Reward, performance, and the response strength method in self-stimulating rats: validation and neuroleptics

Area of Science:

• Behavioral neuroscience
• Animal models of drug effects

Background:

• Understanding the neural mechanisms of reinforcement and performance is crucial.
• Existing methods may not fully disentangle reward and motor components of behavior.

Purpose of the Study:

• To introduce and validate the response strength method for analyzing reinforcement and performance.
• To investigate the effects of neuroleptics on these distinct behavioral functions.

Main Methods:

• Subjects were exposed to variable interval schedules of reinforcement at different densities.
• Response rate was plotted against reinforcement rate to generate a curve.
• Two parameters from the curve were analyzed, and experimental manipulations (brain stimulation, lever force) were used to validate their distinct roles.
• Neuroleptic administration effects on these parameters were assessed.

Main Results:

• Data fit a negatively accelerated curve, with two parameters reflecting reinforcement and performance functions.
• Reduced brain stimulation frequency selectively shifted the reinforcement parameter.
• Increased lever-press force primarily altered the performance parameter.
• Neuroleptics impaired both reinforcement and performance parameters in self-stimulating rats.

Conclusions:

• The response strength method effectively separates reinforcement and performance functions.
• Neuroleptic drugs exert a dual effect, impacting both reward and motor/performance capabilities in rats.