Hallucination is?

Ans. is 'b' i.e., Perception without external stimulus Hallucinations* Hallucination is perceiving sensory input in the absence of any actual external stimulus, i.e., perception without stimulus. Subjectively hallucinations are similar to normal perception in that modality of sensation. They are as intense, as vivid, and as real as his/her normal perception. Hallucination should fulfill the following criteria : -i) Absence of corresponding external perceptual stimuli.ii) Hallucinations should have vividness, force and reality value of a normal perception.iii) The experience occurs spontaneously.iv) It cannot be produced or terminated at will by subject (not in conscious control).v) Perceived as being in external objective space, i.e., they are experienced as being out there in the world and as inhabiting objective space (in contrast to memory images and illusion where the image is imaginated inside the mind, i.e., inner subjective space).vi) Have relative permanency (i.e., remain constant and unchanged).vii) Hallucinations are usually experienced alongside and simultaneously with normal perceptions.