WAIS - Wechsler Adult Intelligence Scale FSIQ and GAI Interpretation Questions and Answers 1 — Questions and Answers
Question 1: An examiner notes the following WAIS-IV index scores for a client: Verbal Comprehension Index (VCI) = 118, Perceptual Reasoning Index (PRI) = 115, Working Memory Index (WMI) = 88, and Processing Speed Index (PSI) = 85. When interpreting these results, which statement is most accurate?
- The Full Scale IQ (FSIQ) is likely an underestimate of the client's general reasoning ability. (Correct answer)
- The General Ability Index (GAI) will be significantly lower than the Full Scale IQ (FSIQ).
- The profile is consistent and unitary, making the FSIQ the only summary score needed for interpretation.
- The client's performance suggests a primary weakness in verbal abstract reasoning.
Correct answer: The Full Scale IQ (FSIQ) is likely an underestimate of the client's general reasoning ability.
The General Ability Index (GAI) is calculated from the VCI and PRI subtests and is less influenced by Working Memory and Processing Speed. In this case, the client's WMI and PSI scores are significantly lower than their VCI and PRI scores. This discrepancy will pull the FSIQ down, making it a potential underestimate of the client's core reasoning and verbal abilities, which are better represented by the GAI.
Question 2: A psychologist calculates both the Full Scale IQ (FSIQ) and the General Ability Index (GAI) for an individual. The GAI is found to be significantly higher than the FSIQ. This pattern most strongly suggests that the individual's overall cognitive performance is being negatively impacted by relative weaknesses in which domains?
- Verbal comprehension and fluid reasoning.
- Visual-spatial processing and perceptual organization.
- Cognitive efficiency, specifically working memory and processing speed. (Correct answer)
- Abstract reasoning and crystallized knowledge.
Correct answer: Cognitive efficiency, specifically working memory and processing speed.
The FSIQ incorporates all four major indices: VCI, PRI, WMI, and PSI. The GAI, however, is derived primarily from the VCI and PRI, with reduced emphasis on the WMI and PSI. Therefore, when the GAI is significantly higher than the FSIQ, it indicates that lower scores on the Working Memory and/or Processing Speed indices are pulling down the comprehensive FSIQ score. These two indices are often collectively referred to as measures of cognitive efficiency.
Question 3: Under which of the following circumstances is calculating and interpreting the General Ability Index (GAI) most warranted?
- When there is a large discrepancy between the Verbal Comprehension Index (VCI) and the Perceptual Reasoning Index (PRI).
- When the examiner suspects the client did not put forth their best effort on the test.
- When all four index scores (VCI, PRI, WMI, PSI) are within a few points of each other.
- When there is a significant discrepancy between the VCI/PRI cluster and the WMI/PSI cluster. (Correct answer)
Correct answer: When there is a significant discrepancy between the VCI/PRI cluster and the WMI/PSI cluster.
The primary purpose of the GAI is to provide a summary score of general ability that is less sensitive to the influence of working memory and processing speed. It is most useful when there is a significant and unusual discrepancy between the core reasoning indices (VCI and PRI) and the cognitive efficiency indices (WMI and PSI). Such a discrepancy can cause the FSIQ to be an inaccurate representation of an individual's general reasoning abilities.
Question 4: The General Ability Index (GAI) is considered a measure of cognitive abilities that are less susceptible to certain influences compared to the FSIQ. For which of the following clinical populations might the GAI be a more representative estimate of underlying reasoning ability than the FSIQ?
- Individuals with gifted intelligence and uniform cognitive profiles.
- Individuals with specific phobias unrelated to test performance.
- Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD). (Correct answer)
- Individuals with a history of social anxiety but no cognitive complaints.
Correct answer: Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD).
Conditions like ADHD, traumatic brain injury, and certain learning disabilities are often characterized by deficits in working memory and/or processing speed. These deficits can depress the WMI and PSI scores, which in turn lowers the FSIQ. The GAI, by de-emphasizing these two indices, can provide a more accurate estimate of the individual's core verbal and perceptual reasoning abilities in these specific clinical populations.
Question 5: Which of the following best describes the conceptual difference between the Full Scale IQ (FSIQ) and the General Ability Index (GAI)?
- The FSIQ measures crystallized intelligence, while the GAI measures fluid intelligence.
- The FSIQ is a measure of potential, while the GAI is a measure of current academic achievement.
- The GAI is an outdated score, while the FSIQ is the modern standard for all interpretations.
- The FSIQ provides a broader summary of cognitive abilities, including cognitive efficiency, while the GAI focuses more narrowly on verbal and perceptual reasoning. (Correct answer)
Correct answer: The FSIQ provides a broader summary of cognitive abilities, including cognitive efficiency, while the GAI focuses more narrowly on verbal and perceptual reasoning.
The FSIQ is a comprehensive score derived from subtests across all four indices, reflecting verbal comprehension, perceptual reasoning, working memory, and processing speed. The GAI is a composite score derived only from the core Verbal Comprehension and Perceptual Reasoning subtests. Thus, the FSIQ provides a broader measure of overall cognitive functioning, including cognitive proficiency/efficiency, whereas the GAI provides a summary score that focuses more specifically on reasoning abilities.
Question 6: On the WAIS-IV, the General Ability Index (GAI) is derived from the core subtests of which two indices?
- Working Memory Index and Processing Speed Index.
- Verbal Comprehension Index and Perceptual Reasoning Index. (Correct answer)
- Perceptual Reasoning Index and Working Memory Index.
- Verbal Comprehension Index and Processing Speed Index.
Correct answer: Verbal Comprehension Index and Perceptual Reasoning Index.
The GAI is calculated using the sum of scaled scores from the three core Verbal Comprehension Index (VCI) subtests (Similarities, Vocabulary, Information) and the three core Perceptual Reasoning Index (PRI) subtests (Block Design, Matrix Reasoning, Visual Puzzles). This composition is designed to measure general ability while reducing the influence of working memory and processing speed.
An examiner notes the following WAIS-IV index scores for a client: Verbal Comprehension Index (VCI) = 118, Perceptual Reasoning Index (PRI) = 115, Working Memory Index (WMI) = 88, and Processing Speed Index (PSI) = 85.
When interpreting these results, which statement is most accurate?