Meta-analysis about cognitive intervention effect applied to dementia patients

Abstract

OBJECTIVE: The study tries to explore what effects multiple cognitive intervention, computer-based intervention, and memory training program had on dementia patients through meta-analysis.

METHOD: Data was collected using an overseas search engine and 13 pieces of research published from January 2001 to April 2015 were selected. On papers that fit the selection criteria qualitative evaluation was conducted using Jadad evaluation and using pre-post average, standard deviation, and sample size of cognitive function, meta-analysis was conducted.

RESULTS: The 13 studies selected included 6 multiple interventions, 4 computer-based interventions, and 3 memory training programs. In the Jadad evaluation all had 3 points or higher and there were 474 research participants and in the result of effect size analysis memory training intervention was found to be ‘large effect size’, computer-based intervention ‘medium effect size’, and multiple cognitive intervention ‘small effect size’. All three intervention methods were all statistically significant (p < 0.05).

CONCLUSION: It was found that the effect on dementia patients was in the order of memory training intervention, computer-based intervention, and multiple cognitive intervention. Clinically, this can be objective basis for treatment method for cognitive intervention of dementia patients.

Keywords

Dementia cognitive intervention cognitive function meta-analysis

1 Introduction

Dementia is a chronic degenerative disease that leads to damage and deterioration of memory and overall cognitive domain (Cummings, 2004) which is characterized by memory defects (Santana-Sosa et al., 2008; Van Iersel et al., 2004). Also dementia patients show defects in main cognitive functions such as attention, spatiotemporal capabilities, problem-solving skills, and executive function (Bahar-Fuchs, Clare, & Woods, 2013; Sitzer, Twamley, & Jeste, 2006). Due to this it appears as decrease in voluntary action, difficulties in independent daily life, communication skills, interpersonal relationships, and social participation (Alzheimer’s Association, 2014; Keightley, & Mitchell, 2004).

Because in dementia faster early detection and early intervention delays or ceases decline in brain function and the possibilities of improvement increase (Alzheimer’s Association, 2011; Wenisch et al., 2007), early detection and early intervention are very important (Wenisch et al., 2007). Currently in occupational therapy they are not only greatly interested about various intervention approaches for dementia patients but they are also making rapid progress (Walton, Mowszowski, Lewis, & Naismith, 2014).

Treatments to delay symptoms of dementia patients can be categorized into drug treatment and nondrug treatment (Oh, 2010). For nondrug treatment, various cognitive intervention, occupational therapy, multisensory stimulation, and physical activity are suggested (International Psychogeriatric Association, 2002). Also apart from drug treatment the need for accompaniment of cognitive intervention(Lee, Yun & Park, 2007) which is a nondrug treatment with the purpose of improving symptoms is being emphasized (Acevedo & Loewenstein, 2007; Olazaran et al., 2010).

For dual cognitive intervention, there are things like multiple cognitive intervention which applies various methods, computer-based intervention, memory training, reality orientation, and reminiscence therapy (International Psychogeriatric Association, 2002; Oh, 2009; Oh, 2010).

Multiple cognitive intervention can induce active participation by inducing interest from dementia patients compared to other repetitive programs by applying various intervention programs (Lee & Park, 2007). In these interventions, overall details about general cognitive function strengthening activity including social role, memory, language skills, concentration, executive function, are included in the activity task and the concept of recognizing reality is included in the treatment contents (Clare, 2003).

Computer-based intervention provides individualized treatment based on neuropsychological patterns of the patient to stimulate the damaged areas of the cerebrum (Talassi et al., 2007). Also it has the advantages that the patients execute and learn by themselves, it reduces time of therapist intervention, and it can provide immediate and accurate feedback about performance (Bellucci, Glaberman, & Haslsm, 2002).

Memory training is for improving impairment of memory which is a characteristic cognitive symptom that appear in dementia patients and mainly practice and repetition, use of external aid, gradual word disappearance, time difference recollection training, and error exclusion training are used (Bier et al., 2008).

Looking at previous studies, cognitive intervention programs were divided into cognitive training, cognitive stimulation, and cognitive rehabilitation according to the 3 purposes (Clare & Woods, 2003; Walton, Mowszowski, Lewis, & Naismith, 2014). Meta-analysis on dementia patients presents evidence that cognitive training or cognitive stimulation has significant influence on memory and that there is effect of overall improvement of cognitive function (Spector et al., 2003; Woods et al., 2012). Also according to research that categorized cognitive intervention into compensation and restoration approaches restoration approach was more effective than conversation approach (Sitzer et al., 2006). As above in these previous studies intervention effect of detailed domains related to early dementia that show problems in memory defect while maintaining daily life domain and (Gates et al., 2011; Jeong, Sung, & Sim, 2014) detailed intervention methods such as multiple intervention of various areas and computer cognitive intervention program could not be confirmed.

