Charak Samhita
निवृत्तेन्द्रियवाक्चेष्टः सुप्तः स्वप्नगतो यदा। विषयान् सुखदुःखे च वेत्ति नाज्ञोऽप्यतः स्मृतः ॥२३॥
A person who is asleep and dreaming experiences happiness and sorrow even in the absence of functioning senses, speech and other activities. So he isn't without consciousness.
english translation
nivRttendriyavAkceSTaH suptaH svapnagato yadA। viSayAn sukhaduHkhe ca vetti nAjJo'pyataH smRtaH ॥23॥
hk transliteration by Sanscript