Which of the following is described as a perceptual change in LSD intoxication?

• A. Nystagmus
• B. Tremor
• C. Illusions
• D. Sweating

Answer: (C)

LSD intoxication predominantly changes how you perceive things, especially visuals. Illusion refers to misinterpreting real external stimuli, which is a classic perceptual change with LSD—colors may seem more vivid, patterns may bend, and objects can appear altered in size or shape. This contrasts with other signs that are not about perception: nystagmus is an involuntary eye movement (a motor/oculomotor sign), tremor is rhythmic shaking (a motor symptom), and sweating is an autonomic bodily response. So the best answer reflects the perceptual distortions LSD produces, namely illusions.