Therefore the study, to confirm what kind of effects multiple cognitive intervention, computer-based intervention, and memory training program has on dementia patients, used meta-analysis that is statistically reliable which can be generalized through summarization and conclusions of various study results.

2 Method

2.1 Study design

Meta-analysis is a scientific method that summarizes and analyzes through systematic methods of previous studies to derive clinical efficacy and agreement which can suggest a more generalized verification. The study analyzed the study results about verifying effects of cognitive intervention programs on dementia patients with meta-analysis and grouped result measurement tools appropriate to research characteristics and through standardization on intervention cognitive intervention programs were classified in detail to explore the degree of change in cognitive function.

2.2 Study subjects and data collection procedure

The subjects were studies about dementia and cognitive intervention published from 2001 January to 2015 April. Data collection was done through online search method. Cochrane Datacase, EBSCO (CINAHL), PubMed, ProQuest, and ScienceDirect were used for searching papers and keywords used in the search included “dementia”, “cognitive Intervention”, “Computer-base”, and “cognitive test”. Two researchers conducted independent search of studies and selected a total of 13 papers.

2.3 Study selection and inclusion criteria

The selection criteria of the subject studies for meta-analysis are as follows.

First, studies where the study participants were Alzheimer dementia or vascular dementia patients.

Second, randomized controlled studies participants were classified into dementia patient groups.

Third, studies that conducted standardized evaluation to compare commission-based intervention effect.

Fourth, studies that provided data for calculation of effect size (average, standard deviation, number of subjects).

2.4 Coding of data

To analyze the 13 subject studies, data coding was conducted according to the characteristics of each study.

2.5 Meta-analysis method

The selected studies were analyzed for statistical heterogeneity, effect size, sensitivity, publication bias using Comprehensive Meta-Analysis 2.0 (Biostat, Englewood, NJ, USA) program.

2.5.1 Qualitative meta-analysis method

On the 13 studies selected for final selection two researchers conducted qualitative analysis of the studies using Jadad evaluation. Jadad evaluation is a tool for qualitative analysis of RCT papers and it is composed of five items including adequacy of randomization, adequacy of the serial numbers used in the treatment group assignment, adequacy of double-blind, adequacy of comparison between control group, and adequacy of subject follow-up technique. One point is given for each item and it is evaluated from 0 5. If the points of the qualitative evaluation of the study is between 0 2 it is a low-quality paper and if the points are between 3 5 it is a high-quality paper.

2.5.2 Statistical heterogeneity verification

Statistical heterogeneity represents statistical difference between measurement about treatment effect of each study results and size of summary data of corresponding confidence intervals and to confirm this, significant test about Q statistics was conducted through Chi-square test. Because for meta-analysis there is low number of studies used and statistically the statistical power is lowered, and by raising the level of significance if the p value of Q statistics is lowered in 0.1 it is determined that there is statistical heterogeneity between studies. If heterogeneity is confirmed through this test, a fixed effect model can be used but if heterogeneity assumption is not satisfied due to study effect size differences such as ages of participants, period of intervention, level of education, and dementia duration, random effects model is applied (Hedges & Olkin, 1985; Lau, Ioannidis, & Schmid, 1997).

2.5.3 Effect size calculation

The effect size used in the study used average, standard deviation, and statistical significant verification to calculate the effect size of multiple cognitive intervention, computer-based intervention, and memory training intervention applied on dementia patient. According to the standards of Cohen (1988) the effect size calculated the study was interpreted as a large effect when it is over 0.8, medium effect when it is around 0.5, and small effect when it is under 0.2.

2.5.4 Sensitivity verification

For sensitivity verification, to verify the rigor of the estimated integrated effect size, using methods suggested in study by Lau et al. (1997), comparison of results of fixed effect model or model derived from random effect model was done to see how the value of integrating estimates was influenced according to change in presented assumptions.

