Reward and addiction
In this section, we'll cover reward, addiction, and drugs of abuse.
1) We'll start with a primer on reward and addiction:
2) Read this article for more information on the reward system: Know Your Brain - Reward System
3) Watch this video for a quick review of the reward system:
4) Finally, answer these questions to test your understanding:
1. Dopamine is the primary neurotransmitter responsible for generating feelings of pleasure in the brain.
- A. True
- B. False
Show Answer
Correct answer: B
Despite popular conceptions, dopamine is not thought to directly produce feelings of pleasure. Instead, it seems to play a key role in motivation and reward learning—helping the brain recognize cues associated with rewards and driving behavior to seek them out again.
2. The dopamine neurons that travel in the mesolimbic dopamine pathway (a major pathway in the reward system) mostly originate in which structure?
- A. nucleus accumbens
- B. amygdala
- C. hippocampus
- D. ventral tegmental area (VTA)
Show Answer
Correct answer: D
Most dopamine neurons in the mesolimbic pathway originate in the ventral tegmental area (VTA) of the midbrain. These neurons project to the nucleus accumbens and other regions, playing a central role in reward, motivation, and reinforcement learning.
3. This structure is the main component of the ventral striatum, and is thought to play an important role in reward processing:
- A. amygdala
- B. globus pallidus
- C. nucleus accumbens
- D. ventral tegmental area
Show Answer
Correct answer: C
The nucleus accumbens is the major component of the ventral striatum, and is best known for its role in reward processing.
4. Hypofrontality, a phenomenon sometimes seen in addiction, refers to:
- A. increased activity in the brain's reward pathway
- B. reduced activity in the nucleus accumbens
- C. increased dopamine release from the substantia nigra
- D. reduced activity in the prefrontal cortex
Show Answer
Correct answer: D
In addiction, hypofrontality refers to reduced activity in parts of the prefrontal cortex, a brain region involved in decision-making, impulse control, and evaluating consequences. This reduced frontal lobe activity can make it more difficult to resist drug-related urges and other rewarding but potentially harmful behaviors.
5. During drug tolerance, an individual typically experiences:
- A. an increased response to a drug after repeated use
- B. a decreased response to a drug after repeated use
- C. a complete loss of all drug effects after one use
- D. a stronger withdrawal reaction each time the drug is used
Show Answer
Correct answer: B
Tolerance occurs when repeated exposure to a drug causes its effects to diminish, so larger doses may be needed to produce the same effect.
