Which one alters thoughts and perceptions without any sensory stimulus?

Options

A. Sedative and tranquillisers
B. Cocaine
C. Opiate narcotics
D. Hallucinogen

Answer

To answer the question "Which one alters thoughts and perceptions without any sensory stimulus?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question is asking for a substance that can change thoughts and perceptions without any external sensory input. This means we are looking for a drug that can create alterations in mental state or perception without requiring any physical stimuli.

2. **Analyze the Options**: The options provided are:
- Sedative and tranquilizers
- Cocaine
- Opiate (narcotics)
- Hallucinogen

3. **Evaluate Each Option**:
- **Sedative and Tranquilizers**: These substances are primarily used to treat anxiety and sleep disorders. They slow down brain activity but do not primarily alter thoughts and perceptions in the way the question describes.
- **Cocaine**: This stimulant increases energy and produces feelings of euphoria. It acts on the central nervous system but does not primarily alter thoughts and perceptions without sensory input.
- **Opiate (Narcotics)**: These drugs bind to opioid receptors in the brain and slow down body functions. They can alter perception but are not primarily known for changing thoughts without sensory stimuli.
- **Hallucinogen**: This type of drug is known for altering mood, behavior, thoughts, and perceptions. Hallucinogens can create a dream-like state and cause hallucinations, which means they can change perceptions without any actual sensory stimulus.

4. **Identify the Correct Answer**: Based on the evaluations, the substance that alters thoughts and perceptions without any sensory stimulus is **Hallucinogen**.

5. **Conclusion**: Therefore, the correct answer to the question is option **4: Hallucinogen**.