PSY610 Final Term Questions 2025

PSYP610 Final Exam questions 2025

✅ 1. Write a detailed note on the structure and functions of the thalamus.

The thalamus is a large, dual-lobed mass of grey matter located in the diencephalon, just above the brainstem. It forms part of the forebrain and consists of multiple nuclei that serve different functions.

Acts as the main relay station for sensory information. Nearly all sensory inputs (except smell) pass through the thalamus before reaching the cerebral cortex. Involved in motor functions, as it connects to the basal ganglia and cerebellum. Plays a crucial role in consciousness, alertness, and attention. Integrates emotional and cognitive information, due to connections with the limbic system and prefrontal cortex.

Essentially, the thalamus controls what sensory information is allowed to reach your awareness.

✅ 2. How is a person’s biological clock determined — is it biologically controlled or influenced by environmental factors?

The biological clock is the body's internal system that regulates circadian rhythms, which are physical, mental, and behavioral changes following a 24-hour cycle.

What determines it:

It is primarily controlled by the suprachiasmatic nucleus (SCN) in the hypothalamus, which acts as the master clock. The biological clock is biologically innate, but it is also entrained (adjusted) by environmental cues—especially light (via the retina). Other external cues like meal times, sleep schedules, and social interaction can also influence it. So yes, it’s biologically determined, but also environmentally influenced, making it a flexible but internally guided system.

✅ 3. Explain the role of dopamine in the development of schizophrenia.

Dopamine is a neurotransmitter involved in motivation, reward, motor control, and cognition.

What it does in schizophrenia:

According to the dopamine hypothesis, hyperactivity of dopamine in certain brain regions (especially the mesolimbic pathway) contributes to positive symptoms like hallucinations and delusions. Conversely, hypoactivity in the mesocortical pathway may be linked with negative symptoms such as apathy and impaired executive functioning. Antipsychotic drugs that block D2 dopamine receptors have been effective in reducing positive symptoms, supporting the role of dopamine in the disorder.

The key idea is that dopamine imbalance across pathways contributes to the symptom profile of schizophrenia.

✅ 4. Define homeostasis and explain its importance in physiological and behavioral regulation.

Homeostasis is the process by which the body maintains a stable internal environment despite changes in the external surroundings. It’s a self-regulating process.

Maintains balance in systems like body temperature, blood pressure, glucose levels, and pH. In the brain, it helps regulate hormone levels, sleep-wake cycles, and emotional stability. Controlled by multiple brain areas including the hypothalamus, which integrates neural and hormonal signals to maintain internal balance.

Example: When you’re cold, homeostasis triggers shivering to warm you up. When you're hungry, it stimulates feeding behavior to restore energy balance. ✅ 5. What is the principle of mass action in brain function?

The principle of mass action is a theory proposed by Karl Lashley, based on his studies of rats and memory after brain lesions.

What it says:

The brain works as a whole system in executing complex functions like learning and memory. The degree of impairment in function is more dependent on the amount of tissue damaged, rather than its specific location. It opposes strict localization theories, instead suggesting distributed processing across the cortex.

In short, the more extensive the brain damage, the greater the learning impairment, regardless of the specific area.

✅ 6. Describe the structure and functions of the corpus striatum.

The corpus striatum is a subcortical part of the forebrain, located in the basal ganglia. It consists of two main structures:

Caudate nucleus

Putamen

Together, these structures form the striatum, which is heavily involved in motor and cognitive functions.

It plays a central role in voluntary motor control, habit formation, and procedural learning. Receives dopaminergic input from the substantia nigra, crucial for regulating motor activity. Involved in the reward system and motivation, through connections with the limbic system. Damage or dysfunction in this region is associated with disorders like Parkinson’s disease, Huntington’s disease, and OCD.