3 Results

3.1 General characteristics of the studies analyzed

There were a total of 13 studies analyzed in this study and it is as follows (Table 1). The selected studies were RCT studies published in English between 2000 to 2015. The participants were dementia patients over the age of 65 and there were a total of 474 participants. The experiment the group received cognitive intervention and control group did not receive cognitive intervention. The qualitative evaluation of the study showed 3 5 points based on Jadad evaluation. Intervention programs included 6 multiple interventions, 4 computer-based interventions, and 3 memory training. Also by grouping result measurement tools appropriate to study characteristics, through standardization of intervention, the degree of change in cognitive function was confirmed.

3.1.1 Statistical heterogeneity test

In the heterogeneity verification of subject studies the Q statistics of degree of change in cognitive function according to intervention method, multiple intervention showed 3.72 (df = 5, p = 0.59), computer-based intervention showed 3.99 (df = 3, p = 0.26), and memory training intervention showed 23.92 (df = 3, p = 0.00). Data exploring multiple intervention computer-based intervention were homogenous (p > 0.10), and data exploring effects of memory training intervention was heterogeneous (p < 0.10). Therefore in the study results integration of multiple intervention and computer-based intervention fixed effect model was used and for study results integration of memory training intervention, random effects model was used (Table 2).

3.1.2 The effects of multiple cognitive intervention on degree of change in cognitive function in dementia patients

In the meta-analysis about change in cognitive function in multiple cognitive intervention, the effect size range was between –0.60 to 2.35. The total effect size was 0.26 (95% confidence interval: 0.04 0.49) which can be interpreted as “small effect size”. The calculated effect size showed a positive (+) value which showed that the experiment of group applying multiple cognitive intervention showed positive influence in change in cognitive function compared to the control group and there was a statistically significant result (p < 0.05) (Fig. 1).

3.1.3 The effects of computer-based intervention on degree of change in cognitive function in dementia patients

In the meta-analysis about change in cognitive function in computer-based intervention, the effect size range was between –0.92 to 2.06. The total effect size was 0.57 (95% confidence interval: 0.12 1.01) which can be interpreted as “medium effect size”. The calculated effect size showed a positive (+) value which showed that the experiment of group applying computer-based intervention showed positive influence in change in cognitive function compared to the control group and there was a statistically significant result (p < 0.05) (Fig. 2).

3.1.4 The effects of memory training intervention on degree of change in cognitive function in dementia patients

In the meta-analysis about change in cognitive function in memory training intervention, the effect size range was between –0.97 to 2.91. The total effect size was 1.57 (95% confidence interval: –0.60 3.73) which can be interpreted as “large effect size”. The calculated effect size showed a positive (+) value which showed that the experiment of group applying memory training intervention showed positive influence in change in cognitive function compared to the control group and there was a statistically significant result (p < 0.05) (Fig. 3).

3.1.5 Sensitivity verification

Comparing the effect size of random effect model and fixed effect model and 95% confidence interval, it was shown to be identical in multiple cognitive intervention and computer-based intervention, and in memory training intervention random effect model showed a large trend (Table 3).

3.1.6 Publication bias verification

In multiple cognitive intervention, all 6 values are distributed within the domain and it showed an asymmetrical pattern where many points are distributed in the right where the effect is large. In computer-based intervention, all 4 values are distributed within the domain and it showed an asymmetrical pattern where many points are distributed on the left. In memory training intervention, 2 values are distributed within the domain and it showed an asymmetrical pattern where more points are distributed on the left (Fig. 4).

4 Discussion

Cognitive intervention programs for dementia patients have been categorized into cognitive training, cognitive stimulation, and cognitive rehabilitation (Clare et al., 2014) or composition approach and restoration approach (Sitzer et al., 2006). As such, cognitive intervention programs are being studied in large categories (Olazaren et al., 2010; Woods et al., 2012) and the detailed cognitive and vendor program effect applied clinically could not be confirmed. For this the study explored the effects of multiple cognitive intervention, computer-based intervention, and memory training program on dementia patients through meta-analysis.

In the result of applying multiple cognitive intervention on dementia patients, ‘small effect size’ was confirmed to exist with 0.26 (Cohen, 1988). This signifies that by applying multiple cognitive intervention there is improvement of cognitive function and it matches previous research where changes in cognitive function in elderly with dementia was confirmed through applying various intervention programs (Ji, Choi, & Cho, 2003; Lee & Park, 2007). Also it is determined to be because training on various cognitive domains can more stimulate brain change (Gates, Sachdev, Singh, & Valenzuela, 2011) and because it can induce interest from the subjects compared to repetitive programs to promote inducement of active participation (Gates et al., 2011; Lee & Park, 2007).

