Within-Session Changes in Adjunctive and Instrumental Responding

Area of Science:

• Behavioral neuroscience
• Animal behavior studies

Background:

• Rats were trained to press levers for food rewards under fixed interval schedules.
• Adjunctive behaviors, such as drinking or running, were available during some experimental conditions.

Purpose of the Study:

• To investigate within-session changes in instrumental lever pressing and adjunctive behaviors in rats.
• To examine the relationship between instrumental and adjunctive behaviors during experimental sessions.

Main Methods:

• Rats' lever pressing, drinking, and running behaviors were recorded under fixed interval schedules.
• The availability of drinking spouts or running wheels varied across experimental conditions.
• Within-session response patterns and correlations between behaviors were analyzed.

Main Results:

• Lever pressing, drinking, and running rates frequently changed within experimental sessions.
• Within-session patterns of lever pressing remained consistent regardless of adjunctive behavior availability.
• Correlations between lever pressing and adjunctive behaviors were inconsistently positive or negative.

Conclusions:

• Factors influencing within-session changes affect both instrumental and adjunctive behaviors.
• Arousal or interference from adjunctive behaviors are unlikely explanations for within-session response changes.