Table 1.

Task parameters and sequence of tasks.

Task	Pre-cue Delay	Cue Duration	Number of sessions
Visual discrimination task	0 sa	32 sa	Criterionc
Attention Task 1	0 sa	2 sa	8
Attention Task 2	0 sa	1 sa	15
Attention Task 3	0, 2, 4 sb	1 sa	20
Attention Task 4	0, 2, 4 sb	0.8, 1.0, 1.4 sb	20
Attention Task 5	0, 4, 8 sb	0.4, 0.8, 1.0 sb	6

^aConstant across trials.

^bVariable across trials.

^c80% correct for two out of three consecutive sessions with at least 50 response trials in each testing session.