Rhesus Macaques Monkeys Can Perceive Their Internal Heartbeats Through Interoception: New Study

Interoception is the ability to sense the internal processes of one's body.

Previously discovered in human babies, a new study suggested that rhesus macaques monkeys are capable of such perceptive skills.

The groundbreaking research is the "first-of-its-kind animal model" on interoception.

New Animal Model

In their new paper published in the Proceedings of the National Academy of Sciences (PNAS), scientists found rhesus macaques are able to observe and perceive their own heartbeat, whether it is in rhythm or out of rhythm, as cited by the American Association for the Advancement of Science (AAAS).

Researchers from the University of California (UC Davis), the Royal Holloway, and the University of London developed a new animal model using the monkey rhesus as a subject to determine if it is capable of interoception.

Rhesus Macaques Experimentation

Led by the California National Primate Research Center at UC Davis, the research team monitored four rhesus monkeys that they placed in front of an infrared eye tracker, which displayed stimuli that bounced and created a sound (either faster or slower) in line with the monkeys' heartbeats, as per AAAS.

They observed that the macaques are looking at things that are unexpected or surprising to them.

In particular, all four subjects spent more time gazing at the stimuli, which resembles an out of rhythm with their heartbeats, compared to stimuli that synchronized with their usual and predictive heartbeats.

By analysis, the monkeys noticed more patterns that are not in line with their routine heartbeats.

This entailed the primates were able to recognize any potential anomaly or discrepancies from the throb of their hearts or internal heart pulse.

The team confirmed that the results are consistent with previous behavioral evidence that rhesus macaques have a human-like tendency to monitor their heartbeats using interoception, as per the UC Davis website.

Importance to Future Treatment

The study claimed that self-monitoring physiological systems are important in all human aspects; since being able to sense the internal state of one's body can lead to the identification of any irregularities, as per the UC Davis site.

For instance, the study showed that an impaired interoceptive awareness is linked with unstable control of one's emotions and increases vulnerability to mental health problems, including anxiety and depression.

The UC Davis team reportedly highlighted the significance of their interoception research for future treatment of various neurological diseases, including Alzheimer's disease.

It is also helpful for emotion regulation and mental health for adults.

Following the discovery, the study highlighted the potential usage of the interoceptive animal model for new studies concerning anxiety, depression, and Alzheimer's disease.

How Does Interoception Works?

Since interoception is the process where an organism understands, integrates, and regulates signals of its internal world, the ability to sense systems within the body sends a message to the central nervous system (CNS), as per the National Center for Complementary and Integrative Health (NCCIH).

This is made possible when ascending pathways reach the CNS, which is responsible for decoding interoceptive-based signals between physiological systems.

The CNS, in turn, communicates with the physiological system via descending pathways, says the NCCIH.