Table 1.

Tone frequencies and intensities used in the auditory recognition task

Phase Aa
Phase B
Frequency	4987*
Loudness	35**
Phase C
Frequency	1600	4987*	15,542
Loudness	35**	55	75
Level 1
Frequency	1600	2825	4987*	8803	15,542	27,437
Loudness	35**	45	55	65	75	80
Level 2
Frequency	1950	3121	4987*	7981	12,771	20,435
Loudness	35**	43	51	59	67	75
Level 3
Frequency	2370	3438	4987*	7234	10,494	15,215
Loudness	35**	41	47	53	59	65
Level 4
Frequency	2885	3794	4987*	6557	8622	11,335
Loudness	35**	39	43	47	51	55
Level 5
Frequency	3515	4190	4987*	5944	7085	8440
Loudness	35**	37	39	41	43	45
Level 6
Frequency	4275	4619	4987*	5388	5821	6285
Loudness	35**	36	37	38	39	40

Frequency values are in hertz (Hz), and Loudness values are in decibel sound pressure level (dB SPL). For each trial, the tone frequency and intensity were selected independently and randomly from the list corresponding to the current difficulty level. For any specific level, the probability that any of the six frequencies and intensities will be selected is equal. The asterisks indicate target stimuli for the FR (*) and LR (**) tasks.

^aGo response rewarded without auditory stimuli.