In the result of applying computer-based intervention on dementia patients, ‘medium effect size’ was confirmed to exist with 0.57 (Cohen, 1988). Significant improvement was seen in Alzheimer’s dementia patients after applying computer-based intervention and it matched the result of previous study that confirmed delay of cognitive function deterioration in follow-up inspection (Galante, Venturini, & Fiaccadori, 2007; Lee, et al., 2013; Zhuang, et al., 2013). In computer-based intervention the patients execute and learn by themselves, it reduces time of therapist intervention, and it can provide immediate and accurate feedback about performance which is determined to be the cause of promotion of positive effects (Bellucci, Glaberman, & Haslsm, 2002; Lee, et al., 2013).

It could be confirmed that there was ‘large effect size’ and application of memory training intervention (Cohen, 1988). It matches the previous study that conducted memory training on Alzheimer’s dementia patients (Cahn-Weiner et al., 2003; Lee et al., 2013; Tsantali et al., 2009). Among the 3 studies included in the study, in 2 studies the subjects of intervention were early dementia patients. Is determined that there was large intervention effect in domains related to memory defect that can be shown as early dementia that show problems that maintain language and daily life domain (Gates et al., 2011; Jeong, Sung, & Sim, 2014).

Among the three intervention methods, the order of effect size could be confirmed in the order of memory training intervention, computer-based intervention, and multiple cognitive intervention. In multiple cognitive intervention where there was ‘small effect size’ it is determined to be because the intervention goals are comprehensive and wide in range which means there is limitations in acquiring specific intervention goals and because there was lack of adequate intervention to use strategies learned through intervention by automating (Kurz et al., 2012). Also memory training that showed ‘large effect size’ intensively trains memory defect (Santana-Sosa et al., 2008; Van Iersel et al., 2004) which is a core symptom of dementia patients which can be seen to be the reason why it is effective in learning specific intervention goals hundred and comprehensive and broad intervention goals (Kurz et al.,2012).

In the result of publication bias verification, although there was ‘large effect size’ memory training intervention, there was publication bias. This can be due to that all three studies used in the analysis showed positive results in changes of cognitive function but in one of the studies the average scores of study subjects before intervention showed significant differences to other studies which could have contaminated the analysis results.

As above, it was found that multiple cognitive intervention, computer-based intervention, and memory training program all were effective treatment methods for improvement of cognitive function and dementia patients but effect size was diverse. Therefore, if adequate cognitive intervention program is accompanied according to the organic degree of disability of dementia that show differences in degree of response according to environmental countermeasures it will be possible to use as a more useful intervention method.

This study broke down cognitive intervention programs to conduct meta-analysis to explore the effects. However there were not many randomized experimental researches that solely applied a single intervention program which became a limitation in conducting analysis dividing them and many intervention programs could not be included. However the significance of this study is that it objectively proved the effects of intervention programs used on dementia patients clinically. It is deemed that through this it will be useful as evidence base for clinicians to apply cognitive intervention programs on dementia patients.

It is expected that through comparing intervention programs not included in this paper with the results of the study it will be possible to confirm the changes in cognitive function and dementia patients and functional changes in actual everyday life to explore how much it affects maintenance and restoration of function.

5 Conclusion

The study conducted meta-analysis on multiple cognitive intervention, computer-based intervention, and memory training intervention program to confirm the effects of detailed cognitive intervention programs actually applied to dementia patients clinically. As a result it was confirmed that it was effective in the order of memory training intervention, computer-based intervention, and multiple cognitive intervention, and it is expected that it can be used as evidence base for clinicians that apply cognitive treatment on dementia patients.

Conflict of interest

None to declare.

References

Acevedo

, & Loewenstein

D. A.

(2007). Nonpharmacological cognitive interventions in aging and dementia. Journal of Geriatric Psychiatry and Neurology, 20(4), 239–249.

Alzheimer’s Association. (2011). 2011 Alzheimer’ disease facts and figures. Alzheimer’s & Dementia. 7(2), 208–244.

Bahar-Fuchs

, Clare

, & Woods

(2013). Cognitive training and cognitive rehabilitation for persons with mild to moderate dementia of the Alzheimer’s or vascular type: A review. Therapy, 5, 35–35.

Bellucci

D. M.

, Glaberman

, & Haslsm

(2002). Computer-assisted cognitive rehabilitation reduces negative symtoms in the severely mentally ill. Schizophrenia Research, 59, 225–222.

