If you travel into the realm of Embodied Cognition in particular (not sure about the other similar varieties), they see a tangible basis for all metaphors. It’s hidden right in front of us in our languages themselves quite often.
Lakoff is the king of that, and some brain-scan type studies seem to have confirmed some of it.
For example, thinking of someone who is emotionally distant versus emotionally close activates the same regions in the brain as visual distance vs visual closeness.
Also, pain. Emotional heartbreak activates same pain regions as heart attack. So… food for thought.
We humans may be far simpler creatures than we think.
There’s more than just the phonological loop though.
Have you never thought in music? Images? Feelings without images or words associated?
To have language = thought excludes thinking from language-less humans or species.
Colonies of bacteria communicate. They know the difference between self and other due to the complicated messaging systems they use and can act in concert (although not always) upon perceived threats or purpose.
Is this thought? I have no reason to believe it’s not.