Response summation to a compound stimulus in a context of choice.

Researchers worked with pigeons in a lab. The birds first learned to peck when they saw a light or heard a tone.

Next the team gave the birds a choice. They could peck near a single stimulus or near a light-plus-tone combo.

Some birds had only known reward. Others had faced extinction during part of their training.

Birds with a pure reward history almost always picked the compound stimulus. More cues meant more pecks.

Birds that had met extinction showed mixed picks. Their choice pattern flipped as the session went on.

Schmitt (1976) showed cooperation wins when it pays only a bit more than competition. Both studies prove that small payoff tweaks steer choice.

McSweeney et al. (1993) later mapped how responding drifts within one session. That drift helps explain why the extinction birds changed their minds mid-test.

Lowe et al. (1995) found the same drift under multiple VI schedules. Their water-reinforcer data echo the 1977 pattern: history sets the path, but moment-to-moment shifts still occur.

Your client's history, not just the current reward, decides how they treat a rich cue pile. If past reinforcement was spotty, expect mixed or shifting choices. Track within-session data to spot when their preference flips, then adjust prompt timing or reinforcement density right at that point.