An animal model of the interpersonal communication of interoceptive (private) states

Pigeons were taught to interact communicatively (i.e., exchange discriminative stimuli) based on 1 pigeon's internal state, which varied as a function of cocaine, pentobarbital, and saline administration. These performances generalized to untrained pharmacological agents (d-amphetamine and chlordiazepoxide) and were observed in the absence of aversive stimulation, deprivation, and unconditioned reinforcement. The training procedure used in this study appears similar to that by which humans learn to report on (tact) their internal environments and may be construed as a rudimentary animal model of the interpersonal communication of private events.