Table 1.

Description of the subtests used in the cognitive assessment.

Test	Subtests	Description
WISC-IV/WAIS-IV	Vocabulary	A core Verbal Comprehension subtest assessing several cognitive factors such as verbal comprehension, language development, and crystallised knowledge. No speed component.
	Matrix Reasoning	A core Perceptual Reasoning subtest assessing broad visual intelligence. No speed component.
	Digit Span	A core Working Memory test assessing auditory short-term memory and auditory sequential processing. Both WISC-IV and WAIS-IV contain Digit Span Forward (repeating digits as given) and Digit Span Backward (repeating digits in reverse order). WAIS-IV also contains Digit Span Sequencing, where the test taker is asked to repeat the digits in an ascending numerical sequence. A higher raw score indicates better performance for all conditions.
	Coding	A core Processing Speed test assessing visual motor-coordination, visual short-term memory, attention, and concentration.
D-KEFS	Verbal Fluency	Assesses fluent productivity in the verbal domain in three conditions: Letter Fluencya Category Fluencya Category Switchingb A higher raw score indicates better performance for all conditions.
	Trail Making Test	Assesses the flexibility of thinking on a visual-motor task in five conditions: Visual Scanninga Number Sequencinga Letter Sequencinga Number-Letter Switchingb Motor Speeda A lower raw score indicates better performance for all conditions.
	Colour-Word Interference Test	Assesses verbal inhibition of an overlearned verbal response as well as flexibility in four conditions. Based on the Stroop procedure. Colour Naminga Word Readinga Inhibitionb Inhibition/Switchingb A lower raw score indicates better performance for all conditions.
WISC-IV integrated	Elithorn Mazes	A non-verbal measure of executive functioning that requires self-monitoring, planning, and inhibition of impulses. A higher raw score indicates better performance.
NEPSY-II	Verbal Memory	Assesses direct and delayed verbal recall using a list of 15 words. A higher raw score indicates better performance.

WISC, Wechsler Intelligence Scale for Children; WAIS, Wechsler Adult Intelligence Scale; D-KEFS, Delis-Kaplan Executive Function System; NEPSY-II, A Developmental NEuroPSYchological Assessment.

^aA sub-test from D-KEFS assessing fundamental cognitive skills.

^bA sub-test from D-KEFS assessing executive functioning.