Neural Development and Developmental Disorders

NeuralDevelopment and Developmental Disorders

Abstract

Thepurpose of this paper was to analyze the film Memento with a focus onthe accuracy with which it depicts the neuropsychological disorderknown as amnesia. The director of the movie selected Leonard as themain character who is used to depict the occurrence and the mainfeatures of amnesia as it occurs in real situations. Anterogradeamnesia occurs after following traumatizing events that subjects anindividual to painful experiences. This neurodevelopment disorder ischaracterized by an individual’s ability to recall events thathappened prior to the occurrence of the traumatizing event andlimited capacity to process and store the memory of events that takesplace after the emotional incident. Features of amnesia that matcheswith the scientific characterization of amnesia include the Leonard’sability apply motivated forgetting to avoid recalling the incident,failure of the damage to affect his semantic memory, ability torecall old events and instantly forget the new ones, and partialimpairment of implicit memory.

Keywords: Amnesia, implicit memory, traumatizing event, semantic memory,remote memory.

NeuralDevelopment and Developmental Disorders

Althoughmost of the movies are used as a source of entertainment, some ofthem are educational and can be used to illustrate certain medicalconditions. Memento is one of the films that were acted to illustratethe occurrence and signs of amnesia. The movie was written anddirected by Nolan Christopher, who derived the story from experiencewith his brother named Memento Mori. The film begins with interspacedblack and white sequences where Leonard Shelby, the man sufferingfrom amnesia, speaks to an unknown telephone caller. Leonard sufferedfrom amnesia after an attack by two men, which culminated in the rapeand killing of his wife. Although police explains that Lenard wasattacked by one person, Leonard believes and explains that he wasattacked by two people, killed one, and the other one escaped (Nolan,2000). Leonard decides to conduct his own investigations because thepolice believe that the attacker had already been killed.

Leonardbelieves that the attacker who managed to escape was named John withthe other name starting with G. He later managed to get the tattoo ofJohn G from his license plate. Leonard finds a note in his clothesrequiring him to meet with bar attendant named Natalie. Natalieunderstands Leonard’s condition and requests drive anothercharacter named Dodd out of town in exchange for a license plate thatwould ease his investigations. The full name of the owner of thelicense plate is John Edward Gammell, which matches with theattackers’ name John G. Leonard gets John, drives him to a secretplace, and kills him (Nolan, 2000). Leonard meets Teddy towards theend of the film, and Teddy asserts that Lenard had confused someelements of his dead life with those of Sammy who was a bachelor conman. Teddy explains that Leonard’s wife was diabetic and survivedthe attack only to die later as a result of an insulin overdose.Teddy holds that John G. is a common name that Leonard will continueforgetting and start his investigations afresh.

Mementofilm is a clear depiction of the neuropsychological condition knownas amnesia. The film shows how the human brain collects and stitchesup sensory inputs from the environment as well as emotional responsesto form memories that generate a unique identity. The film shows thatLeonard suffered from short-term memory loss as a result of braindamage. Leonard is able to recall all events that happened before hewas attacked, but his brain cannot store events that occurredafterwards (Nolan, 2000). Leonard survives by creating an artificialmemory composed of written notes, Polaroid pictures, and tattoos. Heis able to utilize conditioned learning and repetition to overcomethe challenge of short-term loss of memory. Leonard’s sense of selfhas been frozen and stopped evolving since the last incident, anattack by two men. Leonard has been used in the film to show twotypes of memory. First, the incident in which he picks up a thickglass dish with the knowledge that it will be heavy and coldrepresents semantic memory. Secondly, Leonard closes his eyes whentrying to reach the warm feelings he had with his dead wife and thisrepresents implicit memory. Leonard tries to erase the memories ofthe traumatizing event as well as his dead wife by burning his wife’sfavorite book, but all events that occurred before the attack cannotget out of his mind.