Bier

, Vanier

, & Meulemans

(2002). Errorless learning: A method to help amnesic patients learn new information. Journal of Cognitive Rehabilitation, 20, 12–18.

Cahn-Weiner

D. A.

, Malloy

P. F.

, Rebok

G. W.

, & Ott

B. R.

(2003). Results of a randomized placebo-controlled study of memory training for mildly impaired Alzheimer’s disease patients. Applied Neuropsychology, 10, 215–223.

Clare

(2003). Cognitive training and cognitive rehabilitation for people with early-stage dementia. Reviews in Clinical Gerontology, 13, 75–83.

Clare

, & Woods

(2003). Cognitive rehabilitation and cognitive training for early-stage Alzheimer’s disease and vascular dementia. Cochrane Database Systematic Review CD003260.

Clare

, Linden

D. E.

, Woods

R. T.

, Whitaker

, Evans

S. J.

, Parkinson

C. H.

, & Rugg

M. D.

(2010). Goal-oriented cognitive rehabilitation for people with early-stage Alzheimer disease: A single-blind randomized controlled trial of clinical efficacy. American Journal of Geriatric Psychiatry, 18, 928–939.

10.

Cohen

(1988), Statistical power analysis for the behoral sciences (2nd ed.). New York, NY: Lawrence Erlbaum Associates.

11.

Galante

, Venturini

, & Fiaccadori

(2007). Computer-based cognitive intervention for dementia: Preliminary results of a randomized clinical trial. Giornale italiano di medicina del lavoro ed ergonomia, 29(3), B26.

12.

Hedges

Y. J.

, & Olkin

(1985), Statistical methods for meta-analysis. New York, NY: Academic Press.

13.

International Psychogeriatric Association. (2002). Behavioral and psychological symptoms of dementia (BPSD) education pack: Module 5. Non-pharmacological management. Skokie.

14.

Jadad

A. R.

, Moore

R. A.

, Carroll

, Jenkinson

, Reynolds

D. J. M.

, & Gavaghan

D. J.

, et al. (1996). Assessing the quality of reports of randomized clinical trials: Is blinding necessary? Controlled Clinical Trials, 17(1), 1–12.

15.

Jeong

P. Y.

, Sung

J. E.

, & Sim

H. S.

(2014). Meta-Analysis of cognition-focused intervention for people with mild cognitive impairment and dementia. Disorders, 19(2), 199–212.

16.

Keightley

, & Mitchell

(2004). What factors influence mental health professionals when deciding whether or not to share a diagnosis of dementia with the person? Aging and Mental Health, 8(1), 13–20.

17.

Koltai

D. C.

, Welsh-Bohmer

, & Schmechel

D. E.

(2001). Influence of anosognosia on treatment outcome among dementia patients. Neuropsychological Rehabilitation, 11(3/4), 455–475 . DOI: 10.1080/09602010042000097

18.

Kurz

, Thone-Otto

, Cramer

, Egert

, Frolich

, Gertz

H. J.

, & Werheid

(2012). CORDIAL: Cognitive rehabilitation and cognitive-behavioral treatment for early dementia in Alzheimer disease: A multicenter, randomized, controlled trial. Associated Disorders, 26, 246–253.

19.

Lau

, Ioannidis

J. P.

, & Schmid

C. H.

(1997). Quantitative synthesis in systematic reviews. Annals of internal medicine, 127(9), 820–826.

20.

Lee

G. Y.

, Yip

C. C.

, Yu

E. C.

, & Man

D. W.

(2013). Evaluation of a computer-assisted errorless learning-based memory training program for patients with early Alzheimer’s disease in Hong Kong: A pilot study. Clinical Interventions in Aging, 8, 623–633.

21.

Lee

Y. M.

, & Park

N. H.

(2007). The Effects of dementia prevention program on cognition, depression, self-esteem and quality of life in the elderly with mild cognitive disorder. Journal of Korean Academy of Adult Nursing, 9(5), 104–114.

22.

Neely

A. S.

, Vikstrm

, & Josephsson

(2009). Collaborative memory intervention in dementia: Caregiver participation matters. Neuropsychological Rehabilitation, 19, 696–715.

23.

Niu

, Tan

, Guan

, Zhang

, & Wang

(2010). Cognitive stimulation therapy in the treatment of neuropsychiatric symptoms in Alzheimer’s disease: A randomized controlled trial. Clinical Rehabilitation, 24, 1102–1111. doi: 10.1177/0269215510376004

24.

