WAIS Working Memory Index (WMI) 2 — Questions and Answers
Question 1: Which WAIS-IV subtest requires the examinee to listen to a sequence of letters and numbers, then recall the numbers in ascending order followed by the letters in alphabetical order?
- Digit Span
- Letter-Number Sequencing (Correct answer)
- Arithmetic
- Symbol Search
Correct answer: Letter-Number Sequencing
Letter-Number Sequencing requires mental reordering of a mixed sequence, making it a core WMI subtest.
Question 2: On the WAIS-IV Digit Span subtest, which condition is considered the most sensitive measure of working memory manipulation?
- Digit Span Forward
- Digit Span Backward
- Digit Span Sequencing (Correct answer)
- All conditions equally
Correct answer: Digit Span Sequencing
Digit Span Sequencing requires the examinee to reorder digits from lowest to highest, demanding active mental manipulation rather than simple repetition.
Question 3: A clinician notes that an examinee scores significantly higher on Digit Span Forward than Digit Span Backward. What does this discrepancy most likely indicate?
- Superior crystallized intelligence
- Difficulty with active mental manipulation (Correct answer)
- Enhanced phonological loop capacity
- Stronger visuospatial working memory
Correct answer: Difficulty with active mental manipulation
A large forward-backward discrepancy suggests the examinee can passively hold information but struggles to actively manipulate it in working memory.
Question 4: Which component of Baddeley's working memory model is most directly engaged during the WAIS Arithmetic subtest?
- Visuospatial sketchpad
- Phonological loop
- Central executive (Correct answer)
- Episodic buffer
Correct answer: Central executive
The central executive coordinates attention and manipulates information, which is central to solving mental arithmetic problems without paper.
Question 5: The WAIS-IV Arithmetic subtest is classified as a supplemental WMI subtest primarily because:
- It is too easy for most adults
- It also loads on verbal comprehension and numerical ability (Correct answer)
- It measures processing speed rather than working memory
- It cannot be administered to examinees over age 65
Correct answer: It also loads on verbal comprehension and numerical ability
Arithmetic taps working memory but is heavily influenced by crystallized numerical knowledge, making it a supplemental rather than core WMI measure.
Question 6: Which standard score metric is used to express the WAIS-IV Working Memory Index?
- T-score (mean=50, SD=10)
- z-score (mean=0, SD=1)
- Composite standard score (mean=100, SD=15) (Correct answer)
- Scaled score (mean=10, SD=3)
Correct answer: Composite standard score (mean=100, SD=15)
WAIS-IV index scores, including the WMI, are reported as composite standard scores with a mean of 100 and SD of 15.
Question 7: When computing the WMI from WAIS-IV core subtests, which two subtests are combined?
- Digit Span and Arithmetic
- Digit Span and Letter-Number Sequencing (Correct answer)
- Letter-Number Sequencing and Arithmetic
- Digit Span and Coding
Correct answer: Digit Span and Letter-Number Sequencing
The WMI is derived from Digit Span and Letter-Number Sequencing as its two core subtests.
WAIS Working Memory Index (WMI) 2
Which WAIS-IV subtest requires the examinee to listen to a sequence of letters and numbers, then recall the numbers in ascending order followed by the letters in alphabetical order?