Literaturereview

Characterizinganterograde amnesia

Anterogradeamnesia is characterized by a complete or partial loss of memory withpredominance of psychological factors that occurs in the absence ofany corresponding brain structure. A case study conducted by Fujiwara(etal.,2008) revealed that all cases of memory loss results from theoccurrence of extremely nerve-racking experiences or acute trauma.The results of this case study showed that the subjects did not losethe identity they had before the occurrence the traumatizingincidents (Smith, etal.,2010). People suffering from amnesia do not suffer from structuralbrain damage, but suffer from cerebella hyper-metabolism. Althoughthe findings of the case study are consistent with the description ofamnesia available in the literature a similar study has shown thatsome people may suffer from slight brain damage. For example, anexperimental study conducted by Hannula, Tranel &amp Cohen (2006)showed that memory loss among people suffering from amnesia resultsfrom the damage of the hippocampus. This is a region of the brainthat is responsible for processing of short-term memories prior totheir storage. The damaged hippocampus fails to process events thatoccur from the time of damage, but it does not affect memories thatare already stored. This explains why people suffering from amnesiacannot store recent events in their memory, but they cannot forgetthe events that occurred before the occurrence of stressfulexperiences.

Amnesiaand motivated forgetting

Althoughpeople who suffer from amnesia do not forget the traumatizingincident and events that occurred prior to the incident, they canutilize inhibitory controls to repress emotional memories. Anderson &ampHanslmayr (2014) reviewed literature that focused on the capacity ofpatients suffering from amnesia to limit the retention of unwantedemotional memories. The review revealed that the retrieval ofunwanted memories is limited by truncating and disrupting theirencoding. The use of item-method of motivated forgetting helps thepatient in conduct selective rehearsal to forget the bad events andallow retrieval of the best moments that occurred before thetraumatizing experience. The affected individuals load their memorywith to-be-remembered items and drop off the to-be-forgotten eventsfrom their working memory. However a meta-analysis conducted byDimoska (etal.,2011) contradicted the findings reported by Hannula, Tranel &ampCohen (2006) because they showed that people suffering from amnesiaand other forms of brain damage loss their capability for inhibitorycontrol and experience the loss of drive. This means that theaffected persons have limited capacity to repress the unwantedmemories or inhibit habitual as well as impulsive behaviors.Similarly, the surface-based and voxel-based assessments haveproduced similar results showing that amnesia patients suffer frominhibitory control deficit (Depue etal.,2014). However, the case study conducted by Fujiwara (etal.,2008) indicated that there are cognitive mechanisms that can lead tosuccessful repression of emotional memories. This suggests thatpatients with amnesia can be motivated to forget events they do notwant to remember and retrieve the best moments from the memory.

Extensionof amnesia to semantic memory

Mostof the previous studies have shown that amnesia affects theprocessing of recent events (Fujiwara (etal.,2008) and Depue etal.,2014), but there are instances in which amnesia extends to semanticmemory. An experimental study performed on Alzheimer patients showedthat amnesia may at times affect the retrieval of old events from thememory (Meeter, Kollen &amp Scheltens, 2007). This suggests thatextension of amnesia to semantic memory. In addition, the testsconducted to test for amnesia contains an overlap of items for bothsemantic and remote memory because both of them evaluate oldmemories. Semantic memory is considered to be a part of long-termmemory that represent human knowledge about facts, objects, concepts,and words as well as their meanings (Meeter, Kollen &amp Scheltens,2007).

Theexplanation given for the loss of meaning of some words is that wordsrequire repetition to be retained in the lexical memory. This leadsto the loss of memory of words learned a long time before theoccurrence of emotional event. However, these findings areinconsistent with the results of an observation study conducted byBright, Buckman, Fradera (2014) which showed that the damagehippocampus affects only the processing and retrieval of the recentoccurrences or events that took place after the traumatizingincident. According to Bright, Buckman, Fradera (2014) semanticmemory is only affected if brain damage goes beyond the temporalcortex and reaches the lateral regions. This results in severeimpairment of memory that reduces the capacity of the affected personto recall semantic or autobiographical items. This suggests that theextension of amnesia to semantic memory is caused by damage of thebrain parts in addition to hippocampus. This implies that a pureamnesia affects the processing and storage of events that occurredafter the traumatizing event, without reducing the capacity toretrieve old memories.

Impairmentof implicit memory among the amnesic patients

Currently,the available literature has no clear cut as to whether amnesia canbe characterized with the impairment of implicit memory. This isbecause the impairment of implicit memory in this population dependson different factors that reduce the capacity of researchers to givethe conclusive evidence. For example, an experimental study performedby Verfaellie, Page &amp Orlando (2005) showed that amnesicindividuals had an intact implicit memory and impaired explicitrecall for studied words, the recalls ability for non-presented lurewas completely impaired irrespective of retrieval instructions used.The partial impairment of implicit memory, especially for the gistinformation results from the lack of ability to encode robustrepresentations of the gist. The amnesic persons have limited abilityto encode gist information, but they can encode verbatim information.This is because processing, storage, and retrieval of item specificfeature in the context of implicit completion tasks results inactivation of lexical or perceptual representation that isresponsible for the mediation of priming of verbatim data(Verfaellie, Page &amp Orlando, 2005). Priming of non-representedfeatures, on the other hand, occurs in tasks in which word priming isat minimum in part conceptually based, but not in cases in which itis entirely perceptually based. This implies that the assessment ofthe impairment of implicit memory depends on whether the researcherused verbatim or gist information.

