Schmolck et al (2002)

• Aim

  To investigate the effects of damage to the medial temporal lobe (MTL) and anterolateral temporal cortex on semantic knowledge.
• Sample

  • 8 male controls; and 1 female and 5 male participants
  • Two participants had damage to the hippocampal formation (HF)
  • Three participants had medial temporal lobe lesions with damage to the anterolateral temporal cortex (MTL+)
  • HM had a bilateral medial temporal lobe resection for severe epilepsy
• Schmolck et al. (2002) found that medial temporal lobe damaged patients scored 78.1% for pointing/naming picture
• • The damage to the anterolateral temporal cortex leads to a loss of semantic knowledge and confusion. (1)
  • The patients with damage limited to the hippocampal formation performed normally in every aspect on tests of semantic knowledge (1).
  • The language impairment by HM was unrelated to his condition/brain damage but his upbringing - low socioeconomic status and interrupted education.
• Conclusion

  • The damage to the anterolateral temporal cortex leads to a loss of semantic knowledge and confusion. (1)
  • The patients with damage limited to the hippocampal formation performed normally in every respect on tests of semantic knowledge (1).
  • The language impairment by HM was unrelated to his condition/brain damage but his upbringing - low socioeconomic status and interrupted education. (1)
• Reliability All participants were given nine tests based on the same line drawings of 24 animals and 24 objects. ⇒ The procedure was standardised with all participants seeing the same drawings which controls for variables increasing the reliability of the findings about semantic memory.
• • Reliability In tests 1 to 5, and test 7, participant answers were scored. Objectivity is increased by using a scoring system as a quantitative measure for participant responses which eliminates experimenter bias.
• Application The study also helps us understand the risks of brain surgery and the side-effects of brain damage, which would enable doctors and patients to weigh up the risks of surgical procedures
• Ethics Could only get partial consent as the patients would not have remembered giving consent to them or having the study explained.
• Lacks task validity: Categorising pictures of common items was used to test participant memory. The task of picture categorising is unnatural and so the test of memory lacks internal (task) validity as people do not usually categorise pictures of common items.
• Reliability, Some participants and the control group were given four additional semantic tests using different images and cards to the line drawing tests. Not all of the original 6 participants completed the additional four tasks which increases the chance that anomalies could skew the data on such a small sample size.