Antonia et al. (2011)

neurotransmitters

• The role of neurotransmitters in behaviour is a central concept in the biological approach.

• Neurotransmitters are the chemical messengers that facilitate communication between neurons and influence various behaviours , including memory processes.

• Spacial memory involves the encoding and retrieval of information about one’s environment and navigation, a process linked to the hippocampus and modulated by acetylcholine

  THEORY

• Acetylcholine has long been associated with memory encoding, particularly in the hippocampus, studies like Rodger’s and Kenner (2003) in rats have shown that blocking acetylcholine receptors with scopolamine imparted the acquisition of new spatial memories. These findings suggest that acetylcholine plays a key role in creating cognitive maps, or mental representations of spatial environments.

  EVIDENCE

  Atonova sought to investigate weather acetylcholine plays a similar role in humans by observing its effect on activity in the hippocampus

• AIM - To determine how acetylcholine influences the encoding of spatial memory in humans.

• METHOD - Using a double blind study, repeated measures design, 20 male participants were injected with either scopolamine or a placebo and underwent fMRI scanning while completing the ‘Arena Task’ a virtual reality spacial memory test. Participants were scanned twice, with conditions counterbalanced to control for practice effects.

  FINDINGS

• Scopolamine significantly reduced activity in the hippocampus during the task compared to the placebo, indicating that acetylcholine is critical for encoding spacial memory in humans. However, behaviour differences (errors made) were not statistically significant.

  APPLICATION

• This study supports the theory that acetylcholine is essential for encoding of new spacial memories, it also has implications for understanding memory related conditions, such as Alzheimer’s disease, where acetylcholine deficits contribute to cognitive decline.

  EVALUATION

  strengths :

• The use of fMRI provided direct evidence of activity in the hippocampus.

• The double blind, counterbalanced design reduced bias and controlled for practice effects.

  LIMITATIONS

• The sample size (20) reduces the generalisability of findings.

• During debriefing, several participants expressed they had felt stressed from injections or fMRI enclosure, may have affected results.

• Although there was a higher rate of error in the scopolamine group, it was not a significant difference, difference in hippocampal activity was. Meaning that task as designed may not have been the best for showing performance differences : without the use of fMRI, there would be no way to know that at the biological level, there were significant differences in the two conditions.

  ETHICAL CONSIDERATIONS

• Participants reported stress from the procedure, raising concerns about participant well being.

  UNANSWERED QUESTIONS

• To what extent does stress influence hippocampal activity in studies like this?

• How does acetylcholine interact with other neurotransmitters in the encoding of spatial memory?

  PRACTICAL USE

• These findings have practical implications for understanding and treating memory related disorders, for example, therapies targeting acetylcholine systems could be developed to improve spatial memory in conditions such as Alzheimer’s disease.

  CONCLUSION

• Antonova provides compelling evidence that acetylcholine plays a critical role in spatial memory encoding in humans, supporting findings from animal research

• The study highlights the importance of neurotransmitters in cognitive processes and contributes to our understanding of the biological underpinnings for memory.