Does bilingualism influence neuropsychological test performance in older adults? A systematic review

Figures & data

Figure 1. Flowchart of literature search and study selection process.

Table 1. Summary of findings of cross-sectional studies.

First author, year	Neuropsychological tests	Controlled for	Main findings
Anderson et al. (2017)	D-KEFS	Age Education (years) Cognitive status (MMSE)	The results indicate that BL^a healthy group had poorer performance than their ML^b counterparts on the Stroop and category fluency subtests. BLs with AD^c had lower scores in letter fluency task and reduction in inhibition/switching errors on the Stroop task than their ML peers. Despite a lower baseline performance, BLs showed less decline in cognitive scores from HA^d to MCI^e than their monolingual counterparts.
Bialystok et al. (2008)	Corsi blocks (Forward and Backward) PPVT-III, Form B CVF and LVF (Milner, 1964)	Age of English acquisition Vocabulary knowledge	BLs and MLs performed equivalently on the Corsi block task. The results from lexical access tasks indicated consistent monolingual advantages.
Bialystok, Poarch, et al. (2014)	Study 1 Shipley Vocabulary Test Cattell Culture Fair Test Stroop Task Study 2 Shipley Vocabulary Test Cattell Culture Fair Test	––––––	Study 1 BLs performed poorer than MLs on the Shipley Vocabulary Test and BLs had significantly faster completion times and less interference than MLs in the Stroop Task. Study 2 BLs obtained lower scores than MLs on the Cattell Culture Fair Test and Shipley Test.
Clare, Whitaker, Craik, et al. (2016)	MMSE NART Spot-the-Word Test BPVS BNT D-KEFS WMS-III (Spatial and Digit Span) TEA (Elevator Counting with Distraction) Stroop	Educational level Use of acetylcholinesterase-inhibiting medication (AChEI) MMSE scores at time of diagnosis	The findings show that BLs performed worse than MLs on the MMSE at the time of diagnosis and BLs did not demonstrate a clear advantage in EF^f, but they may have some relative advantage compared to MLs in the domain of inhibition and management of response conflict (TEA).
Clare, Whitaker, Martyr, et al. (2016)	NART Spot-the-Word Test BPVS BNT D-KEFS WMS-III (Spatial and digit span) TEA (Elevator counting with distraction, Visual Elevator) Stroop	Age Gender Educational level SES Health status Functional ability Mood Cognitive status (MMSE) Word reading ability Cognitive reserve	The findings show that there were no overall differences in EF tasks performance between MLs and BLs. For each measure, there was a trend for MLs to have a better performance, which was less pronounced in the domain of inhibition and management of response conflict.
Friesen et al. (2015)	Shipley Vocabulary Test D-KEFS (VF)	WCST performance Vocabulary knowledge	Category fluency performance showed decline in older adults and was not influenced by bilingualism status, whereas, better letter fluency performance was associated with bilingualism status.
Ihle et al. (2016)	MHVS TMT (A and B)	Language of test administration Educational level Number of leisure activities Occupational complexity Gainful activity	Higher number of languages spoken was associated with better performance in verbal abilities and processing speed, but not after considering educational level and cognitive level of job.
Kousaie et al. (2014)	Stroop WMS-III (Forward and Backward Digit Span WCST BNT COWAT (CVF and LVF)	Age Education (years) Cognitive status (MoCA)	The results do not support a bilingual advantage on the EF tasks and no bilingual disadvantage was observed in language tasks. A small bilingual advantage was observed only in the Stroop interference, with BLs showing smaller interference than both ML groups.
Kowoll et al. (2015)	CERAD	Gender Depression German as a non-dominant language	The results do not indicate significant differences in cognitive performance between MLs and BLs across diagnostic groups.
Luo et al. (2013)	Shipley Vocabulary Test Cattell Culture Fair Test Corsi Block Test	Education (years) English vocabulary level Nonverbal intelligence	The results reveal that bilingualism was associated with better performance in forward and backward conditions of Corsi Block Test.
Massa et al. (2020)	Stroop TMT (A and B) VF	Age Education (years) Cognitive status (MMSE)	The findings show higher number of correct responses in the Stroop test and higher number of words in the letter fluency for BLs as compared to MLs.
Nielsen et al. (2019)	CTT FDT MMSE (language items) VF (Semantic) Copying of a Greek cross and star CRT	Education Gender Ethnicity Years of residence in a new country	After controlling for the covariates, bilingualism was associated with a better performance in executive functions and task switching ability.
Ossher et al. (2013)	MMSE D-KEFS (Color-Word Naming) VF	Education (years) Gender	The findings indicate no significant difference between language groups in each aMCI^g subgroup on the MMSE and D-KEFS except for the slower completion time on the color-word naming condition in bilingual multiple domain aMCI group.
Papageorgiou et al. (2019)	Background measures BPVS-III RPMT WAIS-IV (Digit span backward and forward) Main measure TOL	Gender Age Educational level SES	The results do not indicate an effect of bilingualism on the TOL and there was a trend toward a bilingual disadvantage in response times in this test.
Rosselli et al. (2000)	LVF CVF (fruits and animals) BDAE (The Cookie Theft) MAE (Sentence Repetition)	Age Education (years) Cognitive status (MMSE)	The results found no protective or detrimental effect of bilingualism on language test performance except for the lower scores in the semantic fluency task in BLs.
Rosselli et al. (2019)	Background measures WAIS-R (Block Design) MINT TMT-A Stroop Main measure ROCF (Benson Figure)	Age Gender Education (years) Cognitive status (MMSE and MOCA)	The results indicate no differences in performance between MLs and BLs on the Benson Figure Test.
Sheppard et al. (2016)	BNT	Age Education (years)	BLs performed better in the language of their choice administration than in the English-only administration, with lowest performance in the French-only administration.
Soltani et al. (2019)	VF	––––––	The results showed no differences in verbal fluency performance between MLs and BLs, when BLs were tested in their second and most frequently used language.

