ABSTRACT
Impairments of short-term and working memory (STM, WM), both verbal and non-verbal, are ubiquitous in aphasia. Increasing interest in assessing STM and WM in aphasia research and clinical practice as well as a growing evidence base of STM/WM treatments for aphasia warrant an understanding of the range of standardised STM/WM measures that have been utilised in aphasia. To date, however, no previous systematic review has focused on aphasia. Accordingly, the goals of this systematic review were: (1) to identify standardised tests of STM and WM utilised in the aphasia literature, (2) to evaluate critically the psychometric strength of these tests, and (3) to appraise critically the quality of the investigations utilising these tests. Results revealed that a very limited number of standardised tests, in the verbal and non-verbal domains, had robust psychometric properties. Standardisation samples to elicit normative data were often small, and most measures exhibited poor validity and reliability properties. Studies using these tests inconsistently documented demographic and aphasia variables essential to interpreting STM/WM test outcomes. In light of these findings, recommendations are provided to foster, in the future, consistency across aphasia studies and confidence in STM/WM tests as assessment and treatment outcome measures.
Acknowledgements
We would like to thank Helen Kelly (University College Cork, Ireland) for her advice and assistance with the literature searches and Paul Conroy (University of Manchester, UK) for providing us with information about the Rey Complex Figure Test.
Disclosure statement
No potential conflict of interest was reported by the authors.
Notes
1The combination of the two versions of the Digit Span (forward and backward recall) in and visuo-spatial correlates in (e.g., forward and backward WMS-R visuo-spatial span subtests), does not imply that the two versions reflect similar processes. Although backward recall is often regarded as a WM (as opposed to an STM) task, it does differ from the other WM tasks we came across in terms of its complexity. Serial recall is not an explicit feature of WM tasks. Furthermore, we did not encounter separate exploration or description of the psychometric properties of standardised forward versus backward recall subtests.
2Only a limited number of RTT subtests are non-serial tasks.