WAIS Processing Speed Index (PSI) 5

Question 1

In WAIS-IV scoring, what happens to the PSI if an examinee completes a supplemental subtest (e.g., Cancellation) but not both core subtests?

Accepted Answer

The PSI cannot be computed without both core subtests completed

Answer

Cancellation can fully replace Coding to form the PSI

Answer

The examiner prorates the score using one core subtest

Answer

The PSI defaults to the mean score of 100

Question 2

Research comparing PSI performance across cultures suggests that which factor MOST accounts for cross-cultural differences?

Accepted Answer

Familiarity with pencil-and-paper timed tasks and test-taking culture

Answer

Differences in crystallized verbal knowledge

Answer

Genetic variation in neural conduction velocity

Answer

Language differences in understanding test instructions

Question 3

Which index on the WAIS-IV is computed WITHOUT including PSI subtests, making it useful when processing speed is confounded?

Accepted Answer

General Ability Index (GAI)

Answer

Full Scale IQ (FSIQ)

Answer

Cognitive Proficiency Index (CPI)

Answer

Working Memory Index (WMI)

Question 4

An examinee who scores in the Superior range on VCI and PRI but Low Average on PSI would BEST be described as having:

Accepted Answer

A specific processing speed weakness relative to intact higher-order cognition

Answer

Global intellectual disability

Answer

Normal variation with no clinical significance

Answer

Evidence of malingering

Question 5

Which medication class is MOST known to artificially improve PSI scores by increasing alertness and motor speed in individuals with ADHD?

Accepted Answer

Stimulant medications (e.g., methylphenidate)

Answer

Antidepressants (SSRIs)

Answer

Antipsychotics

Answer

Benzodiazepines

Question 6

Why is the PSI considered a particularly useful index for detecting the early cognitive effects of multiple sclerosis (MS)?

Accepted Answer

MS causes demyelination that directly slows neural transmission speed

Answer

MS primarily destroys hippocampal neurons first

Answer

MS impairs verbal retrieval before all other functions

Answer

MS elevates PSI scores due to cortical reorganization

Question 7

If an examiner inadvertently gives extra time on the Coding subtest, which psychometric principle is MOST violated?

Accepted Answer

Standardized administration required for normative comparison

Answer

Content validity

Answer

Inter-rater reliability

Answer

Construct irrelevant variance