"entirely unaffected by each other's writings"; "fibers remained apparently unaffected by the treatment"
is similar to
(usually followed by `to') not affected by a given influence
"immune to persuasion"
is similar to
(often followed by `to') above being affected or influenced by
"he is superior to fear"; "an ignited firework proceeds superior to circumstances until its blazing vitality fades"
is similar to
not moved to serious regard
"trying to appear unimpressed"
is similar to
not influenced or affected
"stewed in its petty provincialism untouched by the brisk debates that stirred the old world"- V.L.Parrington; "unswayed by personal considerations"
see also
emotionally unmoved
"always appeared completely unmoved and imperturbable"