Recognition memory, chlordiazepoxide and rhesus monkeys: some problems and results

Area of Science:

• Neuroscience
• Cognitive Psychology
• Pharmacology

Background:

• The Konorski pair comparison task is a standard method for assessing mnemonic processing in animals.
• Chlordiazepoxide (CDP) is a benzodiazepine anxiolytic with known effects on cognitive function.
• Previous studies have shown CDP impairs performance in pigeons on similar tasks.

Purpose of the Study:

• To investigate the effects of chlordiazepoxide (CDP) on mnemonic processing in monkeys using a pair comparison task.
• To determine if stimulus presentation duration influences CDP's effects on cognitive performance.
• To assess CDP's impact on signal detection performance.

Main Methods:

• Monkeys were trained on a simultaneous pair comparison task involving same/different color stimuli.
• Delays were introduced between stimuli to assess forgetting curves.
• Chlordiazepoxide (CDP) was administered at various doses (up to 80 mg/kg) to evaluate its effects.
• Stimulus presentation times were shortened, and signal detection was assessed in subsequent experiments.

Main Results:

• High doses of chlordiazepoxide (CDP) did not significantly impair percent correct performance on the pair comparison task.
• Response latencies increased with CDP administration, occasionally leading to missed responses.
• No significant disruption in mnemonic processing was observed in monkeys, contrasting with previous findings in pigeons.

Conclusions:

• Chlordiazepoxide (CDP) does not appear to significantly disrupt mnemonic processing in monkeys on this specific pair comparison task.
• Increased response latencies suggest a potential, albeit subtle, effect of CDP on cognitive processing speed or response initiation.
• Further research may be needed to elucidate the precise mechanisms and dose-dependency of CDP's effects on primate cognition.