In an impassive manner.

With indifference; in an indifferent manner.

ETYM Latin apathia, Greek; a priv. + pathos, from pathein to suffer: cf. French apathie. Related to Pathos.
1. An absence of emotion or enthusiasm.
2. The trait of lacking enthusiasm for or interest in things generally; SYN. indifference, spiritlessness.
3. Indifference; lack of enthusiasm; intellectual dullness.

State of being drowsy.

Apathy, indifference, lack of feeling; calmness; lack of sensitivity to pain
The quality of being impassive.

ETYM Latin indifferentia similarity, want of difference: cf. French indifférence.
Unbiased impartial unconcern.