Current Research into False Memories: From Cannabis to Schizophrenia

   Current studies are often the best way to observe the curious ways that psychology and science as a whole can grasp ideas and theories, such as that of false memories, and take them in the direction of practical uses and deeper understanding of the human mind. Psychologists have more opportunity now than ever to focus so specifically on different aspects and impacts of false memories as more is known every year about how they occur.

   To find these studies and pieces of research I searched the very general topic of 'false memories' on google scholar  (a search engine which filters through websites and only displays scholarly articles useful to students, researchers etc.) and sorted by most relevant and set the filters to only show me articles that were published this year in 2020.

   Of the many potentially influential and groundbreaking leads in cognitive neuroscience and psychology recently, here are the three that really pulled me in with the possibilities of the conclusions that these studies could bring.


"False Memories: The Other Side of Forgetting"


   I could only gain access to the abstract of this dissertation yet this does a very good job in summarising the method results and conclusion to the study conducted. The aim of the study was to explore the perception of false memories of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) from caregivers and clinicians. They hypothesised that false memories would occur as often in patients as forgetting.

   They gave a questionnaire with 20 false-memory based questions and 20 forgetting based questions to a very large sample consisting of 226 clinicians and 150 family members of three groups of people- those with AD, those with MCI and healthy older control subjects.
 
   They found that false memories occurred almost as often as forgetting as hypothesised. They also found that those with AD had more false memories than those in the other two groups as well as a few other key findings. They, therefore, concluded that patients with AD have a higher frequency of false memories along with and as often as forgetting and the questionnaire can even be used quite practically.

"Cannabis increases susceptibility to false memory"


  Thankfully, since this one drew me in the most, I could get access to the full document as oppose to just the abstract. Upon reading the source, I feel it is incredibly useful both to my research and to real world situations on a vastly bigger scale. I made my own analysis of the data found from the study (in table 1 and it's related graphs) to explore how to interpret data from experiments as it is something that I will have to do more if I choose to do psychology at university and conduct my own research.

(My own analysis of data is in italics and information I gained from simply reading, interpreting and summarising the dissertation is not.)
 
   The study is a double-blind, placebo-controlled trial using an experimental method in order to observe the effects of cannabis intoxication on false memory production both immediately after an event as well as after a period of delay. The experiment was conducted on 64 healthy volunteers and the method was as follows:

   The three groups that participants were split into were intoxicated cannabis users, non-intoxicated cannabis users given a placebo drug, and a non-using control group. They did two types of test to see if either 'spontaneous' false memories or 'suggestion-based' false memories were influenced by the intoxication of cannabis.

   The first was a version of the Deese-Roediger-McDermott paradigm in which a set of semantically linked words are presented visually to participants then they are tested (immediately after then one week after) by asking if they recall seeing certain words that experimenters ask them. Four types of word were asked about: true recognition words which were words shown within the original set, false alarm critical lure words which were words immediately related to the set but not shown, false alarm relating words, and false alarm unrelated words that aren't semantically similar to the set of words originally shown.

   The second type was using the misinformation paradigm in which participants used a virtual reality (VR) headset to see and act as eyewitnesses to 'crimes' shown to them through the technology. They were then introduced post event information. Questions about what they remember of the event shown were asked immediately after as well as one week after in terms of 'presented' material which were things that actually occurred in the event seen, 'suggested' material which was never in what they saw on the VR headset but was suggested  in the post-event information, and 'non-suggested' material that was in neither.

   From the data set in the figures presented, in the DRM, more false memories were induced for the intoxicated group than the placebo group in the immediate test as they recognised as having seen the critical lure (false alarm) words more (0.62>0.56). However in the test one week later, the results were more mixed with the placebo group falling for more critical lure false alarms and the intoxicated group  having a higher rate of false memories for the unrelated false alarm words.

   Furthermore, in the misinformation paradigm tests, those in the intoxicated group continued to form false memories more frequently than the placebo group. They 'remembered' more of the suggested facts from the event that were never really shown in the clip than the placebo group both immediately after and one week later. 
   
   To conclude this study, the researchers claim that while more research should be carried out to ensure reliability, the experiment has provided evidence that using cannabis increases the risk of creating false memories. This conclusion can be used practically within the judicial system as evidence towards the argument that witnesses to crimes who are potentially intoxicated users of cannabis should be questioned after a period of delay as oppose to immediately after in order to become sober to decrease the risk of false memories developing.

"False memory production in schizophrenia: A neurophysiological investigation"


   This study follows a similar premise to the above study except it focuses on schizophrenic participants as oppose to cannabis users. Not only does it explore the already researched link between memory abnormalities and schizophrenia but goes deeper at looking into the specific neural connections and the implication this neural network has on the production of false memories in schizophrenic people.

   The researchers compared 17 patients suffering psychosis as a result of schizophrenia against 33 healthy controls in a version of the Deese-Roediger-McDermott task. They also used electroencephalography which is a method of monitoring electrical activity in the brain. From what I can understand, the electroencephalography method uses wave-forms with specific potentials named P2 and N400.

   The patients with schizophrenia were less able to distinguish between true and false memories and also were shown have the P2 lower in amplitude at the frontal electrode region. The amplitude of N400 was more negative in the centro-parietal electrode site. This difference in amplitude contributes to the idea that schizophrenic patients have a different neural strategy in their brain when performing the DRM tasks. 

   This document was incredibly scientific with jargon that required me to look up a lot of definitions such as with the method of brain monitoring used. This means that I feel like I cannot do this piece of research justice in explaining its method. While I now understand its basic model and conclusions and have spent time understanding a concept of the method used, I feel like I haven't fully grasped how the results in terms of the P2 and N400 correlate to the conclusions as I sadly cannot adequately teach myself the theory behind these. I recognise this as a limitation in my research!  

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