Mark Aaron Balbin

Have you ever been curious about how a single bad meal can spoil your favorite food for life?


Researchers at Princeton University discovered a neural process that accounts for how animals, including humans, learn to link the taste of food with its after-effects even when the effects occur hours or even days later.

The study, published on April 2, 2025, entitled "A neural mechanism for learning from delayed postingestive feedback" showed how the brain associates the taste of food with feelings of discomfort or satisfaction, which may not be experienced until long after eating.

The scientists conducted experiments with mice, offering them new flavors followed by a delayed period of digestive upset from the lithium chloride that they have injected to the rodents moments after introducing them to the flavors.

Two days after the first period of the experiment, the scientists offered the same food to the mice. 

This time, those that went sick recognized the food as dangerous, while those that tasted it without getting sick did not have flashback memories in their amygdala, a region of the brain involved for emotional processing.

Their research indicates that the amygdala plays a role in linking the sensation of food taste with slow body responses. 

When the mice that got sick encountered the flavor once again, the cells in their amygdala reinstated memories of the flavor they had eaten, associating the taste with the unpleasant feeling of discomfort.

This happens with humans, too. 

Without a mechanism to correlate eating experiences with post-ingestive effects, they would be stuck in a loop of food poisoning.

Moreover, the research also pushes the wider field of neuroscience to consider rethinking memory's conceptualization. 

Memories, in the past, were perceived as being comparatively stable once established. 

Yet this research adds evidence that memories are not just fixed after it is formed, but are dynamic ones that could change when introduced with new relevant information.

Memory is not merely about documenting the here and now, but about continuously updating according to what comes next. 

In a sense, the brain's capacity to wait, listen, and revise could be one of its brightest ideas.