What are the cognitive tests for assessing Working Memory (WM)?

From the Guidelines

Cognitive tests for working memory, such as the N-back task, digit span test, and operation span task, are essential for assessing this critical cognitive function, as they can help identify deficits that may impact daily functioning, particularly in conditions like ADHD, dementia, or traumatic brain injury, where working memory is often affected. These tests are valuable because working memory is essential for complex cognitive tasks like reasoning, comprehension, and learning. The N-back task requires participants to indicate when a current stimulus matches one presented n steps earlier, with difficulty increasing as n increases. The digit span test involves remembering and repeating sequences of numbers in forward or backward order, while the operation span task requires solving math problems while remembering words or letters. Other effective assessments include the Corsi block-tapping test for visuospatial working memory and the reading span task for verbal working memory, as noted in studies such as 1. Working memory capacity is limited, typically allowing storage of 4-7 items simultaneously, and these tests help identify deficits that may impact daily functioning, as discussed in 1. Regular assessment can track changes in cognitive function over time, particularly important for monitoring conditions where working memory is often affected, and can be conducted using a core neuropsychological test battery, as proposed in 1. Some key points to consider when selecting cognitive tests for working memory include:

• The test should assess several domains found to be most sensitive to tumor and treatment effects, as noted in 1
• The test should have standardized materials and administration procedures, as discussed in 1
• The test should have published normative data, as mentioned in 1
• The test should have moderate to high test–retest reliability, as noted in 1
• The test should have alternate forms or be relatively insensitive to practice effects, as discussed in 1. In terms of specific tests, the following are some options:
• Digits Forward and Backward (WAIS-III) for auditory attention, as mentioned in 1
• Trail Making Test (Parts A and B) for psychomotor speed and sequencing, as discussed in 1
• Brief Test of Attention for auditory working memory, as noted in 1
• Hopkins Verbal Learning Test—Revised for verbal memory, as mentioned in 1
• Grooved Pegboard Test for motor speed and dexterity, as discussed in 1. It is also important to consider the use of self-report scales to assess the impact of disease and treatment on the patient’s quality of life, such as the EORTC-QLQ 30 and the BCM 20, as mentioned in 1. Overall, the selection of cognitive tests for working memory should be based on the specific needs of the patient and the goals of the assessment, and should take into account the latest evidence and research in the field, such as that presented in 1 and 1.

From the Research

Cognitive Tests for Working Memory

• The Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) Working Memory Index (WMI) is a commonly used measure of working memory, which is the cognitive ability to hold a discrete amount of information in mind for utilization in mental tasks 2.
• Studies have shown that the WAIS-III WMI can be improved by incorporating additional subtests, such as Matrix Reasoning and Vocabulary, to better assess working memory 2.
• The Digit Span subtest from the Wechsler Adult Intelligence Scale-4th Edition (WAIS-IV) has been updated to better measure working memory and has been shown to differentiate between individuals with amnestic mild cognitive impairment, probable dementia of the Alzheimer type, and those with subjective cognitive complaints 3.
• The Letter-Number Sequencing subtest from the WAIS-IV has also been shown to be a useful measure of working memory, but may have a low manipulation load and may not be sensitive to modality effects 4.
• The N-back task is another commonly used measure of working memory, which requires participants to decide whether each stimulus in a sequence matches the one that appeared n items ago 5, 6.
• Modified versions of the N-back task, such as the executive n-back task, have been developed to better assess the manipulation of working memory load and have been shown to activate the left dorsolateral prefrontal cortex (DLPFC) and the left frontal opercula 6.