Which term best describes perceptions experienced in the absence of external stimuli?

• A. Hallucinations
• B. Anxiety
• C. Phobia
• D. PTSD

Answer: (A)

Perceptions without external input are called hallucinations. They involve sensing something—like hearing voices, seeing people, or feeling sensations—that isn’t actually present. They can feel very real to the person experiencing them, which can be confusing or distressing.

This is different from illusions, which are misinterpretations of real stimuli (for example, mistaking a rope for a snake). It’s also distinct from anxiety, phobia, or PTSD, which are about fear, avoidance, or re-experiencing trauma rather than producing new sensory experiences without any external source.

Hallucinations can occur in several situations, such as during certain mental health conditions, medical issues, sleep problems, or substance effects, but the defining idea is the presence of sensory experiences without external stimuli.