WAIS Processing Speed Index (PSI) 4

Question 1

Which brain region is MOST associated with the neural substrate underlying processing speed as measured by the PSI?

Accepted Answer

Myelinated white matter tracts

Answer

Hippocampus

Answer

Prefrontal cortex gray matter volume

Answer

Cerebellum exclusively

Question 2

A PSI score of 85 falls at approximately which percentile rank?

Accepted Answer

16th percentile

Answer

2nd percentile

Answer

25th percentile

Answer

37th percentile

Question 3

Which condition is MOST likely to produce a profile where the PSI is significantly higher than all other WAIS indexes?

Accepted Answer

Dyslexia with intact perceptual and motor speed

Answer

Alzheimer's disease

Answer

Intellectual disability

Answer

Advanced Parkinson's disease

Question 4

The Cancellation subtest on the WAIS-IV includes two trials: one with randomly arranged stimuli and one with structured rows. What is the MAIN purpose of having both formats?

Accepted Answer

To assess how stimulus organization affects scanning efficiency

Answer

To double the number of scorable items for reliability

Answer

To replace Symbol Search in clinical populations

Answer

To measure verbal encoding of visual stimuli

Question 5

When a PSI score is significantly lower than the General Ability Index (GAI), it most commonly suggests:

Accepted Answer

Processing speed is a relative weakness compared to higher-level reasoning abilities

Answer

The examinee has superior crystallized intelligence

Answer

The GAI is invalid and should be discarded

Answer

Verbal comprehension is elevated due to education

Question 6

What does a high error rate on the Coding subtest despite fast completion suggest about the examinee?

Accepted Answer

Impulsive response style or poor attention to accuracy under speed pressure

Answer

Strong processing speed with excellent accuracy

Answer

Superior working memory capacity

Answer

Evidence of exceptional learning efficiency

Question 7

Which of the following BEST illustrates a valid accommodation when administering the PSI to an individual with a physical hand tremor?

Accepted Answer

Use Symbol Search instead of Coding since it requires less fine motor precision

Answer

Allow unlimited time on all PSI subtests

Answer

Remove the PSI from the battery entirely

Answer

Administer the test orally