Criticalanalysis of the film Memento

Mementofilm is an accurate and realistic depiction of amnesia in motionpictures. There are four major features of the film that show theaccuracy of the movie in representing amnesia. First, the ability ofLeonard to retain earlier identity, recall early events, and failureto process recent events is a clear depiction of anterograde amnesia.For example, Leonard remembers the good times he had with hisdiabetic wife before two men attacked his family (Nolan, 2000).However, Leonard fails to store even the simple events that happenduring his investigation and pursuit of the attack who managed toescape. He is forced to use artificial reminders, such as tattoos,written notes, and Polaroid pictures to keep track of events thathappen during his investigation. This is consistent with scientificevidence showing that people suffering from anterograde amnesia canrecall events that occurred prior to the emotional occurrence, butcannot process events that take place after the traumatizing event(Fujiwara, etal.,2008, Anderson &amp Hanslmayr, 2014, and Hannula, Tranel &amp Cohen2006).

Secondly,the attempt made by Leonard to apply motivated forgetting to erasethe incident that resulted in the death of his wife is an evidencethat amnesic persons retains the capacity to recall what they want toremember and avoid what they wish to forget. However, this ability islimited to events that occurred prior to the emotional event thatsubjected them to the risk of suffering from amnesia. The motivatedforgetting is only possible with the help of motivational mechanismbecause amnesic persons suffer from inhibitory control deficit asshown by Depue (etal.,2014). In the case of Leonard, he has to burn the wife’s favoritebook to forget the deadly event that culminated in her death.However, there seem to be some contradictions with scientificevidence showing that amnesic can motivational mechanisms tocompletely forget events because the memories of Leonard’s wifekeeps on coming back from time to time. This result from Leonard’sattempt to remember the good moments he had with his wife and in theprocess, he remembers the event that terminated the good times.Therefore, it is clear that motivated forgetting is effective, but itcan be weakened by amnesic persons who attempts to recall parts ofwhat they are learning to forget.

Third,the film’s depiction of the hippocampus is consistent with theavailable literature indicating that amnesia does not affect semanticmemory unless other parts of the brain have been damaged (Bright,Buckman, Fradera, 2014). Similarly, Leonard retains the memory that athick glass dish must be heavy and cold (Nolan, 2000). This confirmsthat Leonard is suffering from hippocampus damage while other partsof the brain are intact. This means that he retains the ability torecall facts, objects, concepts, and words that he learned before hishippocampus was damaged.

Fourth,the film depicts the effect of hippocampus damage on implicit memoryin a way that gives mixed reaction. The available literature fails togive clear evidence as to whether hippocampus damage leads to theimpairment of implicit memory (Verfaellie, Page &amp Orlando, 2005).This means that it is not clear whether amnesia impairs one’sability to link a person or an object with some feelings. The filmshows that Leonard can link warm feelings with his wife, but with alot of difficulties (Nolan, 2000). He has to close his eyes for himto successfully recall the good times he enjoyed with his wife. Thestruggles he goes through to recall the warm moments may suggest thathis implicit memory is partially impaired or partially dysfunctional.

Conclusion

Thefilm Memento is a clear depiction of the neuropsychological disorderreferred to as amnesia. Leonard is the character who is used toillustrate how amnesia occurs and the common features of this type ofcondition. The capacity of Leonard to recall events that happenedbefore his family was attacked by two men and his failure to processrecent events shows that he is suffering from anterograde amnesia.The mode of occurrence as well as major signs of amnesia depicted inthe film is consistent with scientific findings. The attack thatculminated in the death of his wife is the direct cause of Leonard’samnesia. In addition, Leonard is able to partially overcomeinhibitory control deficit, which allows him to forget the deadlyevent for some time, but these memories returns from time to time.Moreover, the effect of hippocampus damage on Leonard’s semanticand implicit memory is consistent with the scientificcharacterization of amnesia.

References

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