Brain systems, memory and HM amnesia
Relate the limbic system, hippocampus, amygdala and cerebellum to memory while using HM’s case as evidence and noting a broader account.
Original teaching mapped to Cambridge IGCSE Psychology 0266 Version 3 for 2027–2029. The course is independent study support, not Cambridge material, an official mark scheme or an awarded grade. Named-study notes summarise the required findings; candidates are not expected to evaluate named studies. Self-check practice is not official grading, a timed Paper 1/2 simulator or teacher review.
Before you begin
- Use the Version 3 syllabus and confirm availability in your administrative zone with Cambridge and your school. Both papers are compulsory. The updated named-study summaries are required context; full original research articles are not required.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
Before brain systems, memory and hm amnesia, which approach is most useful?
What you will learn
- Explain localisation and the limbic system
- Compare hippocampus, amygdala and cerebellum roles
- Use HM’s case to explain memory loss and preserved procedural learning
- Recognise that memory also involves the cerebral cortex
Different brain areas contribute to memory
Localisation means particular brain areas have specialised functions. The limbic system is a network involved in emotion, learning and memory. The amygdala contributes to consolidating emotionally arousing memories; the hippocampus helps consolidate information from STM into LTM. The cerebellum contributes to balance and procedural memory, such as learned action sequences.
Damage can affect memory in different ways
HM underwent surgery that removed much of his hippocampus and amygdala to treat severe seizures. Afterwards, he struggled to form new memories of people, places and events and had difficulty recalling some events from before surgery. Yet he could slowly improve on a simple maze task, suggesting some procedural learning remained. This separates aspects of declarative and procedural memory.
Named study: Milner and colleagues’ HM follow-up
Researchers followed HM over many years using memory and intelligence tests and observations. He retained normal general intelligence and childhood memories, showed retrograde and severe anterograde amnesia, and made gradual gains on a maze task. These findings support a role for the hippocampal region in forming new memories, but the syllabus also notes that other regions, including the cerebral cortex, contribute to memory.
Pause and explain
Which response best shows understanding of brain systems, memory and hm amnesia?
Worked example
A patient cannot form new episodic memories after damage to a brain area but improves slowly at a practiced hand task. Explain the pattern.
Show the worked solution
- Episodic facts and events are declarative memories.
- Practice of a motor task uses procedural learning.
- The pattern is consistent with different memory functions depending on brain systems.
Answer The patient may have impaired hippocampal consolidation of new declarative memories while some cerebellum-linked procedural learning remains.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A patient can practise a balance routine but cannot remember meeting the instructor yesterday. Which memory distinction helps explain this?
Give me a hint
Separate knowing how from remembering an event.
Compare my reasoning
- The routine is a learned procedure.
- The meeting is an event that would be declarative memory.
- Different memory systems can be affected differently.
Procedural learning may remain while declarative memory for new events is impaired.
Look for these in your work
- Labels each memory
- Recognises different systems
- Avoids overclaiming
What result in HM’s case supports the role of the hippocampal region in forming new memories?
Give me a hint
Focus on new learning after the surgery.
Compare my reasoning
- HM struggled to form new memories of people, places and events.
- He could still recall many childhood events.
- Together these show memory formation and older recall can be affected differently.
His severe difficulty forming new post-surgery memories supports a role for the hippocampal region in new memory formation.
Look for these in your work
- Mentions new memories
- Distinguishes older recall
- Connects to the claim
A researcher finds that memory performance can also change after damage to areas outside the hippocampus. How should this qualify a localisation claim?
Give me a hint
A specialised area need not work alone.
Compare my reasoning
- The hippocampus has an important role.
- Other areas, including cerebral cortex, are also implicated.
- The evidence supports a contribution, not a single-area explanation of all memory.
The hippocampus contributes to memory, but memory also involves other brain regions such as the cerebral cortex.
Look for these in your work
- Keeps hippocampal role
- Adds cortical contribution
- Avoids an absolute claim
Common mistakes
- Saying the amygdala stores every memory.
- Assuming HM lost all learning or intelligence.
- Claiming one case proves a single brain area explains all memory.
What can you explain now?
Which named brain area is linked to consolidating STM into LTM?
Compare with the explanation
Hippocampus
The syllabus links the hippocampus with consolidation from STM to LTM.
After trying it yourself, choose your next review. This is your self-assessment.
Your review choice appears on Today. Sign in to sync it across devices.
Make it stick
Which memory functions are linked to the hippocampus, amygdala and cerebellum, and what did HM’s case show?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.