Table 1.

Percent changes in performance between sessions (i.e., learning effect) and conditions. Percent changes between sessions represent ((session 2 − session 1)/(session 1) × 100). Percent changes between conditions represent ((caffeine − placebo)/(placebo) × 100).

Subject ID	Session 1 Treatment	Session 1 Total Repetitions	Session 2 Total Repetitions	Percent Change between Sessions	Percent Change between Conditions
1	Placebo	214	240	12.1	12.1
2	Caffeine	300	339	13.0	−11.5
3	Caffeine	372	373	0.3	−0.3
4	Placebo	581	611	5.2	5.2
5	Placebo	458	485	5.9	5.9
6	Placebo	431	456	5.8	5.8
7	Placebo	510	611	19.8	19.8
8	Caffeine	467	512	9.6	−8.8
9	Caffeine	461	486	5.4	−5.1
10	Caffeine	374	473	2.0	−20.9
11	Placebo	460	458	−0.4	−0.4
12	Placebo	423	421	−0.5	−0.5
13	Caffeine	533	474	−11.1	12.4
14	Placebo	519	551	6.2	6.2
15	Caffeine	585	607	3.8	−3.6
16	Placebo	534	541	1.3	1.3
17	Caffeine	379	410	3.8	−7.6
18	Placebo	630	711	8.2	12.9
19	Caffeine	366	420	14.8	−12.9
20	Caffeine	450	480	6.7	−6.3