D-KEFS: Delis-Kaplan Executive Function System; PPVT: Peabody Picture Vocabulary Test; CVF: category verbal fluency; LVF: letter verbal fluency; MMSE: Mini Mental State Exam; NART: National Adult Reading Test; BPVS: British Picture Vocabulary Scale; BNT: Boston Naming Test; TEA: Test of Everyday Attention; WMS: Wechsler Memory Scale; TMT: Trail Making Test; Color-CTT: Trails Test; FDT: Five Digit Test; CRT: Clock-Reading Test; MHVS: Mill Hill Vocabulary Scale; WCST: Wisconsin Card Sorting Test; COWAT: Controlled Oral Word Association Test; MoCA: Montreal Cognitive Assessment; CERAD: Consortium to Establish a Registry for Alzheimer’s Disease; CTT: Color Trails Test; FDT: Five Digit Test; CRT: Clock Reading Test; VF: Verbal Fluency; WAIS: Wechsler Adult Intelligence Scale; RPMT: Raven’s Progressive Matrices Task, TOL: Tower of London; BDAE: Boston Diagnostic Aphasia Examination; MAE: Multilingual Aphasia Examination; MINT: Multilingual Naming Test; ROCF: Rey–Osterrieth Complex Figure Test.

^aBilinguals; ^bmonolinguals; ^cAlzheimer’s disease; ⁴healthy older adults; ^emild cognitive impairment; ^fexecutive function; ^gamnestic mild cognitive impairment.

Table 2. Summary of findings of longitudinal studies.

