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

Processing speed is strongly linked to the integrity and myelination of white matter tracts that support rapid neural signaling.

Question 2

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

Accepted Answer

16th percentile

Answer

A score of 85 is one standard deviation below the mean (100), which corresponds to approximately the 16th 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

Dyslexia primarily impairs phonological and verbal processes; motor and visual scanning speed can remain relatively intact, producing a relatively higher PSI.

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

Comparing random versus structured Cancellation trials reveals whether organization of the visual field aids or does not affect the examinee's scanning speed.

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

A GAI > PSI discrepancy indicates that higher-order reasoning and verbal abilities outpace the examinee's speed of information processing.

(WAIS) Wechsler Adult Intelligence Scale Practice Test

(WAIS) Wechsler Adult Intelligence Scale Practice Test

WAIS Processing Speed Index (PSI) 4