Table 1.

Five Variants of the Continuous Performance Task Paradigm

Variantcitation	Cue	Probe	Sequence	Features
X-CPT4	None	Fixed and rare	A X Q Q B X	Limited case of context processing, confounded with vigilance, no control for generalized deficits
IP-CPT7	Any	Any repeat	A X Q Q B X	Simple case of context processing, not optimally sensitive to context deficits (no competing response), no control for generalized deficits-
AX-CPT4,6	Fixed and rare	Fixed and rare	A X Q Q B X	Not optimally sensitive to context deficits (no competing response), no control for generalized deficits
Expectancy AX-CPT3	Fixed and common	Fixed and common	A X A X B X	Sensitive to context deficits (competing responses), control for generalized deficits (AY vs BX errors)
Dot pattern expectancy task50	Fixed and common	Fixed and common		Sensitive to context deficits (competing responses), parametrically manipulated stimuli increase demands on context representation, control for generalized deficits (AY vs BX errors)

Note: Targets in sequence are bold and underlined. CPT, continuous performance task; IP, identical pairs.