Reinforcement-induced within-trial resetting of an internal clock

Area of Science:

• Behavioral neuroscience
• Animal cognition
• Learning and memory

Background:

• Interval timing is crucial for behavior and cognition.
• Peak-interval timing procedures assess temporal discrimination abilities.
• Understanding timing mechanisms informs cognitive models.

Purpose of the Study:

• To investigate how reinforcement at earlier criterion durations affects temporal response functions in rats.
• To examine the ability of rats to make conditional discriminations of interval duration under specific reinforcement conditions.

Main Methods:

• Rats were trained on a modified peak-interval timing procedure with three distinct criterion durations (10, 30, 90 s).
• Response levers were associated with specific durations, with independent reinforcement delivery.
• The tone stimulus remained active during reinforcement delivery, and primed times did not reset.

Main Results:

• Reinforcement delivery at an earlier criterion duration caused a rightward shift in temporal response functions for subsequent durations.
• This shift was proportional to the elapsed time within the trial.
• Significant discrepancies arose between programmed and expected reinforcement times.

Conclusions:

• The findings suggest rats are unable to perform conditional reinforcement-based discriminations of interval duration in this paradigm.
• The reset in temporal accumulation disrupts accurate interval timing.
• This challenges assumptions about temporal information processing in rats.