B. H.

(2009). Diagnosis and treatment for behavioral and psychological symptoms of dementia. Journal of the Korean Medical Association, 52(11), 1048–1054.

25.

Olazaran

, Reisberg

, Clare

, Cruz

, Pena-Casanova

, & Del Ser

, et al. (2010). Nonpharmacological therapies in Alzheimer’s disease: A systematic review of efficacy. Dementia and Geriatric Cognitive Disorders, 30(2), 161–178.

26.

B. H.

(2010). Outline of psychiatric disorders of the elderly. Journal of the Korean Medical Association, 53(11), 953–957.

27.

Rabey

J. M.

, Dobronevsky

, Aichenbaum

, Gonen

, Marton

R. G.

, & Khaigrekht

(2013). Repetitive transcranial magnetic stimulation combined with cognitive training is a safe and effective modality for the treatment of Alzheimer’s disease: A randomized double-blind study. Neurology and Preclinical Neurological Studies, 120, 813–819. doi: 10.1007/s00702-012-0902-z

28.

Rosenthal

, & Rubin

D. B.

(1982). Comparing effect sizes of independent studies. Psychological Bulletin, 92(2), 500.

29.

Santana-Sosa

, Barriopedro

M. I.

, Lopez-Mojares

L. M.

, Perez

, & Lucia

(2008). Exercise training is beneficial for Alzheimer’s patients. International Journal of Sports Medicine, 29(10), 845–850. doi: 10.1055/s-2008-1038432

30.

Schmid

A. A.

, Spangler-Morris

, Beauchamp

R. C.

, Wellington

M. C.

, Hayden

W. M.

, Porterfield

H. S.

, & Callahan

C. M.

(2015). The home-based Occupational Therapy intervention in the Alzheimer’s Disease multiple intervention trial (ADMIT). Occupational Therapy in Mental Health, 31(1), 19–34.

31.

Sitzer

D. I.

, Twamley

E. W.

, & Jeste

D. V.

(2006). Cognitive training in Alzheimer’s disease: A meta-analysis of the literature. Acta Psychiatrica Scandinavica, 114, 75–90 .

32.

Talassi

, Guerreschi

, Feriani

, Fedi

, Bianchetti

, & Trabucchi

(2007). Effectiveness of a cognitive rehabilitation program in mild dementia (MD) and mild cognitive impairment (MCI): A case control study. Archives of Gerontology and Geriatrics, 44, 391–399.

33.

Tarraga

, Boada

, & Modinos

(2006). A randomized pilot study to assess the efficacy of an interactive, multimedia tool of cognitive stimulation in Alzheimer’s disease. . Journal of Neurology Neurosurgery Psychiatry, 77(10), 1116–1121.

34.

Tsantali

, Tsolaki

, & Economides

(2009). The effects of a cognitive training program on trained and untrained cognitive functions of non demented elderly and Alzheimer’s patients. International Journal of Psychosocial Rehabilitation, 14, 77–98.

35.

Van Iersel

M. B.

, Hoefsloot

, Munneke

, Bloem

B. R.

, & Olde Rikkert

M. G. M.

(2004). Systematic review of quantitative clinical gait analysis in patients with dementia. Zeitschrift Fur Gerontologie Und Geriatrie, 37(1), 27–32.

36.

Walton

, Mowszowski

, Lewis

S. J.

, & Naismith

S. L.

(2014). Stuck in the muck: Time for change in the implementation of cognitive training research in ageing? Front Aging Neurosci, 6, 43.

37.

Wenisch

, Cantegreil-Kallen

, De Rotrou

, Garrigue

, Moulin

, Batouche

, & Rigaud

A. S.

(2007). Cognitive stimulation intervention for elders with mild cognitive impairment compared with normal aged subjects: Preliminary results. Aging Clinical and Experimental Research, 19, 316–322.

38.

Woods

, Aguirre

, Spector

A. E.

, & Orrell

(2012). Cognitive stimulation to improve cognitive functioning in people with dementia. Cochrane Database Systematic Review, 2, CD005562.

39.

Zhuang

J. P.

, Fang

, Feng

, Xu

X. H.

, Liu

L. H.

, Bai

Q. K.

, & Chen

S. D.

(2013). The impart of human-computer interaction-based comprehensive training on the cognitive functions of cognitive impairment elderly individuals in a nursing home. Journal of Alzheimer’s Disease, 36, 245–251. DOI: 10.3233/JAD-130158