Schmolck et al is the cognitive contemporary study

Description

Aim

Schmolck aimed to

  • investigate whether a particular part of the brain is associated with semantic long term memory
  • see if HM is unique among the patients.

Procedure

IV – Extent of brain injury (damage to medial temporal lobe (MTL) / hippocampal formation only OR damage to MTL/HF and temporal cortex)

DV – Scores on the cognitive tests

Type – Naturalistic experiment.

Sample – 6 participants (3 MTL (including HM), 3 MTL+) 8 controls.

She had a set of 48 drawings: 24 animals, 24 objects, which were all further subcategorised, for example into 6 land animals.

She then had each participant complete 9 tasks, for example: defintions (Shown a picture, had to define it by the theme), category sorting (asked to sort into living or man-made categories).

They were all tape recorded and checked by 14 raters, who checked each recording for reliabilty, and to also lok for grammatical errors because this is a sign of semantic memory difficulties.

Results

HM scored in between MTL+ patients and other MTL patients.

Overall: Controls: 99%, MTL (Excluding HM): 100%, MTL+: 78%.

Positive correlation between severity of brain damage and mistakes on the test.

Conclusion

Correlation between temporal lobe damage and semantic memory difficulties.

Correlation between hippocampus damage and episodic memory loss, but not semantic memory.

Therefore semantic and episodic memory are located in different parts of the brain.

HM was an anomoly. This could have been because of his unique brain damage, his background as he was from a low-socioeconomic background or due to his school time which he missed due to his seizures.

Evaluation

Generalisability

(-) Small sample of participants, only 6 therefore any anomolous result wouldn’t be averaged out.

(+) Schmolck identified HM as an anomoly, which is a positive.

(-) Participants are very rare and therefore if you try to generalise to the general population, the sample doesn’t have good population validity.

(-) Half of the participants had an illness such as herpes simplex enceohalitis and therefore may not be generalisable to the

Reliability

(+) 9 standardised tests, with 48 standardised items. This makes it very repeatable.

(+) As he recorded all of the conversations, it means that it has higher reliability because they can be checked by other people.

(+) Use of 14 raters means it has high inter-rater reliability.

(-) However, the participants are very rare and therefore it’s not as replicable.

Applications

(+) Informing future research about cognitive psychology, as it identified that the hippocampus is associated with episodic memory and the temporal lobe is associated with semantic memory.

(+) Brain surgery. This is because it can indicate what damage can cause and therefore can be used to inform whether brain surgery is needed. For example, HM wouldn’t have had his surgery had he known it would have led to his memory deficits.

Validity

(+) MRI scans showed that temporal lobe showed activity when using semantic memory.

(-) Ecological validity –> Lab experiment. Artificial environment and artificial tests.

Ethics

(-) As the participants has memory loss, they couldn’t give informed consent as they would forget the purpose of the experiment. Therefore they received presumptive consent.

(+) However, it could be argued that the experiment was worth it because of the greater good as it has informed research and should help future patients with memory loss.

Example Essay

Schmolck aimed to investigate what part of the brain is associated with semantic long term memory.

Her study used a standardised set of 9 tasks and 48 line drawings which were used during her study. The use of these 48 resources improves the reliability of her research because it means that it is replicable, as another researcher could use the exact same resources in a replication.

In addition, Schmolck recorded the conversations with the participants. She then used 14 raters to check the recordings and to look for grammatical and syntactic errors with the speech as this is a sign of semantic memory deficits. Due to this, the inter-rater reliability of the research could be considered high because each researcher can check whether they come to an agreement.

However, due to the sue of participants who only had damage to their MTL and some who also had damage to their temporal lobe, the study could be said to be unreliable. This is because it is difficult to replicate the study because suitable participants are hard to find.

Moreover, the study used 3 participants with damage to their MTL, and 4 with damage to their MTL and the temporal lobe. Therefore, the generalisability is questioned due to thee use of only 6 participants. This is because any anomalous result wouldn’t be averaged out. However, Schmolck identified HM as an anomaly and therefore it’s likely that if there was another anomaly, they would have been identified.

In addition, the study used 6 participants with memory deficits, who all had difficulty encoding long term memories, therefore it is impossible to gain informed consent, because they don’t have the capacity to give it. Therefore, presumptive consent was given instead, which reduces the ethical integrity of the experiment.

To conclude, Schmolck conducted a largely reliable naturalistic experiment due to her use of standardisation. However, the ethics of the study could be questioned, although it could be argued that the ethical concerns should be overlooked due to the study’s contributions to the greater good.