained task dependent upon WM and PS. Gains were linked to continuously challenging level of task difficulty.
Yeo et al. 22 (2018)	n = 227; Age: 60–80 years.	n = 109; BRAINMEM (attention and WM).	n = 118; passive control.	8 weeks; 3 sessions of 40 minutes per week.	RBANS and RBMT-II.	The game intervention promoted no general gains or improvements in cognitive performance or in specific cognitive domains, such as attention and delayed memory. Neither were there improvements in memory performance in everyday tasks.
Iizuka et al. 4 (2019)	N = 72; mean age: 76.8 (±5.4) years.	n = 25: Go game group lessons; n = 25: Go game individual lessons.	n = 22; lecture on health maintenance.	12 weeks; 1 session of 60 minutes per week; follow-up: after 3 months.	VMST, DST, LM, TMT-A, and TMT-B.	The study results showed the intervention could improve visual WM in older adults. These findings suggest increased social interaction by playing board games face to face is more effective to improve cognitive function than playing alone.
Perrot et al. 23 (2019)	n = 36; age: 60–71 years.	n = 12; Kawashima Brain Training.	n = 12:Super Mario Bros.; n = 11: passive control.	8 weeks; 3 sessions of 60 minutes per week.	Matrix reasoning, Stroop, TMT, DSST, Corsi clock, spatial relation, and number comparison.	Both types of training promoted significant improvements in some aspects of cognitive functions of participants, such as inductive reasoning. The CT game promoted less transfer to cognitive tasks than the action video game.
Faust et al. 24 (2020)	n = 151; age: ≥ 60 years.	n = 39: InSight (games training visual processing and memory); n = 38: Brain Fitness (games training auditory processing, memory, and language); n = 37: both games combined (visual and auditory).	n = 37; passive control.	8–10 weeks; 30–40 sessions of 30–40 minutes per week (at least 900 minutes); follow-up: after 3 months.	HVLT, RBANS, and WAIS.	Visual training yielded transfer effects to WM in the main sample and transfer to PS in the pilot sample. There were no comparable transfer effects for auditory training. Combined visual and auditory training failed to yield synergistic effects or any significant transfer effects.
Lee et al. 25 (2020)	n = 59; age: 65–79 years.	n = 29; CT program with 17 games.	n = 30; 13 commercially available computer games.	10 weeks; 5 sessions of 42 minutes per week.	DSST, pattern comparison, letter comparison, N-back, visual short-term memory, spatial working memory, trail-making, attentional blink, Stroop, general life satisfaction, self-efficacy, perceived stress, odor identification, standing balance, and Flanker.	Home-based adaptive CT participants outperformed their counterparts who played non-adaptive CT games in cognitive performance. Improvements were greatest for PS and WM.
West et al. 26 (2020)	n = 69; age: ≥ 80 years.	n = 39; CogniFit Personal Coach.	n = 30; CogniFit.	8 weeks; 3 sessions of 60 minutes per week; follow-up: after 3 months.	Word List Memory, Logical Memory Story A, Target Cancellation Tests, TMT-A and TMT-B, DSST, DST, Similarities, BNT, and Category Fluency and Letter Fluency tests.	Using linear mixed models, there were no significant differences between the CT and control group on language functioning, attention, executive functioning, or memory.

Abbreviations: BNT, Boston Naming Test; COWAT, Controlled Oral Word Association; BRAINMEM, the training system has attention, working memory, and delayed recall game components; CPAL, Continuous Paired Association Learning; CPAR, Continuous Paired Association; CPQ, Computer Proficiency Questionnaire; CT, cognitive training; DSST, Digit Symbol Substitution Test; DST, Digit Span Test; DVT, Digit Vigilance Test; FSS, The Flow State Scale; HVLT, Hopkins Verbal Learning Test; IADL, Instrumental Activities of Daily Living; IDN, Identification; LM, The logical memory; MDPQ, Mobile Device Proficiency Questionnaire; MON, Monitoring; n-Back tasks, Simultaneous storage and manipulation of information; OCL, One Card Learning; ONB, One-back; OWL, One Word Learning; OWLR, One Word learning. n-Back tasks, Simultaneous storage and manipulation of information. PRD, Card Prediction; PS, processing speed; RAPM, Raven Advanced Progressive Matrices; RAVLT, Rey Auditory Verbal Learning Test; RBANS, Repeatable Battery for the Assessment of Neuropsychological Status; RBMT-II, Rivermead Behavioral Memory Test; SDMT, Symbol Digit Modalities; Stroop, Stroop Color and Word; TMT, Trail-Making Tests; TMT-A and TMT-B, parts A and B of the Trail-Making Test; UFOV, Useful Field of View; UMCFAB, University of Miami Computer-Based Functional Assessment Battery; VMST, Visual Memory Span Test; WAIS, Wechsler Adult Intelligence Scale; WM, Working memory; WMS-R, Wechsler Memory Scale-Revised; OWLR, One Word learning; N-back, tasks simultaneous storage and manipulation of information.