A Remote Malay Executive Function Assessment for People with Aphasia: Evidence from Healthy Malay Speakers

Introduction
Executive functions (EF), also known as executive control or cognitive control, encompass a set of top-down cognitive processes essential for activities requiring sustained attention. There is strong evidence that EF impairments commonly co-occur in aphasia and influence language profiles and outcomes (Murray, 2012; Villard & Kiran, 2016; Penn et al., 2016). Such relations between language abilities and cognitive functions (EF) are to be expected given the interrelationships among both processes. Thus, the implication of EF abilities in people with aphasia (PWA) should be considered within the context of understanding PWA cognitive profile and the clinical management of aphasia (Murray, 2017). Therefore, the measurement of EF should form a crucial part of clinical and research in understanding PWA. However, there remains significant gaps in assessing EF in different linguistic populations because many EF tests are mainly developed in Western countries for English speakers (Amunts et al., 2021; Kusi-Mensah et al., 2022).

Research aim
The aim of this thesis is to develop a Malay Executive Function Test Battery (M-EF) for future use with people with aphasia (PWA) through (i) developing healthy performance baseline data for the M-EF battery from younger and older Malay-speaking adults, and (ii) considering M-EF performance measures in relation to published norms for comparable tasks in other languages.

Methods
In Study 1, ten speech and language therapists (SLTs) based in Malaysia participated in a questionnaire survey to understand the current provision of EF assessment in Malaysia and clinicians’ perspectives on using remote assessment tools.

In Study 2, fifty-one healthy younger adults and twenty healthy older adults took part in the M-EF assessment, consisting of three verbal EF tasks, Verbal Fluency Test (VFT), Digit Span (DS), Malay-Hayling Sentence Completion Test (M-HSCT) and 1 non-verbal EF task (SFT). Number of correct responses were measured in each task and response time was measured for one verbal EF task, M-HSCT.

Results
In Study 1, it was found that the options of test batteries available in Malay are limited and the majority of SLTs are delivering EF tests in the English language. The number of remote assessments carried out was limited due to lack of standardised assessment tools for usage in remote settings and poor internet connectivity on the patient's end.
In Study 2, the group level comparisons between the younger and older participants demonstrated the existence of age-related declines in the verbal tasks DS, VFT and HSCT. For the non-verbal EF task (SFT), the healthy older adults group performed slightly better than the younger group. The pattern of performance across the three verbal component tasks (DS, VFT, M-HSCT) showed similar results to previous cross-linguistic studies in healthy adults.

Conclusion
Results from Study 1 suggest that there is an immediate need for a validated EF assessment tool which can improve practicality of usage by clinicians and addresses accessibility in terms of culture, language, and physical location. Findings from Study 2 confirms the presence of age-related decline in healthy Malay speakers across the EF domains comparable to performance in other linguistics groups. Importantly, this research extends the number of available EF assessments for a new linguistic and cultural group as well as enables the future usage of the normative data gathered with PWA.