kernel vs mental object

kernel and mental object both are nouns.

Word	Noun	Adjective	Verb	Adverb
kernel	Yes	No	No	No
mental object	Yes	No	No	No

As nouns, mental object is a hypernym of kernel; that is, mental object is a word with a broader meaning than kernel:

kernel: the choicest or most essential or most vital part of some idea or experience
mental object: the sum or range of what has been perceived, discovered, or learned

Other hypernyms of kernel include cognitive content, content.

kernel (noun)	mental object (noun)
the choicest or most essential or most vital part of some idea or experience	the sum or range of what has been perceived, discovered, or learned
a single whole grain of a cereal
the inner and usually edible part of a seed or grain or nut or fruit stone