Rhesus monkeys have an interoceptive sense of their beating hearts

Area of Science:

• Neuroscience
• Comparative Psychology
• Evolutionary Biology

Background:

• Interoception, the sense of internal bodily signals, is crucial for homeostasis, emotions, and self-awareness.
• The evolutionary origins and presence of interoception in nonhuman animals are not well understood.

Purpose of the Study:

• To investigate the presence of innate cardiac interoception in rhesus monkeys.
• To explore the evolutionary basis of interoceptive abilities.
• To establish rhesus monkeys as a model for studying human interoceptive function and dysfunction.

Main Methods:

• An experimental paradigm was used where rhesus monkeys viewed visual stimuli.
• Stimuli were presented either synchronously or asynchronously with the monkeys' heartbeats.
• Behavioral responses, specifically viewing time, were recorded and analyzed.

Main Results:

• Rhesus monkeys significantly preferred viewing stimuli presented asynchronously with their heartbeats.
• This preference mirrors findings in human infants, suggesting a shared capacity for integrating cardiac signals with audiovisual information.
• This study provides the first behavioral evidence of innate cardiac interoceptive ability in a nonhuman primate.

Conclusions:

• Rhesus monkeys possess a human-like capacity for cardiac interoception.
• These findings have significant implications for understanding the evolution of interoception and self-awareness.
• Rhesus monkeys may serve as a valuable animal model for studying interoceptive processing and its disorders in psychiatric research.