First author, year	Neuropsychological tests	Controlled for	Baseline findings	Longitudinal findings
Bak et al. (2014)	WAIS-III (Letter–Number Sequencing, Matrix Reasoning, Block Design, Digit Symbol and Symbol Search) WMS-III (Logical Memory, Spatial Span, Verbal Paired Associates, Digit Span Backward) MHT NART LVF	Age at time of testing Gender Socio-economic class (participants’ and their fathers)	------	The results of the cohort who had been first tested in 1947 and subsequently between 2008 and 2010 suggest a protective effect of bilingualism on the NART in BLs^a. As compared to bilingualism, multilingualism showed a greater advantage in the NART, general intelligence and verbal fluency, independent of childhood intelligence, even if the second language is acquired in adulthood.
Bialystok, Craik, et al. (2014)	MMSE BNA D-KEFS (TMT, CWIT, VF)	Lifestyle factors Immigration Cognitive status (MMSE)	BLs had poorer performance than MLs^b on the MMSE and BNA, however, BLs were significantly older than MLs. First session BLs in the MCI^d group performed slower on the TMT-B, with no language difference in the AD^c group. There was no difference between MLs and BLs on the CIWT, but BLs showed a smaller Stroop effect than MLs in both diagnostic groups.	After 6.2 months, the results revealed that BLs and MLs had comparable declining scores through disease progression on the subtests of D-KEFS.
Chertkow et al. (2010)	MMSE	Gender Immigrant/native status Education (years)	The results showed that rate of cognitive decline in MMSE scores were similar between language groups at the diagnostic visit.	The performance in one-year follow-up visit was comparable between a subset of multilingual and ML patients with AD.
Costumero et al. (2020)	MMSE BNT VF CDT	Age Gender Education (years) Immigration Cultural background Cognitive status (MMSE)	MLs and BLs with aMCI were matched on neuropsychological test results.	A follow-up of 7 months revealed a greater a decline on the MMSE and letter fluency task for MLs with aMCI when compared to BLs with aMCI.
Cox et al. (2016)	D-KEFS (Tower Test) MHT	Age MHT (IQ at age 11) Social class (participants’ and their fathers’) L2 acquisition before age 11	------	The results did not indicate an effect of bilingualism on the Tower Test over the 63-year period.
Mungas et al. (2018)	3MS SEVLT	Age Gender Education (years)	When language use and proficiency included in the analysis, Spanish MLs had poorer performance on the 3MS, but there was no significant differences in the 3MS and SEVLT between English MLs and BLs.	The results revealed that bilingualism status did not have an impact on the rate of cognitive decline over six years.
Padilla et al. (2016)	3MS SEVLT	Age Gender Education (years) Household income Depression	The results revealed a bilingual advantage on the 3MS, particularly on the items of language, praxis, EF. Language/executive and language/praxis items distinguished between MLs and BLs.	With or without adjustment for demographic variables and depressive symptoms, there were no significant differences in rates of cognitive decline on the 3MS and SEVLT learning trials between MLs and BLs over approximately 6 years.
Yeung et al. (2014)	3MS	Age Education (years) Gender Subjective memory loss Literacy	TIME 1 and TIME 2 The results indicated that the group with English as a L2 had a lower performance on the 3MS at baseline and follow-up of 5 years than those whose spoke English as a L1.	FROM TIME 1 to TIME 2 Bilingualism was not associated with a change in cognitive test scores over the 5-year period.
Zahodne et al. (2014)	SRT BNT BDAE WAIS-R (Similarities) MDRS (Identities and Oddities, LVF, CTT)	Country of origin Gender Education (years) Amount of time spent in the USA Recruitment wave	The findings suggest that independent of covariates, higher bilingualism scores were associated with better baseline scores on the measures of EF^e (WAIS-R, MDRS), the task switching (CTT) and episodic memory (SRT).	Bilingualism status did not appear to have an independent protective effect against age-related cognitive decline in a follow-up of 23 years.

WAIS: Wechsler Adult Intelligence Scale; WMS-III: Wechsler Memory Scale; MHT: Moray House Test; NART: National Adult Reading Test; LVF: Letter verbal fluency; MMSE: Mini Mental State Examination; BNA: Behavioral Neurology Assessment; D-KEFS: Delis-Kaplan Executive Function System; TMT: Trail Making Test; CWIT: Color-Word Interference Test; VF: Verbal Fluency Test; CDT: Clock Drawing Test; 3MS: Modified Mini-Mental State Examination; SEVLT: Spanish English Verbal Learning Test; SRT: Selective Reminding Test; BNT: Boston Naming Test; BDAE: Boston Diagnostic Aphasia Examination; WAIS-R: Wechsler Adult Intelligence Scale-Revised; MDRS: Mattis Dementia Rating Scale; CTT: Color Trails Test.

------ indicates no data available; ^abilinguals; ^bmonolinguals; ^cAlzheimer’s disease; ^dmild cognitive impairment; ^eexecutive function.

Figure 2. Confounding variables stated in the articles.

Anderson, J. A., Saleemi, S., & Bialystok, E. (2017). Neuropsychological assessments of cognitive aging in monolingual and bilingual older adults. Journal of Neurolinguistics, 43(A), 17–27. https://doi.org/https://doi.org/10.1016/j.jneuroling.2016.08.001

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