Factors affecting conditional discrimination learning by pigeons.

Paul et al. (1987) worked with pigeons on a conditional task. Birds had to peck the correct color only when the room cue signaled it was time for that color.

Some birds got the two problems on different days. Others got both problems every day. The team watched which schedule built clean conditional control.

Daily alternation won. Birds that saw one color rule per day, paired with the same room cue, soon pecked correctly. Birds that saw both colors every day never locked in.

The pigeons needed the day-long gap and the steady context to sort out when each rule was on.

Blough (1971) showed that a red or green background could turn line-tilt control on or off. Paul et al. (1987) moved that idea into daily practice: the background must stay put for the whole session and alternate across days.

Snapper et al. (1969) found that form cues beat color cues in conditional tasks. Paul et al. (1987) add a fix: if you separate color rules by day and context, color alone can win.

LeFrancois et al. (1993) later added odor cues and locked the birds in the same box. They confirmed what the 1987 paper started: stable, redundant context is required, not optional.

When you teach a learner two similar rules, run one rule per session and give each rule its own clear context. Switch rooms, staff, or signal colors daily. That single-day gap plus a steady cue set can prevent messy stimulus over-selectivity and speed up conditional discrimination.