Contemporary study: Schmolck et al. (2002)

Aim and participants

Aim: to investigate whether damage to the medial temporal lobe (MTL), including the hippocampus, or damage to the lateral temporal cortex next to it, causes loss of semantic knowledge (general knowledge of facts and meanings).

Participants: 6 patients (5 male, 1 female) and 8 male controls.

• MTL+ group (3): amnesia after encephalitis, with extensive MTL damage plus varying damage to the lateral temporal cortex.
• HF group (2): damage limited to the hippocampal formation.
• HM: bilateral MTL removal, with some additional damage to the anterolateral temporal cortex.

Materials and tasks

48 line drawings: 24 living and 24 non-living things, in 8 subcategories of six (for example birds, water creatures, vehicles, musical instruments).

Tasks included: pointing to a picture from its name or a description; naming pictures and naming from descriptions; answering yes/no questions about features; category fluency (naming as many examples as possible in a minute); category sorting at different levels; and giving definitions of items from their names and from pictures. Definitions were scored for detail and errors, and 14 raters tried to identify items from the definitions as a reliability check.

Results and conclusions

• HF patients performed normally on the semantic tests.
• MTL+ patients were mildly to moderately impaired.
• HM was impaired on five of the 11 tests he took, but less severely than the MTL+ patients.
• MTL+ patients gave less detailed, lower quality definitions; HM's definitions contained many grammatical errors, which the authors thought were unlikely to come from his temporal lobe damage.
• Performance was linked to the extent of lateral temporal cortex damage.

Conclusion: semantic memory problems come from damage to the cortex lateral to the MTL, not from hippocampal damage alone. This suggests semantic memory depends on different brain areas from forming new episodic memories.

Evaluation

Strengths: many tasks gave a detailed picture (more valid); objective scoring for most tasks; inter-rater checks on definitions (reliability); a control group for comparison; brain scans located the damage.

Weaknesses: only six patients, so results are hard to generalise; damage differed between patients, so groups were not identical; sorting pictures of everyday objects is an artificial task; controls were all male while the patient group included a woman.

Worked example

Explain why the result for the HF group is important.

1. The HF patients had damage only to the hippocampal formation.
2. They performed normally on semantic tests.
3. So hippocampal damage alone does not destroy semantic knowledge; the lateral temporal cortex matters.

Answer: Normal semantic performance with hippocampal-only damage shows semantic knowledge does not depend on the hippocampus alone.

Check yourself

1. How did the patients with damage limited to the hippocampal formation perform on the semantic tests?
   • Severely impaired
   • Worse than HM
   • Normally
   • They could not be tested
   Show answer

   Normally. HF patients performed normally.

2. What did Schmolck et al. conclude about semantic knowledge?
   • Impairment is linked to damage of the lateral temporal cortex, not the hippocampus alone
   • Semantic knowledge is stored only in the hippocampus
   • HM had no semantic impairment at all
   • Brain damage never affects semantic knowledge
   Show answer

   Impairment is linked to damage of the lateral temporal cortex, not the hippocampus alone. The extent of lateral temporal damage predicted performance.

3. There were 48 line drawings in 8 subcategories. How many items were in each subcategory?
   Show answer

   6 items. 48 / 8 = 6.

4. What percentage of all the participants (patients plus controls) were patients? Give your answer to 1 decimal place.
   Show answer

   42.9 %. 6 / 14 x 100 = 42.9%.

5. In the category fluency task, participants had to
   • sort pictures into living and non-living
   • point to a picture after hearing its name
   • draw objects from memory
   • name as many examples of a category as possible in one minute
   Show answer

   name as many examples of a category as possible in one minute. Fluency tasks measure how many category members can be produced.

6. Give one weakness of Schmolck et al. (2002).
   Show answer

   There were only six patients, and their brain damage differed, so the findings are hard to generalise to other people.. Small, varied samples and artificial tasks limit the conclusions.

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Sources

• Pearson Edexcel International Advanced Subsidiary/Advanced Level in Psychology specification (issue January 2026)
• Pearson International A Level Psychology component guide: WPS01
• Schmolck, Kensinger, Corkin and Squire (2002) Hippocampus 12 (full text)
• IAL Psychology revision site: Schmolck et al. (2002)
• IAL Psychology revision site: Case studies: H.M.

Last updated 8 November 2026. Spotted a mistake? Tell us.