Effects of the home environment on withholding behaviors and conditioning in infant and neonatal rats.

Rats 16 days old received passive-avoidance training in the presence or absence of home litter cues. Rats trained in the context of home litter cues learned the passive avoidance reliably faster than rats trained in isolation. In the presence of home litter cues, 16-day-old rats also exhibited more adultlike spontaneous alternation. Pavlovian conditioning of rats trained at 2 days of age was studied in the presence and absence of conspecifics. These experiments suggest that deficiencies in inhibitory behaviors and conditioning associated with immaturity can be alleviated when the testing environment is made more similar to the home environment.