Training paradigm and criterion to advance rats to the next stage of testing
| Stage | Name | Goal | Stimulus + reward | Criterion |
|---|---|---|---|---|
| 1 | Continuous Access | Pair spout light and tone with reward | No stimulus; 50 µl 16% liquid sucrose bolus | >500 licks per session |
| 2 | Nosepoke Training—left or right side only | Rats nosepoke in operant ports following high luminance stimulus | 8 LEDs over the left or right operant port. Trials only appear on one side port with alternative port blocked. Correct response triggers spout light and tone, indicating availability of 16% sucrose reward | >120 trials/session; 3 session minimum, 6 session maximum |
| 3 | Random cue presentation | Rats respond to the visual cue presentations | 8 LEDs presented at random over the L/R operant port. Correct response triggers spout light and tone indicating availability of 16% sucrose reward. Error response to the nonilluminated operant port triggers the spout light requiring response at reward port, but no reward delivered |
>200 trials/session; <10% error trials; 3 sessions minimum, 6 sessions maximum |
| 4 | Center cue training | Encourage rats to initiate trials by responding to the center “start” cue | Start stimulus presented at the center, followed by random presentation of high luminance stimulus over the L/R operant port. Correct and error responses remain the same |
>200 trials/session; <10% error trials; 3 sessions minimum, 6 sessions maximum |
| 5 | Single-offer only sessions | Rats are introduced to the low luminance cue and associate it with low-value reward | Start cue presented at the center, followed by random presentation of either the high luminance or low luminance cue over the L/R operant port. Response triggers spout light and tone, indicating availability of 16% or 4% sucrose reward, paired to the luminance | 10 sessions (±2); established response time difference for the high and low response latencies |
| 6 | Single- and dual-offer sessions | Final stage of the task | Start cue presented at the center, followed by random presentation of either the high luminance or low luminance cue over the L/R operant port for 2/3 trials. For 1/3 trials, both H/L stimuli are presented over L/R operant ports | 1 session to 5 sessions of testing |