People who have been frightened or disgusted by images have a more acidic pH in the stomach.
- After watching frightening or disgusting videos, participants reported having heart and respiratory sensations, but also gastric sensations.
- The pre-print study also shows that both of these emotions are associated with a more acidic pH in the stomach.
- Further research is needed to understand the mechanism.
Do you have knots in your stomach when you watch a horror or gore movie? Science may have an explanation. A study by the University of Rome “La Sapienza”, published on the site BioRxiv pending peer validation, found that fear and loathing are associated with more acidic gastric pH.
Electronic pills that measure stomach pH
Nausea, gastric movements… we have known for a long time that emotions can have repercussions on the digestive system. Italian scientists wanted to better understand this understudied link because “visceral organs are difficult to access and monitor”.
The team asked 31 male volunteers to ingest an electronic pill that measured the pH, pressure and temperature of their digestive tract. They then had to watch videos that could induce disgust, fear, happiness, sadness, or a state of neutral control.
The participants then had to answer a questionnaire that allowed them to assess their emotional state. Their visceral sensations (ie gastric, respiratory and cardiac) were also recorded.
“We found that when participants watched frightening and disgusting video clips, they reported not only experiencing cardiac and respiratory sensations, but also gastric sensations, such as nausea”say the authors in their article.
A link between emotions and the pH of the stomach
And that’s not all, there was also a connection with the raised acidity in the stomach.
“Furthermore, we found that there was a clear relationship between stomach physiology and perceived emotions. Specifically, when disgusting video clips were displayed, the more acidic the pH, the more participants reported feelings of disgust and fear. The less acidic the pH, the happier they say they are”add the team.
For researchers, gastric signals contribute to unique emotional states. They also argue that the ingestible pills used can “open new avenues to explore the deep physiology of emotions”.
They plan to do further research with a larger sample to verify their findings and understand the mechanisms at play.
