Brain systems
In this section, we’ll explore major brain systems—networks of regions that work together to shape how we think, feel, and act.
1) Watch the following videos and read the associated articles:
Article: Know Your Brain - Limbic System
Article: Know Your Brain - Reward System
Article: Know Your Brain - Default Mode Network
2) Answer these questions to test your understanding:
1. Which of the following structures is not generally considered part of the limbic system?
- A. amygdala
- B. hippocampus
- C. hypothalamus
- D. cerebellum
Show Answer
Correct answer: D
There is a lack of consensus as to what structures should be included in the limbic system, but areas that are often included are the amygdala, cingulate cortex, hippocampus, hypothalamus, septal nuclei, mammillary bodies, prefrontal cortex, certain nuclei of the thalamus, and tracts such as the fornix and medial forebrain bundle.
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. During which of the following activities would the default mode network be most likely to show its strongest activation?
- A. quiet rest with eyes closed while letting your mind wander
- B. tracking a moving dot on a screen and keeping a cursor centered on it
- C. doing rapid mental arithmetic under time pressure
- D. answering questions in a job interview
Show Answer
Correct answer: A
Default mode network is a term used to describe interconnected regions of the brain that display suppressed activity during cognitively demanding tasks focused on external stimuli, and higher activity during states of quiet wakefulness and when someone engages in internally focused thought such as daydreaming or the recall of personal experiences.
5. This gyrus of the cerebral cortex sits directly above the corpus callosum. It is thought to play important roles in emotion and memory, among other things.
- A. precentral gyrus
- B. fusiform gyrus
- C. cingulate gyrus
- D. transverse temporal gyrus
Show Answer
Correct answer: C
The cingulate gyrus sits just above the corpus callosum. Its functions are not fully understood, but it is thought to play important roles in emotion and memory.
