Preference for a segmented schedule using a brief S+ stimulus correlated with a great delay reduction in humans

Area of Science:

• Behavioral psychology
• Animal cognition
• Reinforcement learning

Background:

• Previous studies indicated a preference for unsegmented schedules over segmented ones in pigeons and humans.
• This finding appeared inconsistent with conditioned reinforcement theories, like delay-reduction theory.

Purpose of the Study:

• To resolve the inconsistency between observed preferences and delay-reduction theory.
• To investigate how modifications to segmented schedules affect preference in human participants.

Main Methods:

• Two modifications were made to the standard segmented schedule in human participants.
• The terminal-link stimulus (S+ stimulus) was presented late in the terminal link, closer to reinforcement.
• The S+ stimulus presentation was brief, allowing early terminal-link stimulus reinstatement.

Main Results:

• The study demonstrated a preference for the modified segmented schedule.
• This preference was observed when a brief S+ stimulus was associated with a significant reduction in delay to reinforcement.

Conclusions:

• The findings support delay-reduction theory by showing preference for segmented schedules under specific conditions.
• Modifying segmented schedules, particularly with a brief S+ stimulus, can reverse previously observed preference patterns.