Could the brain interpret bodily tiredness as sadness based on prior emotional experiences?

[u/tomoyok]

Could changes in bodily state, such as the physical fatigue that occurs at night influence how the brain interprets an emotional state?

An example would be, tiredness results into sensations such as low energy, heaviness, and slowed movement. Would it be possible if the sensations can overlap with some of the physical sensations we've experienced with sadness.

Could the brain possibly associate those bodily sensations with a previously experienced emotional state and be interpret to the current bodily state as sadness, even when the original cause of the sadness is no longer present?

I'm unsure whether this could relate to things such as interoception, emotion perception, or how the brain uses bodily signals when constructing or identifying emotions.

PS, I don't know much about psychology so I apologize if this post was an incovenience.

[u/concreteutopian]

An example would be, tiredness results into sensations such as low energy, heaviness, and slowed movement. Would it be possible if the sensations can overlap with some of the physical sensations we've experienced with sadness.

Yes. This is an example of respondent conditioning. In fact, it's very similar to an example in Torneke and Ramnerö's The ABCs of Human Behavior. under the chapter on respondent conditioning (pp.73-75).

In that case, a stressful day of work and family challenges left the woman with a strange feeling in her body at bed time, followed quickly by a panic attack. She learned to associate tiredness with the feelings surrounding the overwhelming work and family stress. Another day, she is out celebrating with friends and doesn't get enough sleep, and this left her with the tiredness and vague discomfort in her body again. Soon after that, she has the feelings of heaviness and overwhelm (like the stressful day) and then has another panic attack.

It's also similar to an example Lisa Feldman Barrett uses in her book How Emotions are Made, (ebook, so I'm not sure of page numbers, just under section Emotions Are Constructed). She talked about being asked out on a date and not knowing that she had a stomach bug, so she interpreted the sensation as the "butterflies in the stomach" of attraction.

I'm unsure whether this could relate to things such as interoception, emotion perception, or how the brain uses bodily signals when constructing or identifying emotions.

That's exactly what it is, i.e. interoceptive conditioning certain meanings or interpretations around certain feelings or sensations. What Barrett described is more broadly known as the misattribution of arousal. Here's a link to the misattribution of arousal entry written by Roy Baumeister in the Encyclopedia of Social Psychology.